CN115190657A - Electric heating equipment control method, device, system and electric heating equipment - Google Patents

Abstract

The application relates to an electric heating device control method, an electric heating device control device, an electric heating device control system and an electric heating device, wherein when the electric heating device runs at a heating power smaller than a preset power threshold value, namely, in a low-power running state, voltage sampling in the running process of the electric heating device can be carried out in real time, and voltage sampling parameters are obtained. And then, performing zero-crossing trend analysis on the voltage sampling parameters to judge whether the electric heating equipment is in a zero-crossing state, and controlling the electric heating equipment to maintain a stable slow fire heating state under the condition that the electric heating equipment is in the zero-crossing state. According to the scheme, the zero-crossing detection of the electric heating equipment is directly realized through the analysis of the voltage sampling parameters, and a hardware circuit for the zero-crossing detection is not required to be additionally arranged, so that the problem of high cost of the slow fire heating circuit is effectively solved.

Description

Electric heating equipment control method, device, system and electric heating equipment

technical field

The present application relates to the field of heating technology, and in particular, to a control method, device, and system for electric heating equipment and electric heating equipment.

Background technique

Electric heating equipment includes IH (Induction Heat, electromagnetic heating) rice cookers, induction cookers, induction heating furnaces, etc. The principle is to pass high-frequency alternating current through the coil, generate a high-frequency alternating magnetic field near the coil, and under the action of the high-frequency alternating magnetic field , make the metal pot produce eddy current, and the Joule heat of the eddy current makes the metal pot heat up, thereby heating the food. Due to its many advantages such as no open flame, high power and good heat transfer efficiency, it is very popular among people.

In order to meet the needs of users, electric heating equipment is often configured with a heating operation mode that realizes slow heating at lower power. During the operation of the electric heating equipment, the zero-crossing detection circuit is used to detect the zero-crossing point, so as to control the thyristor to chop the wave, so that it can run stably at a lower power to achieve slow heating. However, this simmer heating method requires more peripheral devices to realize control, which greatly increases the cost of the simmer heating circuit.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a control method, device, system and electric heating device for an electric heating device in view of the high cost of the slow-fire heating circuit. The electric heating device control method, device, system and electric heating device provided by this application are When the simmer heating control is performed, there is no need to additionally set a hardware circuit for zero-crossing detection, thereby effectively alleviating the problem of high cost of the simmer heating circuit.

A method for controlling an electric heating device, comprising: if the heating power of the electric heating device is less than a preset power threshold, acquiring a voltage sampling parameter of the electric heating device; and performing a zero-crossing trend analysis according to the voltage sampling parameter to obtain the The zero-crossing detection result of the electric heating device; if the zero-crossing detection result represents the occurrence of a zero-crossing event, the simmer heating state is maintained.

The above control method for electric heating equipment can perform real-time voltage sampling during the operation of the electric heating equipment to obtain voltage sampling parameters when the electric heating equipment operates at a heating power less than a preset power threshold, that is, in a low-power operation state. Then, the zero-crossing trend analysis of the voltage sampling parameters can be performed to determine whether the electric heating device is in the zero-crossing state, and when the electric heating device is in the zero-crossing state, the electric heating device is controlled to maintain a stable simmer heating state. In the above solution, the zero-crossing detection of the electric heating device is directly realized through the analysis of the voltage sampling parameters, and no additional hardware circuit for zero-crossing detection is required, thereby effectively alleviating the problem of high cost of the slow heating circuit.

In an embodiment, the performing zero-crossing trend analysis according to the voltage sampling parameter to obtain the zero-crossing detection result of the electric heating device includes: according to the voltage sampling parameter at the current sampling moment and the voltage sampling at the previous sampling moment parameters, and perform trend analysis to obtain trend parameters; perform zero-crossing analysis according to the current trend parameters and the trend parameters obtained from the previous round of trend analysis to obtain the zero-crossing detection result of the electric heating device.

In one embodiment, performing trend analysis to obtain the trend parameter according to the voltage sampling parameter at the current sampling moment and the voltage sampling parameter at the previous sampling moment includes: according to the voltage sampling parameter at the current sampling moment and the voltage at the last sampling moment The sampling parameter is calculated to obtain the initial trend parameter; the initial trend parameter is filtered and analyzed to obtain the trend parameter.

In one embodiment, the initial trend parameter includes an initial slope parameter; the calculating and obtaining the initial trend parameter according to the voltage sampling parameter at the current sampling moment and the voltage sampling parameter at the previous sampling moment includes: obtaining a preset voltage coordinate system , the voltage coordinate system is constructed from historical voltage sampling parameters; extract the coordinates of the voltage sampling parameters at the current sampling moment in the voltage coordinate system and the coordinates of the voltage sampling parameters at the previous sampling moment in the voltage coordinate system; Calculate the slope according to the extracted coordinates to obtain the initial slope parameter.

In one embodiment, the performing filter analysis on the initial trend parameter to obtain the trend parameter includes: performing one-pass filtering in combination with the trend parameter obtained by the previous round of trend analysis and the initial trend parameter to obtain the trend parameter.

In one embodiment, the trend parameter includes a slope parameter; the zero-crossing analysis is performed according to the current trend parameter and the trend parameter obtained by the previous round of trend analysis, and the zero-crossing detection result of the electric heating device is obtained, including: If the current slope parameter is positive and the slope parameter obtained from the previous round of trend analysis is negative, it is determined that a zero-crossing event occurs in the electric heating device.

