Test device and test method for detecting critical rise rate of thyristor on-state current

Abstract

The present invention discloses a test device and method for detecting the critical rate of rise of a thyristor (SCR) on-state current, relating to the field of thyristor testing. The test device comprises: a rectifier control switching unit for rectifying sinusoidal alternating current into half-wave direct current, controlling the delay time of a drive signal, and providing a signal to the thyristor under test based on the control result, thereby switching the operating quadrant of the thyristor under test; the thyristor under test, a device for providing a testing basis for the rectifier control switching unit and the on-off control switching unit; and the on-off control switching unit for adjusting the load size to control the loop current and on-off, and combining the size of the capacitor to impact the thyristor under test, thereby switching the operating quadrant of the thyristor under test. The test device proposed by the present invention has a simple trigger circuit structure and low implementation cost. It can test the four quadrants of unidirectional thyristors and bidirectional thyristors, and uses a rectifier chip to achieve AC / DC conversion, reducing the application cost during the testing process.

Description

Technical Field

[0001] The present invention relates to the field of thyristor testing, and in particular to a testing device and a testing method for detecting a critical rise rate of a thyristor on-state current. Background Art

[0002] The SCR (Silicon Controlled Rectifier) is a semiconductor device widely used in power electronics, primarily for controlling the flow of current. The critical rate of rise of on-state current (di / dt) test is an important test for evaluating the performance of SCR devices, especially their current handling and tolerance capabilities. The test results verify whether the SCR can operate reliably under rapid current changes.

[0003] The rate of rise of on-state current is a key parameter. Too fast a current rise may cause overheating, overcurrent or damage inside the thyristor. Therefore, it is very important to understand the critical current rise rate of the thyristor. By controlling the current rise rate and monitoring the behavior of the thyristor, the maximum current change rate it can withstand can be determined, thereby optimizing the circuit design and avoiding device damage due to too fast current changes.

[0004] However, the test devices for the critical rise rate of the thyristor on-state current in the existing technology all require an additional DC voltage source for power supply. The thyristor trigger circuit is relatively complex and has a high implementation cost, making it impossible to switch measurements between different quadrants of the thyristor, increasing the application cost during the test process.

[0005] Currently, no effective solutions have been proposed for the problems in related technologies. Summary of the Invention

[0006] In response to the problems in the related art, the present invention proposes a test device and a test method for detecting the critical rise rate of the on-state current of a thyristor, so as to overcome the above technical problems existing in the existing related art.

[0007] To this end, the specific technical solutions adopted in the present invention are as follows:

[0008] In a first aspect, the present invention provides a test device for detecting a critical rate of rise of a thyristor on-state current, the test device comprising: a rectifier control switching unit, a thyristor under test, and an on-off control switching unit, wherein the rectifier control switching unit, the thyristor under test, and the on-off control switching unit are sequentially connected;

[0009] The rectifier control switching unit is used to rectify the sinusoidal AC power into half-wave DC power, control the delay time of the drive signal, and provide a signal to the thyristor under test according to the control result to switch the working quadrant of the thyristor under test;

[0010] The thyristor under test is a device used to provide a test basis for the rectifier control switching unit and the on-off control switching unit;

[0011] The on-off control switching unit is used to adjust the load size to control the loop current and on-off, and to impact the thyristor under test in combination with the size of the capacitor to switch the working quadrant of the thyristor under test.

[0012] Preferably, the rectifier control switching unit includes a rectifier module, a control module, a switching module and a drive module, wherein the rectifier module, the control module, the switching module and the drive module are connected in sequence;

[0013] Rectifier module, used to rectify sinusoidal AC into half-wave DC;

[0014] A control module, used to control the delay time of the driving signal;

[0015] Switching module, used to switch the working quadrant of the thyristor under test;

[0016] The driving module is used to provide a driving signal for the thyristor under test.

[0017] Preferably, the rectifier module includes an AC adjustable power supply and a rectifier bridge chip D1;

[0018] The control module includes a resistor R1, a resistor R2 and a capacitor C1;

[0019] The switching module includes a switch S1-1 and a switch S1-2;

[0020] The driving module includes a bidirectional trigger diode D3, a diode D5, a pulse transformer T1 and a diode D4.

