Graded discharge circuit of high-voltage platform

Abstract

The utility model relates to the technical field of power semiconductor devices, in particular to a graded discharge circuit of a high-voltage platform. Comprising a step switch resistor part which is connected with two ends of a discharge capacitor in a resistance-switchable manner, and comprises a voltage-bearing branch which is connected with two ends of the discharge capacitor in a controllable on-off manner; the plurality of resistance reducing branches are sequentially cascaded to the pressure bearing branch, and the resistance reducing branches are controllably conducted step by step based on the discharge voltage of the discharge capacitor in the corresponding stage; and the inverter output part is connected with the two ends of the discharge capacitor, receives the discharge voltage and controllably generates an output voltage based on a test signal. According to the utility model, the grading switch resistor part is added, and the resistance of the discharge resistor is adjusted under the real-time bus voltage working condition through the parallel control of the resistance reducing branch circuit, so that the power of the whole discharge loop is controlled, and the discharge efficiency is improved while the overheat loss of the resistor is prevented.

Description

TECHNICAL FIELD

[0001] The utility model relates to power semiconductor device technical field, concretely relates to a grading discharge circuit of high voltage platform. BACKGROUND

[0002] With the development of power semiconductor application, high voltage IGBT module is widely used in industry control, light storage and new energy field. In actual electrical performance test, high voltage module test is often accompanied by huge capacitor bank to suppress the voltage drop caused by the discharge process. The high voltage and high charge platform after the test poses a considerable challenge to the discharge system. The existing discharge test scheme as shown in the figure, the bus voltage provided by the high voltage source is added to the bus discharge capacitor C1, the discharge resistance R is directly connected to both sides of the discharge capacitor C1, the discharge is controlled by the air switch K, since the discharge capacitor C has high voltage and high charge, the instantaneous discharge will generate a large current, the discharge resistance R has a single resistance value, which cannot effectively limit the current, the discharge resistance R has too large power and is easy to overheat, after the voltage is reduced, the resistance cannot be reduced in time to speed up the discharge speed, resulting in low overall discharge efficiency. Figure 1 The utility model provides a grading discharge circuit of high voltage platform, solves the above technical problem, UTILITY MODEL CONTENTS

[0003] The utility model provides a grading discharge circuit of high voltage platform, solves the above technical problem,

[0004] The technical problem solved by the utility model can be realized by adopting the following technical scheme:

[0005] A grading discharge circuit of high voltage platform, comprising,

[0006] The grading switch resistance part is connected to both ends of a discharge capacitor with switchable resistance value, comprising,

[0007] A pressure-bearing branch is connected to both ends of the discharge capacitor in a controllable on-off manner;

[0008] A plurality of resistance reduction branches are sequentially connected to the pressure-bearing branch, and the resistance reduction branches are controllably turned on in stages based on the discharge voltage of the discharge capacitor at the corresponding stage;

[0009] The inverter output part is connected to both ends of the discharge capacitor, receives the discharge voltage, and controllably generates an output voltage based on a test signal.

[0010] Preferably, the pressure-bearing branch comprises,

[0011] The first switch has a first end connected to the first end of the discharge capacitor;

[0012] The first resistance has a first end connected to the second end of the first switch;

[0013] a first inductor, a first end of the first inductor being connected to a second end of the first resistor, a second end of the first inductor being connected to a second end of the discharge capacitor.

[0014] Preferably, the resistance reduction branch comprises a first-stage resistance reduction branch, the first-stage resistance reduction branch comprising,

[0015] a second switch, a first end of the second switch being connected to a second end of the first switch;

[0016] a second resistor, a first end of the second resistor being connected to a second end of the second switch, a second end of the second resistor being connected to a second end of the first inductor.

[0017] Preferably, the discharge voltage is less than 800V, and the second switch is turned on.

[0018] Preferably, the resistance reduction branch further comprises a second-stage resistance reduction branch, the second-stage resistance reduction branch comprising,

[0019] a third switch, a first end of the third switch being connected to a second end of the second switch;

[0020] a third resistor, a first end of the third resistor being connected to a second end of the third switch, a second end of the third resistor being connected to a second end of the second resistor.

[0021] Preferably, the discharge voltage is less than 400V, and the second switch is turned on.

[0022] Preferably, the inverter output part comprises,

[0023] a first power tube, a drain of the first power tube being connected to a first end of the discharge capacitor, a gate of the first power tube being connected to the test signal;

[0024] a second power tube, a drain of the second power tube being connected to a source of the first power tube, a gate of the second power tube being connected to the test signal;

[0025] a third power tube, a drain of the third power tube being connected to a source of the second power tube and generating the output voltage as an alternating current output end, a gate of the third power tube being connected to the test signal;

[0026] a fourth power tube, a drain of the fourth power tube being connected to a source of the third power tube, a source of the fourth power tube being connected to a second end of the discharge capacitor, a gate of the fourth power tube being connected to the test signal.