In one embodiment, if the current slope parameter is positive and the slope parameter obtained from the previous round of trend analysis is negative, determining that a zero-crossing event occurs in the electric heating device includes: acquiring a time flag; calculating the current time The time interval between the logo and the last time logo; if the time interval is within the preset time threshold range, it is determined that a zero-crossing event occurs in the electric heating device; the time logo is that the slope parameter is positive and the last time The time corresponding to when the slope parameter obtained from the round trend analysis is negative.

In one embodiment, before acquiring the voltage sampling parameter of the electric heating device if the heating power of the electric heating device is less than a preset power threshold value, the method further includes: if the electric heating device enters the continuous heating operation state, acquiring all the parameters of the electric heating device. The heating power of the electric heating device is compared and analyzed with the preset power threshold.

In one embodiment, before the acquisition of the heating power of the electric heating device and the comparison and analysis with the preset power threshold value if the electric heating device enters the continuous heating operation state, the method further includes: when the electric heating device starts to operate , perform a power-on self-test on the electric heating device; if the power-on self-test is successful, detect whether the heating object of the electric heating device is in the heating area; if the heating object is in the heating area, control the electric heating device to enter Continuous heating operation state.

A control device for electric heating equipment, comprising: a parameter acquisition module for acquiring voltage sampling parameters of the electric heating equipment if the heating power of the electric heating equipment is less than a preset power threshold; a zero-crossing detection module for The zero-crossing trend analysis is performed on the voltage sampling parameters to obtain the zero-crossing detection result of the electric heating device; the simmering control module is used to maintain the simmering heating state if the zero-crossing detection result indicates that a zero-crossing event occurs.

An electric heating device control system, comprising a filter circuit, a controller and a drive control circuit, the filter circuit is connected to the controller, the controller is connected to the drive control circuit, the filter circuit connects the electric heating device The working voltage is filtered and transmitted to the controller, and the controller outputs an enable signal to the drive control circuit based on the filtered working voltage and adopts the electric heating device control method described above to adjust the drive Control the running state of the circuit and maintain the simmer heating state.

An electric heating device includes the above-mentioned electric heating device control system.

In one embodiment, the electrical heating device is an electromagnetic heating device.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the traditional technology, the following briefly introduces the accompanying drawings that are used in the description of the embodiments or the traditional technology. Obviously, the drawings in the following description are only the For some embodiments of the application, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic flowchart of a control method for an electric heating device in an embodiment of the application;

2 is a schematic flowchart of a method for controlling an electric heating device in another embodiment of the present application;

3 is a schematic flowchart of a method for controlling an electric heating device in another embodiment of the present application;

4 is a schematic flowchart of a method for controlling an electric heating device in yet another embodiment of the present application;

5 is a schematic flowchart of a method for controlling an electric heating device in another embodiment of the present application;

6 is a schematic flowchart of a method for controlling an electric heating device in another embodiment of the present application;

7 is a schematic flowchart of a method for controlling an electric heating device in yet another embodiment of the present application;

8 is a schematic flowchart of a control method for an electric heating device in another embodiment of the present application;

9 is a schematic flowchart of a method for controlling an electric heating device in another embodiment of the present application;

FIG. 10 is a schematic diagram of a simmer heating process of an electric heating device according to an embodiment of the application;

FIG. 11 is a schematic diagram of a zero-crossing detection process flow in an embodiment of the application;

12 is a schematic structural diagram of a control device for an electric heating device according to an embodiment of the application;

13 is a schematic structural diagram of a control device for an electric heating device in another embodiment of the present application;

14 is a schematic structural diagram of a control device for an electric heating device in yet another embodiment of the application;

15 is a schematic structural diagram of a control system of an electric heating device in an embodiment of the application;

Reference numeral description: 152-filter circuit, 154-controller, 156-drive control circuit.

Detailed ways

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the related drawings. The preferred embodiments of the present application are shown in the accompanying drawings. However, the application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the disclosure of this application is provided.

Referring to FIG. 1 , a method for controlling an electric heating device includes step 102 , step 104 and step 106 .

Step 102: If the heating power of the electric heating device is less than a preset power threshold, acquire voltage sampling parameters of the electric heating device.

Specifically, the method for controlling an electric heating device provided in the present application is applied to an electric heating device, wherein the electric heating device refers to a device that finally converts input electrical energy into thermal energy to realize heating operation, including but not limited to resistance heating devices , Electromagnetic heating (electromagnetic induction heating) equipment. Therefore, the electric heating device provided by the present application may be an electric water heater, an induction cooker, an induction heating furnace, a resistance heating rice cooker, or an IH rice cooker, etc., which is not specifically limited.

The electric heating device includes a heating device, a drive control circuit for controlling the operation of the heating device, a heating object (such as a cookware, etc.) for holding the required heating items, a filter circuit required for voltage sampling, a controller and other parts, and a control method for an electric heating device Specifically implemented in the controller. The simmer heating state is the state of heating at a lower power. If the electric heating device wants to enter the low-power simmer operation state, it is not only necessary to control the heating power of the electric heating device to be less than the preset low-power threshold (that is, in a low-power operation state) , it is also necessary to control the on-off of the power switch tube in the drive control circuit through the zero-crossing detection result, so that the electric heating equipment can run stably at low power by cutting half-wave at low power, so as to maintain the slow heating state. Therefore, it is particularly important to realize the zero-crossing detection in the low-power slow-fire operation state.

The size of the preset power threshold is not unique, as long as it can be indicated that the electric heating device is in a simmer heating operation state below the power threshold. The voltage sampling parameter is the operating voltage sampling parameter of the electric heating device obtained by real-time sampling during the operation of the electric heating device.