[0021] Preferably, the fourth pin of the rectifier bridge chip D1 is connected to one end of the AC adjustable power supply, the other end of the AC adjustable power supply is connected to the second pin of the rectifier bridge chip D1, and the third pin of the rectifier bridge chip D1 is connected to one end of the capacitor C1 and the third pin of the pulse transformer T1;

[0022] A first pin of the rectifier bridge chip D1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the other end of the capacitor C1 and one end of the bidirectional trigger diode D3, and the other end of the bidirectional trigger diode D3 is connected to the first pin of the pulse transformer T1;

[0023] The second pin of the pulse transformer T1 is connected to one end of a diode D5 and one end of a diode D4. The other end of the diode D4 is connected to the fourth pin of the pulse transformer T1 and the first pin of a switch S1-2. The other end of the diode D5 is connected to the first pin of a switch S1-1.

[0024] Preferably, the on-off control switching unit includes an on-off module, a load adjustment module, an impact module and a quadrant switching module, wherein the on-off module, the load adjustment module, the impact module and the quadrant switching module are connected in sequence;

[0025] On / off module, used to control the on / off of the circuit using a relay;

[0026] Load regulation module, used to adjust the load size and control the loop current according to the adjustment result;

[0027] An impact module, used for generating current change rate signals of different strengths according to the size of the capacitance to impact the thyristor under test;

[0028] The quadrant switching module is used to switch the working quadrant of the thyristor under test in combination with the switching module.

[0029] Preferably, the on-off module includes a 220V AC power supply, a relay K1 and a switch S3;

[0030] The load regulation module includes a switch S2, a resistor RL1, a resistor RL2, a resistor RL3 and a resistor RL4;

[0031] The impact module includes a switch S4, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6 and a capacitor C7;

[0032] The quadrant switching module includes a switch S1 - 3 and a switch S1 - 4 .

[0033] Preferably, a first pin of the relay K1 is connected to one end of a 220V AC power supply, the other end of the 220V AC power supply is connected to one end of a switch S3, the other end of the switch S3 is connected to a second pin of the relay K1, a third pin of the relay K1 is respectively connected to one end of a thyristor under test and a sixth pin of the switch S4, and a fourth pin of the relay K1 is connected to a first pin of the switch S2;

[0034] A first pin of the switch S2 is connected to one end of the resistor RL1, a second pin of the switch S2 is connected to one end of the resistor RL2, a third pin of the switch S2 is connected to one end of the resistor RL3 and one end of the resistor RL4, respectively, and the other end of the resistor RL1 is connected to the other end of the resistor RL2, the other end of the resistor RL3, and the other end of the resistor RL4, respectively.

[0035] A first pin of switch S4 is connected to one end of capacitor C2, a second pin of switch S4 is connected to one end of capacitor C3, a third pin of switch S4 is connected to one end of capacitor C4, a fourth pin of switch S4 is connected to one end of capacitor C7, a fifth pin of switch S4 is connected to one end of capacitor C6, and a sixth pin of switch S4 is connected to one end of capacitor C5.

[0036] In a second aspect, the present invention further provides a test method for detecting the critical rise rate of the on-state current of a thyristor, the test method comprising:

[0037] S1. Adjust the voltage value of the AC adjustable power supply according to the type of the thyristor being tested, and turn on the power supply to convert AC power into DC output;

[0038] S2. Adjust the charging time based on the DC output result, and use the adjustment result to drive the thyristor under test to perform a discharge test operation, and obtain the current critical rise rate value according to the test result.

[0039] Preferably, adjusting the voltage value of the AC adjustable power supply according to the type of the thyristor being tested, and connecting the power supply to convert the AC power into a DC power output includes:

[0040] S11. According to the type of the thyristor being tested, respectively turn on switch S1 and switch S2 to select the test quadrant and test load;

[0041] S12, toggle switch S4 to select the test capacitor, adjust the AC adjustable power supply to select the voltage value, and turn on the power fluctuation switch S3 to turn on the relay K1 according to the adjustment result;

[0042] S13. Based on the start-up result, the main circuit is turned on, and the rectifier bridge chip D1 is used to convert the AC power into a DC power output to charge the capacitor bank.