[0027] Preferably, the inverter output part further comprises,

[0028] a first diode, an anode of the first diode being connected to a reference node, a cathode of the first diode being connected to a source of the first power tube;

[0029] a second diode, an anode of the second diode being connected to a source of the third power tube, a cathode of the second diode being connected to an anode of the first diode.

[0030] Preferably, the inverter output part further comprises,

[0031] a first voltage dividing resistor, a first end of the first voltage dividing resistor being connected to a first end of the discharge capacitor, a second end of the first voltage dividing resistor being connected to the reference node;

[0032] a second voltage dividing resistor, a first end of the second voltage dividing resistor being connected to the reference node, a second end of the second voltage dividing resistor being connected to a second end of the discharge capacitor;

[0033] a second inductor, a first end of the second inductor being connected to a drain of the first power tube, a second end of the second inductor being connected to a source of the first power tube.

[0034] Preferably, the inverter output part further comprises a DC power supply, a positive pole of the DC power supply being connected to the first end of the discharge capacitor, a negative pole of the DC power supply being connected to the second end of the discharge capacitor.

[0035] The beneficial effects of the present application are as follows: due to the above technical scheme, the present application increases the hierarchical switch resistor part, controls the parallel connection of the resistance reduction branch, adjusts the discharge resistance value under the real-time bus voltage working condition, controls the power of the whole discharge circuit, prevents the resistance overheating loss, and improves the discharge efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a discharge test circuit diagram of the prior art;

[0037] Figure 2 is a circuit schematic diagram of the hierarchical switch resistor part in the embodiment of the present application;

[0038] Figure 3 is a schematic diagram of the hierarchical discharge circuit of the high-voltage platform in the embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0040] It should be noted that the embodiments in the utility model and the features in the embodiments can be combined with each other without conflict.

[0041] The utility model will be further described below in combination with the drawings and specific embodiments, but not as the limitation of the utility model.

[0042] A kind of high voltage platform's grading discharge circuit, as shown in Figure 2 , Figure 3 It includes,

[0043] Grading switch resistance part, the both ends of discharge capacitor C1 are connected with resistance value being switchable, including,

[0044] One pressure-bearing branch, controllably connected to the both ends of discharge capacitor C1;

[0045] Several resistance reduction branches, in turn, are cascaded in pressure-bearing branch, and resistance reduction branch is controllably turned on step by step based on the discharge voltage of discharge capacitor C1 at corresponding stage;

[0046] Inverter output part, connected to the both ends of discharge capacitor C1, receives discharge voltage, and controllably generates output voltage based on a test signal.

[0047] Specifically, the utility model patent provides a kind of high voltage platform's grading discharge circuit, mainly applied to the discharge process after dynamic test ends, and the instantaneous voltage lifting and large current impact caused by discharge are relieved by modifying grading discharge and additional carrying inductive load, to protect component, increase the purpose of safety performance of experimental platform.

[0048] Specifically, as shown in Figure 2 Compared with prior art, the utility model increases grading switch resistance part, adjusts discharge resistance resistance value to control the power of entire discharge loop under the condition of real-time bus voltage, prevents resistance overheat loss while improving discharge efficiency by parallel control of resistance reduction branch, Figure 2 Right power tube T01 and power tube T02 directly use the switch test circuit of prior art, the source and gate of power tube T01 are connected test inductance L0 and play filtering and energy storage role, and the above inverter structure is only one kind of implementation example of grading discharge application, not the complete technical scheme of the application.

[0049] In a more preferred embodiment, the pressure-bearing branch includes,

[0050] First switch K1, the first end of first switch K1 is connected to the first end of discharge capacitor C1;

[0051] First resistance R1, the first end of first resistance R1 is connected to the second end of first switch K1;

[0052] The first inductor L1 has a first end connected to a second end of the first resistor R1 and a second end connected to a second end of the discharge capacitor C1.

[0053] Specifically, the utility model takes the pressure-bearing branch as the maximum resistance value gear of hierarchical discharge, and adds the first inductor L1 as an inductive load at the maximum resistance value gear.

[0054] In a preferred embodiment, the resistance reduction branch includes a first-stage resistance reduction branch, which includes,

[0055] The second switch K2 has a first end connected to a second end of the first switch K1.

[0056] The second resistor R2 has a first end connected to a second end of the second switch K2 and a second end connected to a second end of the first inductor L1.

