A current sharing system suitable for high-voltage SVG high-power multi-IGBT parallel connection

Abstract

The present invention discloses a current sharing system suitable for high-voltage SVG high-power multi-IGBT parallel connection, including more than one IGBT gate adapter board module capable of realizing multiple IGBT parallel connection; the IGBT gate adapter board module is used to weld multiple parallel IGBTs and a high-voltage SVG drive control board connected to the IGBT gate adapter board module, and a high-power single-channel gate direct drive output circuit module, a gate high-voltage clamping protection circuit module, a high-current sharing coefficient emitter voltage sharing control circuit module, and a high-reliability state detection circuit module are arranged in each IGBT gate adapter board module, and the high-current sharing coefficient emitter voltage sharing control circuit module is electrically connected to the high-reliability state detection circuit module, the gate high-voltage clamping protection circuit module, and the high-power single-channel gate direct drive output circuit module. The present invention can improve the reliability of IGBT working state detection.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage SVG power quality monitoring, and in particular to a high-power multi-IGBT parallel current sharing technology and a high-power multi-IGBT parallel current sharing system suitable for high-voltage SVG. Background Art

[0002] IGBT module (Insulated Gate Bipolar Transistor), insulated gate bipolar transistor, is a composite fully controlled voltage-driven power semiconductor device composed of BJT and MOS, which has the advantages of both high input impedance of MOSFET and low on-state voltage drop of GTR.

[0003] With the rapid development of power electronics technology, IGBT module devices are increasingly used in SVG reactive power compensation, rail transit, motor control and other fields. As the power demand continues to increase, the current and withstand voltage levels of IGBT modules are required to be higher and higher. Manufacturers are limited by process technology conditions and the optimal return on investment, and are far from meeting the needs of the industry. Considering the cost-effectiveness and supply stability, the application party usually uses mature IGBT multi-modules in parallel to meet high power requirements.

[0004] When multiple IGBT modules are connected in parallel, designers hope that the current flowing through each module is as consistent as possible. However, due to the inconsistency of analog device technology, each IGBT module is discrete, such as the turn-on and turn-off time, saturation voltage drop and internal chip stray inductance of each module are different; at the same time, the external copper bus stray inductance and current loop cannot be completely consistent, which determines that the parallel IGBT modules cannot be turned on and off at the same time, and it is difficult to ensure the current balance of the IGBT modules. When the current sharing characteristics are poor, the IGBT module with a large current will be damaged first due to severe heat generation, reducing the life of the equipment.

[0005] Therefore, when the number of IGBTs increases, the possibility of various fault conditions further increases, so the current sharing consistency design of the IGBT module is particularly important. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a current equalization system suitable for high-voltage SVG and high-power multi-IGBT parallel connection, so as to solve the existing defect that when the number of IGBTs increases, the possibility of various fault conditions further increases, resulting in uneven current flowing through the IGBTs.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A current sharing system suitable for high-voltage SVG high-power multi-IGBT parallel connection, comprising more than one IGBT gate adapter board module capable of realizing multiple IGBT parallel connection; the IGBT gate adapter board module is used to weld multiple parallel IGBTs and a high-voltage SVG drive control board connected to the IGBT gate adapter board module, and the following components are arranged in each IGBT gate adapter board module:

[0009] A high-power single-channel gate direct drive output circuit module for directly outputting a single high-power drive signal to the IGBT gate adapter module;

[0010] A gate high voltage clamping protection circuit module used to protect the IGBT switch control when multiple high-power IGBT modules are connected in parallel and when a fault or IGBT abnormality occurs;

[0011] A high current sharing coefficient emitter voltage sharing control circuit module used to improve the robustness of the IGBT gate drive circuit and reduce the discreteness caused by parallel connection of multiple IGBT modules;

[0012] A high-reliability status detection circuit module is used to reduce false alarms of short-circuit faults of multiple IGBT modules in parallel under high-power strong magnetic field interference.

