CN115469637A - Motor controller insulation detection method and system based on CAN bus control - Google Patents

Abstract

The invention discloses a motor controller insulation detection method and system based on CAN bus control, and relates to the technical field of new energy motor controller testing, wherein the motor controller insulation detection method based on CAN bus control includes the following steps: collecting motor The insulation resistance to ground during the controller test; according to the relationship between the insulation resistance to the ground and the thresholds of all levels, feedback and control are carried out through CAN messages to determine whether to maintain the test of the motor controller. The invention can effectively solve the problem that a large number of IGBTs of the motor controller are burned during development due to hardware design defects or software control logic defects in the development stage of the motor controller.

Description

Motor controller insulation detection method and system based on CAN bus control

technical field

The invention relates to the technical field of new energy motor controller testing, in particular to a method and system for detecting insulation of a motor controller based on CAN bus control.

Background technique

With the application of digitalization, electrification and unmanned in the field of new energy vehicles, the design of motor controllers tends to be modularized and intelligent, and the boundary response conditions of dynamic tests are becoming increasingly harsh, which puts forward higher requirements for new energy test equipment, especially In the field of insulation testing of new energy motor controllers.

Since the new energy motor controller is being developed, it is necessary to test the static insulation strength of the motor controller. Generally, a 0-1500V shaker or insulation tester is used for insulation testing; at the same time, the IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) for special treatment to avoid problems such as IGBT breakdown.

However, the above method can only perform insulation detection on the static state of the motor controller. When the motor controller is tested on the bench, the DC bus input terminal of the controller is given a DC high voltage of 0-800V, and the speed (0-20000rpm)/torque (0-20000rpm)/torque (0- 350N.m) motor controller MAP performance test; the power device of the motor controller is under high temperature and high current working environment for a long time, which may easily lead to the insulation drop of the motor controller to the ground, the transient loss of control of the motor controller, and the burning of the internal IGBT of the controller, etc. Risk of electronic components.

Contents of the invention

Aiming at the defects in the prior art, the first aspect of the present invention provides a motor controller insulation detection method based on CAN bus control, which can effectively solve the problem of motor controller failure due to hardware design defects or software control logic defects during the research and development stage. The problem of burning a large number of IGBTs during the development of the controller.

For achieving above object, the technical scheme that the present invention takes is:

A method for detecting insulation of a motor controller based on CAN bus control, the method comprising the following steps:

Collect the insulation resistance to ground during the motor controller test;

According to the relationship between the insulation resistance to ground and the thresholds of all levels, feedback and control are carried out through CAN messages to determine whether to maintain the test of the motor controller.

In some embodiments, according to the size relationship between the ground insulation resistance and the thresholds of all levels, the feedback and control are performed through CAN messages to determine whether to maintain the test of the motor controller, including:

Integrate CAN messages including battery simulators, insulation detection devices and motor controllers, and issue them, wherein the battery simulator is used to power on the motor controller, and the insulation detection device is used to collect the motor controller Ground insulation resistance;

When the ground insulation resistance of the motor controller is greater than the first threshold, feedback and control are performed through the CAN message to maintain the test of the motor controller;

When the insulation resistance to ground of the motor controller is less than the first threshold but greater than the second threshold, feedback and control are performed through the CAN message, the test of the motor controller is maintained, and an early warning is given;

When the ground insulation resistance of the motor controller is less than the second threshold value, feedback and control are performed through the CAN message, the voltage output of the battery simulator is stopped, and the test of the motor controller is stopped.

In some embodiments, before the collection of the insulation resistance to ground during the motor controller test, the method further includes:

Start the battery simulator to power on the motor controller through the CAN message;

Use the insulation detection device to detect the insulation resistance to the ground before the motor controller test;

When the insulation resistance to ground of the motor controller before the test is greater than the second threshold, power-on is completed;

When the insulation resistance to ground of the motor controller before the test is less than a second threshold, the voltage output of the battery simulator is stopped through the CAN message.