It can be understood that the acquisition method of the voltage sampling parameters is not unique. In one embodiment, it can be realized by a sampling circuit. The sampling circuit is set between the voltage input terminal of the electric heating device and the controller, and the sampling circuit is used periodically. Obtain the voltage sampling parameters during the operation of the electric heating device, and transmit the voltage sampling parameters to the controller for filtering, analog-to-digital conversion, etc., or set the corresponding circuit for filtering and analog-digital conversion, and then send the voltage sampling parameters to the The controller can obtain the voltage sampling parameter in digital form, that is, the voltage AD value.

In another embodiment, the controller can also have a sampling function, and a filter circuit is directly set at the voltage sampling port of the controller, the filter circuit is connected to the voltage input end of the electric heating device, and the high frequency is filtered out through the filter circuit. The working voltage of the impurity signal is transmitted to the voltage sampling port of the controller to realize voltage sampling to obtain voltage sampling parameters. Correspondingly, the specific type of the filter circuit is not unique. In a more detailed embodiment, a small capacitor (for example, 22pf can be used) and a current limiting resistor can be used to form an RC filter circuit to transmit the voltage spikes to the controller. Filter out, it is convenient for the controller to sample to obtain the accurate voltage sampling value.

In order to facilitate the understanding of the technical solution of the present application, it can be understood that the controller has a voltage sampling function, and an RC filter circuit is set at the voltage sampling port of the controller, and the RC filter circuit is connected to the voltage input port of the electric heating device to realize Voltage acquisition function.

Step 104 , perform zero-crossing trend analysis according to the voltage sampling parameter, and obtain the zero-crossing detection result of the electric heating device.

Specifically, the zero-crossing detection refers to the detection made when the voltage waveform is converted from the positive half cycle to the negative half cycle and passes through the zero position, and the corresponding zero position is the zero-crossing point. Due to the different positions of the voltage sampling parameters in the same voltage cycle, the change trend will also be different to some extent. Therefore, the technical solution of the present application can determine the current state by performing a zero-crossing trend analysis in combination with the obtained voltage sampling parameters. Next, check whether the electric heating equipment has zero-crossing, and get the zero-crossing detection result.

In step 106, if the zero-crossing detection result indicates that a zero-crossing event occurs, the simmer heating state is maintained.

Specifically, the mode of maintaining the simmer heating state is not unique. For ease of understanding, in the technical solution of the present application, the operation state of the drive control circuit that provides electrical energy for the heating device in the control of the electric heating device is explained to maintain the simmer heating state. illustrate. At this time, chopping can be performed by driving the power switch tube in the control circuit on and off, so as to maintain a stable simmer heating state, and chopping also changes the direct current into another fixed voltage or adjustable voltage direct current.

The drive control circuit is provided with a power switch tube, and during operation, the power switch tube is turned on and off to deliver electric energy to the heating device. Specifically, the on-off of the power switch tube can be controlled by outputting the enable signal. Correspondingly, when the output enable signal enables the power switch tube to be enabled, the drive signal is allowed to be transmitted to the heating device. That is, when the disabled signal is sent to the power switch tube, the power switch tube will not allow the drive signal to be transmitted to the heating device.

It can be understood that, according to the type of the power switch tube (that is, different types of power switch tube with high-level conduction or low-level conduction), when the power switch tube is enabled, the on-off state of the power switch tube will also be The difference is that it can be enabled to make the power switch tube enter a conducting state, and output the drive signal to the heating device; or it can be enabled to make the power switch tube enter an off state, so that the drive signal is output to the heating device. In the actual operation process, only when the zero-crossing is detected, the enable signal transmitted to the power switch tube is reversed, and finally the reversed enable signal is output to the power switch tube, and the power switch tube can be changed accordingly. On-off state, and then decide whether to allow the transmission of the drive signal.

It should be pointed out that the specific type of the power switch tube is not unique. Insulated Gate Bipolar Transistor), etc., for ease of understanding, IGBT is used for explanation below.

The technical solution of this embodiment implements the zero-crossing detection operation by performing algorithm analysis on the voltage sampling parameters during the operation of the electric heating device, and does not need to set an additional zero-crossing detection hardware circuit, thus greatly reducing the cost of the hardware circuit. At the same time, the technical solution of the present application adopts a software algorithm to realize the zero-crossing detection operation, avoids the service life of the zero-crossing detection circuit, affects the service life of the electric heating equipment, and improves the service life of the electric heating equipment; it can also improve the electric heating equipment to a certain extent. The performance of the equipment in terms of interference performance reduces the interference to the outside world when the electric heating equipment works.

The above control method for electric heating equipment can perform real-time voltage sampling during the operation of the electric heating equipment to obtain voltage sampling parameters when the electric heating equipment operates at a heating power less than a preset power threshold, that is, in a low-power operation state. Then, the zero-crossing trend analysis of the voltage sampling parameters can be performed to determine whether the electric heating device is in the zero-crossing state, and when the electric heating device is in the zero-crossing state, the electric heating device is controlled to maintain a stable simmer heating state. In the above solution, the zero-crossing detection of the electric heating device is directly realized through the analysis of the voltage sampling parameters, and no additional hardware circuit for zero-crossing detection is required, thereby effectively alleviating the problem of high cost of the slow heating circuit.

Referring to FIG. 2 , in one embodiment, step 104 includes step 202 and step 204 .

Step 202, according to the voltage sampling parameters at the current sampling moment and the voltage sampling parameters at the previous sampling moment, perform trend analysis to obtain trend parameters; Step 204, perform zero-crossing analysis according to the current trend parameters and the trend parameters obtained by the previous round of trend analysis , get the zero-crossing detection result of the electric heating device.

