Thyristor accelerated aging test platform and method

Abstract

The invention belongs to the field of accelerated aging tests of thyristors, and provides an accelerated aging test platform and method for thyristors. The platform comprises a power supply module, a first voltage regulating module, a second voltage regulating module, a step-down transformer, a step-up transformer and a test control module. The test control module is connected with the test thyristor, and the test control module is used for triggering the test thyristor to be conducted in a 1 / 3 power frequency period when the alternating voltage is a positive cyclic wave, adjusting the thermal stress in the aging process of the test thyristor by adjusting the current flowing through the test thyristor, measuring the voltage at the two ends of the test thyristor, and controlling the test thyristor to be in an aging state. The on-state voltage drop is the on-state voltage drop of the test thyristor; when the alternating voltage is within the time range of the negative half cycle and part of the positive cycle, the test thyristor is controlled to be turned off in total within 2 / 3 of the power frequency cycle, and the current flowing through the test thyristor when the corresponding test thyristor is turned off is obtained by adjusting the magnitude of the voltage stress applied to the test thyristor, namely the leakage current of the test thyristor.

Description

Technical Field

[0001] The invention belongs to the field of thyristor accelerated aging test, and in particular relates to a thyristor accelerated aging test platform and method. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] High-voltage direct current transmission technology is an important means to solve the problems of high voltage, large capacity, long-distance power transmission and grid interconnection. Its stable and healthy operation is of great significance to the power grid. As the key core component for the converter valve of the DC project to realize the AC-DC conversion function, the reliability of the thyristor is directly related to the safe and stable operation of the DC transmission system. For the thyristor devices of the converter valve in the aging process, if the maintenance or replacement time is not timely, they will be damaged due to reaching the operating life; if the maintenance or replacement cycle is too frequent, the system operation cost will be greatly increased. However, through conventional operation and maintenance means, it is impossible to quantitatively analyze and judge the potential aging trend and remaining life of the thyristor, which brings great safety hazards to the project.

[0004] The fatigue aging process of thyristors is very long when they are operating normally. Therefore, in order to comprehensively observe and explore their fatigue aging failure process, it is necessary to design accelerated aging experiments to shorten the research cycle, conduct mechanism analysis and test method research on thyristor aging characteristics, and provide a basis for rationally planning the operation and maintenance of thyristor devices and the timing of replacement, thereby improving the technical and economic efficiency of the operation and maintenance of high-voltage DC projects. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a thyristor accelerated aging test platform and method, which completes the thyristor aging experiment by applying different current and voltage stresses and measures the corresponding characteristic parameters.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A first aspect of the present invention provides a thyristor accelerated aging test platform.

[0007] In one or more embodiments, a thyristor accelerated aging test platform includes: a power supply module, a first voltage regulating module, a second voltage regulating module, a step-down transformer, a step-up transformer, and a test control module; The power supply module provides the first voltage regulating module and the second voltage regulating module with an AC voltage of the same phase; The primary side of the step-down transformer is connected to the regulating end of the first voltage regulating module; the secondary side of the step-down transformer is connected to the input end of the test control module; the output end of the test control module is connected to the primary side of the step-up transformer, and the secondary side of the step-up transformer is connected to the regulating end of the second voltage regulating module; The test control module is connected to the test thyristor, and the test control module is used to: When the AC voltage is a positive cycle, the test thyristor is triggered to conduct within 1 / 3 of the power frequency period. By adjusting the current flowing through the test thyristor, the thermal stress of the test thyristor during the aging process is adjusted. The voltage across the test thyristor is measured, which is the on-state voltage drop of the test thyristor. When the AC voltage is within the negative half-cycle and part of the positive cycle time range, the test thyristor is controlled to be turned off within 2 / 3 of the power frequency cycle. By adjusting the voltage stress applied to the test thyristor, the current flowing through the test thyristor when the corresponding test thyristor is turned off is obtained, which is the leakage current of the test thyristor.