[0043] Preferably, adjusting the charging time based on the DC output result, and using the adjustment result to drive the thyristor under test to perform a discharge test operation, and obtaining the current critical rise rate value according to the test result includes:

[0044] S21, adjusts the resistor R2 to change the charging time of the capacitor C1, and after the capacitor C1 is charged to the preset time, triggers the bidirectional trigger diode D3 to turn on, driving the pulse transformer T1 to work and output a positive signal;

[0045] S22, turning on the diode D5 and the thyristor under test according to the output result, and using the capacitor bank to discharge the thyristor under test based on the conduction result to complete the current rise rate impact processing;

[0046] S23. After the relay K1 reaches the set time, the main circuit is disconnected to complete the current critical rate of rise test process, and the current change rate signal is fed back to the oscilloscope to display the corresponding waveform to obtain the current critical rate of rise value.

[0047] The beneficial effects of the present invention are:

[0048] 1. The test device and test method for detecting the critical rate of rise of the on-state current of a thyristor proposed in the present invention can conveniently, quickly and efficiently measure the critical rate of rise of the on-state current (di / dt) of the thyristor. At the same time, it can test not only unidirectional thyristors but also bidirectional thyristors, and flexibly and conveniently switch between the four quadrants of the bidirectional thyristor and measure the corresponding values. The test method is simple and the equipment is easy to operate, achieving the purpose of providing effective measured data for thyristor R&D personnel, providing reliable data support when applying and selecting thyristors, so as to quickly and effectively select thyristors that meet the circuit and load requirements, greatly shortening the test cycle, reducing test costs, and improving design efficiency.

[0049] 2. The test device proposed in the present invention has a simple trigger circuit structure and low implementation cost. It can test the four quadrants of unidirectional thyristors and bidirectional thyristors. At the same time, it uses a rectifier chip to realize AC-DC conversion, without the need for an additional DC power supply, thereby reducing the application cost during the test process. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 1 is a principle block diagram of a test device for detecting a critical rise rate of a thyristor on-state current according to an embodiment of the present invention;

[0052] Figure 2 is a circuit schematic diagram of a test device for detecting a critical rise rate of a thyristor on-state current according to an embodiment of the present invention;

[0053] Figure 3 is a flow chart of a test method for detecting a critical rise rate of a thyristor on-state current according to an embodiment of the present invention;

[0054] Figure 4 1 is a schematic diagram of calculating the critical rate of rise of current in a test method for detecting the critical rate of rise of on-state current of a thyristor according to an embodiment of the present invention;

[0055] Figure 5 1 is a waveform diagram corresponding to the operation in the test method for detecting the critical rise rate of the thyristor on-state current according to an embodiment of the present invention;

[0056] Figure 6 This is a comprehensive diagram of the measured waveform in the test method for detecting the critical rise rate of the thyristor on-state current according to an embodiment of the present invention;

[0057] Figure 7This is an expanded and enlarged diagram of actual measurement in a test method for detecting a critical rise rate of a thyristor on-state current according to an embodiment of the present invention;

[0058] Figure 8 This is a waveform diagram of the power supply voltage after rectification in a test method for detecting a critical rise rate of a thyristor on-state current according to an embodiment of the present invention;

[0059] Figure 9 1 is a waveform diagram of power supply voltage and source current in a test method for detecting a critical rise rate of a thyristor on-state current according to an embodiment of the present invention;

[0060] Figure 10 1 is a diagram of a rectified voltage waveform and a rectified current waveform in a test method for detecting a critical rise rate of a thyristor on-state current according to an embodiment of the present invention;

[0061] Figure 11 This is a waveform diagram of the voltage across the load resistor and the current flowing through the load resistor in a test method for detecting the critical rise rate of the thyristor on-state current according to an embodiment of the present invention;

[0062] Figure 12 is a structural diagram of another alternative solution according to an embodiment of the present invention.