[0013] Preferably, the gate high-voltage clamping protection circuit module includes more than one single-module IGBT gate drive protection circuit, and the high-current-sharing coefficient emitter voltage-sharing control circuit module is electrically connected to the high-reliability state detection circuit module, the gate high-voltage clamping protection circuit module and the high-power single-channel gate direct drive output circuit module.

[0014] Preferably, the single-module IGBT gate drive protection circuit is connected to a corresponding IGBT, and the single-module IGBT gate drive protection circuit includes a first diode D1 and a second diode D2, a bidirectional voltage regulator D4, a first capacitor C1, a seventh resistor R7, and a third diode D3, which are connected in series with each other. The bidirectional voltage regulator D4, the first capacitor C1, and the seventh resistor R7 are connected in parallel between the E pin and the G pin of the corresponding IGBT, and the E pin of the IGBT is connected to the high-voltage SVG drive control board through the sixth resistor R6 and the fifth resistor R5 connected in parallel, and the G pin of the IGBT is connected to the high-voltage SVG drive control board through the sixth resistor R6 and the fifth resistor R5 connected in parallel. The first resistor R1 and the second resistor R2 are connected to a pin of the high-voltage SVG drive control board, and the G pin of the IGBT is also connected to another pin of the high-voltage SVG drive control board through a third resistor R3 and a fourth resistor R4 connected in parallel, the G pin of the IGBT is also connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the high-voltage SVG drive control board, the cathode of the first diode D1 is connected to the anode of the second diode D2, and the anode of the first diode D1 is connected to the high-voltage SVG drive control board, and the cathode of the second diode D2 is connected to the C pin of the corresponding IGBT.

[0015] Preferably, the high-reliability state detection circuit module includes a transient diode, a comparator and a peripheral circuit. The positive electrode of the transient diode is connected to the 6th pin of the comparator. The flip level of the comparator is increased by adjusting the voltage regulation value of the transient diode, thereby improving the reliability and timeliness of the IGBT working state detection and realizing reliable operation of the system in harsh environments with large current and strong magnetic field.

[0016] The present invention has the following beneficial effects:

[0017] The present invention outputs a high-power drive signal to the IGBT gate adapter board, and the wiring is safe, convenient and concise from the control board to the gate adapter board, thereby reducing the probability of electromagnetic interference. The drive signal is directly sent to an independent gate drive protection circuit, which improves the consistency of current sharing of multiple IGBT modules in parallel, and can more specifically control high-power SVG equipment in real time and reliably. The system meets the functional requirements of easy installation and maintenance, reduced material types, high consistency of current sharing of multiple IGBT modules in parallel, and reliable operation in high-power harsh electromagnetic environments. Therefore, through this technical method, efficient and reliable parallel connection of multiple IGBT modules can be achieved to meet the performance requirements of high-power SVG. It meets the needs of fast installation and convenient maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a definition diagram of the IGBT gate pins when the two IGBTs involved in the present invention are connected in parallel.

[0019] Figure 2 is the system architecture diagram of the present invention;

[0020] Figure 3 is a schematic diagram of the gate drive diagram of the present invention;

[0021] Figure 4 This is the high reliability state detection diagram of the present invention.

[0022] Figure 5 It is a schematic diagram of the connection between the high current sharing coefficient emitter voltage sharing control circuit module and other circuits in the present invention.

[0023] Reference numerals:

[0024] IGBT gate adapter board module 1, high-voltage SVG drive control board 2, high-power single-channel gate direct drive output circuit module 3, gate high-voltage clamping protection circuit module 4, high-current sharing coefficient emitter voltage sharing control circuit module 5, high-reliability status detection circuit module 6, single-module IGBT gate drive protection circuit 7. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1

[0027] like Figure 1-5 As shown, an embodiment of the present invention is: a current sharing system suitable for high-voltage SVG high-power multi-IGBT parallel connection, including more than one IGBT gate adapter board module 1 capable of realizing multiple IGBTs in parallel; the IGBT gate adapter board module 1 is used to weld multiple parallel IGBTs and a high-voltage SVG drive control board 2 connected to the IGBT gate adapter board module 1, and the following components are arranged in each IGBT gate adapter board module 1:

[0028] A high-power single-channel gate direct drive output circuit module 3 for directly outputting a single high-power drive signal to the IGBT gate adapter board module 1;

[0029] A gate high voltage clamping protection circuit module 4 is used to protect the IGBT switch control when multiple high-power IGBT modules are connected in parallel and when a fault or IGBT abnormality occurs;

[0030] High current sharing coefficient emitter voltage sharing control circuit module 5 for improving the robustness of the IGBT gate drive circuit and reducing the discreteness caused by parallel connection of multiple IGBT modules;

[0031] A high reliability state detection circuit module 6 is used to reduce false alarms of short-circuit faults of multiple IGBT modules in parallel under high-power strong magnetic field interference.

[0032] Preferably, the gate high-voltage clamping protection circuit module 4 includes more than one single-module IGBT gate drive protection circuit 7, and the high-current-sharing coefficient emitter voltage-sharing control circuit module 5 is electrically connected to the high-reliability state detection circuit module 6, the gate high-voltage clamping protection circuit module 4 and the high-power single-channel gate direct drive output circuit module 3.

[0033] Preferably, the single-module IGBT gate drive protection circuit 7 is connected to a corresponding IGBT, and the single-module IGBT gate drive protection circuit 7 includes a first diode D1 and a second diode D2, a bidirectional voltage regulator D4, a first capacitor C1, a seventh resistor R7, and a third diode D3 connected in series with each other. The bidirectional voltage regulator D4, the first capacitor C1, and the seventh resistor R7 are connected in parallel between the E pin and the G pin of the corresponding IGBT, and the E pin of the IGBT is connected to the high-voltage SVG drive control board 2 through a sixth resistor R6 and a fifth resistor R5 connected in parallel, and the G pin of the IGBT is connected to the high-voltage SVG drive control board 2 through a sixth resistor R6 and a fifth resistor R5 connected in parallel. The first resistor R1 and the second resistor R2 are connected to a pin of the high-voltage SVG drive control board 2, and the G pin of the IGBT is also connected to another pin of the high-voltage SVG drive control board 2 through the third resistor R3 and the fourth resistor R4 connected in parallel, the G pin of the IGBT is also connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the high-voltage SVG drive control board 2, the cathode of the first diode D1 is connected to the anode of the second diode D2, and the anode of the first diode D1 is connected to the high-voltage SVG drive control board 2, and the cathode of the second diode D2 is connected to the C pin of the corresponding IGBT.

[0034] Preferably, the high-reliability state detection circuit module 6 includes a transient diode, a comparator and a peripheral circuit. The positive electrode of the transient diode is connected to the 6th pin of the comparator. The flip level of the comparator is increased by adjusting the voltage regulation value of the transient diode, thereby improving the reliability and timeliness of the IGBT working state detection and realizing reliable operation of the system in harsh environments with large current and strong magnetic field.

[0035] The function of the high-power single-channel gate direct drive output circuit module described in this embodiment is: the control board directly outputs a single high-power drive signal to the IGBT module, which reduces the risk of interference from the drive line compared to the control board outputting multiple signals to the IGBT module. When the number of IGBTs is greater than 3 in parallel, a single drive line has obvious advantages in production wiring.

[0036] The function of the gate high voltage clamping protection circuit module is: when multiple high-power IGBT modules are connected in parallel, when a fault or IGBT abnormality occurs, the gate voltage tends to rise to an extremely high voltage, and is connected to the VCC terminal through the D3 clamping diode to provide a stable potential for reliable switch control;

[0037] The function of the IGBT gate adapter board module 1 that can achieve fast and efficient parallel connection is: when multiple IGBT modules are connected in parallel, it is necessary to weld the gate adapter board and apply thermal grease on the bottom of the IGBT. This adapter board is welded separately on an independent IGBT module, and is connected to the adjacent IGBT module through the transfer terminal designed on the adapter board, which can easily, quickly and accurately achieve parallel connection of multiple IGBT modules. Compared with the method of welding multiple IGBTs to a whole large gate adapter board, this solution has better electrical characteristics and convenient production operation;

