A high-power, multi-channel, protected multilevel IGBT drive circuit

Abstract

This invention discloses a high-power, multi-channel, protected, multi-level IGBT driver circuit, including a power supply circuit, an isolated power generation circuit, at least four mutually isolated IGBT driver circuits, and a fault feedback circuit. The power supply circuit includes a through-hole socket and a three-terminal voltage regulator chip; the isolated power generation circuit includes a switching power supply chip and at least two independent isolation transformers; the IGBT driver circuit includes a first logic chip and an isolation optocoupler; the fault feedback circuit includes a second logic chip and a switching diode. The second logic chip and the switching diode perform an OR operation on all level signals. When any IGBT driver circuit outputs a level signal, the fault feedback circuit outputs a fault signal and feeds it back to one pin of the through-hole socket. This invention only requires a +15V circuit to generate four completely isolated power supply circuits. This driver can directly drive a three-level IGBT module, and it has a relatively large output current and strong driving capability.

Description

Technical Field

[0001] This invention relates to the field of analog circuit technology, and more specifically to a high-power, multi-channel, protected multilevel IGBT drive circuit. Background Technology

[0002] With the rapid development of power electronics technology, insulated gate bipolar transistors (IGBTs) have been widely used due to their advantages such as high voltage, high current, ease of driving, and wide operating frequency.

[0003] IGBTs, as high-voltage, high-power transducers, possess advantages such as high input impedance, low on-state voltage drop, and relatively simple drive circuits, and have received increasing attention as high-power transducer devices. However, IGBTs are relatively expensive and operate in high-voltage, high-power environments, making them susceptible to damage. Therefore, the design of IGBT drive circuits must incorporate adequate protection functions for the IGBTs, leading to a growing emphasis on research into IGBT drive circuits.

[0004] In the use of IGBTs, IGBT protection is paramount. This is primarily because IGBT devices are relatively expensive, and IGBT damage severely impacts the normal operation of equipment. Furthermore, IGBTs play a central role in power conversion and variable frequency speed control, and their applications are diverse and often operate in harsh environments, making IGBT protection especially crucial. IGBT overcurrent faults are among the most common IGBT failures. If overcurrent faults are not addressed promptly, they can cause permanent damage to the IGBT, resulting in significant economic losses and consequences.

[0005] The IGBT drive circuit is the interface between the IGBT and the control circuit, realizing the isolation, amplification and protection of the control signal. The drive circuit plays a very important role in the normal operation and protection of the IGBT, and has different degrees of influence on the IGBT's on-state voltage, switching, switching losses and short-circuit withstand capability. Therefore, the design of the drive circuit has a significant impact on the dynamic and static performance of the IGBT. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a high-power, multi-channel, protected multi-level IGBT drive circuit.

[0007] This invention discloses a high-power multi-channel multi-level IGBT driving circuit with protection, including a power supply circuit, an isolation power generation circuit, at least four mutually isolated IGBT driving circuits, and a fault feedback circuit.

[0008] The power supply circuit includes a through-hole socket and a three-terminal voltage regulator chip. After the external power supply passes through the through-hole socket and the three-terminal voltage regulator chip in sequence, it outputs a +5V power supply. The PWM signal controls different IGBT drive circuits through different pins of the through-hole socket.

[0009] The isolated power generation circuit includes a switching power supply chip and at least two independent isolation transformers. The power supply pin of the switching power supply chip is connected to an external power supply, and the output pin is connected to one pin of the isolation transformer. The switching power supply chip is also connected to a power soft-start circuit for configuring the output frequency. The other pin of the isolation transformer is connected to an external power supply, so that the isolation transformer generates two sets of isolated DC high-frequency power supplies.

[0010] The IGBT drive circuit includes a first logic chip and an isolation optocoupler. The DC high-frequency power supply generated by the isolation transformer is connected to the isolation optocoupler. The PWM signal is inverted by the first logic chip and input to the cathode of the isolation optocoupler. The anode of the isolation optocoupler is connected to the +5V power supply. The signal output pin of the isolation optocoupler is connected to the output amplifier circuit.

