A High-Voltage-Level IGBT Identification, Screening, and Gate Protection System

Abstract

An embodiment of the present invention discloses a high-voltage-level IGBT identification and screening and gate protection system, which includes: an IGBT identification and screening unit, a gate signal monitoring unit, a gate energy release unit, a main control unit, and a fault information recording unit; the IGBT identification and screening unit can collect the gate feedback signal of the IGBT device under the action of the IGBT drive signal and generate an IGBT identification and screening signal; the gate signal monitoring unit can compare the gate drive signal with a preset second reference potential, third reference potential, and fourth reference potential respectively, and obtain corresponding gate drive signal monitoring and evaluation information; the gate energy release unit can stop the power supply for maintaining the turn-on level when the main control unit determines that the turn-on level of the gate drive signal exceeds a preset value, etc. The present invention can be constructed into a multi-level protection system, improving the reliability of the IGBT driver; at the same time, it is equipped with a fault information recording function, increasing the practicality of the IGBT driver.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a high-voltage IGBT identification and screening and gate protection system. Background Art

[0002] The protection system of modern IGBT drivers mainly makes protection actions based on specific information generated after the occurrence of IGBT failure faults. For example, overcurrent protection, which is the fastest and most effective protection function among all protection system functions, and the protection completion time can reach about 9 us. Although the protection action has been carried out within an extremely short time period, the short-circuit current under high voltage conditions has also risen to a very large range. Then there is a possibility that the bonding wire tying point part inside the IGBT melts, which will lead to the existence of potential safety hazards. When a short-circuit fault comes again, there is a high probability that an IGBT failure fault will occur. Therefore, the protection system relying on the IGBT failure is already the last level of protection for the driver.

[0003] Moreover, the previous protection systems for IGBT drivers mainly focused on desaturation protection, protection, dynamic active clamping protection, etc. These protection measures perform protection actions when an IGBT failure fault occurs, but there is a risk of mild damage to the IGBT during the protection process under high voltage, thus leaving potential safety hazards.

[0004] After investigation by the applicant, it is found that the main cause of IGBT failure accidents comes from problems with the gate drive signal. To achieve the purpose of IGBT driver protection and reduce the existence of potential safety hazards, it is crucial to add a protection system related to the gate drive signal. Therefore, it is necessary to develop a protection system that can effectively solve IGBT failure accidents caused by gate drive problems. Summary of the Invention

[0005] Based on this, to solve the deficiencies of the prior art, a high-voltage IGBT identification and screening and gate protection system is specifically proposed.

[0006] A high-voltage IGBT identification and screening and gate protection system, characterized in that it includes: an IGBT identification and screening unit, a gate signal monitoring unit, a gate energy release unit, a main control unit, and a fault information recording unit;

[0007] Among them, the IGBT identification and screening unit is electrically connected to the IGBT device and the main control unit respectively. The IGBT identification and screening unit can collect the gate feedback signal of the IGBT device under the action of the IGBT drive signal, compare it with a preset first reference potential, and then generate an IGBT identification and screening signal; the gate signal monitoring unit is electrically connected to the IGBT device and the main control unit respectively. The gate signal monitoring unit can compare the gate drive signal with a preset second reference potential, a preset third reference potential, and a preset fourth reference potential respectively, and obtain corresponding gate drive signal monitoring and evaluation information; the gate energy release unit is electrically connected to the IGBT device and the main control unit respectively. When the main control unit determines that the turn-on level of the gate drive signal exceeds a preset value, the gate energy release unit can stop the power supply for maintaining the turn-on level and use the energy release circuit to accelerate the release of the turn-on level energy, so as to ensure the reliable turn-off of the IGBT.