[0063] In the picture:

[0064] 1. Rectification control switching unit; 2. Tested thyristor; 3. On-off control switching unit. DETAILED DESCRIPTION

[0065] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention. They are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. By referring to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and the advantages of the present invention.

[0066] According to an embodiment of the present invention, a testing device and a testing method for detecting a critical rise rate of a thyristor on-state current are provided.

[0067] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. Figure 1 As shown, a test device for detecting the critical rise rate of the on-state current of a thyristor according to an embodiment of the present invention comprises: a rectifier control switching unit 1, a thyristor under test 2, and an on-off control switching unit 3, wherein the rectifier control switching unit 1, the thyristor under test 2, and the on-off control switching unit 3 are connected in sequence;

[0068] The rectifier control switching unit 1 is used to rectify the sinusoidal AC power into half-wave DC power, control the delay time of the driving signal, and provide a signal to the thyristor under test according to the control result to switch the working quadrant of the thyristor under test 2;

[0069] The thyristor 2 under test is a device used to provide a test basis for the rectifier control switching unit 1 and the on-off control switching unit 3;

[0070] The on-off control switching unit 3 is used to adjust the load size to control the loop current and on-off, and to impact the thyristor 2 under test in combination with the size of the capacitor to switch the working quadrant of the thyristor 2 under test.

[0071] In one embodiment, the rectifier control switching unit 1 includes a rectifier module, a control module, a switching module and a drive module, wherein the rectifier module, the control module, the switching module and the drive module are connected in sequence;

[0072] The rectifier module is used to rectify the sinusoidal alternating current into half-wave direct current; the control module is used to control the delay time of the drive signal; the switching module is used to switch the working quadrant of the thyristor 2 under test; and the drive module is used to provide a drive signal for the thyristor 2 under test.

[0073] In one embodiment, the rectifier module includes an AC adjustable power supply and a rectifier bridge chip D1;

[0074] The control module includes a resistor R1, a resistor R2 and a capacitor C1;

[0075] The switching module includes a switch S1-1 and a switch S1-2;

[0076] The driving module includes a bidirectional trigger diode D3, a diode D5, a pulse transformer T1 and a diode D4.

[0077] In one embodiment, the fourth pin of the rectifier bridge chip D1 is connected to one end of the AC adjustable power supply, the other end of the AC adjustable power supply is connected to the second pin of the rectifier bridge chip D1, and the third pin of the rectifier bridge chip D1 is connected to one end of the capacitor C1 and the third pin of the pulse transformer T1; the first pin of the rectifier bridge chip D1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the other end of the capacitor C1 and one end of the bidirectional trigger diode D3, and the other end of the bidirectional trigger diode D3 is connected to the first pin of the pulse transformer T1; the second pin of the pulse transformer T1 is connected to one end of the diode D5 and one end of the diode D4, the other end of the diode D4 is connected to the fourth pin of the pulse transformer T1 and the first pin of the switch S1-2, and the other end of the diode D5 is connected to the first pin of the switch S1-1.

[0078] In one embodiment, the on-off control switching unit 2 includes an on-off module, a load adjustment module, an impact module and a quadrant switching module, wherein the on-off module, the load adjustment module, the impact module and the quadrant switching module are connected in sequence;

[0079] The on-off module is used to control the on-off of the circuit using a relay; the load adjustment module is used to adjust the load size and control the circuit current according to the adjustment result; the impact module is used to generate current change rate signals of different intensities according to the capacitance size to impact the thyristor 2 under test; the quadrant switching module is used to switch the working quadrant of the thyristor 2 under test in combination with the switching module.

[0080] In one embodiment, the on-off module includes a 220V AC power supply, a relay K1 and a switch S3;

[0081] The load regulation module includes a switch S2, a resistor RL1, a resistor RL2, a resistor RL3 and a resistor RL4;

[0082] The impact module includes a switch S4, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6 and a capacitor C7;

[0083] The quadrant switching module includes a switch S1 - 3 and a switch S1 - 4 .