[0011] The IGBT driving circuit with at least four mutually isolated IGBTs for driving the external transistors also includes a VCE detection circuit. The VCE detection circuit is connected to the DESAT pin of the isolation optocoupler. When the DESAT pin exceeds the internal 6.5V, the Fault pin of the isolation optocoupler changes from high configuration to logic low and outputs a level signal.

[0012] The fault feedback circuit includes a second logic chip and a switching diode. The second logic chip and the switching diode perform an "OR" operation on all the level signals. When any of the IGBT drive circuits outputs the level signal, the fault feedback circuit outputs a fault signal and feeds it back to one pin of the through-hole socket.

[0013] Preferably, a first filter circuit is provided between the straight-in plug-in socket and the three-terminal voltage regulator chip. The first filter circuit includes four capacitors connected in parallel, including two electrolytic capacitors C128 and C129 and two ceramic capacitors C34 and C124.

[0014] Preferably, a second filter circuit is provided between the external power supply input and the switching power supply chip. The second filter circuit includes ceramic capacitors C101, C103, C35, C119, C120 and resistor R1.

[0015] Among them, one end of the ceramic capacitors C101 and C103, which are connected in parallel, is connected to the external power supply, and the other end is grounded; one end of the ceramic capacitors C35, C119, and C120, which are connected in parallel, is connected to one end of the resistor R1, and the other end is grounded. The other end of the resistor R1 is connected to the external power supply, and the connection between the resistor R1 and the ceramic capacitors C35, C119, and C120 is also connected to the switching power supply chip.

[0016] Preferably, the power soft-start circuit includes resistors R163 and R162, diode D64 and capacitor C36. One end of each of resistors R163, R162 and diode D64 is connected to a pin of the switching power supply chip, the other end of resistor R163 is grounded, and the other ends of resistor R162 and diode D64 are grounded through capacitor C36.

[0017] Preferably, the LO pin of the switching power supply chip is connected to MOSFET Q22 through a gate resistor to drive a low-level output, and the HO pin is connected to MOSFET Q21 through a gate resistor to drive a high-level output; the output pin of the switching power supply chip is connected to the external power supply through diode D2, and is connected to the VB pin of the switching power supply chip through capacitor C33, and the capacitor C33 and the VB pin are connected to the external power supply through resistor R154 and diode D63.

[0018] Preferably, a rectifier and voltage regulator circuit is provided between the DC high-frequency power supply generated by the isolation transformer and the isolation optocoupler. The rectifier and voltage regulator circuit includes diodes D44 and D45, and capacitors C1, C2, C74, and C75.

[0019] The midpoints of diodes D44 and D45 are connected to the secondary output of the isolation transformer. Capacitors C1 and C74 are connected in parallel, and capacitors C2 and C75 are connected in parallel. The other secondary output of the isolation transformer is connected to one end of capacitors C1, C2, C74, and C75. The other end of capacitors C1 and C74 is connected to the VDD1 pin of the isolation optocoupler, and the other end of capacitors C2 and C75 is connected to the VEE1 pin of the isolation optocoupler.

[0020] Preferably, a third filter circuit is provided between the isolation optocoupler and the rectifier and voltage regulator circuit, and the third filter circuit includes C28, C60, and C61;

[0021] The capacitors C28, C60, and C61 are connected in parallel to the VDD1 and VEE1 pins of the isolation optocoupler, respectively.

[0022] Preferably, the VCE detection circuit includes resistors R98, R129, and R133, and diodes D31, D35, D43, and D27;

[0023] The DESAT pin of the isolation optocoupler is connected to IGBT_AC1 in sequence through resistors R98 and R129, diodes D31 and D35. The VDD1 pin of the isolation optocoupler is connected to one end of resistor R133. Resistor R133 is connected to one end of resistors R98 and R129 and diodes D43 and D27 connected in parallel. The other end of diodes D43 and D27 is connected to IGBT_AE1.