In some embodiments, the first threshold is 250kΩ, and the second threshold is 150kΩ.

In some embodiments, the sampling frequency of the CAN message is less than 5ms.

In some embodiments, the motor controller is tested by a dynamometer.

In some embodiments, the test of the motor controller includes: speed/torque test, motor/generation MAP test and/or voltage fluctuation test.

The second aspect of the present invention provides a motor controller insulation detection system based on CAN bus control, which can effectively solve the problem of a large number of IGBTs in the development of the motor controller due to hardware design defects or software control logic defects in the development stage of the motor controller. burning problem.

For achieving above object, the technical scheme that the present invention takes is:

A motor controller insulation detection system based on CAN bus control, including:

an insulation detection device, which is used to collect the ground insulation resistance of the motor controller;

The control device is used to perform feedback and control through CAN messages according to the relationship between the ground insulation resistance and the threshold values of each level, so as to determine whether to maintain the test of the motor controller.

In some embodiments, the control device includes:

a battery simulator for powering up the motor controller;

Computer CAN network main control system, which is used to integrate CAN messages including battery simulator, insulation detection device and motor controller, and issue them;

And when the insulation resistance to ground is greater than the first threshold, the insulation detection device feeds back to the computer CAN network main control system through the CAN message, and the computer CAN network main control system controls the battery based on the CAN message. The simulator completes the power-up and keeps the test of the motor controller;

When the insulation resistance to ground is less than the first threshold but greater than the second threshold, the insulation detection device feeds back the CAN message to the computer CAN network master control system, and the computer CAN network master control system is based on the CAN report The paper controls the battery simulator to complete power-on, keeps the test of the motor controller, and carries out early warning;

When the insulation resistance to ground is less than the second threshold, the insulation detection device feeds back to the computer CAN network master control system through the CAN message, and the computer CAN network master control system stops the voltage output of the battery simulator and stops the motor controller test.

In some embodiments, the CAN message sampling frequency set by the computer CAN network main control system is less than 5ms.

Compared with the prior art, the present invention has the advantages of:

The motor controller insulation detection method based on CAN bus control in the present invention forms a CAN bus control new energy motor controller insulation detection system message by integrating CAN messages including a battery simulator, an insulation detection device and a motor controller. According to the relationship between the insulation resistance to ground and the thresholds at all levels, by testing the CAN message status of the battery simulator, insulation detection device and motor controller, and performing real-time monitoring and display of parameters, it can effectively solve the problem of developing new energy motor controllers. Due to the low test methods, a large number of IGBTs were burned in the development of new energy motor controllers. Through the development and application of this system, the research and development costs were reduced, the technical level of new energy research and development and testing was improved, and electrical fire accidents were prevented.

Description of drawings

Fig. 1 is the flow chart of the motor controller insulation detection method based on CAN bus control in the embodiment of the present invention;

Fig. 2 is the flowchart of step S2 among Fig. 1;

Fig. 3 is a circuit diagram of a motor controller insulation detection system based on CAN bus control in an embodiment of the present invention.

detailed description

The technical solution (including the preferred technical solution) of the present invention will be further described in detail below by means of the accompanying drawings and listing some optional embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower" and so on is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed, or operate in a particular orientation, and thus should not be construed as limiting the application. Unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, It can also be an electrical connection; it can be a direct connection, or an indirect connection through an intermediary, or an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

Further, in this application, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations, any such actual relationship or order exists. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The embodiment of the present invention discloses a method for detecting insulation of a motor controller based on CAN bus control. The method includes the following steps:

S1. Collect the insulation resistance to ground when the motor controller is tested.

S2. According to the relationship between the insulation resistance to ground and the thresholds of all levels, feedback and control are performed through CAN messages to determine whether to maintain the test of the motor controller.

It is worth noting that in this embodiment, the insulation resistance to ground of the motor controller is mainly collected through the insulation detection device; System integration includes CAN messages from the battery simulator, insulation detection device and motor controller, which are sent to the battery simulator, insulation detection device and motor controller.