[0008] Optionally, in one embodiment, the IGBT identification and screening unit includes an IGBT identification and screening subunit, a first reference potential subunit, and a gate feedback subunit; among them, the gate feedback subunit is electrically connected to the gate of the IGBT device, and the gate feedback subunit can collect the gate feedback signal of the IGBT device under the action of the IGBT drive signal; the positive feedback input terminal of the IGBT identification and screening subunit is electrically connected to the gate feedback subunit, its negative feedback input terminal is electrically connected to the first reference potential subunit, and its output terminal is electrically connected to the main control unit. It can compare the gate feedback signal with the first reference potential preset in the first reference potential subunit through the first reference potential subunit, and generate an IGBT identification and screening signal.

[0009] Optionally, in one embodiment, the gate signal monitoring unit includes: a drive signal processing subunit, a second reference potential output and comparison subunit, a third reference potential output and comparison subunit, and a fourth reference potential output and comparison subunit; wherein, the drive signal processing subunit is electrically connected to the IGBT device and the main control unit respectively, and the drive signal processing subunit can perform scaling processing on the IGBT drive signal; the second reference potential output and comparison subunit is electrically connected to the main control unit, and the second reference potential output and comparison subunit can obtain the data output after comparing the processed gate drive signal with the second reference potential via a comparator, and determine whether the actual output time amount of the gate drive signal meets the preset value. The third reference potential output and comparison subunit is electrically connected to the main control unit, and the third reference potential output and comparison subunit can obtain the data output after comparing the processed gate drive signal with the third reference potential via a comparator, and determine whether the actual output amplitude amount of the gate drive signal meets the preset value. The fourth reference potential output and comparison subunit is electrically connected to the main control unit, and the fourth reference potential output and comparison subunit can obtain the data output after comparing the processed gate drive signal with the fourth reference potential via a comparator, and determine whether the actual maximum output amplitude of the gate drive signal meets the preset value. Exceeding the maximum amplitude preset value is likely to cause gate breakdown; thereby obtaining the corresponding gate drive signal monitoring and evaluation information.

[0010] Optionally, in one embodiment, the gate energy release unit includes a gate energy release circuit, and the gate energy release circuit includes: a first circuit, a second circuit, and a third circuit. Among them, the first circuit includes: a first capacitor CA3 and a seventh resistor RA30. One side of the first capacitor CA3 is connected to the gate of the IGBT device, and the other side is connected to the seventh resistor RA30; the seventh resistor RA30 is connected to the positive power supply side; the second circuit includes: a second capacitor CA5 and an eighth resistor RA40. One side of the second capacitor CA5 is connected to the gate of the IGBT device, and the other side is connected to the eighth resistor RA40; the eighth resistor RA40 is connected to the negative power supply side; the third circuit includes: a bidirectional transient suppression diode D2, a diode D1, a first MOS transistor Q3, a second MOS transistor Q4, a transient diode Q5, a ninth resistor RA31, a tenth resistor RA34, an eleventh resistor RA41, a third capacitor CA4, and a first electronic component Q2; one side of the bidirectional transient suppression diode D2 is connected to the gate of the IGBT device, and the other side is connected to the source of the second MOS transistor Q4; one side of the diode D1 is connected to the gate of the IGBT device, and the other side is connected to the drain of the first MOS transistor Q3; the gate of the first MOS transistor Q3 is connected to the drain of the second MOS transistor Q4, and two reverse-connected zener diodes are provided between the drain and the source of the first MOS transistor Q3; one side of the transient diode Q5 is connected to the gate of the first MOS transistor Q3, and the other side is grounded; one side of the first electronic component Q2 is connected to the tenth resistor RA34 via the ninth resistor RA31, and the other side of the first electronic component Q2 is connected to the tenth resistor RA34 via the third capacitor CA4; the tenth resistor RA34 is connected to the drain of the second MOS transistor Q4; one side of the eleventh resistor RA41 is connected to the gate of the second MOS transistor Q4, and the other side is grounded.

