An intelligent detection device for locomotive inverter drive

Abstract

The invention relates to an intelligent detection device for a locomotive current converter drive, comprising a controller and a fault information display, a program-controlled DC power supply and a photoelectric conversion module connected thereto, wherein the photoelectric conversion module is connected to a load switching board, and the detection items are: switch signal test, protection function test and reliability test; the switch signal test comprises a voltage performance test, a consistency test, a feedback signal test and a delay test; the protection function test comprises a short-circuit overcurrent protection, an undervoltage protection, an overtemperature protection, a short pulse suppression and an interlocking function; a reliability test; the photoelectric conversion module comprises an optical signal conversion and an electrical signal conversion, and the switch signal test of the drive signal is completed by voltage tracking, response time tracking and waveform information tracking of the drive signal; the short-circuit overcurrent protection adopts a low-voltage system to simulate the actual high-voltage short-circuit condition of an IGBT, and Vref is applied between C\E of the IGBT; the invention has the advantages of realizing the driver performance evaluation and ensuring the driver protection function and reliability.

Description

Technical Field

[0001] The invention belongs to the technical field of rail transportation, and in particular relates to an intelligent detection device for a locomotive inverter driver. Background Art

[0002] As a key component of the locomotive, the performance and quality of the inverter are directly related to the stable operation of the locomotive. During the daily operation and maintenance of the locomotive inverter, the railway bureau locomotive must conduct a comprehensive fault analysis of the inverter faults, record the fault phenomena, find troubleshooting methods, analyze and formulate preventive measures, so as to reduce the failure rate of the inverter. IGBT and driver are the core components of the inverter, and the performance of the driver is directly related to the reliable operation of the inverter. At present, the railway bureau is limited to judging whether the driver is faulty or not during daily maintenance. It is unable to simulate the fault phenomenon and thus cannot safely and effectively evaluate the driver performance. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems and provide a locomotive inverter driver intelligent detection device, which realizes the driver performance evaluation, ensures the driver protection function and reliability, and is beneficial to the reliability and efficiency of the maintenance of the railway bureau inverter driver.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An intelligent detection device for a locomotive inverter drive includes a controller and a fault information display, a programmable DC power supply and a photoelectric conversion module connected thereto. The photoelectric conversion module is connected to a dummy load switching board through a photoelectric interface. The detection items mainly include: switch signal test, protection function test and reliability test; the switch signal test includes voltage performance test, consistency test, feedback signal test and delay test; the protection function test includes short circuit overcurrent protection, undervoltage protection, overtemperature protection, short pulse suppression and interlocking function; the reliability test is mainly a continuous pulse test;

[0006] The photoelectric conversion module includes optical signal conversion and electrical signal conversion, and completes the voltage performance test, consistency test, feedback signal test, and delay test of the driver signal by tracking the voltage, response time, and waveform information of the drive signal;

[0007] The short-circuit overcurrent protection adopts a low-voltage system to simulate the actual high-voltage short-circuit condition of the IGBT, applies Vref between C\E of the IGBT, and sets a soft shutdown for the driver;

[0008] Reliability test: Connect the driver to the IGBT load, send a PWM signal of rated frequency through the main controller, monitor the gate waveform of the IGBT, and compare whether the gate voltage Vge is normal and whether the pulse signal is lost.

[0009] Furthermore, the driving voltage mainly tests Vgeon and Vgeoff;

[0010] The consistency test is to test the ΔT between Vge signals. For the block parallel mode driver in the four-quadrant mode of the converter, the parallel driver used in the locomotive converter mainly includes two modules: single driver direct drive and dual driver parallel drive;

[0011] The feedback signal test is to track and match the waveform of the feedback signal under normal working and fault conditions, mainly for the state feedback detection of the driver under normal working, undervoltage fault, short circuit fault and overtemperature fault;

[0012] The delay test is to test the delay time of Ton and Toff of Vgeon and Vgeoff, and is mainly aimed at the response time from input to output of the driver under load conditions.