[0008] As an implementation mode of the first aspect of the present invention, the test control module includes a first thyristor, a second thyristor, a sampling resistor, a current limiting resistor, an insulated gate bipolar transistor, a first diode and a second diode; the first thyristor is connected to the positive electrode of the secondary side of the step-down transformer, and the negative electrode of the secondary side of the step-down transformer is grounded through the current limiting resistor; the first thyristor is also grounded to the second thyristor in turn through the test thyristor; the second thyristor is connected in parallel with the sampling resistor; the connection point between the first thyristor and the test thyristor is also connected to the cathode of the first diode, and the anode of the first diode is connected to the insulated gate bipolar transistor; the connection point between the first thyristor and the test thyristor is also connected to the anode end of the second diode, and the second diode is connected in parallel with the branch where the first diode and the insulated gate bipolar transistor are located; the cathode connection point between the insulated gate bipolar transistor and the second diode is also connected to the positive electrode of the primary side of the step-up transformer, and the negative electrode of the primary side of the step-up transformer is grounded.

[0009] The advantage of the above technical solution is that during the operation of the converter valve, the thyristor bears current stress and voltage stress alternately within the power frequency cycle. When the thyristor is turned on, the current flowing through it bears current thermal stress, and the turn-on time is 1 / 3 of the power frequency cycle. When it is turned off, it bears voltage stress, and the turn-off time is 2 / 3 of the power frequency cycle. The test control module of this embodiment simulates the operating environment of the thyristor of the converter valve, and alternately bears current thermal stress and voltage stress within the power frequency cycle. The current thermal stress and voltage stress application time are 1 / 3 of the power frequency cycle and 2 / 3 of the power frequency cycle, respectively, which is consistent with the actual operating environment, and can accelerate the aging process of the thyristor. At the same time, thyristor characteristic parameter monitoring is designed to grasp the change trend of characteristic parameters during the thyristor aging process.

[0010] As an implementation manner of the first aspect of the present invention, the first voltage regulating module is a first voltage regulator, and a first switch is connected in series between the first AC power source and the first voltage regulator.

[0011] The advantage of the above technical solution is that the first switch is used to control the on-off of the circuit between the first AC power source and the first voltage regulator.

[0012] As an implementation manner of the first aspect of the present invention, a first fuse is further connected in series between the first switch and the first voltage regulator.

[0013] The advantage of the above technical solution is that the first fuse is used to prevent the circuit from overcurrent.

[0014] As an implementation manner of the first aspect of the present invention, the second voltage regulating module is a second voltage regulator; and a second switch is connected in series between the second AC power supply and the second voltage regulator.

[0015] The advantage of the above technical solution is that the second switch is used to control the on-off of the circuit between the second AC power source and the second voltage regulator.

[0016] As an implementation manner of the first aspect of the present invention, a second fuse is further connected in series between the second switch and the second voltage regulator.

[0017] The advantage of the above technical solution is that the second fuse is used to prevent the circuit from overcurrent.

[0018] As an implementation manner of the first aspect of the present invention, the current limiting resistor is also grounded through a third fuse.

[0019] The advantage of the above technical solution is that the third fuse is used to prevent the circuit from overcurrent.

[0020] A second aspect of the present invention provides a test method based on a thyristor accelerated aging test platform.

[0021] In one or more embodiments, a test method based on the thyristor accelerated aging test platform as described above includes: When the AC voltage is a positive cycle and the voltage phase is 60 degrees, the first thyristor, the second thyristor and the test thyristor are triggered simultaneously. At this time, the secondary side of the step-up transformer, the first thyristor, the test thyristor, the second thyristor and the current limiting resistor form a loop that withstands the forward voltage. The first thyristor, the test thyristor and the second thyristor are all turned on after receiving the trigger signal; during the period of 60°-180°, the first thyristor, the test thyristor and the second thyristor remain turned on; during this period, the gate trigger voltage of the insulated gate bipolar transistor is a negative value, the insulated gate bipolar transistor is in an off state, and withstands the forward voltage of the step-up transformer, and the second diode connected in parallel with the insulated gate bipolar transistor withstands the forward voltage of the step-up transformer.