[0011] Optionally, in one embodiment, the fault information recording unit includes a fault storage sub-unit, an optical fiber communication sub-unit, a communication configuration sub-unit, and a program storage sub-unit; among them, the fault storage sub-unit is electrically connected to the main control unit, and the fault storage sub-unit can store the fault information of the IGBT device. The fault information at least includes the fault occurrence time, the fault elimination time, and the state of the comparison and judgment variable bits at the time of fault occurrence; the optical fiber communication sub-unit is respectively electrically connected to the main control unit and the communication configuration sub-unit, and the optical fiber communication sub-unit can provide an optical fiber interface and its matching circuit; the communication configuration sub-unit is respectively electrically connected to the main control unit, the optical fiber communication sub-unit, and the program storage sub-unit, and the communication configuration sub-unit can provide the main control unit control file and the optical fiber communication file for the main control unit to call; the program storage sub-unit is electrically connected to the communication configuration sub-unit, and the program storage sub-unit can store the program files applied in the main control unit.

[0012] Implementing the embodiments of the present invention will have the following beneficial effects:

[0013] The present invention aims to address and control the factors that trigger IGBT failure accidents. Meanwhile, in combination with the currently mature passive protection system after IGBT failure accidents, a multi-level protection system is constructed, enhancing the reliability of the IGBT driver. At the same time, a fault information recording function is equipped, facilitating the cause analysis after IGBT failure faults and increasing the practicality of the IGBT driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0015] Among them:

[0016] Figure 1 is the input-output relationship diagram between the novel IGBT driver and external devices in an embodiment;

[0017] Figure 2 is the circuit design framework diagram of the system in an embodiment;

[0018] Figure 3 is the schematic diagram of the parasitic capacitance principle of the IGBT device in an embodiment;

[0019] Figure 4 is the schematic diagram of the signal comparison and recognition principle of the IGBT identification and screening unit in an embodiment;

[0020] Figure 5 is the circuit schematic diagram of the IGBT identification and screening unit in an embodiment;

[0021] Figure 6 is the schematic diagram of the comparison and recognition principle of gate monitoring signal 1 of the gate signal monitoring unit in an embodiment;

[0022] Figure 7 is the schematic diagram of the comparison and recognition principle of gate monitoring signal 2 of the gate signal monitoring unit in an embodiment;

[0023] Figure 8 is the schematic diagram of the comparison and recognition principle of gate monitoring signal 3 of the gate signal monitoring unit in an embodiment;

[0024] Figure 9 is the circuit schematic diagram of the gate signal monitoring unit in an embodiment;

[0025] Figure 10 is the circuit schematic diagram of the gate energy release unit in an embodiment;

[0026] Figure 11 is the circuit schematic diagram of the fault information recording unit in an embodiment;

[0027] Figure 12 is the specific circuit design diagram of the system in an embodiment;

[0028] In the figure, A, reference potential 1, B, 0 V, C, IGBT identification and screening signal, D, reference potential 2, E, reference potential 3, F, reference potential 4, W1, gate monitoring signal 1, W2, gate monitoring signal 2, W3, gate monitoring signal 3. Detailed implementation

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. It can be understood that the terms "first", "second", etc. used in the present invention can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first element can be called the second element, and similarly, the second element can be called the first element. Both the first element and the second element are elements, but they are not the same element.

[0031] In this embodiment, a high-voltage level IGBT identification and screening and gate protection system, namely a new IGBT driver, is specifically proposed. This system is applied to the new driver of the high-power semiconductor device IGBT, and it can be compatible with the existing protection system. It is particularly suitable for the IGBT identification and screening and gate protection technology of IGBT drivers under high voltage levels (above 4500 V), such as Figure 1-2 As shown, this system is electrically connected to the IGBT device and communicates with the drive master unit / host computer via optical fiber;

[0032] Specifically, the high-voltage level IGBT identification and screening and gate protection system is characterized by including: an IGBT identification and screening unit, a master control unit, a gate signal monitoring unit, a gate energy release unit, and a fault information recording unit;