[0013] Furthermore, undervoltage protection mainly detects whether the driver stops outputting when the power supply voltage Vpower is lower than Vpoweref, thereby verifying the undervoltage protection function of the driver;

[0014] Short pulse suppression protection: To verify the anti-interference ability of the driver, when Tpulse is less than the driver setting value T, the driver does not respond to the pulse;

[0015] Interlocking function: The main controller sends the same-direction pulse to the driver to detect whether the driver blocks the pulse;

[0016] Over-temperature protection: Monitor the change in the resistance of the NTC resistor on the IGBT module. According to the characteristics of the negative temperature coefficient of the NTC resistor, input the voltage VNTC at the sampling port of the driver. When VNTC is less than the over-temperature protection threshold VTH, observe the output and feedback waveform of the driver to determine the over-temperature protection function.

[0017] Furthermore, the current conversion driver includes a traction drive and an auxiliary drive, and the application circuits of the driver are all in half-bridge mode.

[0018] Furthermore, the interface of the current converter driver connection fixture includes a driving power supply, an optical / electrical signal interface, an IGBT interface, a short-circuit fault detection point, and an over-temperature protection detection point.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The intelligent detection device for the converter driver of the present invention realizes switch signal test: voltage performance test, consistency test, feedback signal test, delay test; protection function test: short circuit overcurrent protection, undervoltage protection, overtemperature protection, short pulse suppression, interlocking function; reliability test: continuous pulse test. It realizes the full-state operation simulation of the converter driver, realizes the driver performance evaluation, ensures the driver protection function and reliability, and is conducive to the reliability and efficiency of the maintenance of the converter driver of the railway bureau. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only for more clearly illustrating the embodiments of the present invention or the technical solutions in the prior art. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 The schematic diagram of the circuit of the present invention;

[0023] Figure 2 This is the voltage performance test diagram;

[0024] Figure 3 This is a delay test chart;

[0025] Figure 4 It is the feedback signal test diagram;

[0026] Figure 5 It is the resistance-capacitance voltage division diagram;

[0027] Figure 6 This is the diode Vcesat voltage detection diagram;

[0028] Figure 7 This is a comparison chart of soft shutdown and normal shutdown waveforms. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments. However, the embodiments are only intended to illustrate the present invention and not to limit the present invention.

[0030] like Figure 1 The locomotive inverter drive intelligent detection device shown includes a controller and a fault information display, a programmable DC power supply and a photoelectric conversion module connected thereto. The photoelectric conversion module is connected to a dummy load switching board through a photoelectric interface.

[0031] The main functions of the driver in the locomotive converter include:

[0032] Switching signal test: voltage performance test, consistency test, feedback signal test, delay test;

[0033] Protection function test: short circuit overcurrent protection, undervoltage protection, overtemperature protection, short pulse suppression, interlocking function;

[0034] Reliability test: continuous pulse test.

[0035] 1. The signals of the inverter drive mainly include the drive pulse signal and the state feedback signal. At present, the signal processing methods of the locomotive application drive mainly include electrical signal conversion and optical signal conversion. This solution integrates the two solutions of photoelectric conversion and electrical signal conversion. By tracking the voltage, response time and waveform information of the drive signal, the voltage performance test, consistency test, feedback signal test and delay test of the drive signal are completed.

[0036] 1) Driving voltage mainly tests V geon and Vg eoff This parameter affects the actual working loss of IGBT in the converter. The difference between the on-resistance of Vge at 11V and 15V is close to 0.2V, and the power consumption at 1200A and rated frequency full load is 6%. Therefore, this test directly determines the reliability of the converter operation. Figure 2 shown.

[0037] 2) The consistency test is to test the ΔT between Vge signals. It is mainly aimed at the block parallel mode driver in the four-quadrant mode of the converter. The parallel driver used in the locomotive converter mainly includes two modules: the first is a single driver direct drive, and the second is a dual driver parallel drive. Since the switching speed of IGBT is in the μs level, if the switching speed of the parallel IGBT modules does not match in parallel applications, it is easy to cause one of the parallel IGBTs to fail due to overcurrent after long-term operation. Therefore, the consistency of the signal in parallel applications is the main evaluation indicator of the driver. For these two parallel drive modes, this solution ensures that the signal ΔT<200ns output by the driver meets the parallel application requirements through the test of input and output signals.