[0022] As an implementation manner of the second aspect of the present invention, the test method of the thyristor accelerated aging test platform further includes: When the AC voltage phase is 180°, the AC voltage enters a negative half-cycle, and the secondary side of the step-down transformer, the first thyristor, the test thyristor, the second thyristor and the current limiting resistor form a loop that is subjected to negative pressure, causing the first thyristor, the test thyristor and the second thyristor to be turned off, and the secondary side of the step-up transformer forms a loop with the sampling resistor, the test thyristor and the second diode, and the secondary side voltage of the step-up transformer is applied to the test thyristor, that is, the test thyristor is subjected to a negative voltage; during the voltage phase of 180°-360°, the gate trigger voltage of the insulated gate bipolar transistor is a negative value, the insulated gate bipolar transistor is in the off state, and the first diode in this branch is subjected to a reverse voltage.

[0023] As an implementation manner of the second aspect of the present invention, the test method of the thyristor accelerated aging test platform further includes: When the AC voltage phase is 0°, the first thyristor, the test thyristor and the second thyristor have no trigger signal and remain in the off state; the gate trigger voltage of the insulated gate bipolar transistor is positive, the insulated gate bipolar transistor is triggered to turn on, and the secondary side of the step-up transformer forms a loop with the insulated gate bipolar transistor, the first diode, the sampling resistor and the test thyristor, and the test thyristor is subjected to a positive voltage.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses a test control module to trigger the test thyristor to turn on within 1 / 3 of the power frequency cycle when the AC voltage is a positive cycle, and adjusts the current flowing through the test thyristor to adjust the thermal stress during the aging process of the test thyristor. The on-state voltage drop of the test thyristor is obtained by measuring the voltage across the test thyristor. When the AC voltage is within the negative half cycle and part of the positive cycle time range, the test thyristor is controlled to be turned off within 2 / 3 of the power frequency cycle. By adjusting the voltage stress applied to the test thyristor and measuring the current flowing through the test thyristor when the corresponding test thyristor is turned off, the leakage current of the test thyristor can be obtained.

[0025] (2) The current thermal stress and voltage stress application time of the present invention are 1 / 3 power frequency cycle and 2 / 3 power frequency cycle respectively, which are consistent with the actual operating environment, can accelerate the aging process of thyristors, and can better simulate the aging process of thyristors; at the same time, thyristor characteristic parameter monitoring is designed, and the accelerated aging test of thyristors under different current stresses and voltage stresses is realized through the characteristic parameter test platform, so as to grasp the change trend of characteristic parameters in the thyristor aging process.

[0026] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 It is a schematic diagram of the structure of a thyristor accelerated aging test platform according to an embodiment of the present invention; Figure 2 This is the aging test platform power supply of the embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0033] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0034] Terminology explanation: (1) Thyristor: Thyristor is the abbreviation of thyristor, also known as silicon controlled rectifier; thyristor is a PNPN four-layer semiconductor structure, it has three poles: cathode and gate; thyristor has the characteristics of silicon rectifier device, can work under high voltage and high current conditions, and its working process can be controlled, and is widely used in electronic circuits such as controlled rectification, AC voltage regulation, contactless electronic switch, inverter and frequency conversion. The conduction condition of thyristor is: positive voltage is applied and there is trigger current at the gate.

[0035] (2) Insulated Gate Bipolar Transistor: The Insulate-Gate Bipolar Transistor (IGBT) combines the advantages of the Giant Transistor (GTR) and the Power Field Effect Transistor (Power MOSFET), has good characteristics, and is widely used. IGBT is also a three-terminal device: gate, collector, and emitter.

[0036] The insulated-gate bipolar transistor (IGBT) combines the advantages of the giant transistor (GTR) and the power field effect transistor (Power MOSFET), has good characteristics, and is widely used. IGBT is also a three-terminal device: gate, collector and emitter. IGBT (Insulated Gate Bipolar Transistor) is a MOS structure bipolar device, which is a power device with the high-speed performance of power MOSFET and the low-resistance performance of bipolar. The application range of IGBT is generally in the area of ​​withstand voltage above 600V, current above 10A, and frequency above 1kHz. It is mostly used in industrial motors, small-capacity civilian motors, converters (inverters), camera strobes, induction heating (Induction Heating) rice cookers and other fields. According to the different packages, IGBT is roughly divided into two types. One is a three-terminal monomer package sealed with molded resin, and a series has been formed from TO-3P to small surface mount. The other is a module type that packages IGBT and FWD (Flee Wheel Diode) in pairs (2 or 6 groups), which is mainly used in industry. The types of modules are divided into various shapes and packaging methods according to different uses, and they have formed a series.