[0033] Among them, since the main function of the gate drive signal is to turn on or off the IGBT device, for IGBTs from different manufacturers, with different models, and different arrangements, the specific details of the gate drive signal vary greatly. To ensure the uniqueness of the gate drive signal corresponding to the IGBT under different circumstances, an IGBT identification and screening unit with an IGBT identification and screening function is designed. In one embodiment, the IGBT identification and screening unit is electrically connected to the IGBT device and the main control unit respectively, so as to use the parasitic capacitance contained in the IGBT device itself to discriminate the IGBT device. The internal parasitic capacitance structure of the IGBT device is as Figure 3 shown. Its gate capacitance Cge is composed of the input capacitance Cies and the feedback capacitance Cres, and for different IGBTs under different circumstances, the gate capacitance value is also different. In view of this, an IGBT identification and screening unit is designed. This IGBT identification and screening unit can collect the gate feedback signal of the IGBT device under the action of the IGBT drive signal and generate an IGBT identification and screening signal after comparing it with a preset first reference potential. Specifically, when the IGBT driver is powered on and gives a certain IGBT drive signal, this signal instantaneously emits a narrow pulse to briefly charge and discharge the gate capacitance Cge of the IGBT device. According to the gate feedback circuit, that is, the gate feedback sub-unit, the feedback curve waveform signal is sent to the input side of the IGBT identification and screening sub-unit (such as a comparator), and the IGBT identification and screening signal generated after comparing with the set reference potential 1 (given by the reference potential sub-unit) value through the IGBT identification and screening sub-unit. Subsequently, its duration is compared with the preset first reference potential value. If the requirements are met, it can continue to output so that when a specific model of IGBT (that is, meeting the requirements) is determined through this unit, the IGBT can be driven to work, and when it is determined to be an IGBT of other models, it stops working. The principle is as Figure 4 shown; this function can avoid misoperations caused by replacing similar model IGBTs and prevent events such as incorrect installation positions of IGBT drivers. Preferably, different models of IGBTs correspond to different matching reference potentials, which can be specifically adjusted by the main control unit.

[0034] Based on the above design points, a corresponding circuit design example is that the IGBT identification and screening unit includes an IGBT identification and screening subunit, a first reference potential subunit, and a gate feedback subunit; wherein, the gate feedback subunit is electrically connected to the gate of the IGBT device, and the gate feedback subunit can collect the gate feedback signal of the IGBT device under the action of the IGBT drive signal; the positive feedback input terminal of the IGBT identification and screening subunit is electrically connected to the gate feedback subunit, its negative feedback input terminal is electrically connected to the first reference potential subunit, and its output terminal is electrically connected to the main control unit, and it can compare the gate feedback signal with the first reference potential preset in the first reference potential subunit through the first reference potential subunit, and generate an IGBT identification and screening signal. Specifically, its circuit design Figure 5 As shown, the gate feedback subunit includes: a first resistor RA19, a first resistor RA20, and a first resistor RA21; the IGBT identification and screening subunit includes a comparator U12B. Based on this, it can be known that the IGBT identification and screening function of this case can realize the judgment of the specific model of the IGBT. After the preset value in the application program is determined, there is one and only one IGBT that can operate normally. Replacing the IGBT with other signals will stop working.