[0084] In one embodiment, a first pin of the relay K1 is connected to one end of a 220V AC power supply, the other end of the 220V AC power supply is connected to one end of a switch S3, the other end of the switch S3 is connected to the second pin of the relay K1, the third pin of the relay K1 is respectively connected to one end of the thyristor 2 under test and the sixth pin of the switch S4, and the fourth pin of the relay K1 is connected to the first pin of the switch S2; the first pin of the switch S2 is connected to one end of the resistor RL1, the second pin of the switch S2 is connected to one end of the resistor RL2, the third pin of the switch S2 is respectively connected to one end of the resistor RL3 and one end of the resistor RL4, and the other end of the resistor RL1 is respectively connected to the other end of the resistor RL2, the other end of the resistor RL3, and the other end of the resistor RL4; the first pin of the switch S4 is connected to one end of the capacitor C2, the second pin of the switch S4 is connected to one end of the capacitor C3, the third pin of the switch S4 is connected to one end of the capacitor C4, the fourth pin of the switch S4 is connected to one end of the capacitor C7, the fifth pin of the switch S4 is connected to one end of the capacitor C6, and the sixth pin of the switch S4 is connected to one end of the capacitor C5.

[0085] like Figure 2As shown, it needs to be explained that the test device for detecting the critical rise rate of the thyristor on-state current is mainly composed of three parts, among which: Part A is the rectification, delay control, drive, and quadrant switching circuit, whose main functions are: rectifying the sinusoidal AC into half-wave DC, and is composed of an AC adjustable power supply, a rectifier bridge chip D1, etc.; controlling the delay time of the drive signal (composed of resistor R1, resistor R2, and capacitor C1); switching the working quadrant of the thyristor (composed of switch S1-1 and switch S1-2); providing a drive signal for the thyristor under test (composed of a bidirectional trigger diode D3, a pulse transformer T1, and a diode D5); Part B is the thyristor under test.

[0086] Part C is the rectification, on-off control, adjustable load, adjustable capacitor and quadrant switching circuit. Its main functions are: 1. Control the on-off of the circuit (composed of relay K1 and 220V AC power supply); adjust the load size to control the circuit current (composed of switch S2 and resistors RL1 to RL4); adjust the capacitor size to generate di / dt signals of different intensities to impact the thyristor under test (composed of switch S4 and capacitor C2 to capacitor C7); switch the working quadrant of the thyristor (composed of switches S1-3 and S1-4, which are linked with switches S1-1 and S1-2).

[0087] like Figure 3 According to another embodiment of the present invention, a test method for detecting the critical rise rate of the on-state current of a thyristor is provided. The test method includes:

[0088] S1. Adjust the voltage value of the AC adjustable power supply according to the type of the thyristor being tested, and turn on the power supply to convert AC power into DC output;

[0089] S2. Adjust the charging time based on the DC output result, and use the adjustment result to drive the thyristor under test to perform a discharge test operation, and obtain the current critical rise rate value according to the test result.

[0090] In one embodiment, adjusting the voltage value of the AC adjustable power supply according to the type of the thyristor being tested, and turning on the power supply to convert the AC power into a DC power output includes:

[0091] S11. According to the type of the thyristor being tested, respectively turn on switch S1 and switch S2 to select the test quadrant and test load;

[0092] S12, toggle switch S4 to select the test capacitor, adjust the AC adjustable power supply to select the voltage value, and turn on the power fluctuation switch S3 to turn on the relay K1 according to the adjustment result;

[0093] S13. Based on the start-up result, the main circuit is turned on, and the rectifier bridge chip D1 is used to convert the AC power into a DC power output to charge the capacitor bank.

[0094] In one embodiment, the charging time is adjusted based on the DC output result, and the adjustment result is used to drive the thyristor under test to perform a discharge test operation. The critical current rise rate value is obtained according to the test result, including:

[0095] S21, adjusts the resistor R2 to change the charging time of the capacitor C1, and after the capacitor C1 is charged to the preset time, triggers the bidirectional trigger diode D3 to turn on, driving the pulse transformer T1 to work and output a positive signal;

[0096] S22, turning on the diode D5 and the thyristor under test according to the output result, and using the capacitor bank to discharge the thyristor under test based on the conduction result to complete the current rise rate impact processing;

[0097] S23. After the relay K1 reaches the set time, the main circuit is disconnected to complete the current critical rate of rise test process, and the current change rate signal is fed back to the oscilloscope to display the corresponding waveform to obtain the current critical rate of rise value.