In this embodiment, the motor controller is tested by a dynamometer, wherein the motor controller test mainly includes a speed/torque test, an electric/power generation MAP test and/or a voltage fluctuation test.

When the motor controller starts testing, it can detect the insulation resistance to the ground in real time, and realize the insulation detection and control of the motor controller by the CAN bus through the relationship between the insulation resistance to the ground and the threshold values of all levels.

Specifically, as shown in FIG. 2, step S2 includes:

S21. Integrate the CAN message including the battery simulator, the insulation detection device and the motor controller, and issue it, wherein the battery simulator is used to power on the motor controller, and the insulation detection device is used to collect the motor controller insulation resistance to ground.

S22. When the insulation resistance to ground of the motor controller is greater than the first threshold value during the test, perform feedback and control through the CAN message, and keep the test of the motor controller.

S23. When the insulation resistance to ground of the motor controller is less than the first threshold but greater than the second threshold, perform feedback and control through the CAN message, keep the test of the motor controller, and give an early warning.

S24. When the ground insulation resistance of the motor controller is less than the second threshold value, perform feedback and control through the CAN message, stop the voltage output of the battery simulator, and stop the test of the motor controller.

In this embodiment, the first threshold is greater than the second threshold, for example, the first threshold may be set to 250 kΩ, and the second threshold may be set to 150 kΩ. It can be understood that the values of the first threshold and the second threshold can be reasonably set as required, which is not limited in this embodiment of the present invention.

It can be understood that, based on the set first threshold and second threshold, the motor controller can be set to three levels of alarm limits for ground insulation classification:

The first level, the main control system of the computer CAN network detects that the insulation of the motor controller to the ground is >250kΩ, and the maximum measured current to the ground is <0.35mA; it is judged that the insulation to the ground is normal;

The second level, early warning value (VW): <250kΩ; the maximum measured current to the ground is <0.35mA, which is judged as a system early warning; but it does not trigger the shutdown of the main control system of the computer CAN network;

The third level, setting the alarm value (AL): <150KΩ; and the maximum measured current to the ground> 0.35mA, at this time, the main control system of the computer CAN network transiently sends CAN messages to close each output.

In addition, the sampling frequency of the CAN message can also be reasonably set according to needs, for example, it can be set to be less than 5ms.

As a preferred implementation, in order to minimize the need to stop the test after the motor controller has started the test, this embodiment also includes:

Start the battery simulator through the CAN message to power on the motor controller; use the insulation detection device to detect the ground insulation resistance of the motor controller before the test; when the ground insulation resistance of the motor controller before the test is greater than the first When the second threshold is reached, the power-on is completed; when the insulation resistance to ground of the motor controller before testing is less than the second threshold, the voltage output of the battery simulator is stopped through the CAN message.

That is to say, before the test starts, first use the insulation detection device to detect the insulation resistance to ground of the motor controller before the test, if it is greater than the second threshold, it is considered that the test requirements are met, and the power-on can be completed; if it is less than the second threshold , it is considered that there is a fault, and the voltage output of the battery simulator needs to be stopped, thereby reducing the probability that the test needs to be stopped after the test.

The following is a specific example to further describe the above steps:

See Figure 3, which is the circuit diagram of the computer CAN network main control system, battery simulator, insulation detection device and motor controller, CAN_H, CAN_L of the computer CAN network main control system, CAN_H, CAN_L of the battery simulator, and insulation detection The CAN_H and CAN_L of the device are connected to the CAN bus, and a 120Ω resistor is added to the terminal of the main control system of the computer CAN network to improve the transmission capacity of the CAN bus.

The positive pole of the output terminal of the battery simulator is connected to the input terminal B+ of the motor controller, and the insulation detection device L+ is connected at the same time, the negative pole of the output terminal of the battery simulator is connected to the motor controller B-, and the insulation detection device L- is connected at the same time.