[0035] Among them, since it is also necessary to monitor whether the drive signal issued by the IGBT driver is normal, stable and continuous output, a gate signal monitoring unit is designed. Specifically, the gate signal monitoring unit is electrically connected to the IGBT device and the main control unit respectively. The gate signal monitoring unit can obtain the corresponding gate drive signal monitoring and evaluation information after comparing the gate drive signal with the preset second reference potential, third reference potential and fourth reference potential respectively; the gate signal monitoring unit includes: a drive signal processing subunit, a second reference potential output and comparison subunit, a third reference potential output and comparison subunit, and a fourth reference potential output and comparison subunit; wherein, the drive signal processing subunit is electrically connected to the IGBT device and the main control unit respectively, and the drive signal processing subunit can perform scaling processing on the IGBT drive signal; the second / third / fourth reference potential output and comparison subunit is electrically connected to the main control unit, and the second / third / fourth reference potential output and comparison subunit can output the preset second / third / fourth reference potential, and compare it with the processed drive signal respectively to obtain the corresponding gate drive signal monitoring and evaluation information; the function of the second / third / fourth reference potential output and comparison subunit is to generate the required reference potential for protecting the entire system, that is, the square wave signal with a fixed frequency and different duty cycles issued by the main control unit. After being scaled by the second / third / fourth reference potential output and comparison subunit, a DC reference potential is output here, and different amplitude reference potentials can be obtained by changing the duty cycle ratio in the later stage, such as, such as Figures 6 to 8 As shown in the reference potential, among which, Figure 6The second reference potential, i.e., reference potential 2 therein, is used to compare the gate drive signal with reference potential 2 to obtain the gate monitoring signal 1 and determine whether the data output by the comparator conforms to the preset value of the actual output time quantity of the gate drive signal. Among them, Figure 7 The third reference potential, i.e., reference potential 3 therein, is used to compare the gate drive signal with reference potential 3 to obtain the gate monitoring signal 2 and determine whether the data output by the comparator conforms to the preset value of the actual output amplitude quantity of the gate drive signal. Among them, Figure 8 The fourth reference potential, i.e., reference potential 4 therein, is used to compare the gate drive signal with reference potential 4 to obtain the gate monitoring signal 3 and determine whether the data output by the comparator conforms to the preset value of the actual maximum output amplitude of the gate drive signal, so as to prevent the gate breakdown problem caused by exceeding the maximum amplitude preset value. Based on this, the output signal state is comprehensively evaluated to achieve the purpose of monitoring the gate drive signal. Preferably, as Figure 9 shown, the drive signal processing sub-unit at least includes: the fourth resistor RA26, the fifth resistor RA27, and the sixth resistor RA28 as the buffer high amplitude, or a RC filter is further connected for filtering processing; the second / third / fourth reference potential output and comparison sub-units each include comparators U12A, U12C, and U12D. Based on this, the gate signal monitoring function of this case can achieve long-term stable operation under normal gate drive waveform applications. When simulating a fault waveform to test this function, the driver can stop working at a response speed of the order of microseconds. In addition, Figure 2 the second / third / fourth reference potential output and comparison sub-units and the first reference potential sub-unit in it are combined into a reference potential unit for identification.

[0036] Among them, since the gate drive signal is usually composed of an on level, an off level, and an edge level, the gate energy release unit is set to implement the gate energy release function (that is, when it is determined that the gate on level does not conform to the preset value for operation, it prevents the remaining energy of the on level from continuously acting on the IGBT to accelerate the energy release speed of the on level).

[0037] The gate energy release unit is electrically connected to the IGBT device and the main control unit respectively. When the main control unit determines that the turn-on level of the gate drive signal exceeds a preset value, the gate energy release unit can stop the power supply for maintaining the turn-on level. Specifically, the gate energy release unit includes a gate energy release circuit, and the gate energy release circuit includes: a first circuit, a second circuit, and a third circuit. Among them, the first circuit includes: a first capacitor CA3 and a seventh resistor RA30. One side of the first capacitor CA3 is connected to the gate of the IGBT device, and the other side is connected to the seventh resistor RA30; the seventh resistor RA30 is connected to the positive power supply side; the second circuit includes: a second capacitor CA5 and an eighth resistor RA40. One side of the second capacitor CA5 is connected to the gate of the IGBT device, and the other side is connected to the eighth resistor RA40; the eighth resistor RA40 is connected to the negative power supply side; the third circuit includes: a bidirectional transient suppression diode D2, a diode D1, a first MOS transistor Q3, a second MOS transistor Q4, a transient diode Q5, a ninth resistor RA31, a tenth resistor RA34, an eleventh resistor RA41, a third capacitor CA4, and a first electronic device Q2 (to ensure that the current always flows from the anode to the cathode); one side of the bidirectional transient suppression diode D2 is connected to the gate of the IGBT device, and the other side is connected to the source of the second MOS transistor Q4; one side of the diode D1 is connected to the gate of the IGBT device, and the other side is connected to the drain of the first MOS transistor Q3; the gate of the first MOS transistor Q3 is connected to the drain of the second MOS transistor Q4, and two back-to-back zener diodes (bidirectional voltage regulation) are arranged between the drain and the source of the first MOS transistor Q3; one side of the transient diode Q5 is connected to the gate of the first MOS transistor Q3, and the other side is grounded; one side of the first electronic device Q2 is connected to the tenth resistor RA34 via the ninth resistor RA31, and the other side of the first electronic device Q2 is connected to the tenth resistor RA34 via the third capacitor CA4; the tenth resistor RA34 is connected to the drain of the second MOS transistor Q4; one side of the eleventh resistor RA41 is connected to the gate of the second MOS transistor Q4, and the other side is grounded. Based on the above designed circuit, as Figure 10 shown, when the main control unit determines that the turn-on signal of the gate drive signal does not meet the preset value, it stops the power supply for maintaining the turn-on level, and at the same time actively issues an energy release signal, uses the energy release circuit to accelerate the attenuation of the turn-on level, and finally reaches the turn-off level value to reliably block. Based on this, it can be known that the gate energy release function of this case also operates stably for a long time under the application of a normal gate drive waveform.