[0024] Preferably, the amplifier circuit includes resistors R144, R145, R151 and transistors Q7 and Q12;

[0025] The signal output pin of the isolation optocoupler is connected to one end of resistors R144, R145, and R151 respectively. The other ends of resistors R144 and R145 are connected to the base of transistors Q7 and Q12 and the VDD1 pin of the isolation optocoupler. Resistor R151 is connected in parallel with the base and collector of transistor Q12 and is connected to the VEE1 pin of the isolation optocoupler. The collector of transistor Q7 is connected to the VDD1 pin of the isolation optocoupler, and the emitters of transistors Q7 and Q12 are connected to IGBT_AG1.

[0026] Preferably, the IGBT drive circuit further includes a signal filtering circuit, which includes resistors R84, R91, R102, capacitors C37 and C45, and diode D6.

[0027] The PWM signal is connected to one end of resistor R84. The other end of resistor R84 is connected to one end of resistor R91 and one end of capacitor C37. The other end of capacitor C37 is grounded. The other end of resistor R91 is connected to one end of diode D6, one end of resistor R102 and one end of the first logic chip. The other end of diode D6 is connected to the +5V power supply. Resistor R102 is grounded through capacitor C45.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] This invention requires only one power input to output at least four fully electrically isolated drive channels. These drives can directly drive a three-level IGBT module, and the output current is relatively large, providing strong driving capability. The circuit also features external transistor protection for the three-level IGBT, with fast detection speed, ensuring safer and more stable IGBT operation, resulting in excellent technical performance. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 This is the power supply circuit in the present invention;

[0032] Figure 3 This is the isolated power supply generation circuit in the present invention;

[0033] Figure 4 This is the first IGBT drive circuit in this invention;

[0034] Figure 5 This is the second IGBT drive circuit in this invention;

[0035] Figure 6 This is the third IGBT drive circuit in this invention;

[0036] Figure 7 This is the fourth IGBT drive circuit in this invention;

[0037] Figure 8 This is the fault feedback circuit in the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] The present invention will now be described in further detail with reference to the accompanying drawings:

[0040] This invention provides a high-power, multi-channel, protected multilevel IGBT driving circuit.

[0041] Reference Figure 1 The present invention provides a high-power multi-channel multi-level IGBT drive circuit with protection, including a power supply circuit, an isolation power generation circuit, at least four mutually isolated IGBT drive circuits, and a fault feedback circuit.

[0042] Reference Figure 2The power supply circuit includes a through-hole socket and a three-terminal voltage regulator chip. The external power supply passes through the through-hole socket and the three-terminal voltage regulator chip in sequence to output a +5V power supply. The PWM signal controls different IGBT drive circuits through different pins of the through-hole socket. A first filter circuit is provided between the through-hole socket and the three-terminal voltage regulator chip. The first filter circuit includes four capacitors connected in parallel. The four capacitors include two electrolytic capacitors C128 and C129 and two ceramic capacitors C34 and C124.

[0043] Specifically, J9 is a 14-pin through-hole socket. Pin 1 is connected to the IGBT's NTC temperature sampling; pins 2, 5, 7, 9, 11, and 13 are connected to GND; pins 3 and 4 are connected to the +15V input power supply; and pin 6 is connected to the IGBT_FAULT signal from the fault feedback circuit, which is then returned to the microcontroller for processing via the socket. Pins 8, 10, 12, and 14 of the socket are connected to PWM_AG1, PWM_AG2, PWM_AG3, and PWM_AG4, respectively. The input power supply is then connected to the positive terminals of electrolytic capacitors C128 and C129 and the top terminals of C34 and C124. The negative terminals of electrolytic capacitors C128 and C129 and the bottom terminals of ceramic capacitors C34 and C124 are connected to GND. The input capacitor is filtered by the filter capacitor and then enters the VIN of the U7 chip L78L05A. Pins 2, 3, 6, and 7 of the U7 chip are directly connected to GND. Pin 1 is the output pin of the chip. The top of C121 is connected to the output 5V, and the bottom is connected to GND.

[0044] Reference Figure 3 The isolated power generation circuit includes a switching power supply chip and at least two independent isolation transformers. The power supply pin of the switching power supply chip is connected to an external power supply, and the output pin is connected to one pin of the isolation transformer. The switching power supply chip is also connected to a power soft-start circuit for configuring the output frequency. The other pin of the isolation transformer is connected to an external power supply, so that the isolation transformer generates two sets of isolated DC high-frequency power supplies.