The main control system of the computer CAN network composes CAN messages for the three systems of battery simulator, insulation detection device and motor controller; defines the messages through the DBC file, and writes the message name, message ID, sending type, period, Length, accuracy, etc., set the message input AI, output AO sampling and control frequency; such as battery simulator: bus voltage: SG_SET_LIM_U_MN; bus current SG_SET_LIM_I_N_MN; bus power SG_SET_LIM_I_P_MN; detect motor controller bus voltage: SG_MotorDCbusVolt; Current: SG_MotorDCbusCur; switch status of the ground insulation detection device: SG_SET_SWITCH; message information such as the status of ground insulation SG_SET_R.

Specifically, the DBC file definition of the battery simulator is as follows:

SG_SET_LIM_U_MN;

SG_SET_LIM_I_N_MN;

SG_SET_LIM_I_P_MN;

The DBC file definition of the motor controller is as follows:

SG_MotorDCbusVolt;

SG_MotorDCbusCur;

The DBC file definition of the insulation detection device is as follows:

SG_SET_SWITCH;

SG_SET_R;

By integrating the above three DBC files to form a total DBC file, the CAN message control logic can be implemented.

Subsequently, the computer CAN network main control system will import the integrated DBC file into the system for system configuration; set the message name, sampling frequency, define message display accuracy, control accuracy; DI digital input alarm; DO digital output control, etc. .

Next, you can first set the CAN message control logic (static verification): When the computer CAN network main control system starts the battery simulator and powers on at high voltage, the insulation detection device will automatically detect the ground insulation impedance of the motor controller. Ground insulation resistance > 250kw, the system allows the battery simulator to be powered on, and the output corresponds to a DC voltage (according to the voltage required by the motor controller) 0-800V. The motor controller receives the power-on voltage and feeds back to the computer CAN network master through CAN messages. control system, power-on is completed, SWITCH=0 (the system has no alarm); if the insulation detection device detects that the insulation resistance to ground is less than 150KΩ during the power-on process of the battery simulator, the main control system of the computer CAN network will automatically stop the battery. Simulator voltage output, and output alarm SWITCH=2 at the same time, the system is seriously faulty, stop the machine to check the insulation performance of the motor controller to the ground, and prevent the motor controller IGBT from high-voltage power-on breakdown, so as not to cause a fire in the laboratory.

Then you can set the CAN message control logic (dynamic verification): when the main control system of the computer CAN network is powered on according to the control logic, there is no alarm; then proceed to the next step: the dynamometer and the sample (motor and motor control) device) to start the test conditions: speed/torque test, motor/generator MAP test and/or voltage fluctuation test.

The speed/torque test is mainly to carry out the load test of the speed 0-20000rpm/torque 0-350N.m, and the voltage fluctuation test can fluctuate between 300-500V, for example. When the above test is carried out, the temperature of the motor controller is usually already at 100°C. At this time, the insulation detection device has been monitoring the insulation resistance of the motor controller B+ and B- to ground in real time.

After long-term system verification with high voltage, high current, and heat load, when the insulation resistance of the motor controller to the ground is >250kΩ, and the measured current to the ground is <0.35mA, it is judged that the system is normal, and SWITCH=0 at this time; If the insulation resistance to the ground of the device is less than 250kΩ, the insulation detection device will automatically send the CAN message to the main control system of the computer CAN network for alarm and early warning SWITCH=1; if the insulation resistance to the ground continues to drop to <150KΩ or the current to the ground is <0.35mA; The ground insulation detection device automatically sends the time <5ms through the CAN message, and the alarm shutdown command SWITCH=2, at this time, the alarm is a serious failure of the system, the computer CAN network main control system issues the highest emergency stop command, and the system stops the dynamometer instantaneously Running, the battery simulator stops the high-voltage output instantaneously, and the motor controller stops sending and receiving messages.