[0038] Among them, a fault information recording unit is also provided in this case to complete the fault information recording function, which mainly means starting from the moment when the IGBT fault occurs, recording the relevant variables of the gate drive signal and the working states of various protection functions within a certain period of time; therefore, the fault information recording unit includes a fault storage sub-unit, an optical fiber communication sub-unit, a communication configuration sub-unit, and a program storage sub-unit; among them, the fault storage sub-unit is electrically connected to the main control unit respectively, and this fault storage sub-unit can store the fault information of the IGBT device, and the fault information at least includes the fault occurrence time, the fault elimination time, and the state of the comparison and judgment variable bits at the time of fault occurrence; the optical fiber communication sub-unit is electrically connected to the main control unit and the communication configuration sub-unit respectively, and this optical fiber communication sub-unit can provide an optical fiber interface and its matching circuit; the communication configuration sub-unit is electrically connected to the main control unit, the optical fiber communication sub-unit, and the program storage sub-unit respectively, and this communication configuration sub-unit can provide the main control unit control file and the optical fiber communication file for the main control unit to call; the program storage sub-unit is electrically connected to the communication configuration sub-unit, and this program storage sub-unit can store the program files applied in the main control unit. For the specific circuit design, please refer to Figure 11, both the fault storage subunit and the program storage subunit use FLASH devices. One is used to record the fault occurrence time and the fault elimination time, and the other is used to store the program file downloaded by the main control unit, i.e., the FPGA. The specific process of recording fault information is as follows: The host computer - CPU sends an instruction to erase the fault storage subunit through this FPGA. When a fault occurs, after the FPGA actively identifies the fault signal, it writes the current fault occurrence time and the fault elimination time into the fault storage subunit, and cooperates with the CPU to complete a complete process of recording and reading fault information. At the same time, in this case, recording the relevant variables of the gate drive signal and the working status of each protection function within a certain period of time means that when a fault occurs, the corresponding units in the driver (IGBT identification and screening unit, gate signal monitoring unit, gate energy release unit, fault information recording unit) perform action protection. At this time, the main control unit caches the relevant variables of the gate drive signal generated in the current state and the working status of all protection functions, and keeps recording for a period of time. As long as the recording time is reached, the data is loaded into the fault information recording unit. After the fault data is loaded, regardless of whether it is in a fault state, no recording is performed within a buffer time, and the next recording of fault data can be performed after the buffer time. At the same time, the fault data downloaded by the host computer first passes through the optical fiber communication subunit. Since the optical fiber input side is connected to the communication configuration subunit, after the communication configuration subunit receives the command request for downloading fault data, it reads the internal data of the fault storage subunit through the main control unit. One of the purposes of setting the program storage subunit is to ensure the possibility of updating or optimizing the driver application program after a fault occurs. To facilitate the operation of the whole process, for example, when downloading the application program of this driver by optical fiber, after the communication configuration subunit receives the application program download command sent by the host computer, it downloads the application program to the program storage subunit. After the driver is powered on again, the application program is loaded into the main control unit through the communication configuration subunit. In this case, the fault information recording function realizes the collection and recording of information during the fault period, which has important reference value for problem analysis after an accident or performance improvement in product upgrading and replacement. At the same time, the optical fiber communication method is also used to read fault data and download application programs, making the operation more flexible and convenient.