[0037] (3) Step-up transformer: A step-up transformer is a transformer that starts the voltage instantly. The step-up transformer has a strong instantaneous voltage-boosting capability and a good voltage-boosting effect.

[0038] The step-up transformer of this embodiment is an AC step-up transformer, which is a device for converting AC voltage, current and impedance. When AC current flows through the primary coil, AC magnetic flux is generated in the iron core (or magnetic core), so that voltage (or current) is induced in the secondary coil. The transformer is composed of an iron core (or magnetic core) and a coil. The coil has two or more windings, of which the winding connected to the power supply is called the primary coil, and the remaining windings are called secondary coils. The AC step-up transformer has the characteristics of small size, light weight, compact structure, complete functions, strong versatility and easy use. It is particularly suitable for power systems, industrial and mining enterprises, scientific research departments, etc. to conduct insulation strength tests on various high-voltage electrical equipment, electrical components, and insulating materials under frequency or AC high voltage. It is an indispensable and important equipment in high-voltage testing.

[0039] (4) Step-down transformer: A step-down transformer is a transformer that converts a relatively high voltage at the input end into a relatively low ideal voltage at the output, thereby achieving the purpose of stepping down the voltage. The step-down transformer is a very important device in the power transmission and transformation system. Its normal operation is not only related to its own safety and the reliable power supply of users, but also directly affects the stability of the power system.

[0040] (5) Sampling resistor: A sampling resistor is a resistor used as a reference and is often used in feedback circuits. Take a voltage-stabilized power supply circuit as an example. In order to keep the output voltage constant, a portion of the output voltage is taken as a reference (commonly used in the form of a sampling resistor). If the output is high, the input end will automatically lower the voltage to reduce the output.

[0041] (6) Current limiting resistor: The current limiting resistor is a resistor connected in series in the circuit to limit the current in the branch to prevent excessive current from burning out the components in series. At the same time, the current limiting resistor can also play a voltage dividing role.

[0042] (7) Voltage regulator: Voltage regulators are divided into five types: auto-coupling voltage regulator, isolation voltage regulator, oil-immersed induction voltage regulator, column electric voltage regulator and thyristor voltage regulator. The working mode of the voltage regulator is divided into manual voltage regulation and electric voltage regulation. The structure of the voltage regulator is the existing structure.

[0043] (8) Diode: A diode is an electronic device made of semiconductor materials (silicon, selenium, germanium, etc.). A diode has two electrodes, the positive electrode, also called the anode, and the negative electrode, also called the cathode. When a forward voltage is applied between the two electrodes of the diode, the diode is turned on, and when a reverse voltage is applied, the diode is turned off. The conduction and cutoff of a diode are equivalent to the on and off of a switch.

[0044] (9) Fuse: A fuse is an electrical device that uses the heat generated by itself to melt the fuse and disconnect the circuit when the current exceeds the specified value. A fuse is a current protector made based on the principle that after the current exceeds the specified value for a period of time, the heat generated by itself will melt the fuse and disconnect the circuit. Fuses are widely used in high and low voltage power distribution systems and control systems as well as electrical equipment. As a short circuit and overcurrent protector, they are one of the most commonly used protection devices.

[0045] Thyristor failure is mainly caused by thermomechanical fatigue caused by junction temperature fluctuations, and this fatigue aging process is very long during normal operation. Therefore, in order to comprehensively observe and explore the fatigue aging failure process of power modules, it is necessary to design accelerated aging experiments to shorten the research cycle.