Based on the above-mentioned CAN bus control, it can effectively solve the problem of a large number of IGBT burnouts in the motor controller due to hardware design defects or software control logic defects in the development stage of the new energy motor controller; at the same time, it also reduces the research and development cost and realizes new energy. Defects and faults in automobile research and development are moved forward to ensure that the faults of the new energy motor controller are cleared before they are put on the car, and also improve the research and development methods of new energy vehicles.

In summary, the motor controller insulation detection method based on CAN bus control in the present invention forms a CAN bus control new energy motor controller insulation by integrating CAN messages including battery simulators, insulation detection devices and motor controllers. Check system packets. According to the relationship between the insulation resistance to ground and the thresholds at all levels, by testing the CAN message status of the battery simulator, insulation detection device and motor controller, and performing real-time monitoring and display of parameters, it can effectively solve the problem of developing new energy motor controllers. Due to the low test methods, a large number of IGBTs were burned in the development of new energy motor controllers. Through the development and application of this system, the research and development costs were reduced, the technical level of new energy research and development and testing was improved, and electrical fire accidents were prevented.

At the same time, referring to Fig. 2, the embodiment of the present invention also provides a motor controller insulation detection system based on CAN bus control, which includes:

The insulation detection device is used for collecting the ground insulation resistance of the motor controller.

The control device is used to perform feedback and control through CAN messages according to the relationship between the ground insulation resistance and the threshold values of each level, so as to determine whether to maintain the test of the motor controller.

In some embodiments, the control device includes:

a battery emulator for powering up the motor controller.

The computer CAN network main control system is used to integrate CAN messages including battery simulators, insulation detection devices and motor controllers, and issue them.

And when the insulation resistance to ground is greater than the first threshold, the insulation detection device feeds back to the computer CAN network main control system through the CAN message, and the computer CAN network main control system controls the battery based on the CAN message. The simulator completes power-up, maintaining the test of the motor controller.

When the insulation resistance to ground is less than the first threshold but greater than the second threshold, the insulation detection device feeds back the CAN message to the computer CAN network master control system, and the computer CAN network master control system is based on the CAN report The text controls the battery simulator to complete power-on, maintain the test of the motor controller, and perform early warning.

When the insulation resistance to ground is less than the second threshold, the insulation detection device feeds back to the computer CAN network master control system through the CAN message, and the computer CAN network master control system stops the voltage output of the battery simulator and stops the motor controller test.

In some embodiments, before the insulation detection device collects the insulation resistance to ground during the motor controller test:

The computer CAN network main control system starts the battery simulator to power on the motor controller through the CAN message; the insulation detection device is also used to detect the ground insulation resistance of the motor controller before testing;

When the insulation resistance to ground of the motor controller before testing is greater than the second threshold, power-on is completed.

When the insulation resistance to ground of the motor controller before the test is less than the second threshold, the main control system of the computer CAN network stops the voltage output of the battery simulator through the CAN message. Preferably, the first threshold is 250kΩ, and the second threshold is 150kΩ.

In some embodiments, the CAN message sampling frequency set by the computer CAN network main control system is less than 5ms.

In summary, the motor controller insulation detection system based on CAN bus control in the present invention forms a CAN bus to control the insulation of new energy motor controllers by integrating CAN messages including battery simulators, insulation detection devices and motor controllers. Check system packets. According to the relationship between the insulation resistance to ground and the thresholds at all levels, by testing the CAN message status of the battery simulator, insulation detection device and motor controller, and performing real-time monitoring and display of parameters, it can effectively solve the problem of developing new energy motor controllers. Due to the low test methods, a large number of IGBTs were burned in the development of new energy motor controllers. Through the development and application of this system, the research and development costs were reduced, the technical level of new energy research and development and testing was improved, and electrical fire accidents were prevented.

The above descriptions are only specific implementation manners of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims (10)

1. A motor controller insulation detection method based on CAN bus control is characterized by comprising the following steps:

collecting insulation impedance to ground when a motor controller is tested;

and according to the relation between the ground insulation resistance and the threshold values of all levels, performing feedback and control in a CAN message mode to determine whether to keep the test of the motor controller.