Specifically, the trend parameter is a parameter representing the change trend of the current voltage sampling parameter relative to the last collected voltage sampling parameter. The current sampling time is also the current sampling period, and the last sampling time is also the previous sampling period. During the operation of the electric heating device, the controller can collect voltage sampling parameters at a certain sampling period, and combine the voltage collected in the current sampling period. The sampling parameters and the voltage sampling parameters collected in the previous sampling period are used for trend analysis to obtain the trend parameters corresponding to the current sampling time, that is, the current trend parameters.

The analysis of trend parameters by the controller is also carried out in real time. Whenever a voltage sampling parameter (as the voltage sampling parameter at the current sampling time) is obtained, the obtained voltage parameters and the last obtained voltage sampling parameters (also That is, the voltage sampling parameter at the last sampling time) is calculated to obtain a trend parameter. Therefore, when performing the zero-crossing detection analysis, the trend parameters obtained by the current trend analysis can be combined with the trend parameters obtained according to the trend analysis of the voltage sampling parameters at two adjacent moments before this (that is, the trend parameters obtained from the previous round of trend analysis) The trend parameter), to carry out the analysis and detection of zero-crossing. For example, in one embodiment, when two adjacent trend parameters are detected to jump, it is considered that the electric heating device has a zero-crossing, but the trend parameters detected two adjacent times do not jump, it is considered that the electric heating device has undergone zero-crossing. No zero crossings have occurred for the heating device.

In the above solution, trend parameter analysis is performed by using the voltage sampling parameters obtained twice adjacently, and then zero-crossing detection is realized by using the trend parameters obtained by two adjacent trend analysis, which has the advantage of strong detection reliability.

Referring to FIG. 3 , in one embodiment, step 202 includes step 302 and step 304 .

Step 302: Calculate and obtain an initial trend parameter according to the voltage sampling parameter at the current sampling moment and the voltage sampling parameter at the previous sampling moment; Step 304, perform filter analysis on the initial trend parameter to obtain the trend parameter.

Specifically, in the solution of this embodiment, when calculating with the voltage sampling parameter at the current sampling time and the voltage sampling parameter at the previous sampling time, the calculation result is not directly used as the current trend parameter, but the calculation After the obtained initial trend parameters are filtered, the final trend parameters can be obtained, so as to realize the zero-crossing detection and analysis.

The scheme filters the calculated initial trend parameters, and uses the filtered trend parameters for zero-crossing detection and analysis, which can further improve the accuracy of zero-crossing detection.

Further, referring to FIG. 4 , in one embodiment, the initial trend parameter includes an initial slope parameter, and step 302 includes step 402 , step 404 and step 406 .

Step 402, obtain a preset voltage coordinate system; Step 404, extract the coordinates of the voltage sampling parameters at the current sampling moment in the voltage coordinate system and the coordinates of the voltage sampling parameters at the previous sampling moment in the voltage coordinate system; Step 406, according to The extracted coordinates are subjected to slope calculation to obtain initial slope parameters.

Specifically, the voltage coordinate system is constructed from historical voltage sampling parameters. In the solution of this embodiment, the slope parameter is used to characterize the change trend of two adjacent voltage sampling parameters. In order to obtain the slopes of the two adjacent voltage sampling parameters, a corresponding coordinate system needs to be constructed for analysis and calculation. First, the controller will combine the voltage sampling parameters obtained in history, take the sampling times as the abscissa and the actual voltage sampling value as the ordinate, build the corresponding plane coordinate system, obtain the voltage coordinate system, and store it in the controller. In the subsequent acquisition of voltage sampling parameters, each time a voltage sampling parameter is acquired, it will be updated to the voltage coordinate system, and the corresponding coordinates can be obtained by combining its voltage sampling value and sampling times.

Then, when calculating the initial slope parameter, as long as the calculation is performed with the coordinates of the sampling points of two adjacent sampling times, the difference between the ordinate of the sampling point after the sampling time and the coordinate difference of the sampling point before the sampling time, and the horizontal The corresponding initial slope parameters can be obtained by comparing the coordinate differences.

The above scheme performs slope calculation by constructing a voltage coordinate system, and uses the slope parameter as a trend parameter to perform zero-crossing detection analysis, which has the advantages of simple calculation method and high calculation rate, and improves the zero-crossing detection efficiency to a certain extent.

Referring to FIG. 5 , in one embodiment, step 304 includes step 502 .

Step 502: Perform one-pass filtering in combination with the trend parameters obtained by the previous round of trend analysis and the initial trend parameters to obtain the trend parameters.

Specifically, in the solution of this embodiment, a one-pass filtering method is used to filter and analyze the initial trend parameter, so as to obtain the trend parameter corresponding to the current sampling time. In addition, in the process of one-pass filtering, the final trend parameters obtained in the previous round of trend parameter analysis should also be combined.

It can be understood that the specific manner of one-pass filtering is not unique, and in a more detailed embodiment, the following one-pass filtering parameters can be used to implement. Y=r*x _n +(1-r)x _n+1 , where 0<r<1, Y represents the final output trend parameter, x _n represents the trend parameter obtained from the previous round of trend parameter analysis, x _n+1 represents the initial trend parameter. In the actual analysis process, r can be adjusted according to actual needs. To ensure the smoothness of the data of each trend parameter finally obtained, the value of r can be slightly larger; to ensure the fast response of the data, the value of r can be appropriate. decrease.

It should be noted that, in a more detailed embodiment, the initial trend parameter for sampling the above-mentioned one-pass filtering method for filtering may be the initial slope parameter. In this embodiment, by creating an array pair coordinate system, for the updated voltage acquisition parameters, Combined with the last updated voltage acquisition parameters, the line calculation is performed to obtain the corresponding initial slope parameters. After the initial slope parameters are filtered as above, they are placed in the created array to update, so as to realize zero-crossing detection and analysis.

