CN106771907A - Low voltage equipment intellectuality power frequency withstanding voltage pilot system and method - Google Patents

Abstract

The invention belongs to the technical field of power frequency withstand voltage test, and relates to an intelligent chemical industry frequency withstand voltage test system and method for low-voltage electrical equipment. The test power supply, protection switch, voltage regulator, choke inductor, test transformer and test product are connected in sequence. The display unit, voice prompt unit, IGBT drive unit and operation panel are all connected to the DSP processor. The IGBT drive unit, IGBT connected with the motor in turn; DSP processor, isolation amplifier unit V is connected with voltage transformer and test transformer in turn; DSP processor, isolation amplifier unit A is connected with current transformer and test transformer in turn; printer, industrial computer, communication unit and DSP Processors are connected sequentially. It realizes the centralized control and automatic data management of the low-voltage DC switch experiment process, the on-off capability test and inspection of on-off and electrical life, and has the advantages of simple structure, convenient operation, good stability, strong safety and high level of intelligence.

Description

Low-voltage electrical equipment intelligent chemical industry frequency withstand voltage test system and method

technical field

The invention belongs to the technical field of power frequency withstand voltage test, and in particular relates to an intelligent industrial frequency withstand voltage test system and method for low-voltage electrical equipment.

Background technique

The power frequency withstand voltage test of low-voltage electrical equipment requires a certain high voltage to be applied between electrically isolated components during normal operation and lasts for a certain period of time to verify the ability of the solid insulation of low-voltage electrical equipment to withstand transient overvoltages. The power frequency withstand voltage test is an important formal test item, and it is also the basis for fault discrimination after the humidity test, breaking test and short circuit test. The conventional power frequency withstand voltage test device is composed of contactors, time relays, intermediate relays, overcurrent relays, etc. The device has many parts and poor stability. The test process requires manual operation, complicated operation, poor safety, and low level of intelligence.

Contents of the invention

Aiming at the problems existing in the above-mentioned prior art, the present invention proposes an intelligent chemical industry frequency withstand voltage test system and method for low-voltage electrical equipment. And intelligent low-voltage electrical equipment intelligent chemical industry frequency withstand voltage test system and method.

In order to achieve the above-mentioned purpose of the invention, the present invention is achieved through the following technical solutions:

Low-voltage electrical equipment intelligent chemical industry frequency withstand voltage test system, including industrial computers and printers, also includes test power supply, protection switch, voltage regulator, choke inductor, test transformer, test product, DSP processor, display unit, voice prompt unit , IGBT drive unit, IGBT, motor, voltage transformer, current transformer, isolation amplifier unit V, isolation amplifier unit A, operation panel and communication unit; the test power supply is connected to the protection switch, and the protection switch is connected to the voltage regulator , the voltage regulator is connected to the test transformer through the choke inductance, the test transformer is connected to the test product, the display unit is connected to the DSP processor, the voice prompt unit is connected to the DSP processor, the IGBT drive unit is connected to the DSP, and the IGBT It is connected with the IGBT drive unit, and the motor is connected with the IGBT; both the voltage transformer and the current transformer are connected with the test transformer; the isolation amplifier unit V is connected with the voltage transformer, and the isolation amplifier unit A is connected with the current transformer; Both the amplification unit V and the isolation amplification unit A are connected to the DSP processor, the operation panel is connected to the DSP processor, the industrial computer is connected to the DSP processor through the communication unit, and the printer is connected to the industrial computer.

The output end of the test power supply is connected to the input end of the protection switch, the output end of the protection switch is connected to the power input end of the voltage regulator, and the voltage output end of the voltage regulator is connected to the primary side phase of the test transformer through a choke inductor. Connection, the secondary side of the test transformer is connected to the power frequency withstand voltage test part of the test product, the input terminal of the display unit is connected to the signal output terminal of the DSP processor, the input terminal of the voice prompt unit is connected to the signal output terminal of the DSP processor The output terminals are connected, the input terminal of the IGBT drive unit is connected to the signal output terminal of the DSP, the base of the control signal input terminal of the IGBT is connected to the drive signal output terminal of the IGBT drive unit, and the winding of the motor is connected to the collector and emitter of the IGBT. The poles are connected; the measuring terminal of the voltage transformer is connected with the voltage signal output terminal of the test transformer, and the measuring terminal of the current transformer is connected with the current signal output terminal of the test transformer; the signal input terminal of the isolation amplifier unit V is connected with the voltage transformer The signal output terminals of the isolated amplifier unit A are connected with the signal output terminals of the current transformer; the signal output terminals of the isolated amplifier unit V and the isolated amplifier unit A are connected with the signal input terminals of the DSP processor , the signal output terminal of the operation panel is connected with the signal input terminal of the DSP processor, the industrial computer is connected with the communication signal input terminal of the DSP processor through the communication unit, and the signal input terminal of the printer is connected with the USB interface of the industrial computer.

