Thyristor aging characteristic testing device based on superlong wave tail impact test

Abstract

The invention relates to a thyristor aging characteristic testing device based on a superlong wave tail impact test. The device comprises a charging transformer, a silicon rectifier stack, a charging resistor, an adjustable capacitor module and a relay, one end of the charging transformer is grounded, the other end of the charging transformer is connected with one end of the silicon rectifier stack, the other end of the silicon rectifier stack is sequentially connected with the charging resistor and the adjustable capacitor module in series, and the other end of the adjustable capacitor module is grounded. The two ends of the relay connected in series with the thyristor to be tested are respectively connected to the two ends of the adjustable capacitor module. Compared with the prior art, the device has the advantages that effective testing of the aging characteristic of the thyristor is completed on the premise that mistaken conduction and damage to the thyristor are avoided, and the like.

Description

Technical Field

[0001] The invention relates to the technical field of thyristors, and in particular to a thyristor aging characteristic testing device based on ultra-long wave tail impact testing. Background Art

[0002] Thyristors are the core components of converter valves. They are subjected to long-term electrical and thermal stresses during service. Once the device characteristics degrade and cause systemic failure, it will seriously affect the safe operation of the converter valve and even the entire DC transmission project. Therefore, it is necessary to study the aging characteristics of thyristors and master their aging laws in order to complete replacement in time before the performance of thyristors decays to the point where they cannot meet engineering requirements. The aging characteristics of thyristors include gate trigger characteristics, common-mode voltage, reverse recovery characteristics, and leakage resistance, among which the leakage resistance changes significantly with the increase in the use time of the thyristor. Therefore, by measuring the leakage resistance, the aging characteristics of the thyristor can be effectively tested. However, there are few thyristor aging characteristic test methods for measuring leakage resistance in the prior art, and the existing test methods still have problems such as mis-conduction and damage of thyristors. Therefore, how to effectively test the aging characteristics of thyristors without mis-conduction and damage to the thyristors has become a problem that needs to be solved in this field. Summary of the invention

[0003] The purpose of the present invention is to provide a thyristor aging characteristic testing device based on ultra-long wave tail impact test in order to overcome the defects of the above-mentioned prior art such as mis-conduction and damage to thyristors.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] The present invention provides a thyristor aging characteristic testing device based on ultra-long wave tail impact test, comprising a charging transformer, a rectifier silicon stack, a charging resistor, an adjustable capacitor module and a relay, wherein one end of the charging transformer is grounded, and the other end is connected to one end of the rectifier silicon stack, the other end of the rectifier silicon stack is connected in series with the charging resistor and the adjustable capacitor module in sequence, the other end of the adjustable capacitor module is grounded, and after the relay is connected in series with the anode end of the thyristor to be tested, the other end of the relay and the cathode end of the thyristor to be tested are respectively connected to the two ends of the adjustable capacitor module.

[0006] As a preferred technical solution, the switching voltage of the relay is >10 kVDC and the breakdown voltage is >15 kVDC.

[0007] As a preferred technical solution, the output voltage range of the charging transformer is 0-10 kV, the ripple noise is ≤0.5% and the voltage regulation rate is ≤0.1%.

[0008] As a preferred technical solution, the rectifier silicon stack has a withstand voltage of >50kV and a current of >100mA.

[0009] As a preferred technical solution, the resistance range of the charging resistor is 0.1 to 1 MΩ.

[0010] As a preferred technical solution, the adjustable capacitor module includes a tap switch for selecting capacitance, a first capacitor, a second capacitor and a third capacitor, one end of the tap switch is connected to the charging resistor, and one end of the first capacitor, one end of the second capacitor and one end of the third capacitor are all grounded.

[0011] As a preferred technical solution, the capacitance of the first capacitor is 2mF, the capacitance of the second capacitor is 10mF, and the capacitance of the third capacitor is 20mF.

[0012] As a preferred technical solution, the device also includes a high-voltage probe and an acquisition card for testing the voltage waveform across the thyristor to be tested, the input end of the high-voltage probe is connected to one end of the thyristor to be tested, and the output end is connected to the acquisition card.

[0013] As a preferred technical solution, the measurement peak value of the high voltage probe is >20kV.