[0038] 3) Delay test is to test V geon and Vg eoff The delay time of Ton and Toff is mainly for the response time from the driver input to the output (under load conditions). This test is mainly to ensure the accurate response from the converter module main controller to the actual switching operation of the IGBT. Figure 3 shown.

[0039] 4) The feedback signal test is based on the drive technology settings, tracking and matching the waveform of the feedback signal in normal operation and fault conditions. It mainly tests the state feedback function of the drive in normal operation, undervoltage fault, short circuit fault, and overtemperature fault, ensuring that the inverter master monitors the module status and responds to the protection of the power device in a timely manner. Figure 4 shown.

[0040] 2. Protection function test:

[0041] Short-circuit overcurrent protection. The short-circuit protection modes of the driver in the existing locomotive inverter mainly include Vce resistor-capacitor voltage division monitoring and diode Vcesat voltage monitoring. In essence, they monitor the saturation voltage Vcesat during the IGBT opening process. When the saturation voltage exceeds a certain threshold, the IGBT is judged to be short-circuited. This solution uses a low-voltage system to simulate the actual high-voltage short-circuit condition of the IGBT, and applies Vref between the C\E of the IGBT. When Vref>Vsc, the driver protection circuit is activated. Soft shutdown is a slow shutdown protection mechanism set by the driver to prevent the IGBT from failing due to shutting down too quickly under high current. This device mainly detects the short-circuit protection response time T and the short-circuit soft shutdown protection waveform, and determines the driver soft shutdown action when Tscoff>Toff. Figure 5-7 shown.

[0042] Undervoltage protection mainly detects whether the driver stops output when the power supply voltage Vpower is lower than Vpoweref, verifying the undervoltage protection function of the driver.

[0043] Short pulse suppression protection, this solution is aimed at the low-frequency and high-power characteristics of the locomotive. In order to verify the anti-interference ability of the driver, when Tpulse is less than T (driver setting value), the driver does not respond to the pulse.

[0044] Interlocking function, in the half-bridge module of the locomotive converter, in order to prevent the upper and lower direct signals from causing converter short-circuit failure, it is necessary to verify the interlocking function of the upper and lower bridge arm signals of the driver. In this solution, the main controller sends the same-direction pulse to the driver to detect whether the driver blocks the pulse.

[0045] Over-temperature protection: The driver used in the locomotive auxiliary module integrates the over-temperature protection function. The main implementation method is to monitor the resistance change of the NTC resistor on the IGBT module. According to the characteristics of the negative temperature coefficient of the NTC resistor, the voltage VNTC is input at the sampling port of the driver. When VNTC is less than the over-temperature protection threshold VTH, the output and feedback waveform of the driver are observed to judge the over-temperature protection function.

[0046] 3. Reliability Test

[0047] In order to verify the reliability of the driver after long-term operation in daily maintenance of the locomotive inverter, this solution connects the driver to the IGBT load, sends a PWM signal of rated frequency through the main controller, monitors the gate waveform of the IGBT, and compares whether the gate voltage Vge is normal and whether the pulse signal is lost.

[0048] Specific implementation process of the program:

[0049] Since the converter drivers in the locomotive are mainly divided into traction drive and auxiliary drive, and the application circuits of the drivers are all half-bridge mode, the test fixture of this device is a half-bridge structure to meet parallel applications.

[0050] First, determine the complete connection plan according to different types of drivers, and connect the driver to the test fixture. The interface includes drive power supply, optical / electrical signal interface, IGBT interface, short-circuit fault detection point, and over-temperature protection detection point.

[0051] The device sends a double-pulse drive signal through the main control board. The output signal and feedback signal of the driver are detected. After the main controller processes the signal, it determines the voltage, consistency, feedback, and delay performance of the switch signal. The failure threshold is set according to the different types of drivers.