The test voltage of the test system is directly related to the rated insulation voltage of the low-voltage electrical equipment, the frequency of the test power supply is 45-65Hz alternating current, and the output voltage is a sine wave; in order to ensure that the impedance of the test power supply is far less than the leakage resistance, the test power supply The capacity is that after the output voltage of the test transformer is adjusted to the test voltage, the output terminal is short-circuited and the output current is at least 200mA; in order to prevent voltage shock during the test, when the voltage rises, it starts from less than 1/2 of the test voltage value and lasts for about 5s The specified value is gradually increased within a certain period of time.

The intelligent chemical frequency withstand voltage test method of low-voltage electrical equipment is to connect the voltage output terminal of the test transformer of the test system with the test object, that is, the measurement part of the low-voltage electrical appliance, through wires before the test. The specific operation steps of the test are as follows:

(1) The system is powered on, initialized, and self-tested;

(2) The operation panel transmits the test voltage value and pressure application time to the DSP processor;

(3) The DSP processor sends control instructions to drive the motor to drive the voltage regulator to generate voltage, and at the same time collects voltage information and compares it with the set value;

(4) The applied voltage is within the required range of the set value, and the voltage stabilization operation is performed;

(5) The DSP processor starts counting and compares it with the pressure time;

(6) After the withstand voltage time is reached, the system resets and clears, and the DSP transmits the test parameters and test results to the industrial computer for storage and printing;

(7) The equipment is restored and the test is over.

The test results of the power frequency withstand voltage test of the low-voltage electrical equipment are determined: during the entire power frequency withstand voltage test process, the low-voltage electrical equipment should have no internal or external insulation flashover, breakdown or any other destructive discharge. Except glow discharge.

The current transformer and DSP wiring circuit include resistor R1, resistor R2, resistor R3, capacitor C1, capacitor C2, power supply, and signal processor OPO7 in the circuit, wherein the power supply is divided into VCC terminal, -VCC terminal and GND terminal; The line connection relationship is as follows: the current feedback signal is connected to the terminal 3 of the signal processor OPO7 and the capacitor C1 after passing through the resistor R1, the other end of the capacitor C1 is connected to the GND terminal of the power supply, and the terminal 2 of the signal processor OPO7 passes through the resistor R2, resistor R3 are connected with the signal input terminal of DSP and capacitor C2, the connection terminal 6 of signal processor OPO7 is connected with the signal input terminal of DSP and capacitor C2 through resistor R3, and the other end of capacitor C2 is connected with the GND terminal of the power supply Connection, the connection terminal 7 of the signal processor OPO7 is connected to the VCC terminal of the power supply, the connection terminal 4 of the signal processor OPO7 is connected to the -VCC terminal of the power supply, and the connection terminals 1, 3 and 5 of the signal processor OPO7 are suspended; The output 0-5V signal of the transformer is converted into a 0-3.3V signal that can be recognized by the DSP and sent to the signal input terminal of the DSP after passing through the current transformer and the DSP wiring circuit.

Advantage of the present invention and beneficial effect are:

The invention utilizes the powerful control and data processing capabilities of the DSP processor to realize the centralized control and data automatic management of the low-voltage DC switch experiment process. Combining the inspection requirements of GB/T 14048.1 2012 "Low-voltage switchgear and control equipment", the present invention can complete the on-off capability test and inspection of connection, breaking and electrical life, and has the advantages of simple structure, convenient operation, good stability and safety. It has the advantages of strong performance and high level of intelligence.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a structural diagram of the intelligent chemical industry frequency withstand voltage test system for low-voltage electrical equipment of the present invention;

Fig. 2 is a wiring diagram of the current transformer and DSP in the present invention.