[0046] The present invention conducts mechanism analysis and test method research on the aging characteristics of thyristors, provides a basis for rationally planning the operation and maintenance and replacement timing of thyristor devices, thereby improving the technical and economic efficiency of the operation and maintenance of high-voltage DC projects, and proposes a thyristor accelerated aging test platform and method, which completes the thyristor aging experiment by applying different current and voltage stresses, and measures the corresponding characteristic parameters.

[0047] The specific scheme of the present invention is given in detail below in conjunction with a specific circuit and a schematic diagram of a control signal.

[0048] according to Figure 1 As shown, in Figure 1 In the figure, AC1 and AC2 are the first AC power source and the second AC power source, respectively, with the same phase; BR1 and BR2 are the first switch and the second switch; F1, F3, and F2 are the first fuse, the second fuse, and the third fuse, respectively, used to protect the circuit from overcurrent; T1 and T2 are the first voltage regulator and the second voltage regulator respectively; T3 is a step-down transformer; T4 is a step-up transformer; TH1 and TH3 are the first thyristor and the second thyristor, respectively, which are used for circuit control thyristors; TH2 is the test thyristor; S1, S2, and S3 are the trigger signals of the thyristors; R3 is the sampling resistor; R1 is the current limiting resistor; D1 and D2 are respectively the first diode and the second diode; IG1 is an IGBT (insulated gate bipolar transistor) used for circuit control; S4 is the trigger signal of IGBT.

[0049] The thyristor accelerated aging test platform of the embodiment of the present invention comprises: a power supply module, a first voltage regulating module, a second voltage regulating module, a step-down transformer T3, a step-up transformer T4 and a test control module; The power supply module provides the first voltage regulating module and the second voltage regulating module with an AC voltage of the same phase; The primary side of the step-down transformer is connected to the regulating end of the first voltage regulating module; the secondary side of the step-down transformer is connected to the input end of the test control module; the output end of the test control module is connected to the primary side of the step-up transformer, and the secondary side of the step-up transformer is connected to the regulating end of the second voltage regulating module; The test control module is connected to the test thyristor, and the test control module is used to: When the AC voltage is a positive cycle, the test thyristor is triggered to conduct within 1 / 3 of the power frequency period. By adjusting the current flowing through the test thyristor, the thermal stress of the test thyristor during the aging process is adjusted. The voltage across the test thyristor is measured, which is the on-state voltage drop of the test thyristor. When the AC voltage is within the negative half-cycle and part of the positive cycle time range, the test thyristor is controlled to be turned off within 2 / 3 of the power frequency cycle. By adjusting the voltage stress applied to the test thyristor, the current flowing through the test thyristor when the corresponding test thyristor is turned off is obtained, which is the leakage current of the test thyristor.

[0050] In this embodiment, combined with Figure 1 The test control module includes a first thyristor TH1, a second thyristor TH3, a sampling resistor R3, a current limiting resistor R1, an insulated gate bipolar transistor IG1, a first diode D1 and a second diode D2; the first thyristor TH1 is connected to the positive electrode of the secondary side of the step-down transformer T3, and the negative electrode of the secondary side of the step-down transformer T3 is grounded through the current limiting resistor; the first thyristor TH1 is also grounded to the second thyristor TH3 through the test thyristor TH2 in turn; the second thyristor TH3 is connected in parallel with the sampling resistor R3; the first thyristor TH1 and The connection point of the test thyristor TH2 is also connected to the cathode of the first diode D1, and the anode of the first diode D1 is connected to the insulated gate bipolar transistor IG1; the connection point of the first thyristor TH1 and the test thyristor TH2 is also connected to the anode end of the second diode D2, and the second diode D2 is connected in parallel with the branch where the first diode D1 and the insulated gate bipolar transistor IG1 are located; the cathode connection point of the insulated gate bipolar transistor IG1 and the second diode D2 is also connected to the positive electrode of the primary side of the step-up transformer T4, and the negative electrode of the primary side of the step-up transformer T4 is grounded.

