High voltage sensor test bench

Abstract

The present invention provides a high-voltage sensor test bench, comprising: a main power supply, a UC3842 circuit, an IGBT tube, a main transformer, and a digital display screen; the main power supply supplies power to each component, and the main transformer generates a test high voltage through the main power supply, the UC3842 circuit, and the IGBT tube, and the high-voltage sensor to be tested is tested, and the digital display screen comprises a first display screen and a second display screen, and the first display screen and the second display screen are respectively connected to the input end and the output end of the high-voltage sensor to be tested, and the voltage values ​​at the two ends are displayed, and the voltage indications at the two ends are compared to obtain the test result. The present invention has a simple structure, and when testing the high-voltage sensor, the labor intensity is greatly reduced, a large amount of manpower and material resources are saved, and the work efficiency is improved, and it has the advantages of low cost and high test reliability.

Description

Technical Field

[0001] The present invention relates to the field of testing devices, in particular to a high-voltage sensor testing platform, in particular to a high-voltage sensor testing platform for a subway train. Background Art

[0002] High voltage sensors (hereinafter referred to as high voltage sensors) are widely used in the traction box and auxiliary reverse box of subway trains, and are one of the important components to ensure the normal operation of the train. The performance test of high voltage sensors is a necessary task for the overhaul and daily maintenance of train frames. High voltage sensors have different brands and models, including domestic ones, German Siemens, French Alstom and other manufacturers. Originally, the detection of high voltage sensors could only be carried out with the help of the traction box or the auxiliary reverse box for overall testing. If there is no functioning box or the box is undergoing other maintenance operations, the high voltage sensor cannot be tested. Therefore, the traditional detection method is not only cumbersome to operate, but also takes a long time to test a sensor. Installation, inspection, power-on, 1500V high voltage test, power off and shutdown, safe discharge, etc. require a lot of manpower and material resources. Two people are required for testing, one for operation and one for monitoring.

[0003] In the Chinese utility model patent document with publication number CN207067377U, a voltage sensor test device is disclosed, which is used to test the performance status of subway voltage sensors at different temperatures and record voltage data. The voltage conversion device allows the voltage to be converted to the rated working voltage of the voltage sensor. The constant temperature box can set the different temperatures required for voltage sensor detection, and the test is kept at a constant temperature through the constant temperature box, thereby improving the accuracy of the system detection data. The voltage sensor to be tested and the standard voltage sensor are placed in the constant temperature box. The A / D acquisition module is used to collect and transform the voltage data in the constant temperature box. The data processing main control board is used to control data transmission and compare the voltage data results, thereby achieving the purpose of evaluating the performance status of subway train voltage sensors at different temperatures. Summary of the invention

[0004] In view of the defects in the prior art, an object of the present invention is to provide a high-voltage sensor test bench.

[0005] A high-voltage sensor test bench provided by the present invention includes: a main power supply, a UC3842 circuit, an IGBT tube, a main transformer, and a digital display screen;

[0006] The positive pole of the main power supply is respectively connected to the power supply end of the UC3842 circuit, the first port of the primary coil of the main transformer and the power supply end of the digital display screen, the output end of the UC3842 circuit is connected to the gate of the IGBT tube, the collector of the IGBT tube is connected to the second port of the primary coil of the main transformer, the emitter of the IGBT tube is connected to the negative pole of the main power supply, and the first port of the secondary coil of the main transformer constitutes the input connection end of the high-voltage sensor to be measured; the first port of the secondary coil of the main transformer is connected to a voltage divider circuit, a sampling circuit, a voltage stabilizing circuit and an optical coupler, and the first port of the secondary coil of the main transformer is connected to the UC3842 circuit after passing through the voltage divider circuit, the sampling circuit and the optical coupler;

[0007] The digital display screen comprises a first display screen and a second display screen, wherein the first display screen is connected to a voltage divider circuit, and the second display screen is connected to an output end of a high-voltage sensor to be measured.

[0008] Preferably, the main transformer adopts an isolation step-up transformer, and the input voltage of the isolation transformer is 18V and the operating frequency is a square wave of 55-65KHz.

[0009] Preferably, the main power supply is connected to an 18V power supply, the 18V power supply supplies power to the UC3842 circuit, and the UC3842 circuit outputs a square wave with a frequency of 55 to 65KHz to the gate of the IGBT tube.

[0010] Preferably, the main transformer is composed of multiple groups of independent windings, and each group of windings has an independent rectification circuit, filtering circuit and load circuit.

[0011] Preferably, multiple groups of independent windings are connected in series to form a high-voltage output end of the main transformer.

[0012] Preferably, a switch protection absorption circuit and a power supply feedback circuit are connected between the collector of the IGBT tube and the first port of the primary coil of the main transformer, the switch protection absorption circuit is used to absorb the interference wave generated by the main transformer, and the power supply feedback circuit is used to stabilize and adjust the output of the main transformer.