In the figure: test power supply 1, protection switch 2, voltage regulator 3 choke inductor 4, test transformer 5, test product 6, DSP processor 7, display unit 8, voice prompt unit 9, IGBT drive unit 10, IGBT11, motor 12. Voltage transformer 13, current transformer 14, isolation amplifier unit V15, isolation amplifier unit A16, operation panel 17, communication unit 18, industrial computer 19, printer 20.

detailed description

In order to achieve the purpose of the above invention, the present invention proposes an intelligent chemical industry frequency withstand voltage test system and method for low-voltage electrical equipment. in. The structural diagram of the intelligent chemical industry frequency withstand voltage test system for low-voltage electrical equipment is shown in Figure 1, mainly including test power supply 1, protection switch 2, voltage regulator 3, choke inductor 4, test transformer 5, test product 6, and DSP processing Device 7, display unit 8, voice prompt unit 9, IGBT drive unit 10, IGBT11, motor 12, voltage transformer 13, current transformer 14, isolation amplifier unit V15, isolation amplifier unit A16, operation panel 17, communication unit 18, Industrial computer 19 and printer 20 are composed. The output terminal of the test power supply 1 is connected to the input terminal of the protective switch 2, the output terminal of the protective switch 2 is connected to the power supply input terminal of the voltage regulator 3, and the voltage output terminal of the voltage regulator 3 is connected to the test circuit through the choke inductor 4. The primary side of the transformer 5 is connected, the secondary side of the test transformer 5 is connected to the power frequency withstand voltage test part of the test product 6, the input terminal of the display unit 8 is connected to the signal output terminal of the DSP processor 7, and the voice prompt The input terminal of the unit 9 is connected with the signal output terminal of the DSP processor 7, the input terminal of the IGBT drive unit 10 is connected with the signal output terminal of the DSP processor 7, and the control signal input terminal base of the IGBT11 is connected with the IGBT drive unit 10. The drive signal output terminals are connected, and the winding of the motor 12 is connected to the collector and emitter of the IGBT11. The measuring end of the voltage transformer 13 is connected with the voltage signal output end of the test transformer 5 , and the measuring end of the current transformer 14 is connected with the current signal output end of the test transformer 5 . The signal input end of the isolation amplifier unit V15 is connected to the signal output end of the voltage transformer 13 , and the signal input end of the isolation amplifier unit A16 is connected to the signal output end of the current transformer 14 . The signal output terminals of the isolation amplifier unit V15 and the isolation amplifier unit A16 are all connected with the signal input terminals of the DSP processor 7, the signal output terminals of the operation panel 17 are connected with the signal input terminals of the DSP processor 7, and the industrial computer 19 passes through the communication The unit 18 is connected with the communication signal input end of the DSP processor 7 , and the signal input end of the printer 20 is connected with the USB interface of the industrial computer 19 .

DSP (Demand-Side Platform) stands for Digital Signal Processor, which is a microprocessor that is especially suitable for digital signal processing operations. The role of DSP in the test device: ①It is used to collect the operation signal of the operation panel, and process it, and send the control command to control the motor movement through the IGBT drive unit and IGBT, and adjust the output voltage of the test device; ②Receive the voltage and current signal, and calculate the output voltage and current value of the test device, and judge the test object's ability to withstand power frequency withstand voltage; ③Send signals to the display unit and voice prompt unit to display the system voltage, current, and test running time and other parameters, and at the same time give safety reminders during the test operation process and voice prompts for the final results of the test ④Send communication signals to realize the storage and printing of test data.

IGBT (Insulated Gate Bipolar Transistor) stands for Insulated Gate Bipolar Transistor, which is a composite fully-controlled voltage-driven power semiconductor device composed of BJT (Bipolar Transistor) and MOS (Insulated Gate Field Effect Transistor), with MOSFET The advantages of high input impedance and low conduction voltage drop of GTR. The DSP weak current signal is received by the IGBT drive unit, and the motor action is controlled by the IGBT on and off, so as to realize the effective adjustment and control of the output voltage of the test device.

The test voltage of low-voltage electrical equipment intelligent chemical industry frequency withstand voltage test is directly related to the rated insulation voltage of low-voltage electrical equipment. The frequency of the test power supply is 45-65Hz alternating current, and the output voltage must be a sine wave. In order to ensure that the impedance of the test power supply is much smaller than the leakage resistance, the capacity of the test power supply is that after the output voltage of the test transformer is adjusted to the test voltage, the output terminal is short-circuited and the output current is at least 200mA. In order to prevent voltage shock during the test, the voltage should start from less than 1/2 of the test voltage value and gradually increase to the specified value within about 5s.