2. The insulation detection method of the motor controller based on the CAN bus control as claimed in claim 1, wherein the step of performing feedback and control in a CAN message manner according to the insulation resistance to ground and the magnitude relation of each level of threshold value to determine whether to maintain the test of the motor controller comprises:

integrating CAN messages comprising a battery simulator, an insulation detection device and a motor controller, and issuing, wherein the battery simulator is used for electrifying the motor controller, and the insulation detection device is used for collecting the ground insulation impedance of the motor controller;

when the insulation resistance to the ground is larger than a first threshold value during the test of the motor controller, the feedback and the control are carried out through the CAN message, and the test of the motor controller is kept;

when the ground insulation impedance of the motor controller in the test is smaller than a first threshold value but larger than a second threshold value, the feedback and control are carried out through the CAN message, the test of the motor controller is kept, and early warning is carried out;

and when the insulation resistance to the ground is smaller than a second threshold value during the test of the motor controller, the voltage output of the battery simulator is stopped through the feedback and control of the CAN message, and the test of the motor controller is stopped.

3. The insulation detection method for the motor controller based on the CAN bus control as claimed in claim 2, further comprising before the step of collecting insulation resistance to ground when the motor controller is tested:

starting the battery simulator to electrify the motor controller through the CAN message;

detecting the insulation resistance to the ground before the test of the motor controller by using an insulation detection device;

when the insulation resistance to the ground before the motor controller is tested is larger than a second threshold value, finishing electrifying;

and when the insulation resistance to the ground before the motor controller is tested is smaller than a second threshold value, stopping the voltage output of the battery simulator through the CAN message.

4. The CAN-bus-control-based motor controller insulation detection method according to claim 2, characterized in that: the first threshold value is 250k Ω, and the second threshold value is 150k Ω.

5. The CAN-bus-control-based motor controller insulation detection method according to claim 2, characterized in that: and the sampling frequency of the CAN message is less than 5ms.

6. The CAN-bus-control-based motor controller insulation detection method according to claim 1, characterized in that: and testing the motor controller through a dynamometer.

7. The CAN-bus-control-based motor controller insulation detection method according to claim 1 or 6, wherein the testing of the motor controller comprises: a speed/torque test, a motoring/generating MAP test, and/or a voltage ripple test.

8. The utility model provides an insulating detecting system of machine controller based on CAN bus control which characterized in that includes:

the insulation detection device is used for acquiring the insulation resistance to the ground of the motor controller;

and the control device is used for carrying out feedback and control in a CAN message mode according to the size relation between the ground insulation resistance and each level of threshold value so as to determine whether to keep the test of the motor controller.

9. The CAN bus control-based motor controller insulation detection system of claim 8, wherein the control device comprises:

a battery simulator for powering up the motor controller;

the computer CAN network master control system is used for integrating and issuing CAN messages comprising a battery simulator, an insulation detection device and a motor controller;

when the ground insulation impedance is larger than a first threshold value, the insulation detection device feeds back the insulation detection device to the computer CAN network master control system through the CAN message, and the computer CAN network master control system controls the battery simulator to complete electrification based on the CAN message and keeps the test of the motor controller;

when the ground insulation impedance is smaller than a first threshold value but larger than a second threshold value, the insulation detection device feeds back the insulation detection device to the computer CAN network master control system through the CAN message, and the computer CAN network master control system controls the battery simulator to complete power-on based on the CAN message, keeps the test of the motor controller and carries out early warning;

and when the ground insulation impedance is smaller than a second threshold value, the insulation detection device feeds back the insulation detection device to the computer CAN network master control system through the CAN message, and the computer CAN network master control system stops the voltage output of the battery simulator based on the CAN message and stops the test of the motor controller.

10. The CAN bus control-based motor controller insulation detection system of claim 8, wherein the sampling frequency of the CAN messages set by the computer CAN network master control system is less than 5ms.

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