[0051] The advantage of the above technical solution is that during the operation of the converter valve, the thyristor bears current stress and voltage stress alternately within the power frequency cycle. When the thyristor is turned on, the current flowing through it bears current thermal stress, and the turn-on time is 1 / 3 of the power frequency cycle. When it is turned off, it bears voltage stress, and the turn-off time is 2 / 3 of the power frequency cycle. The test control module of this embodiment simulates the operating environment of the thyristor of the converter valve, and alternately bears current thermal stress and voltage stress within the power frequency cycle. The current thermal stress and voltage stress application time are 1 / 3 of the power frequency cycle and 2 / 3 of the power frequency cycle, respectively, which is consistent with the actual operating environment, and can accelerate the aging process of the thyristor. At the same time, thyristor characteristic parameter monitoring is designed to grasp the change trend of characteristic parameters during the thyristor aging process.

[0052] In this embodiment, the first voltage regulating module is a first voltage regulator T1, and a first switch BR1 is connected in series between the first AC power source AC1 and the first voltage regulator T1. This embodiment uses the first switch to control the on / off of the circuit between the first AC power source and the first voltage regulator.

[0053] The first switch BR1 may be a manual switch or an automatic control switch, and those skilled in the art may make specific settings according to actual conditions, which will not be described in detail here.

[0054] In this embodiment, a first fuse F1 is connected in series between the first switch BR1 and the first voltage regulator T1, so that the first fuse is used to prevent the circuit from overcurrent.

[0055] In this embodiment, the second voltage regulator is a second voltage regulator T2, a second switch BR2 is connected in series between the second AC power source AC2 and the second voltage regulator T2, and the second switch is used to control the on-off of the circuit between the second AC power source and the second voltage regulator.

[0056] The second switch BR2 may be a manual switch or an automatic control switch, and those skilled in the art may make specific settings according to actual conditions, which will not be described in detail here.

[0057] In this embodiment, a second fuse F3 is connected in series between the second switch BR2 and the second voltage regulator T2, so as to prevent the circuit from overcurrent by utilizing the second fuse.

[0058] In this embodiment, the current limiting resistor R1 is also grounded via the third fuse F2, so that the third fuse is used to prevent the circuit from overcurrent.

[0059] This embodiment uses a test control module to trigger the test thyristor to turn on when the AC voltage is a positive half-cycle, and adjusts the current flowing through the test thyristor to adjust the thermal stress during the aging process of the test thyristor. The on-state voltage drop of the test thyristor is obtained by measuring the voltage across the test thyristor; and when the AC voltage is a negative half-cycle, the test thyristor is controlled to be turned off, and the voltage stress applied to the test thyristor is adjusted. The current flowing through the test thyristor when the corresponding test thyristor is turned off is measured to obtain the leakage current of the test thyristor, and the current thermal stress and voltage stress application time are 1 / 3 of the power frequency cycle and 2 / 3 of the power frequency cycle respectively, which is consistent with the actual operating environment, can accelerate the aging process of the thyristor, and can better simulate the aging process of the thyristor; This embodiment also designs thyristor characteristic parameter monitoring, and implements accelerated aging testing of thyristors under different current stresses and voltage stresses through a characteristic parameter testing platform, so as to understand the characteristic parameter variation trend during the thyristor aging process.

[0060] In one or more embodiments, a test method based on the thyristor accelerated aging test platform as described above comprises the following steps: Phase 1: Reference Figure 2 When the AC voltage is a positive cycle and the voltage phase is 60 degrees, the first thyristor TH1, the second thyristor TH3 and the test thyristor TH2 are triggered at the same time. At this time, the secondary side of the step-up transformer T4, the first thyristor TH1, the second thyristor TH3, the test thyristor TH2 and the current limiting resistor R1 form a loop to withstand the forward voltage. The first thyristor TH1, the second thyristor TH3 and the test thyristor TH2 are all turned on after receiving the trigger signal; during the period of 60°-180°, the first thyristor TH1, the second thyristor TH3 and the test thyristor TH2 remain turned on; during this period, the gate trigger voltage of the insulated gate bipolar transistor IG1 is a negative value, the insulated gate bipolar transistor IG1 is in the off state, and withstands the forward voltage of the step-up transformer T4, and the second diode D2 connected in parallel with the insulated gate bipolar transistor IG1 withstands the forward voltage of the step-up transformer T4.