Low-voltage electrical equipment intelligent chemical industry frequency withstand voltage test method, before the test, connect the test transformer voltage output terminal of the test device with the measuring part of the test product (low-voltage electrical appliance) through the wire. The specific operation steps of the test are as follows:

(1) The system is powered on, initialized, and self-tested;

(2) The operation panel transmits the test voltage value and pressure application time to the DSP processor;

(3) The DSP processor sends control instructions to drive the motor to drive the voltage regulator to generate voltage, and at the same time collects voltage information and compares it with the set value;

(4) The applied voltage is within the required range of the set value, and the voltage stabilization operation is performed;

(5) The DSP processor starts counting and compares it with the pressure time;

(6) After the withstand voltage time is reached, the system resets and clears, and the DSP transmits the test parameters and test results to the industrial computer for storage and printing;

(7) The equipment is restored and the test is over.

Judgment of the test results of the power frequency withstand voltage test of low-voltage electrical equipment: During the whole process of the power frequency withstand voltage test, the low-voltage electrical equipment should have no internal or external insulation flashover, breakdown or any other destructive discharge, glow Except discharge.

As shown in Fig. 2, Fig. 2 is a wiring diagram of the current transformer and DSP in the present invention. The circuit includes a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C2, a power supply, and a signal processor OPO7, wherein the power supply is divided into a VCC terminal, a -VCC terminal and a GND terminal. The line connection relationship is as follows: the current feedback signal is connected to the terminal 3 of the signal processor OPO7 and the capacitor C1 after passing through the resistor R1, the other end of the capacitor C1 is connected to the GND terminal of the power supply, and the terminal 2 of the signal processor OPO7 passes through the resistor R2, resistor R3 are connected with the signal input terminal of DSP and capacitor C2, the connection terminal 6 of signal processor OPO7 is connected with the signal input terminal of DSP and capacitor C2 through resistor R3, and the other end of capacitor C2 is connected with the GND terminal of the power supply Connection, the connection terminal 7 of the signal processor OPO7 is connected to the VCC terminal of the power supply, the connection terminal 4 of the signal processor OPO7 is connected to the -VCC terminal of the power supply, and the connection terminals 1, 3 and 5 of the signal processor OPO7 are suspended. The output 0-5V signal of the current transformer is converted into a 0-3.3V signal that can be recognized by the DSP and sent to the signal input terminal of the DSP after passing through the wiring diagram of the current transformer and the DSP.

Claims (6)

1. low voltage equipment intellectuality power frequency withstanding voltage pilot system, including industrial computer（19）And printer（20）, It is characterized in that：Also include experiment power supply（1）, protection switch（2）, pressure regulator（3）, choke induction（4）, testing transformer（5）, examination Product（6）, dsp processor（7）, display unit（8）, voice alerting unit（9）, IGBT driver elements（10）、IGBT（11）, motor （12）, voltage transformer（13）, current transformer（14）, isolation amplifying unit V（15）, isolation amplifying unit A（16）, operating surface Plate（17）And communication unit（18）；Wherein experiment power supply（1）With protection switch（2）It is connected, protection switch（2）With pressure regulator （3）It is connected, pressure regulator（3）By choke induction（4）With testing transformer（5）It is connected, testing transformer（5）With test product （6）It is connected, display unit（8）With dsp processor（7）It is connected, voice alerting unit（9）With dsp processor（7）It is connected Connect, IGBT driver elements（10）With dsp processor（7）It is connected, IGBT（11）With IGBT driver elements（10）It is connected, it is electronic Machine（12）With IGBT（11）It is connected；Voltage transformer（13）Summation current transformer（14）And testing transformer（5）It is connected； Isolation amplifying unit V（15）With voltage transformer（13）It is connected, isolation amplifying unit A（16）With current transformer（14）It is connected Connect；Isolation amplifying unit V（15）, isolation amplifying unit A（16）And dsp processor（7）It is connected, guidance panel（17）With Dsp processor（7）It is connected, industrial computer（19）By communication unit（18）With dsp processor（7）It is connected, printer （20）With industrial computer（19）It is connected.