[0098] It should be explained that the test method proposed in this embodiment mainly utilizes three basic functions of thyristors: thyristor rectification switching function; thyristor zero-crossing shutdown function; and capacitor charging and discharging function. Its specific working principle is as follows:

[0099] When the circuit is powered on (taking one cycle as an example), the power supply starts to charge the capacitor. When the thyristor under test is triggered to turn on (the thyristor conduction angle can be adjusted), the capacitor discharges to the thyristor under test, completing a di / dt impact. When the power supply signal passes through zero, the thyristor is cut off. The above process is repeated at the beginning of the next power supply signal cycle until the main circuit is controlled to be disconnected or the thyristor under test fails. The current detection device detects the current flowing through the thyristor and calculates the waveform by observing the waveform with an oscilloscope. di / dt (current change rate signal) value, calculated as follows Figure 4 As shown, the specific di / dt The value is calculated as:

[0100]

[0101] Where, di / dt Indicates the critical rate of rise of current, Δ i Indicates the current change, Δ t Indicates the time change.

[0102] like Figure 5 As shown in the figure, by controlling the conduction angle of the thyristor in a single cycle, the current flowing through the thyristor under test is adjusted (when the LC circuit is fixed), thereby achieving regulation. di / dt , while combining Figures 6 and 7 The measured waveform shown in the figure is Figure 6 is the global graph, Figure 7 To expand the enlarged diagram, channel 1 is the voltage waveform across the thyristor under test, channel 2 is the thyristor drive signal voltage waveform, and channel 3 is the current waveform flowing through the thyristor under test.

[0103] like Figure 8 As shown, channel 2 is the power supply voltage waveform, and channel 1 is the waveform of the power supply voltage after rectification. Figure 9 As shown, channel 2 is the power supply voltage waveform, and channel 3 is the power supply current waveform. Figure 10 As shown, channel 1 is the voltage waveform after rectification, and channel 3 is the current waveform after rectification. Figure 11 As shown, channel 1 is the voltage waveform across the load resistor, and channel 3 is the current waveform flowing through the load resistor.

[0104] The action relationship is described as follows:

[0105] According to the type of thyristor to be tested, toggle switch S1 to select the test quadrant, toggle switch S2 to select the appropriate load, toggle switch S4 to select the appropriate capacitor, and adjust the AC adjustable power supply to select the appropriate voltage value. After the power is turned on, press switch S3 to start the time relay (K1) to work, the main circuit is connected, and the rectifier bridge chip D1 converts AC power into DC power output, and charges the capacitor (taking C2 as an example) through the load resistor RL. At the same time, by adjusting the resistor R2, the charging time of the capacitor C1 can be adjusted. When both ends of the capacitor C1 are charged to 30V, DB3 (D3) is triggered to turn on, driving the pulse transformer T1 to work, the transformer secondary outputs a positive signal, and the diode D5 is turned on, which in turn drives the thyristor to be tested Q1 to turn on. After the thyristor to be tested Q1 is turned on, the capacitor (taking C2 as an example) discharges to the thyristor to be tested Q1, and the test is completed. di / dt Impact, when the time relay K1 reaches the set time, the main circuit is disconnected and the test is completed. The current clamp will di / dt The signal is fed back to the oscilloscope and the corresponding waveform is displayed, and the di / dt value.

[0106] At the same time Figure 12 As shown, the simple principle of this embodiment is as follows: the power supply can be replaced by mains electricity, the capacitor can be a fixed value, di / dtThe test can be performed using external devices such as current clamps and oscilloscopes. A high-power incandescent lamp can be used as the load. When the thyristor being tested is in the rectifier switch state, the load bulb will have different steady-state brightness depending on the conduction angle. When the thyristor being tested fails, the thyristor is in the direct-through state and the bulb will be at its brightest. The brightness of the bulb can be used to quickly determine whether the thyristor has failed.