[0038] The function of the high current sharing coefficient emitter voltage sharing control circuit module 5 is to improve the robustness of the IGBT gate drive circuit through the parallel resistors R5 and R6, reduce the discreteness caused by the parallel connection of multiple IGBT modules, and improve the consistency of the current sharing of multiple high-power IGBTs in parallel;

[0039] The function of the high reliability state detection circuit module 6 is to reduce the switching characteristics and consistency of multiple high power IGBTs in parallel, to reduce the false alarm of short circuit fault of multiple IGBT modules in parallel under high power strong magnetic field interference, to increase the threshold voltage of the fault detection circuit, and to improve the stability of the system.

[0040] The high-voltage SVG drive control board 2 in the present invention outputs a single high-power drive signal to the IGBT gate adapter board, and connects adjacent IGBTs safely, reliably and quickly through the adapter board transfer terminal to achieve multi-module parallel connection; the high reliability and current sharing consistency of the IGBT multi-module parallel connection are achieved through the circulating current suppression circuit and the gate voltage protection circuit; the system is reliable in the harsh environment of high current and strong magnetic field through the high-reliability state detection circuit. The high-voltage SVG drive control board 2 outputs a single-strand 5-core twisted pair high-power drive signal to the IGBT gate adapter board, and the wiring is safe, convenient and concise from the control board to the gate adapter board, reducing the probability of electromagnetic interference. The drive signal is directly sent to the independent gate drive protection circuit to improve the current sharing consistency of the IGBT multi-module parallel connection.

[0041] Through the adapter board transfer terminal, the adjacent IGBTs can be connected safely, reliably and quickly. Figure 1 As shown, the No. 1 terminal of the 3# adapter board is connected to the output control line of the driver board, the No. 2 terminal is connected to the No. 3 terminal of the 1# adapter board through a short cable, the No. 3 terminal is connected to the No. 3 terminal of the 4# adapter board through a short cable, and so on. It can flexibly and conveniently realize engineering applications such as single IGBT silicone grease application, module crimping, gate adapter board welding, and multi-module parallel connection;

[0042] pass Figure 3 The D3 gate voltage protection diode clamps the IGBT gate voltage at the VCC power supply amplitude, so that the IGBT can be reliably shut down under abnormal conditions to protect the safety of the equipment.

[0043] The fifth resistor R5, the sixth resistor R6, the ring current suppression resistor and the gate circuit are used to realize the high reliability and current sharing consistency of multiple IGBT modules in parallel. Later, the external parameters are adjusted to make the switching characteristics consistent when multiple modules are connected in parallel, thereby improving the current sharing consistency of multiple IGBT modules in parallel.

[0044] pass Figure 4 The circuit realizes that the 2nd pin of the TVS tube is connected to the 6th pin of the comparator. By adjusting the voltage regulation value of the TVS, the flip level of the comparator is increased, thereby improving the reliability and timeliness of the IGBT working state detection, and realizing the reliable operation of the system in the harsh environment of large current and strong magnetic field. The protection value voltage can be set to the highest supply voltage, which is much higher than the threshold comparison voltage provided by the driver chip.

[0045] It should be noted in this application that the high-voltage SVG drive control board 2 and the method of obtaining data belong to conventional technologies in this field, so they are not described in detail. In addition, the circuit structures and models involved in the IGBT gate adapter board module 1, high-voltage SVG drive control board 2, high-power single-channel gate direct drive output circuit module 3, gate high-voltage clamping protection circuit module 4, high-current-sharing coefficient emitter voltage-sharing control circuit module 5, high-reliability state detection circuit module 6, and single-module IGBT gate drive protection circuit 7 all belong to conventional technologies in this field, so they are not described in detail.