The above scheme, combined with the trend parameters obtained in the previous round of analysis, can obtain the current corresponding trend parameters after first-pass filtering the initial trend parameters, so as to avoid sampling fluctuations affecting the trend analysis results, improve the accuracy of the trend parameters, and further improve the zero-crossing detection. accuracy.

Referring to FIG. 6 , in one embodiment, the trend parameter includes a slope parameter, and step 204 includes step 602 .

Step 602, if the current slope parameter is positive and the slope parameter obtained from the previous round of trend analysis is negative, it is determined that a zero-crossing event occurs in the electric heating device.

Specifically, in the solution of this embodiment, the trend parameter is used as the slope parameter for explanation. When the slope analysis and calculation is performed according to the obtained voltage sampling parameter, as long as the voltage sampling values at two adjacent moments are inconsistent, the corresponding The slope parameter of is not zero. Therefore, in the solution of this embodiment, it is directly judged whether the zero-crossing event has occurred by judging whether the slope parameter has changed from negative to positive. It has strong detection convenience and detection reliability.

It should be noted that, in a more detailed embodiment, in order to facilitate analysis and processing, after the controller performs the slope calculation, if the slope is positive, write 1 to the storage bit; if the slope is negative, write to the storage bit Enter zero, that is, in the form of a binary array, to represent the slope change of the voltage sampling parameter at adjacent times. In the subsequent zero-crossing detection, it is only necessary to detect whether the adjacent binary array jumps from 0 to 1, and then it can be intuitively obtained whether the off-slope parameter has changed from negative to positive, and the zero-crossing detection result can be obtained. This storage method greatly reduces the required storage space and alleviates the problem that RAM (Random Access Memory, random access memory) occupies a lot in the controller.

Further, referring to FIG. 7 , in one embodiment, step 602 includes step 702 , step 704 , and step 706 .

Step 702, obtain a time stamp; Step 704, calculate the time interval between the current time stamp and the previous time stamp; Step 706, if the time interval is within the preset time threshold range, determine that a zero-crossing event occurs in the electric heating device.

Specifically, the time is marked as the time corresponding to when the slope parameter is positive and the slope parameter obtained by the previous round of trend analysis is negative. The solution of this embodiment, when the slope parameter changes from negative to positive, that is, the array stored in the storage bit of the controller, jumps from 0 to 1, it is not directly considered that a zero-crossing has occurred, and further according to the phase The time interval between two adjacent 0 to 1 transitions is analyzed. The controller has a timing function. Whenever a transition from 0 to 1 in the array is detected, a time stamp will be obtained. After two consecutive transitions from 0 to 1 in the array are detected, the two acquired The time stamp is calculated to obtain the time interval between the two jumps. Only when the time interval is within the preset time threshold range, will it be considered that zero-crossing has indeed occurred at this time.

Correspondingly, if the array jumps from 0 to 1 and the time interval from the last jump is within the preset time threshold range, the controller will set its internal zero-crossing flag bit, which is the state corresponding to the zero-crossing flag bit. The quantity is modified to represent the state quantity of the zero-crossing event. According to the state quantity corresponding to the setting, the subsequent corresponding chopper control operation is realized to maintain the simmering heating. For example, set the zero-crossing flag bit to 1.

It can be understood that, in another embodiment, the time interval between the currently obtained time stamp and the time stamp obtained in the previous round is not within the preset time threshold range, and it is considered that no zero-crossing event has occurred, and the zero-crossing flag is at this time. Reset state, the corresponding state quantity will be 0. It should be noted that, in another embodiment, the state quantity corresponding to the zero-crossing event may also be set to 0, while the state quantity of the zero-crossing event not occurring is set to 1, which is not specifically limited.

In the solution of the above embodiment, when the time interval is too large, it is judged that it is in an abnormal open state, the zero-crossing flag needs to be reset, and the controller outputs the detection result that zero-crossing does not occur. Correspondingly, in order to facilitate the timely detection of subsequent zero-crossings, it is necessary to return to the operation of acquiring voltage sampling parameters during the operation of the electric heating device, and perform zero-crossing detection and analysis with the acquired voltage sampling parameters again. Through the above solution, it can avoid the situation that it is mistaken for a zero-crossing when abnormal opening occurs, and further improve the zero-crossing detection accuracy.

Referring to FIG. 8 , in one embodiment, before step 102 , the method further includes step 802 .

Step 802, if the electric heating device enters the continuous heating operation state, obtain the heating power of the electric heating device, and compare and analyze it with a preset power threshold.

Specifically, in the technical solution of the present application, before zero-crossing detection and simmer heating control are performed in combination with voltage sampling parameters, the electric heating device needs to enter a low-power simmer heating state, otherwise there is no need to control the on-off of the power switch for chopping. . Therefore, in the solution of this embodiment, it is first necessary to obtain the heating power corresponding to the continuous heating state of the electric heating device, and compare and analyze it with the preset power threshold. Only when the heating power is less than the preset power threshold, will the heating power be Enable to perform subsequent zero-crossing detection analysis operations.

It can be understood that the method of detecting the heating power is not unique, and the heating power can be obtained by calculation by detecting the voltage and current. In another embodiment, it can also be realized by detecting the output signal of the power adjustment button (eg gear adjustment button, etc.) of the electric heating device. During the operation of the electric heating device, the heating power corresponding to each gear is also fixed. Therefore, the actual heating power can be obtained only by detecting the current gear.

Further, referring to FIG. 9 , in one embodiment, before step 802 , the method further includes step 902 , step 904 and step 906 .

Step 902, when the electric heating device starts running, perform a power-on self-check on the electric heating device; Step 904, if the power-on self-check is successful, check whether the heating object of the electric heating device is in the heating area; Step 906, if the heating object is under heating area, then control the electric heating equipment to enter the continuous heating operation state.