[0039] Among them, the master control unit uses a programmable logic control chip, namely an FPGA chip, as the center of this driver, and sets a certain fault recognition mechanism. For example, within a certain period of time after a fault occurs, it judges whether a software reset has been performed and the reset has been lifted. Otherwise, it powers off and restarts itself and notifies the CPU to send a fault reading instruction. At the same time, the FPGA reads the fault occurrence time and the fault recovery time from the fault storage subunit and uploads them to the CPU data through the bus. Subsequently, the CPU sends an erase instruction again to erase the fault information in the fault storage subunit, thereby realizing a complete process of recording and reading fault information. Therefore, it can be said that this case focuses on preventing problems, discovering problems, and solving problems at the source, forming a new protection measure, comprehensively improving the safety of the IGBT driver and enhancing the reliability of the IGBT driver.

[0040] Based on the above design scheme, as Figure 12 shown, a more specific circuit design scheme is given. It combines with the design of this system to complete a new type of 4500V IGBT driver, which is used to drive the IGBT with 4500V and 1200A in the converter module. Through the performance test of this design, it is found that: it can only be applied to a specified type of IGBT. When other types of IGBTs are replaced, the driver stops working; when simulating the abnormal working state of the drive conduction level, the instrument measurement shows that the conduction level will not exceed +18V, reducing the probability of gate breakdown; the failure rate of the converter module of the IGBT driver after installing this case decreases. At the same time, after a fault, the fault information can be downloaded, directly understanding the root cause of the problem. When changing and optimizing the program, it is convenient and fast, not only saving the time for querying problems, but also improving the overall work efficiency. Therefore, by adding the IGBT driver with the above IGBT identification and screening and gate protection system, the safety and reliability of the product operation at high voltage levels are improved, and the failure rate of the IGBT driver is also reduced.