[0013] Preferably, a switching device protection sampling circuit is connected between the IGBT tube and the negative pole of the main power supply, and the switching device protection sampling circuit includes a protection resistor, one end of the protection resistor is respectively connected to the emitter of the IGBT tube and pin 3 of the UC3842 circuit, and the other end of the protection resistor is connected to the negative pole of the main power supply.

[0014] Preferably, the main power supply is connected to the power supply of the high-voltage sensor under test.

[0015] Preferably, a voltage conversion circuit is connected between the second display screen and the output end of the high-voltage sensor under test.

[0016] Preferably, the UC3842 circuit is connected to a potentiometer for adjusting the output of the main transformer.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention has a simple structure and greatly reduces the labor intensity when testing the high-pressure sensor;

[0019] 2. The present invention only requires one person to complete the detection work, saving a lot of manpower and material resources;

[0020] 3. The present invention improves work efficiency and has the advantages of low cost and high test reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0022] Figure 1 It is a structural block diagram of a high-voltage sensor test bench in an embodiment of the present invention;

[0023] Figure 2 4 is a circuit diagram of a high-voltage sensor test bench in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0025] The present invention introduces a high-voltage sensor test bench, referring to Figure 1 and Figure 2 , including: main power supply, UC3842 circuit, IGBT tube, main transformer, and digital display screen. The main power supply is a 220V AC input and outputs 100V / 150W isolated power supply. The main power supply is powered by the voltage power supply described by each component in the test bench, and the main power supply outputs 100V to the first port of the primary coil of the main transformer. The main transformer adopts an isolated step-up transformer, and the input power of the isolated step-up transformer is 18V and the operating frequency is a square wave of 55~65KHz. The main transformer is composed of multiple independent windings, each of which has an independent rectifier circuit, filter circuit and load circuit. Multiple independent windings are connected in series to form the high-voltage output end of the main transformer.

[0026] The UC3842 circuit is powered by an 18V power supply, which is input by the main power supply. The UC3842 circuit has a current limiting protection circuit, a voltage stabilizing circuit, a duty cycle control and adjustment circuit (used to adjust the pulse width), etc. After the UC3842 circuit is powered on, it generates a pulse voltage with a controllable pulse width and a pulse frequency of 55KHz to 65KHz, which is provided to the IGBT tube for operation. When the power is turned on, the UC3842 circuit generates a square wave with a duty cycle of 0% and a main frequency of 55 to 65KHz. The square wave is amplified by the power inside the UC3842 circuit and output from the 6th pin of the UC3842 circuit to control the switching device IGBT tube. The 6th pin of the UC3842 circuit is connected to the gate of the IGBT tube.

[0027] The pulsating voltage output by the UC3842 circuit controls the IGBT tube connected to the primary coil of the main transformer. The input voltage of the main transformer is 18V and the operating frequency is a square wave of 55-65KHz. When the IGBT tube starts to switch, the primary end "K1" of the main transformer T1 is powered by 100V. When the current passes through the primary coil of the main transformer, then through the IGBT tube of the switch function, and then through the switch device to protect the sampling circuit to the negative pole of the 100V power supply to form a power supply loop. When the IGBT tube switches, the current flowing through the primary of the main transformer is pulsating and alternating, and an alternating magnetic field is generated on the iron core of the transformer. With the alternating magnetic field, the main transformer starts to work on boosting. Then, in order to make the high voltage have a stable output, the output voltage can be adjusted in a range such as 750V to 1900V. Therefore, a voltage-dividing sampling circuit is adopted for the high-voltage output, and a pulse signal width adjustment circuit is added to the sampling circuit. Then, a closed-loop control is performed on the pulse generating circuit of UC3842 through an optical coupler. When the output voltage is to be increased, the pulse width is increased. When the pulse width is decreased, the output voltage decreases.

[0028] The collector of the IGBT tube is connected to the second port of the primary coil of the main transformer, and the collector of the IGBT tube is connected to the first port of the primary coil of the main transformer through the protection absorption circuit and the power feedback circuit. Since the IGBT switch tube controls the primary current of the transformer, especially when it is turned off, the transformer will generate many interference waves, such as the first to third harmonics, etc. These interference waves will affect itself and interfere with other equipment, so a protection absorption circuit is designed. The power feedback circuit is essentially a circuit for stabilizing the output power supply, and it is also a circuit for adjusting the output level. The emitter of the IGBT tube is connected in series with the negative electrode of the main power supply with a switch device protection sampling circuit. The switch device protection sampling circuit includes a protection resistor, one end of which is connected to the emitter of the IGBT tube and the No. 3 pin of the UC3842 circuit respectively, and the other end of the protection resistor is connected to the negative electrode of the main power supply. The function of the switch device protection sampling circuit is to detect the current flowing through the IGBT when it is turned on, and generate a voltage value on the protection resistor. This voltage value is then input to pin 3 of UC3842. The internal comparison circuit of UC3842 monitors the working current of the IGBT. Once the upper limit of the working current is exceeded, the IGBT is forcibly shut down to provide current limiting protection for the IGBT tube.