2. low voltage equipment according to claim 1 intellectuality power frequency withstanding voltage pilot system, it is characterized in that：It is described Experiment power supply（1）Output end and protection switch（2）Input be connected, protection switch（2）Output end and pressure regulator（3） Power input be connected, pressure regulator（3）Voltage output end by choke induction（4）With testing transformer（5）Once Side is connected, testing transformer（5）Secondary side and test product（6）Power frequency withstanding voltage experiment position be connected, display unit （8）Input and dsp processor（7）Signal output part be connected, voice alerting unit（9）Input and DSP treatment Device（7）Signal output part be connected, IGBT driver elements（10）Input and DSP（7）Signal output part be connected, IGBT（11）Control signal input base stage and IGBT driver elements（10）Drive signal output end be connected, motor （12）Winding and IGBT（11）Collector and emitter be connected；Voltage transformer（13）Measurement end and testing transformer （5）Voltage signal output end be connected, current transformer（14）Measurement end and testing transformer（5）Current signal output End is connected；Isolation amplifying unit V（15）Signal input part and voltage transformer（13）Signal output part be connected, isolate Amplifying unit A（16）Signal input part and current transformer（14）Signal output part be connected；Isolation amplifying unit V （15）, isolation amplifying unit A（16）Signal output part and dsp processor（7）Signal input part be connected, guidance panel （17）Signal output part and dsp processor（7）Signal input part be connected, industrial computer（19）By communication unit （18）With dsp processor（7）Communication signal input be connected, printer（20）Signal input part and industrial computer （19）USB interface be connected.

3. low voltage equipment according to claim 1 intellectuality power frequency withstanding voltage pilot system, it is characterized in that：It is described The test voltage of pilot system is directly related with the nominal insulation voltage of low voltage equipment, and the frequency of experiment power supply is 45- The alternating current of 65Hz, output voltage is sine wave；In order to the impedance of guarantee test power supply is far smaller than leak resistance, to experiment electricity Source capacity is that after testing transformer output voltage is adjusted to test voltage, output terminal shortcircuit its output current is at least 200mA；Process of the test in order to prevent the impact of voltage, when voltage is raised since the test voltage value less than 1/2, with about 5s's The setting being stepped up in time.

4. low voltage equipment intellectuality power frequency withstanding voltage test method, it is characterized in that：To be tested by wire before the test The testing transformer voltage of system goes out output end and is connected with the i.e. low-voltage electrical apparatus measuring point of test product, and experiment concrete operation step is such as Under：

（1）System electrification, initialization, self-inspection；

（2）Guidance panel is by test voltage value and pressure Time Transmission to dsp processor；

（3）Dsp processor sends control instruction motor and drives pressure regulator life pressure, while collection voltages information, and with setting Value compares；

（4）Applied voltage carries out voltage stabilizing operation in arranges value claimed range；

（5）Dsp processor is started counting up, and is compared in the pressure time；

（6）System reset is reset after reaching pressure-resistant time, and DSP transmission tests parameter and result of the test are gone forward side by side to industrial computer Row storage and printing；

（7）Equipment reduction, off-test.

5. low voltage equipment according to claim 4 intellectuality power frequency withstanding voltage test method, it is characterized in that：It is described Low voltage equipment power frequency withstanding voltage experiment result of the test judges：In whole power frequency withstanding voltage process of the test, low tension Device equipment should without internal or external insulation flashover, puncture and other any disruptive discharges occur, except glow discharge.

6. low voltage equipment according to claim 1 intellectuality power frequency withstanding voltage test method, it is characterized in that：It is described Current transformer and DSP connection circuits, in circuit including resistance R1, resistance R2, resistance R3, electric capacity C1, electric capacity C2, power supply, Signal processor OPO7, wherein power supply are divided into VCC terminal ,-VCC terminal and GND terminal；Line connecting relation is as follows：Electric current is anti- Feedback signal is connected by binding post 3 and electric capacity C1 after resistance R1 with signal processor OPO7, the other end of electric capacity C1 with The GND terminal of power supply is connected, and the binding post 2 of signal processor OPO7 is by resistance R2, the signal input of resistance R3 and DSP End and electric capacity C2 are connected, the binding post 6 of signal processor OPO7 by resistance R3 and DSP signal input part and electric capacity C2 It is connected, the other end of electric capacity C2 is connected with the GND terminal of power supply, binding post 7 and the power supply of signal processor OPO7 VCC terminal is connected, the binding post 4 of signal processor OPO7 and power supply-VCC terminal is connected, signal processor OPO7 Binding post 1,3,5 it is hanging；The output 0-5V signals of current transformer after current transformer and DSP connection circuits by changing Signal input part of the 0-3.3V signals that can be recognized into DSP to DSP.