[0052] The protection function verification process controls the program-controlled power supply to step down the power supply voltage of the driver through the main control board, and monitors the driver output and feedback signals at the same time to determine whether the undervoltage protection function of the driver is normal. Since the present invention simulates the actual operating status of the driver in the converter through a low-voltage system when reprinting, it is necessary to find a low-voltage signal port in the detection circuit of the driver in the short-circuit and over-temperature protection function test, and directly input the simulated fault signal through the device fixture, and compare the feedback and output waveforms to achieve the verification of the short-circuit and over-temperature protection functions. The short pulse suppression verification is directly based on the driver performance requirements. The main controller sends Tpulse less than T (driver setting value), monitors whether the driver responds to the pulse, and determines whether the short pulse suppression works normally. During the interlocking function test, the main control sends two signals with a pulse width of 100μs to test whether the half-bridge driver determines whether the interlocking function is effective by the output pulse. Finally, the reliability test of the 10-minute PWM wave is completed. The main controller mainly monitors the number of pulses and the voltage state to determine the reliability of the drive.

[0053] The contents not described in detail in the present invention are all prior art.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent detection device for a locomotive inverter drive, characterized in that: It includes a controller and a fault information display, a programmable DC power supply and a photoelectric conversion module connected thereto. The photoelectric conversion module is connected to a dummy load switching board through a photoelectric interface. The detection items include: switch signal test, protection function test and reliability test; the switch signal test includes voltage performance test, consistency test, feedback signal test and delay test; the protection function test includes short circuit overcurrent protection, undervoltage protection, overtemperature protection, short pulse suppression and interlocking function; the reliability test is a continuous pulse test; The photoelectric conversion module includes optical signal conversion and electrical signal conversion, and completes the voltage performance test, consistency test, feedback signal test, and delay test of the driver signal by tracking the voltage, response time, and waveform information of the drive signal; The short-circuit overcurrent protection adopts a low-voltage system to simulate the actual high-voltage short-circuit condition of the IGBT, applies Vref between C\E of the IGBT, and sets a soft shutdown for the driver; Reliability test: Connect the driver to the IGBT load, send a PWM signal of rated frequency through the main controller, monitor the gate waveform of the IGBT, and compare whether the gate voltage Vge is normal and whether the pulse signal is lost; The driving voltage is used to test Vgeon and Vgeoff; The consistency test is to test the ΔT between Vge signals. For the block parallel mode driver in the four-quadrant mode of the converter, the parallel driver used in the locomotive converter includes two modules: single driver direct drive and dual driver parallel drive; The feedback signal test is to track and match the waveform of the feedback signal under normal working and fault conditions, and to detect the state feedback of the driver under normal working, undervoltage fault, short circuit fault, and overtemperature fault; The delay test is to test the delay time of Ton and Toff of Vgeon and Vgeoff, which is the response time from input to output of the driver under load conditions; The undervoltage protection detects whether the driver stops outputting when the power supply voltage Vpower is lower than Vpoweref, thereby verifying the undervoltage protection function of the driver; Short pulse suppression protection: To verify the anti-interference ability of the driver, when Tpulse is less than the driver setting value T, the driver does not respond to the pulse; Interlocking function: The main controller sends the same-direction pulse to the driver to detect whether the driver blocks the pulse; Over-temperature protection: Monitor the change in the resistance of the NTC resistor on the IGBT module. According to the characteristics of the negative temperature coefficient of the NTC resistor, input the voltage VNTC at the sampling port of the driver. When VNTC is less than the over-temperature protection threshold VTH, observe the output and feedback waveform of the driver to determine the over-temperature protection function.

2. The intelligent detection device for locomotive inverter drive according to claim 1 is characterized in that: The current conversion driver includes a traction driver and an auxiliary driver, and the application circuits of the driver are all half-bridge modes.

3. A locomotive inverter drive intelligent detection device according to any one of claims 1 to 2, characterized in that: The interface of the variable current driver connection fixture includes a driving power supply, an optical / electrical signal interface, an IGBT interface, a short-circuit fault detection point, and an over-temperature protection detection point.

Images