[0057] In a preferred embodiment, the discharge voltage is less than 800V, and the second switch K2 is turned on.

[0058] In a preferred embodiment, the resistance reduction branch further includes a second-stage resistance reduction branch, which includes,

[0059] The third switch K3 has a first end connected to a second end of the second switch K2.

[0060] The third resistor R3 has a first end connected to a second end of the third switch K3 and a second end connected to a second end of the second resistor R2.

[0061] In a preferred embodiment, the discharge voltage is less than 400V, and the second switch K2 is turned on.

[0062] Specifically, the first switch K1, the second switch K2 and the third switch K3 in the application are all air switches, and the high voltage on the bus is used to perform dynamic performance testing on the IGBT module. After the testing is completed, the discharge is started. When the voltage on the bus is high (the voltage is greater than 800V), the first switch K1 is opened, and the first resistor R1 and the first inductor L1 undertake the first high-voltage discharge. When the voltage is reduced to a medium-high voltage of 400V-800V, the second switch K2 is started to reduce the resistance value of the discharge resistor and improve the discharge efficiency. When the voltage is finally reduced to a low voltage below 400V, the third resistor R3 is started to reduce the resistance value of the discharge resistor to the lowest, and the remaining electric quantity in the discharge capacitor C1 is discharged at the maximum speed.

[0063] In a preferred embodiment, as shown in Figure 3 The inverter output part comprises,

[0064] A first power tube T1, a drain of the first power tube T1 is connected to a first end of a discharge capacitor C1, a gate of the first power tube T1 is connected to a test signal;

[0065] A second power tube T2, a drain of the second power tube T2 is connected to a source of the first power tube T1, a gate of the second power tube T2 is connected to the test signal;

[0066] A third power tube T3, a drain of the third power tube T3 is connected to a source of the second power tube T2 and generates an output voltage as an alternating current output end AC, a gate of the third power tube T3 is connected to the test signal;

[0067] A fourth power tube T4, a drain of the fourth power tube T4 is connected to a source of the third power tube T3, a source of the fourth power tube T4 is connected to a second end of the discharge capacitor C1, a gate of the fourth power tube T4 is connected to the test signal.

[0068] In a preferred embodiment, the inverter output part further comprises,

[0069] A first diode D1, an anode of the first diode D1 is connected to a reference node N, a cathode of the first diode D1 is connected to a source of the first power tube T1;

[0070] A second diode D2, an anode of the second diode D2 is connected to a source of the third power tube T3, a cathode of the second diode D2 is connected to an anode of the first diode D1.

[0071] Specifically, the utility model discloses a first power tube T1, a second power tube T2, a third power tube T3 and a fourth power tube T4 and first diode D1 and second diode D2 constitute an inverter circuit;

[0072] The first power tube T1 and the second power tube T2 are controlled to be turned on, and the third power tube T3 and the fourth power tube T4 are controlled to be turned off.

[0073] The second power tube T2 and the third power tube T3 are controlled to be turned on, and the first power tube T1 and the fourth power tube T4 are controlled to be turned off.

[0074] The first power tube T1 and the fourth power tube T4 are controlled to be turned on, and the second power tube T2 and the third power tube T3 are controlled to be turned off, so that a zero level is formed at the load connected to the AC output end AC;

[0075] The third power tube T3 and the fourth power tube T4 are controlled to be turned on, and the first power tube T1 and the second power tube T2 are controlled to be turned off, so that a negative level voltage is formed at the load connected to the AC output end AC;

[0076] Further specifically, the first power tube T1, the second power tube T2, the third power tube T3 and the fourth power tube T4 are all IGBT tubes, and by periodically switching the on and off states of the IGBT tubes, a three-level voltage waveform composed of a positive level, a zero level and a negative level is obtained at the AC output end AC.

[0077] In a preferred embodiment, the inverter output part further comprises,

[0078] The first voltage dividing resistor R4 has a first end connected to the first end of the discharge capacitor C1 and a second end connected to the reference node N.

[0079] The second voltage dividing resistor R5 has a first end connected to the reference node N and a second end connected to the second end of the discharge capacitor C1.

[0080] The second inductor L2 has a first end connected to the drain of the first power tube T1 and a second end connected to the source of the first power tube T1.

[0081] Specifically, the first voltage dividing resistor R4 and the second voltage dividing resistor R5 serve as voltage dividers to form a zero potential at the reference node N, and the second inductor L2 is used for filtering and energy storage to reduce the amplitude of voltage spikes.