[0061] Phase 2: When the AC voltage phase is 180°, the AC voltage enters a negative half-cycle, and the secondary side of the step-down transformer T3, the first thyristor TH1, the second thyristor TH3, the test thyristor TH2 and the current limiting resistor R1 form a loop that is subjected to negative pressure, causing the first thyristor TH1, the second thyristor TH3, and the test thyristor TH2 to be turned off, and the secondary side of the step-up transformer T4 forms a loop with the sampling resistor R3, the test thyristor TH2, and the second diode D2. The secondary side voltage of the step-up transformer T4 is applied to the test thyristor TH2, that is, the test thyristor TH2 is subjected to a negative voltage; during the voltage phase of 180°-360°, the gate trigger voltage of the insulated gate bipolar transistor IG1 is a negative value, the insulated gate bipolar transistor IG1 is in the off state, and the first diode D1 in this branch is subjected to a reverse voltage.

[0062] Phase 3: When the AC voltage phase is 0°, the first thyristor TH1, the second thyristor TH3, and the test thyristor TH2 have no trigger signal and remain in the off state; the gate trigger voltage of the insulated gate bipolar transistor IG1 is positive, the insulated gate bipolar transistor IG1 is triggered to turn on, and the secondary side of the step-up transformer T4 forms a loop with the insulated gate bipolar transistor IG1, the first diode D1, the sampling resistor R3, and the test thyristor TH2, and the test thyristor TH2 is subjected to a positive voltage.

[0063] In this embodiment, the test thyristor TH2 in phase 1 flows current and is subjected to thermal stress.

[0064] In this embodiment, the test thyristor TH2 is turned off in stage 2 and stage 3, and is subjected to forward and reverse voltage stresses respectively.

[0065] In stage 1, the AC voltage is a positive half-cycle, and the current flows through TH2. The current flowing through the test thyristor TH2 can be adjusted by the voltage regulator T2, thereby adjusting the thermal stress during the thyristor aging process.

[0066] In phase 2 and phase 3, the test thyristor TH2 is turned off, and the secondary voltage of T4 is applied to the thyristor. By adjusting the voltage regulator T1, the voltage stress during the thyristor aging process can be adjusted.

[0067] In the present invention, the characteristic parameters refer to the on-state voltage drop and leakage current of the thyristor; Among them, stage 1 measures the on-state voltage drop, which is the voltage drop of the thyristor when the thyristor is turned on. When current flows through TH2, the voltage across TH2 is detected, which is the on-state voltage drop of the thyristor. Phases 2 and 3 measure the leakage current, which is the current flowing through the thyristor when the thyristor is turned off. The leakage current is measured by the voltage across the resistor R3.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A thyristor accelerated aging test platform, characterized in that: include: A power supply module, a first voltage regulating module, a second voltage regulating module, a step-down transformer, a step-up transformer and a test control module; The power supply module provides the first voltage regulating module and the second voltage regulating module with an AC voltage of the same phase; The primary side of the step-down transformer is connected to the regulating end of the first voltage regulating module; the secondary side of the step-down transformer is connected to the input end of the test control module; the output end of the test control module is connected to the primary side of the step-up transformer, and the secondary side of the step-up transformer is connected to the regulating end of the second voltage regulating module; The test control module is connected to the test thyristor, and the test control module is used to: When the AC voltage is a positive cycle, the test thyristor is triggered to conduct within 1 / 3 of the power frequency period. By adjusting the current flowing through the test thyristor, the thermal stress of the test thyristor during the aging process is adjusted. The voltage across the test thyristor is measured, which is the on-state voltage drop of the test thyristor. When the AC voltage is within the negative half-cycle and part of the positive cycle time range, the test thyristor is controlled to be turned off within 2 / 3 of the power frequency cycle. By adjusting the voltage stress applied to the test thyristor, the current flowing through the test thyristor when the corresponding test thyristor is turned off is obtained, which is the leakage current of the test thyristor.