[0107] In summary, with the aid of the above-mentioned technical solutions of the present invention, the test device and test method for detecting the critical rate of rise of the on-state current of a thyristor proposed in the present invention can conveniently, quickly, and efficiently measure the critical rate of rise of the on-state current (di / dt) of the thyristor. At the same time, it can test not only unidirectional thyristors but also bidirectional thyristors, and flexibly and conveniently switch between the four quadrants of the bidirectional thyristor and measure the corresponding values. The test method is simple and the equipment is easy to operate, achieving the purpose of providing effective measured data for thyristor developers. It provides reliable data support when applying and selecting thyristors, so as to quickly and effectively select thyristors that meet circuit and load requirements, greatly shortening the test cycle, reducing test costs, and improving design efficiency. The test device proposed in the present invention has a simple trigger circuit structure and low implementation cost. It can test the four quadrants of unidirectional thyristors and bidirectional thyristors. At the same time, it uses a rectifier chip to achieve AC-DC conversion, eliminating the need for an additional DC power supply, reducing the application cost during the test process. The present invention utilizes the basic concept of silicon-controlled rectifier switches, automatic zero-crossing shutdown, and capacitor charging and discharging functions to realize the purpose of AC-DC conversion. The invention also achieves the effect of outputting di / dt signals of different intensities by controlling the on-off technology of the main circuit through components, utilizing an AC adjustable power supply, and switching different capacitors.

[0108] 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 principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A test device for detecting the critical rate of rise of the on-state current of a thyristor, characterized in that: The test device comprises: a rectifier control switching unit, a thyristor to be tested and an on-off control switching unit, wherein the rectifier control switching unit, the thyristor to be tested and the on-off control switching unit are connected in sequence; The rectification control switching unit is used to control the delay time of the driving signal after rectifying the sinusoidal alternating current into half-wave direct current, and provide a signal to the thyristor under test according to the control result to switch the working quadrant of the thyristor under test; The thyristor under test is a device used to provide a test basis for the rectification control switching unit and the on-off control switching unit; The on-off control switching unit is used to adjust the load size to control the loop current and on-off, and to impact the thyristor under test in combination with the size of the capacitor to switch the working quadrant of the thyristor under test; The rectification control switching unit includes: Rectifier module, used to rectify sinusoidal AC into half-wave DC; A control module, used to control the delay time of the driving signal; A switching module, used for switching the working quadrant of the thyristor under test; The driving module is used to provide a driving signal for the thyristor under test.

2. The test device for detecting the critical rate of rise of the on-state current of a thyristor according to claim 1, characterized in that: The rectifier module includes an AC adjustable power supply and a rectifier bridge chip D1; The control module includes a resistor R1, a resistor R2 and a capacitor C1; The switching module includes a switch S1-1 and a switch S1-2; The driving module includes a bidirectional trigger diode D3, a diode D5, a pulse transformer T1 and a diode D4.

3. The test device for detecting the critical rate of rise of the on-state current of a thyristor according to claim 2, characterized in that: The fourth pin of the rectifier bridge chip D1 is connected to one end of the AC adjustable power supply, the other end of the AC adjustable power supply is connected to the second pin of the rectifier bridge chip D1, and the third pin of the rectifier bridge chip D1 is connected to one end of the capacitor C1 and the third pin of the pulse transformer T1; The first pin of the rectifier bridge chip D1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the other end of the capacitor C1 and one end of the bidirectional trigger diode D3, and the other end of the bidirectional trigger diode D3 is connected to the first pin of the pulse transformer T1; The second pin of the pulse transformer T1 is connected to one end of the diode D5 and one end of the diode D4, the other end of the diode D4 is connected to the fourth pin of the pulse transformer T1 and the first pin of the switch S1-2, and the other end of the diode D5 is connected to the first pin of the switch S1-1.

4. The test device for detecting the critical rate of rise of the on-state current of a thyristor according to claim 3, characterized in that: The on-off control switching unit includes an on-off module, a load adjustment module, an impact module and a quadrant switching module, wherein the on-off module, the load adjustment module, the impact module and the quadrant switching module are connected in sequence; The on-off module is used to control the on-off of the circuit using a relay; The load adjustment module is used to adjust the load size and control the loop current according to the adjustment result; The impact module is used to generate current change rate signals of different strengths according to the size of the capacitance to impact the thyristor under test; The quadrant switching module is used to switch the working quadrant of the thyristor under test in combination with the switching module.