[0082] In a preferred embodiment, the inverter output part further comprises a DC power supply DC, the positive pole of the DC power supply DC is connected to the first end of the discharge capacitor C1, and the negative pole of the DC power supply DC is connected to the second end of the discharge capacitor C1, the DC power supply DC is used to charge the discharge capacitor C1, and after the discharge capacitor C1 is fully charged, the discharge is performed.

[0083] The above description is only the preferred embodiment of the present application, and does not limit the implementation and protection scope of the present application. For those skilled in the art, it should be realized that any equivalent replacement and obvious changes made according to the content of the present application should be included in the protection scope of the present application.

Claims

1. A staged discharge circuit for a high voltage platform, characterized by, The step-down resistance branch includes a first-stage step-down resistance branch, and the first-stage step-down resistance branch includes: a second switch (K2), a first end of the second switch (K2) being connected to a second end of the first switch (K1); a second resistance (R2), a first end of the second resistance (R2) being connected to a second end of the second switch (K2), and a second end of the second resistance (R2) being connected to a second end of the first inductor (L1). The discharge voltage is less than 800 V, and the second switch (K2) is turned on. The step-down resistance branch further includes a second-stage step-down resistance branch, and the second-stage step-down resistance branch includes:

2. The hierarchical discharge circuit of a high voltage platform according to claim 1, characterized in that, a third switch (K3), a first end of the third switch (K3) being connected to a second end of the second switch (K2); a third resistance (R3), a first end of the third resistance (R3) being connected to a second end of the third switch (K3), and a second end of the third resistance (R3) being connected to a second end of the second resistance (R2). The discharge voltage is less than 400 V, and the second switch (K2) is turned on. The inverter output part includes:

3. The hierarchical discharge circuit of a high voltage platform according to claim 2, characterized in that, a first power tube (T1), a drain of the first power tube (T1) being connected to a first end of the discharge capacitor (C1), and a gate of the first power tube (T1) being connected to the test signal; a second power tube (T2), a drain of the second power tube (T2) being connected to a source of the first power tube (T1), and a gate of the second power tube (T2) being connected to the test signal; a third power tube (T3), a drain of the third power tube (T3) being connected to a source of the second power tube (T2) and generating the output voltage as an alternating current output end (AC), and a gate of the third power tube (T3) being connected to the test signal; 4. The hierarchical discharge circuit of the high voltage platform of claim 3, wherein, a fourth power tube (T4), a drain of the fourth power tube (T4) being connected to a source of the third power tube (T3), a source of the fourth power tube (T4) being connected to a second end of the discharge capacitor (C1), and a gate of the fourth power tube (T4) being connected to the test signal.

5. The hierarchical discharge circuit of the high voltage platform of claim 3, wherein, The inverter output part further includes: a fifth power tube (T5), a drain of the fifth power tube (T5) being connected to a source of the fourth power tube (T4), and a gate of the fifth power tube (T5) being connected to the test signal; a sixth power tube (T6), a drain of the sixth power tube (T6) being connected to a source of the fifth power tube (T5), and a gate of the sixth power tube (T6) being connected to the test signal.

6. The hierarchical discharge circuit of the high voltage platform of claim 5, wherein, ​ 7. The hierarchical discharge circuit of a high voltage platform according to claim 1, wherein, ​ ​ ​ ​ ​ 8. The hierarchical discharge circuit of a high voltage platform according to claim 7, characterized in that, ​ A first diode (D1), an anode of the first diode (D1) is connected to a reference node, a cathode of the first diode (D1) is connected to a source of the first power tube (T1); A second diode (D2), an anode of the second diode (D2) is connected to a source of the third power tube (T3), a cathode of the second diode (D2) is connected to an anode of the first diode (D1).

9. The hierarchical discharge circuit of a high voltage platform according to claim 8, characterized in that, The inverter output part further comprises, A first voltage dividing resistor (R4), a first end of the first voltage dividing resistor (R4) is connected to a first end of the discharge capacitor (C1), a second end of the first voltage dividing resistor (R4) is connected to the reference node; A second voltage dividing resistor (R5), a first end of the second voltage dividing resistor (R5) is connected to the reference node, a second end of the second voltage dividing resistor (R5) is connected to a second end of the discharge capacitor (C1); A second inductor (L2), a first end of the second inductor (L2) is connected to a drain of the first power tube (T1), a second end of the second inductor (L2) is connected to a source of the first power tube (T1).

10. The hierarchical discharge circuit of a high voltage platform according to claim 1, wherein, Further comprising a direct current power supply (DC), a positive pole of the direct current power supply (DC) is connected to a first end of the discharge capacitor (C1), a negative pole of the direct current power supply (DC) is connected to a second end of the discharge capacitor (C1).

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