Specifically, in the solution of this embodiment, when the electric heating device is running, it first starts running according to the received power-on command, and when starting to run, it first needs to perform a self-check, and only when the self-check is successful, will the subsequent analysis be performed operation to ensure the reliability of the start-up of the electric heating equipment.

After the self-test is successful, the controller will further detect the heating object of the electric heating device (the specific type is not unique, it can be a pot, etc.), and only when the heating object is in the heating area, the subsequent slow heating control will be performed. Effective, if the heating object is not in the heating area, indicating that there is no item to be heated at this time, then slow heating is not necessary, otherwise it is easy to cause energy waste.

It can be understood that the self-inspection of the electric heating device is not unique. In a more detailed embodiment, since the subsequent zero-crossing detection depends on the accuracy of the voltage sampling parameters, the self-inspection operation may specifically be the sampling inside the self-inspection controller. Is the function normal. In another embodiment, it can also be detected whether other functions of the electric heating device are normal, for example, whether the heating device can run on a journey, and the like.

Correspondingly, the detection method of whether the heating object is in the heating area is not unique. In one embodiment, a pressure sensor may be provided in the heating area. When the heating object is in the heating area, the pressure sensor can be pressed to output pressure parameters. When it is not in the heating area, the pressure sensor will not output pressure parameters. In another embodiment, an infrared sensor, an ultrasonic sensor, etc. may also be provided in the heating area to directly detect whether the heating object is in place. The specific method to be adopted is not limited here.

In order to facilitate the understanding of the technical solutions of the present application, the present application will be explained below with reference to more detailed embodiments.

Please refer to Figure 10. After the electric heating device is turned on, first perform a power-on self-check to check whether the voltage sampling and other functions of the controller can operate normally. That is to judge the pot. If the cookware is also in the heating area, turn it on for continuous heating operation. During the heating process, the controller can detect in real time whether the heating power is less than the preset power threshold. If it is less than the preset power threshold, it is considered to enter the low-power slow heating state. At this time, in order to ensure the stability of the slow heating, the controller needs to periodically sample the voltage to obtain the voltage. sampling parameters.

Referring to Figure 11, the controller takes the number of voltage sampling as the abscissa and the voltage sampling parameters as the ordinate, builds a voltage coordinate system and stores it, and updates the voltage sampling parameter to the voltage coordinate every time a voltage sampling parameter is acquired. in the department. Then the controller calculates the coordinates (x1, y1) corresponding to the voltage sampling parameters at the current sampling time and the coordinates (x0, y0) of the voltage sampling parameters at the previous sampling time, and obtains the initial slope parameter (y1-y0)/ (x1-x0). After that, the calculated initial slope parameter xn+1 is substituted into the one-pass filter Y=r*xn+(1-r)xn+1, combined with the slope parameter xn obtained by the previous round of slope calculation and analysis, filter processing is performed, and the final result is obtained. The slope parameter Y.

After the slope parameter is obtained, the interval judgment will be performed, and the storage bit will be written according to the trend. The positive slope parameter will be judged as a positive trend, and 1 will be written, while the negative slope parameter will be judged as a negative trend, and 0 will be written. Afterwards, the zero-crossing analysis is carried out in combination with the trend stored as each write. If it is detected that the trend of writing has jumped from 0 to 1, the current time stamp will be recorded, and the time corresponding to the last 0 to 0 jump will be recorded. The time stamps are compared to obtain the time interval. If the time interval is within the range of the preset time threshold, the zero-crossing flag is set, and it is considered that a zero-crossing has occurred at this time, that is, it is determined that a zero-crossing event has occurred in the electric heating device. In other cases, it is considered that zero-crossing has not occurred, and it is only necessary to return to obtain the voltage sampling parameters again.

Finally, when it is judged that zero-crossing has occurred, the controller controls the IGBT enable state of the drive control circuit of the electric heating device to be reversed. On state; if the enable state is reversed and in the disabled state, the IGBT is controlled to shield the drive signal, that is, the IGBT enters the off state. Then, the chopper is realized by the on-off of the IGBT, and the stable simmer heating operation is completed.

It should be understood that, although the steps in the flowcharts involved in the above embodiments are sequentially displayed according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, the execution of these steps is not strictly limited to the order, and these steps may be performed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but may be executed at different times. The order of execution of these steps or stages is also not necessarily sequential, but may be performed alternately or alternately with other steps or at least a portion of the steps or stages in the other steps.

Based on the same inventive concept, an embodiment of the present application further provides a control device for an electric heating device for implementing the above-mentioned control method for an electric heating device. The solution to the problem provided by the device is similar to the solution described in the above method, so the specific limitations in one or more embodiments of the electric heating device control device provided below can refer to the above for the control of electric heating device The limitation of the method is not repeated here.

Please refer to FIG. 12 , an electric heating device control device includes: a parameter acquisition module 122 , a zero-crossing detection module 124 and a slow fire control module 126 .

The parameter acquisition module 122 is used to acquire the voltage sampling parameters of the electric heating device if the heating power of the electric heating device is less than the preset power threshold; the zero-crossing detection module 124 is used to analyze the zero-crossing trend according to the voltage sampling parameters to obtain the electric heating device The simmer control module 126 is used to maintain the simmer heating state if the zero-crossing detection result indicates that a zero-crossing event occurs.

In one embodiment, the zero-crossing detection module 124 is further configured to perform trend analysis according to the voltage sampling parameter at the current sampling moment and the voltage sampling parameter at the previous sampling moment to obtain the trend parameter; according to the current trend parameter and the last round of trend analysis The obtained trend parameters are analyzed by zero-crossing, and the zero-crossing detection result of the electric heating device is obtained.