[0041] The above embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A high-voltage-level IGBT identification and screening and gate protection system, characterized in that, Including: IGBT identification and screening unit, gate signal monitoring unit, gate energy release unit, main control unit, fault information recording unit; Among them, the IGBT identification and screening unit is electrically connected to the IGBT device and the main control unit respectively. The IGBT identification and screening unit can collect the gate feedback signal of the IGBT device under the action of the IGBT drive signal, compare it with a preset first reference potential, and generate an IGBT identification and screening signal; the gate signal monitoring unit is electrically connected to the IGBT device and the main control unit respectively. The gate signal monitoring unit can compare the gate drive signal with a preset second reference potential, a preset third reference potential, and a preset fourth reference potential respectively, and obtain corresponding gate drive signal monitoring and evaluation information; the gate energy release unit is electrically connected to the IGBT device and the main control unit respectively. When the main control unit determines that the turn-on level of the gate drive signal exceeds a preset value, the gate energy release unit can stop the power supply for maintaining the turn-on level and use the energy release circuit to accelerate the release of the turn-on level energy; The gate signal monitoring unit includes: a drive signal processing sub-unit, a second reference potential output and comparison sub-unit, a third reference potential output and comparison sub-unit, and a fourth reference potential output and comparison sub-unit; wherein, the drive signal processing sub-unit is electrically connected to the IGBT device and the main control unit respectively, and the drive signal processing sub-unit can perform scaling processing on the IGBT drive signal; the second reference potential output and comparison sub-unit is electrically connected to the main control unit, and the second reference potential output and comparison sub-unit can obtain the data output after comparing the processed gate drive signal with the second reference potential through a comparator, and determine whether the actual output time amount of the gate drive signal meets the preset value. The third reference potential output and comparison sub-unit is electrically connected to the main control unit, and the third reference potential output and comparison sub-unit can obtain the data output after comparing the processed gate drive signal with the third reference potential through a comparator, and determine whether the actual output amplitude amount of the gate drive signal meets the preset value. The fourth reference potential output and comparison sub-unit is electrically connected to the main control unit, and the fourth reference potential output and comparison sub-unit can obtain the data output after comparing the processed gate drive signal with the fourth reference potential through a comparator, and determine whether the actual maximum output amplitude of the gate drive signal meets the preset value; the gate energy release unit includes a gate energy release circuit, and the gate energy release circuit includes: a first circuit, a second circuit, and a third circuit. Among them, the first circuit includes: a first capacitor CA3 and a seventh resistor RA30. One side of the first capacitor CA3 is connected to the gate of the IGBT device, and the other side is connected to the seventh resistor RA30; the seventh resistor RA30 is connected to the positive power supply side; the second circuit includes: a second capacitor CA5 and an eighth resistor RA40. One side of the second capacitor CA5 is connected to the gate of the IGBT device, and the other side is connected to the eighth resistor RA40; the eighth resistor RA40 is connected to the negative power supply side; the third circuit includes: a bidirectional transient suppression diode D2, a diode D1, a first MOS transistor Q3, a second MOS transistor Q4, a transient diode Q5, a ninth resistor RA31, a tenth resistor RA34, an eleventh resistor RA41, a third capacitor CA4, and a first electronic device Q2; one side of the bidirectional transient suppression diode D2 is connected to the gate of the IGBT device, and the other side is connected to the source of the second MOS transistor Q4; one side of the diode D1 is connected to the gate of the IGBT device, and the other side is connected to the drain of the first MOS transistor Q3; the gate of the first MOS transistor Q3 is connected to the drain of the second MOS transistor Q4, and two reverse-connected zener diodes are provided between the drain and the source of the first MOS transistor Q3; one side of the transient diode Q5 is connected to the gate of the first MOS transistor Q3, and the other side is grounded; one side of the first electronic device Q2 is connected to the tenth resistor RA34 through the ninth resistor RA31, and the other side of the first electronic device Q2 is connected to the tenth resistor RA34 through the third capacitor CA4;The tenth resistor RA34 is connected to the drain of the second MOS transistor Q4; one side of the eleventh resistor RA41 is connected to the gate of the second MOS transistor Q4, and the other side is grounded.

2. The system according to claim 1, wherein The IGBT identification and screening unit includes an IGBT identification and screening subunit, a first reference potential subunit, and a gate feedback subunit; among them, the gate feedback subunit is electrically connected to the gate of the IGBT device. The gate feedback subunit can collect the gate feedback signal of the IGBT device under the action of the IGBT drive signal; the positive feedback input terminal of the IGBT identification and screening subunit is electrically connected to the gate feedback subunit, its negative feedback input terminal is electrically connected to the first reference potential subunit, and its output terminal is electrically connected to the main control unit. It can compare the gate feedback signal with the first reference potential preset in the first reference potential subunit through the first reference potential subunit and generate an IGBT identification and screening signal.

3. The system according to claim 1, wherein The fault information recording unit includes a fault storage subunit, an optical fiber communication subunit, a communication configuration subunit, and a program storage subunit; among them, the fault storage subunit is electrically connected to the main control unit. The fault storage subunit can store the fault information of the IGBT device. The fault information at least includes the fault occurrence time, the fault elimination time, and the state of the comparison and judgment variable bits at the time of fault occurrence; the optical fiber communication subunit is electrically connected to the main control unit and the communication configuration subunit respectively. The optical fiber communication subunit can provide an optical fiber interface and its matching circuit; the communication configuration subunit is electrically connected to the main control unit, the optical fiber communication subunit, and the program storage subunit respectively. The communication configuration subunit can provide the main control unit control file and the optical fiber communication file for the main control unit to call; The program storage subunit is electrically connected to the communication configuration subunit. The program storage subunit can store the program files applied in the main control unit.

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