Claims

1. A current sharing system suitable for high-voltage SVG high-power multi-IGBT parallel connection, characterized by: The invention comprises one or more IGBT gate adapter board modules (1) capable of realizing parallel connection of multiple IGBTs; the IGBT gate adapter board module (1) is used for welding multiple parallel-connected IGBTs and a high-voltage SVG drive control board (2) connected to the IGBT gate adapter board module (1); the following components are arranged in each IGBT gate adapter board module (1): A high-power single-channel gate direct drive output circuit module (3) for directly outputting a single high-power drive signal to an IGBT gate adapter board module (1); A gate high voltage clamping protection circuit module (4) for protecting the IGBT switch control when multiple high-power IGBT modules are connected in parallel and when a fault or IGBT abnormality occurs; A high current sharing coefficient emitter voltage sharing control circuit module (5) for improving the robustness of the IGBT gate drive circuit and reducing the discreteness caused by parallel connection of multiple IGBT modules; A high reliability state detection circuit module (6) is used to reduce false alarms of short-circuit faults of multiple IGBT modules in parallel under high power and strong magnetic field interference, wherein the high current sharing coefficient emitter voltage sharing control circuit module (5) is electrically connected to the high reliability state detection circuit module (6), the gate high voltage clamping protection circuit module (4) and the high power single channel gate direct drive output circuit module (3); The gate high voltage clamping protection circuit module (4) comprises more than one single-module IGBT gate drive protection circuit (7); The single-module IGBT gate drive protection circuit (7) is connected to a corresponding IGBT, and the single-module IGBT gate drive protection circuit (7) comprises a first diode (D1) and a second diode (D2), a bidirectional voltage regulator (D4), a first capacitor (C1), a seventh resistor (R7), and a third diode (D3) which are connected in series with each other, the bidirectional voltage regulator (D4), the first capacitor (C1), and the seventh resistor (R7) being connected in parallel between the E pin and the G pin of the corresponding IGBT, and the E pin of the IGBT is connected to the high-voltage SVG drive control board (2) through the sixth resistor (R6) and the fifth resistor (R5) connected in parallel, and the G pin of the IGBT is connected to the high-voltage SVG drive control board (2) through the first The resistor (R1) and the second resistor (R2) are connected to a pin of the high-voltage SVG drive control board (2), and the G pin of the IGBT is also connected to another pin of the high-voltage SVG drive control board (2) through a third resistor (R3) and a fourth resistor (R4) connected in parallel, the G pin of the IGBT is also connected to the positive electrode of the third diode (D3), the negative electrode of the third diode (D3) is connected to the high-voltage SVG drive control board (2), the negative electrode of the first diode (D1) is connected to the positive electrode of the second diode (D2), and the positive electrode of the first diode (D1) is connected to the high-voltage SVG drive control board (2), and the negative electrode of the second diode (D2) is connected to the C pin of the corresponding IGBT; The high-reliability state detection circuit module (6) comprises a transient diode, a comparator and a peripheral circuit, wherein the positive electrode of the transient diode is connected to the 6th pin of the comparator, and the flip level of the comparator is increased by adjusting the voltage stabilization value of the transient diode, thereby improving the reliability and timeliness of the IGBT working state detection, and realizing reliable operation of the system in a harsh environment with high current and strong magnetic field; The high-voltage SVG drive control board (2) outputs a single high-power drive signal to the IGBT gate adapter board. Through the adapter board transfer terminal, adjacent IGBTs are connected safely, reliably and quickly to achieve multi-module parallel connection. The high reliability and current sharing consistency of the IGBT multi-module parallel connection are achieved through the circulating current suppression circuit and the gate voltage protection circuit. The system can operate reliably in a harsh environment with high current and strong magnetic field through the high-reliability state detection circuit. The high-voltage SVG drive control board (2) outputs a single-strand 5-core twisted pair high-power drive signal to the IGBT gate adapter board. The wiring is safe, convenient and concise from the control board to the gate adapter board, reducing the probability of electromagnetic interference series entry. The drive signal is directly sent to the independent gate drive protection circuit, thereby improving the current sharing consistency of the IGBT multi-module parallel connection.

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