In one embodiment, the zero-crossing detection module 124 is further configured to calculate and obtain the initial trend parameter according to the voltage sampling parameter at the current sampling time and the voltage sampling parameter at the previous sampling time; perform filter analysis on the initial trend parameter to obtain the trend parameter.

In one embodiment, the zero-crossing detection module 124 is further configured to acquire a preset voltage coordinate system, which is constructed from historical voltage sampling parameters; extract the coordinates of the voltage sampling parameters at the current sampling moment in the voltage coordinate system and the upper The coordinates of the voltage sampling parameters at a sampling moment in the voltage coordinate system; the slope is calculated according to the extracted coordinates to obtain the initial slope parameters.

In one embodiment, the zero-crossing detection module 124 is further configured to perform one-pass filtering in combination with the trend parameter obtained by analyzing the trend in the previous round and the initial trend parameter to obtain the trend parameter.

In one embodiment, the zero-crossing detection module 124 is further configured to determine that a zero-crossing event occurs in the electric heating device if the current slope parameter is positive and the slope parameter obtained from the previous round of trend analysis is negative.

In one embodiment, the zero-crossing detection module 124 is further configured to obtain a time stamp; calculate the time interval between the current time stamp and the previous time stamp; if the time interval is within the preset time threshold range, determine that the electric heating device has occurred zero-crossing event.

Referring to FIG. 13 , in one embodiment, before the parameter acquisition module 122 , the electric heating device control apparatus further includes a heating power comparison module 132 .

The heating power comparison module 132 is configured to acquire the heating power of the electric heating device if the electric heating device enters the continuous heating operation state, and compare and analyze it with a preset power threshold.

Referring to FIG. 14 , in one embodiment, before the heating power comparison module 132 , the electric heating device control apparatus further includes a detection module 142 . The detection module 142 is used to perform a power-on self-test on the electric heating device when the electric heating device starts to run; if the power-on self-test is successful, it will detect whether the heating object of the electric heating device is in the heating area; if the heating object is in the heating area, control the The electric heating device enters the continuous heating operation state.

The above-mentioned electric heating device control device can perform real-time voltage sampling during the operation of the electric heating device to obtain voltage sampling parameters when the electric heating device operates at a heating power less than a preset power threshold, that is, in a low-power operation state. Then, the zero-crossing trend analysis of the voltage sampling parameters can be performed to determine whether the electric heating device is in the zero-crossing state, and when the electric heating device is in the zero-crossing state, the electric heating device is controlled to maintain a stable simmer heating state. In the above solution, the zero-crossing detection of the electric heating device is directly realized through the analysis of the voltage sampling parameters, and no additional hardware circuit for zero-crossing detection is required, thereby effectively alleviating the problem of high cost of the slow heating circuit.

Please refer to FIG. 15 , an electric heating device control system includes a filter circuit 152 , a controller 154 and a drive control circuit 156 , the filter circuit 152 is connected to the controller 154 , the controller 154 is connected to the drive control circuit 156 , and the filter circuit 152 connects the electric heating The operating voltage of the device is filtered and transmitted to the controller 154, and the controller 154 outputs an enable signal to the drive control circuit 156 based on the filtered operating voltage and adopts the electric heating device control method as described above to adjust the drive control circuit 156. Running state, maintain simmer heating state.

Specifically, the control method of the electric heating device is as shown in each of the above embodiments and the accompanying drawings, and details are not repeated here. The controller 154 has a sampling function, and a filter circuit 152 is directly set at the voltage sampling port of the controller 154. The filter circuit 152 is connected to the voltage input end of the electric heating device, and the filter circuit 152 filters out the working voltage of the high-frequency impurity signal. , which is transmitted to the voltage sampling port of the controller 154 to implement voltage sampling to obtain voltage sampling parameters. Correspondingly, the specific type of the filter circuit 152 is not unique. In a more detailed embodiment, a small capacitor (for example, 22pf can be used) and a current limiting resistor can be used to form the RC filter circuit 152, which will be transmitted to the controller 154. The voltage spikes of 100 are filtered out, which is convenient for the controller 154 to sample to obtain an accurate voltage sampling value.

The above-mentioned electric heating device control system can perform real-time voltage sampling during the operation of the electric heating device to obtain voltage sampling parameters when the electric heating device operates at a heating power less than a preset power threshold, that is, in a low-power operation state. Then, the zero-crossing trend analysis of the voltage sampling parameters can be performed to determine whether the electric heating device is in the zero-crossing state, and when the electric heating device is in the zero-crossing state, the electric heating device is controlled to maintain a stable simmer heating state. In the above solution, the zero-crossing detection of the electric heating device is directly realized through the analysis of the voltage sampling parameters, and no additional hardware circuit for zero-crossing detection is required, thereby effectively alleviating the problem of high cost of the slow heating circuit.

An electric heating device includes the above-mentioned electric heating device control system.

Specifically, the control system of the electric heating device is as shown in the above-mentioned embodiments and the accompanying drawings, and details are not repeated here. When the electric heating device operates at a heating power less than a preset power threshold, that is, in a low-power operation state, The voltage sampling during the operation of the electric heating equipment can be carried out in real time, and the voltage sampling parameters can be obtained. Then, the zero-crossing trend analysis of the voltage sampling parameters can be performed to determine whether the electric heating device is in the zero-crossing state, and when the electric heating device is in the zero-crossing state, the electric heating device is controlled to maintain a stable simmer heating state. In the above solution, the zero-crossing detection of the electric heating device is directly realized through the analysis of the voltage sampling parameters, and no additional hardware circuit for zero-crossing detection is required, thereby effectively alleviating the problem of high cost of the slow heating circuit.