[0029] Under the action of the switch from pin 6 to the IGBT tube of the switching device, the input 100V (K1 end) DC power supply voltage is chopped by the high-frequency device IGBT tube to form a pulsating voltage. The high-frequency chopped pulsating alternating current passes through the main transformer, and the voltage at the output end (G1 end) begins to rise. The increased voltage is supplied to the input test of the high-voltage sensor under test. A group of high voltage is divided from the high-voltage end of the high-voltage sensor under test to the voltage divider circuit and the sampling circuit, and is connected to the first display screen after passing through the voltage divider circuit and the sampling circuit, thereby displaying the high-voltage voltage value of the high-voltage sensor under test; the second display screen is connected to the output end of the high-voltage sensor under test through the voltage conversion circuit.

[0030] Another group of high voltage is separated from the high voltage end of the high voltage sensor under test. After the voltage regulation requirement is met, the voltage regulation circuit outputs a signal voltage, which is fed back to the UC3842 circuit by the optocoupler isolation circuit to turn off the input of the switching device IGBT tube, thereby stopping the chopping output and the transformer coupling, so that the output high voltage no longer increases, forming a closed loop of voltage regulation; achieving the output stability requirement. Other switch protection absorption and power supply feedback circuits, as well as switch device protection circuit sampling, are used to protect the IGBT tube during operation, and are not described here.

[0031] The output part of the main transformer of the present invention is composed of multiple independent windings. Each winding has its own independent rectification, filtering and resistance load, and then the independent outputs are superimposed to supply the device under test. When testing the high-voltage sensor, the input high voltage is adjusted by a potentiometer, and the adjustment range of the high voltage is greater than or equal to 600V to less than or equal to 1999V. The potentiometer is installed in the UC3842 circuit.

[0032] The output of the high voltage sensor is converted into a voltage shape by the circuit and then displayed on the second display screen. When testing the performance of the high voltage sensor, the input voltage value of the device under test and the output voltage value of the device under test displayed on the digital display screen are compared. When the digital error of the two heads is 5%, it can be proved that the performance of the high voltage sensor is good. When the other digital errors exceed 5%, the performance of the device is reduced, and it is generally repaired or scrapped.

[0033] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A high-voltage sensor test bench, characterized in that: include: Main power supply, UC3842 circuit, IGBT tube, main transformer, and digital display screen; The positive pole of the main power supply is respectively connected to the power supply end of the UC3842 circuit, the first port of the primary coil of the main transformer and the power supply end of the digital display screen, the output end of the UC3842 circuit is connected to the gate of the IGBT tube, the collector of the IGBT tube is connected to the second port of the primary coil of the main transformer, the emitter of the IGBT tube is connected to the negative pole of the main power supply, and the first port of the secondary coil of the main transformer constitutes the input connection end of the high-voltage sensor to be measured; the first port of the secondary coil of the main transformer is connected to a voltage divider circuit, a sampling circuit, a voltage stabilizing circuit and an optical coupler, and the first port of the secondary coil of the main transformer is connected to the UC3842 circuit after passing through the voltage divider circuit, the sampling circuit and the optical coupler; The digital display screen includes a first display screen and a second display screen, wherein the first display screen is connected to the voltage divider circuit, and the second display screen is connected to the output end of the high-voltage sensor to be measured; The main transformer is composed of multiple groups of independent windings, each group of windings has an independent rectification circuit, filtering circuit and load circuit; Multiple independent windings are connected in series to form the high voltage output end of the main transformer; A switch protection absorption circuit and a power supply feedback circuit are connected between the collector of the IGBT tube and the first port of the primary coil of the main transformer, wherein the switch protection absorption circuit is used to absorb the interference wave generated by the main transformer, and the power supply feedback circuit is used to stabilize and adjust the output of the main transformer; A switching device protection sampling circuit is connected between the IGBT tube and the negative pole of the main power supply. The switching device protection sampling circuit includes a protection resistor. One end of the protection resistor is respectively connected to the emitter of the IGBT tube and pin 3 of the UC3842 circuit, and the other end of the protection resistor is connected to the negative pole of the main power supply.

2. A high-voltage sensor test bench according to claim 1, characterized in that: The main transformer adopts an isolation step-up transformer, and the input voltage of the isolation step-up transformer is 18V and the operating frequency is a square wave of 55-65KHz.

3. A high-voltage sensor test bench according to claim 2, characterized in that: The main power supply is connected to an 18V power supply, and the 18V power supply supplies power to the UC3842 circuit, and the UC3842 circuit outputs a square wave with a frequency of 55-65KHz to the gate of the IGBT tube.

4. A high-voltage sensor test bench according to claim 1, characterized in that: The main power supply is connected to the high-voltage sensor under test for power supply.

5. The high-voltage sensor test bench according to claim 1, characterized in that: The second display screen is connected to the output end of the high-voltage sensor under test via a voltage conversion circuit.

6. A high-voltage sensor test bench according to claim 1, characterized in that: The UC3842 circuit is connected with a potentiometer for adjusting the output of the main transformer.

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