[0014] As a preferred technical solution, the sampling frequency of the acquisition card is >40M.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The thyristor aging characteristic measuring device provided by the present invention calculates the leakage resistance of the thyristor through the wave tail time of the pulse discharge of the adjustable capacitor module, and performs aging characteristic test. The generated ultra-long wave tail can avoid mis-conduction of the thyristor and will not cause damage to the thyristor;

[0017] 2. The thyristor aging characteristic measuring device provided by the present invention uses a tap switch and multiple capacitors to form an adjustable capacitor module, that is, the discharge of a very large adjustable capacitor generates an ultra-long wave tail impact, and the voltage change at both ends of the thyristor is obtained without mis-conduction and damage to the thyristor. By calculating the wave tail time, the leakage resistance of the thyristor is obtained, thereby realizing the test of the thyristor aging characteristics;

[0018] 3. The device provided by the present invention uses a relay to control the discharge of the adjustable capacitor module, and does not require an adjustable inductor or an RC series branch. It can effectively simplify the circuit while completing the test, ensure the stability of the circuit, and improve the efficiency of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the test device in Example 1 of the present invention;

[0020] Figure 2 Schematic diagram of the structure of the test device in Example 2 of the present invention. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0022] Example 1

[0023] This embodiment provides a thyristor aging characteristic test device based on ultra-long wave tail impact test, which calculates the leakage resistance of the thyristor through the wave tail time of capacitor pulse discharge, and performs aging characteristic test. The ultra-long wave tail generated can avoid mis-conduction of the thyristor and will not cause damage to the thyristor, and the wave tail time can be adjusted by an adjustable capacitor. Figure 1 As shown, the device includes a charging transformer 1, a rectifier silicon stack 2, a charging resistor 3, an adjustable capacitor module 4 and a relay 5, and also includes a high-voltage probe 7 and an acquisition card 8 for testing the voltage waveform at both ends of the thyristor 6 to be tested. The connection method of each component in the device is as follows:

[0024] One end of the charging transformer 1 is grounded, and the other end is connected to the anode end of the rectifier silicon stack 2. The cathode end of the rectifier silicon stack 2 is connected in series with the charging resistor 3 and the adjustable capacitor module 4 in sequence. The other end of the adjustable capacitor module 4 is grounded. After one end of the relay 5 is connected in series with the anode end of the thyristor 6 to be tested, the other end of the relay 5 and the cathode end of the thyristor 6 to be tested are respectively connected to the two ends of the adjustable capacitor module 4, and the cathode end of the thyristor 6 to be tested is grounded. The input end of the high-voltage probe 7 is connected to one end of the thyristor 6 to be tested, and the acquisition card 8 is connected to the output end of the high-voltage probe 7.

[0025] In addition, the specific characteristics of each component are as follows:

[0026] The output voltage range of the charging transformer 1 is 0-10kV, the ripple noise is ≤0.5%, the voltage regulation rate is ≤0.1%, and the frequency is 50Hz. It has the advantages of high stability and high precision. The output voltage is continuously and linearly adjustable, and the voltage of the adjustable capacitor module 4 can be precisely controlled.

[0027] The rectifier silicon stack 2 has a withstand voltage of >50kV and a current of >100mA. The two ends are respectively connected to a charging transformer 1 and a charging resistor 3 to form a DC charging circuit, which converts the AC voltage into a DC voltage and charges the adjustable capacitor through the charging voltage.

[0028] The charging resistor 3 has a resistance range of 0.1 to 1 MΩ and a power of 1000 W. It uses a high-voltage glass glaze film resistor to limit the DC charging current and prevent overcurrent from burning the device during the charging process of the adjustable capacitor module 4.

[0029] The adjustable capacitor module 4 is used to adjust the capacitance value, has a withstand voltage of at least 35 kV, and is used to generate an ultra-long wave tail impulse voltage with an adjustable wave tail time.

[0030] The switching voltage of the relay 5 is greater than 10 kVDC, and the breakdown voltage is greater than 15 kVDC, and is used to control the discharge of the adjustable capacitor module 4 without the need for an adjustable inductor or RC series branch. At the same time, it can also play the role of setting a switch on the thyristor branch.

[0031] The high voltage probe 7 has a measurement peak value of >20kV, an input impedance of 100MΩ, a bandwidth of 75MHz, and an attenuation factor of 1000X. It is used to accurately measure the voltage across the thyristor sample and obtain the waveform.

[0032] The sampling frequency of acquisition card 8 is >40M, which is used to accurately collect the high-voltage probe signal processing output. Through the high sampling rate acquisition card, it is possible to obtain the voltage waveform of the entire high sampling condition (tens of nanoseconds) on the basis of obtaining the precise voltage value, and then obtain the wave tail time and calculate the leakage resistance.