It can be understood that the specific type of the electric heating device is not unique. In a more detailed embodiment, the electric heating device may be an electromagnetic heating device. More specifically, the electromagnetic heating device may also include an IH rice cooker, an induction cooker, an induction heating furnace, and the like.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the patent application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims (13)

1. A method of controlling an electric heating apparatus, comprising:

if the heating power of the electric heating equipment is smaller than a preset power threshold, acquiring a voltage sampling parameter of the electric heating equipment;

performing zero-crossing trend analysis according to the voltage sampling parameters to obtain a zero-crossing detection result of the electric heating equipment;

and if the zero-crossing detection result indicates that a zero-crossing event occurs, maintaining a slow fire heating state.

2. The method for controlling an electric heating apparatus according to claim 1, wherein the performing zero-crossing trend analysis according to the voltage sampling parameter to obtain a zero-crossing detection result of the electric heating apparatus comprises:

performing trend analysis to obtain a trend parameter according to the voltage sampling parameter at the current sampling moment and the voltage sampling parameter at the last sampling moment;

and performing zero-crossing analysis according to the current trend parameter and the trend parameter obtained by the previous trend analysis to obtain a zero-crossing detection result of the electric heating equipment.

3. The electric heating apparatus control method according to claim 2, wherein performing trend analysis to obtain a trend parameter according to the voltage sampling parameter at the current sampling time and the voltage sampling parameter at the last sampling time comprises:

calculating to obtain an initial trend parameter according to the voltage sampling parameter at the current sampling moment and the voltage sampling parameter at the last sampling moment;

and carrying out filtering analysis on the initial trend parameters to obtain trend parameters.

4. The electric heating apparatus control method according to claim 3, wherein the initial trend parameter includes an initial slope parameter;

the calculating according to the voltage sampling parameter at the current sampling moment and the voltage sampling parameter at the last sampling moment to obtain the initial trend parameter comprises the following steps:

acquiring a preset voltage coordinate system, wherein the voltage coordinate system is established by historical voltage sampling parameters;

extracting the coordinates of the voltage sampling parameter at the current sampling moment in the voltage coordinate system and the coordinates of the voltage sampling parameter at the last sampling moment in the voltage coordinate system;

and calculating the slope according to the extracted coordinates to obtain an initial slope parameter.

5. The electric heating apparatus control method according to claim 3 or 4, wherein the performing filter analysis on the initial trend parameter to obtain a trend parameter comprises:

and carrying out one-pass filtering by combining the trend parameter obtained by the previous trend analysis and the initial trend parameter to obtain a trend parameter.

6. The electric heating apparatus control method according to any one of claims 2 to 4, wherein the trend parameter includes a slope parameter;

the zero-crossing analysis is performed according to the current trend parameter and the trend parameter obtained from the previous trend analysis, so as to obtain the zero-crossing detection result of the electric heating device, and the zero-crossing detection result comprises the following steps:

and if the current slope parameter is positive and the slope parameter obtained by the previous trend analysis is negative, judging that the electric heating equipment has a zero-crossing event.

7. The method for controlling electric heating equipment according to claim 6, wherein if the current slope parameter is positive and the slope parameter obtained from the previous trend analysis is negative, determining that the electric heating equipment has a zero-crossing event comprises:

acquiring a time identifier, wherein the time identifier is the time corresponding to the slope parameter which is positive and the slope parameter obtained by the previous trend analysis is negative;

calculating the time interval between the current time identifier and the last time identifier;

and if the time interval is within the range of a preset time threshold, judging that the electric heating equipment has a zero-crossing event.

8. The method for controlling the electric heating device according to any one of claims 1 to 4, wherein before obtaining the voltage sampling parameter of the electric heating device if the heating power of the electric heating device is less than the preset power threshold, the method further comprises:

and if the electric heating equipment enters a continuous heating running state, acquiring the heating power of the electric heating equipment, and comparing and analyzing the heating power with a preset power threshold value.

9. The method for controlling an electric heating device according to claim 8, wherein before the step of obtaining the heating power of the electric heating device and comparing the heating power with a preset power threshold value for analysis if the electric heating device enters the continuous heating operation state, the method further comprises:

when the electric heating equipment is started to operate, performing power-on self-test on the electric heating equipment;

if the power-on self-test is successful, detecting whether a heating object of the electric heating equipment is in a heating area;

and if the heating object is in the heating area, controlling the electric heating equipment to enter a continuous heating running state.

10. An electric heating apparatus control device, comprising:

the parameter acquisition module is used for acquiring a voltage sampling parameter of the electric heating equipment if the heating power of the electric heating equipment is smaller than a preset power threshold;

the zero-crossing detection module is used for carrying out zero-crossing trend analysis according to the voltage sampling parameters to obtain a zero-crossing detection result of the electric heating equipment;

and the mild fire control module is used for maintaining a mild fire heating state if the zero-crossing detection result represents that a zero-crossing event occurs.

11. An electric heating device control system, characterized by comprising a filter circuit, a controller and a drive control circuit, wherein the filter circuit is connected with the controller, the controller is connected with the drive control circuit, the filter circuit filters and transmits the working voltage of the electric heating device to the controller, and the controller outputs an enable signal to the drive control circuit based on the filtered working voltage and by adopting the electric heating device control method according to any one of claims 1 to 9, so as to adjust the operating state of the drive control circuit and maintain the slow fire heating state.

12. An electric heating apparatus characterized by comprising the electric heating apparatus control system of claim 11.

13. Electrically heated apparatus according to claim 12 wherein the electrically heated apparatus is an electromagnetic heating apparatus.

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