2. The thyristor accelerated aging test platform according to claim 1, characterized in that: The test control module includes a first thyristor, a second thyristor, a sampling resistor, a current limiting resistor, an insulated gate bipolar transistor, a first diode and a second diode; the first thyristor is connected to the positive electrode of the secondary side of the step-down transformer, and the negative electrode of the secondary side of the step-down transformer is grounded through the current limiting resistor; the first thyristor is also grounded to the second thyristor through the test thyristor in turn; the second thyristor is connected in parallel with the sampling resistor; the connection point of the first thyristor and the test thyristor is also connected to the cathode of the first diode, and the anode of the first diode is connected to the insulated gate bipolar transistor; the connection point of the first thyristor and the test thyristor is also connected to the anode end of the second diode, and the second diode is connected in parallel with the branch where the first diode and the insulated gate bipolar transistor are located; the cathode connection point of the insulated gate bipolar transistor and the second diode is also connected to the positive electrode of the primary side of the step-up transformer, and the negative electrode of the primary side of the step-up transformer is grounded.

3. The thyristor accelerated aging test platform according to claim 1, characterized in that: The first voltage regulating module is a first voltage regulator, and a first switch is connected in series between the first AC power source and the first voltage regulator.

4. The thyristor accelerated aging test platform according to claim 3, characterized in that: A first fuse is also connected in series between the first switch and the first voltage regulator.

5. The thyristor accelerated aging test platform according to claim 1, characterized in that: The second voltage regulating module is a second voltage regulator; a second switch is connected in series between the second AC power source and the second voltage regulator.

6. The thyristor accelerated aging test platform according to claim 5, characterized in that: A second fuse is also connected in series between the second switch and the second voltage regulator.

7. The thyristor accelerated aging test platform according to claim 2, characterized in that: The current limiting resistor is also grounded through a third fuse.

8. A test method based on the thyristor accelerated aging test platform according to any one of claims 1 to 7, characterized in that: include: When the AC voltage is a positive cycle and the voltage phase is 60 degrees, the first thyristor, the second thyristor and the test thyristor are triggered simultaneously. At this time, the secondary side of the step-up transformer, the first thyristor, the test thyristor, the second thyristor and the current limiting resistor form a loop that withstands the forward voltage. The first thyristor, the test thyristor and the second thyristor are all turned on after receiving the trigger signal; during the period of 60°-180°, the first thyristor, the test thyristor and the second thyristor remain turned on; during this period, the gate trigger voltage of the insulated gate bipolar transistor is a negative value, the insulated gate bipolar transistor is in an off state, and withstands the forward voltage of the step-up transformer, and the second diode connected in parallel with the insulated gate bipolar transistor withstands the forward voltage of the step-up transformer.

9. The test method of the thyristor accelerated aging test platform according to claim 8, characterized in that: Also includes: When the AC voltage phase is 180°, the AC voltage enters a negative half-cycle, and the secondary side of the step-down transformer, the first thyristor, the test thyristor, the second thyristor and the current limiting resistor form a loop that is subjected to negative pressure, causing the first thyristor, the test thyristor and the second thyristor to be turned off, and the secondary side of the step-up transformer forms a loop with the sampling resistor, the test thyristor and the second diode, and the secondary side voltage of the step-up transformer is applied to the test thyristor, that is, the test thyristor is subjected to a negative voltage; during the voltage phase of 180°-360°, the gate trigger voltage of the insulated gate bipolar transistor is a negative value, the insulated gate bipolar transistor is in the off state, and the first diode in this branch is subjected to a reverse voltage.

10. The test method of the thyristor accelerated aging test platform according to claim 8, characterized in that: Also includes: When the AC voltage phase is 0°, the first thyristor, the test thyristor and the second thyristor have no trigger signal and remain in the off state; the gate trigger voltage of the insulated gate bipolar transistor is positive, the insulated gate bipolar transistor is triggered to turn on, and the secondary side of the step-up transformer forms a loop with the insulated gate bipolar transistor, the first diode, the sampling resistor and the test thyristor, and the test thyristor is subjected to a positive voltage.

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