5. The test device for detecting the critical rate of rise of the on-state current of a thyristor according to claim 4, characterized in that: The on-off module includes a 220V AC power supply, a relay K1 and a switch S3; The load adjustment module includes a switch S2, a resistor RL1, a resistor RL2, a resistor RL3 and a resistor RL4; The impact module includes a switch S4, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6 and a capacitor C7; The quadrant switching module includes a switch S1 - 3 and a switch S1 - 4 .

6. The test device for detecting the critical rate of rise of the on-state current of a thyristor according to claim 5, characterized in that: The first pin of the relay K1 is connected to one end of the 220V AC power supply, the other end of the 220V AC power supply is connected to one end of the switch S3, the other end of the switch S3 is connected to the second pin of the relay K1, the third pin of the relay K1 is respectively connected to one end of the thyristor under test and the sixth pin of the switch S4, and the fourth pin of the relay K1 is connected to the first pin of the switch S2; A first pin of the switch S2 is connected to one end of the resistor RL1, a second pin of the switch S2 is connected to one end of the resistor RL2, a third pin of the switch S2 is connected to one end of the resistor RL3 and one end of the resistor RL4, respectively, and the other end of the resistor RL1 is connected to the other end of the resistor RL2, the other end of the resistor RL3, and the other end of the resistor RL4, respectively; A first pin of the switch S4 is connected to one end of the capacitor C2, a second pin of the switch S4 is connected to one end of the capacitor C3, a third pin of the switch S4 is connected to one end of the capacitor C4, a fourth pin of the switch S4 is connected to one end of the capacitor C7, a fifth pin of the switch S4 is connected to one end of the capacitor C6, and a sixth pin of the switch S4 is connected to one end of the capacitor C5.

7. A test method for detecting the critical rate of rise of the on-state current of a thyristor, for implementing the test of the test device for detecting the critical rate of rise of the on-state current of a thyristor as claimed in any one of claim 6, characterized in that: The test method includes: S1. Adjust the voltage value of the AC adjustable power supply according to the type of the thyristor being tested, and turn on the power supply to convert the AC power into a DC power output; S2. Adjust the charging time based on the DC output result, and use the adjustment result to drive the thyristor under test to perform a discharge test operation, and obtain a current critical rise rate value according to the test result.

8. The test method for detecting the critical rate of rise of the on-state current of a thyristor according to claim 7, characterized in that: The step of adjusting the voltage value of the AC adjustable power supply according to the type of the thyristor being tested, and connecting the power supply to convert the AC power into a DC power output comprises: S11. According to the type of the thyristor being tested, respectively turn on the switch S1 and the switch S2 to select the test quadrant and test load; S12, toggle the switch S4 to select the test capacitor, adjust the AC adjustable power supply to select the voltage value, and turn on the power supply according to the adjustment result, and toggle the switch S3 to turn on the relay K1; S13. Based on the start-up result, the main circuit is turned on, and the rectifier bridge chip D1 is used to convert the AC power into a DC power output to charge the capacitor bank.

9. The test method for detecting the critical rate of rise of the on-state current of a thyristor according to claim 8, characterized in that: The step of adjusting the charging time based on the DC output result, driving the thyristor under test to perform a discharge test operation using the adjustment result, and obtaining the critical current rise rate value according to the test result includes: S21, adjusting the resistor R2 to change the charging time of the capacitor C1, and after the capacitor C1 is charged for a preset time, triggering the bidirectional trigger diode D3 to turn on, driving the pulse transformer T1 to work and output a positive signal; S22, turning on the diode D5 and the thyristor under test according to the output result, and using the capacitor bank to discharge the thyristor under test based on the conduction result to complete the current rise rate impact processing; S23, after the relay K1 reaches the set time, the main circuit is disconnected to complete the current critical rise rate test process, and the current change rate signal is fed back to the oscilloscope to display the corresponding waveform to obtain the current critical rise rate value.

Images