[0033] When the aging characteristics test is performed using the aforementioned device, the charging transformer 1, the rectifier silicon stack 2 and the charging resistor 3 form a charging circuit to charge the adjustable capacitor. After the thyristor 6 to be tested is connected in series in the discharge circuit, the adjustable capacitor module 4 is controlled by the relay 5 to discharge the thyristor 6 to be tested. The voltage change at both ends of the thyristor 6 to be tested is measured by the high-voltage probe 7. The voltage signal is processed and output by the acquisition card 8 to obtain a waveform. The wave tail time T=0.7RC, the leakage resistance of the thyristor 6 to be tested can be calculated, thereby realizing the test of the thyristor aging characteristics.

[0034] In summary, the thyristor aging characteristics test circuit and device provided in this embodiment can calculate the leakage resistance of the thyristor through the wave tail time of the capacitor pulse discharge to perform aging characteristics test. The generated ultra-long wave tail can avoid mis-conduction of the thyristor and will not cause damage to the thyristor, and the wave tail time can be adjusted by an adjustable capacitor.

[0035] Example 2

[0036] The difference between this embodiment and embodiment 1 is that in the device provided in this embodiment, the adjustable capacitor module adopts a circuit structure of a combination of a tap switch and multiple capacitors, as shown in FIG. Figure 2 shown.

[0037] The adjustable capacitor module 4 includes a tap switch 41 for selecting capacitance, a first capacitor 42, a second capacitor 43 and a third capacitor 44, one end of the tap switch 41 is connected to the charging resistor 3, one end of the first capacitor 42, one end of the second capacitor 43 and one end of the third capacitor 44 are grounded, and the other end of each capacitor is used to form an effective loop when the tap switch 41 is closed. Specifically, the capacitance of the first capacitor 42 is 2mF, the capacitance of the second capacitor 43 is 10mF, and the capacitance of the third capacitor 44 is 20mF. That is, in this embodiment, the adjustable capacitor module 4 uses the tap switch 41 to select the capacitance value, and the capacitance value of 2mF / 10mF / 20mF is optional. The capacitance value is extremely large, and the withstand voltage is 35kV, which can generate an ultra-long wave tail impulse voltage and the wave tail time is adjustable, avoiding mis-conduction and damage of the thyristor.

[0038] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A thyristor aging characteristic test device based on ultra-long wave tail impact test, characterized in that: It includes a charging transformer, a rectifier silicon stack, a charging resistor, an adjustable capacitor module and a relay. One end of the charging transformer is grounded, and the other end is connected to one end of the rectifier silicon stack. The other end of the rectifier silicon stack is connected in series with the charging resistor and the adjustable capacitor module in sequence. The other end of the adjustable capacitor module is grounded. The two ends of the relay connected in series with the thyristor to be tested are respectively connected to the two ends of the adjustable capacitor module.

2. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 1 is characterized in that: The relay has a switching voltage >10 kVDC and a breakdown voltage >15 kVDC.

3. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 1 is characterized in that: The output voltage range of the charging transformer is 0-10 kV, the ripple noise is ≤0.5% and the voltage regulation rate is ≤0.1%.

4. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 1 is characterized in that: The rectifier silicon stack has a withstand voltage of >50kV and a current of >100mA.

5. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 1 is characterized in that: The resistance range of the charging resistor is 0.1-1 MΩ.

6. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 1 is characterized in that: The adjustable capacitor module includes a tap switch for selecting capacitance, a first capacitor, a second capacitor and a third capacitor, one end of the tap switch is connected to the charging resistor, and one end of the first capacitor, one end of the second capacitor and one end of the third capacitor are all grounded.

7. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 6 is characterized in that: The capacitance of the first capacitor is 2 mF, the capacitance of the second capacitor is 10 mF, and the capacitance of the third capacitor is 20 mF.

8. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 1 is characterized in that: The device also includes a high-voltage probe and an acquisition card for testing the voltage waveform at both ends of the thyristor to be tested. The input end of the high-voltage probe is connected to one end of the thyristor to be tested, and the output end is connected to the acquisition card.

9. The thyristor aging characteristic test device based on ultra-long wave tail impact test according to claim 8, characterized in that: The measurement peak value of the high voltage probe is >20kV.

10. The thyristor aging characteristic testing device based on ultra-long wave tail impact test according to claim 8, characterized in that: The sampling frequency of the acquisition card is >40M.

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