[0045] Specifically, a second filter circuit is provided between the external power input switching power supply chips. The second filter circuit includes ceramic capacitors C101, C103, C35, C119, C120 and resistor R1.

[0046] Among them, the ceramic capacitors C101 and C103, which are connected in parallel, are connected to an external power supply at one end and grounded at the other end; the ceramic capacitors C35, C119, and C120, which are connected in parallel, are connected to one end of a resistor R1 at one end and grounded at the other end. The other end of the resistor R1 is connected to an external power supply, and the connection between the resistor R1 and the ceramic capacitors C35, C119, and C120 is also connected to a switching power supply chip.

[0047] The power supply soft-start circuit includes resistors R163 and R162, diode D64, and capacitor C36. One end of resistors R163, R162, and diode D64 is connected to a pin of the switching power supply chip, and the other end of resistor R163 is grounded. The other ends of resistor R162 and diode D64 are both grounded through capacitor C36. The LO pin of the switching power supply chip is connected to MOSFET Q22 through a gate resistor to drive a low-level output, and the HO pin is connected to MOSFET Q21 through a gate resistor 160 to drive a high-level output. The output pin of the switching power supply chip is connected to an external power supply through diode D2, and is connected to the VB pin of the switching power supply chip through capacitor C33. Capacitor C33 and the VB pin are connected to the external power supply through resistor R154 and diode D63.

[0048] The IGBT driver circuit includes a first logic chip and an isolation optocoupler. The DC high-frequency power supply generated by the isolation transformer is connected to the isolation optocoupler. The PWM signal is inverted by the first logic chip and input to the cathode of the isolation optocoupler. The anode of the isolation optocoupler is connected to the +5V power supply. The signal output pin of the isolation optocoupler is connected to the output amplifier circuit.

[0049] At least four mutually isolated IGBT drive circuits are used to drive the external IGBTs. The IGBT drive circuit also includes a VCE detection circuit. The VCE detection circuit is connected to the DESAT pin of the isolation optocoupler. When the DESAT pin exceeds the internal 6.5V, the Fault pin of the isolation optocoupler changes from high configuration to logic low and outputs a level signal.

[0050] Specifically, regardless of the number of drive circuits, there are only two IGBT drive circuits for protecting the outer tube each time, and the rest of the extended drive circuits are the same.

[0051] The fault feedback circuit includes a second logic chip and a switching diode. The second logic chip and the switching diode perform an "OR" operation on all level signals. When any IGBT drive circuit outputs a level signal, the fault feedback circuit outputs a fault signal and feeds it back to one pin of the through-hole socket.

[0052] Taking a 4-channel drive circuit as an example,

[0053] The first driving circuit is as follows: Figure 4As shown, a rectifier and voltage regulator circuit is also provided between the DC high-frequency power supply generated by the isolation transformer and the isolation optocoupler. The rectifier and voltage regulator circuit includes diodes D44 and D45, and capacitors C1, C2, C74, and C75. The midpoints of diodes D44 and D45 are connected to the secondary output of the isolation transformer. Capacitors C1 and C74 are connected in parallel, and C2 and C75 are also connected in parallel. The other secondary output of the isolation transformer is connected to one end of each of capacitors C1, C2, C74, and C75. The other end of capacitors C1 and C74 is connected to the VDD1 pin of the isolation optocoupler, and the other end of capacitors C2 and C75 is connected to the VEE1 pin of the isolation optocoupler. Through the rectification of the high-frequency power supply by the diodes and the voltage regulation by the capacitors in this circuit, an isolated power supply is generated.

[0054] The IGBT driver circuit also includes a signal filtering circuit, which includes resistors R84, R91, R102, capacitors C37 and C45, and diode D6. PWM_AG1 is the signal input for the first PWM channel. The PWM signal is connected to the left side of R84 and the right side is connected to R91. The right side of R91 is connected to diode D6 and resistor R102. R102 is connected in series with GND through capacitor C45. The midpoint of R84 and R91 is connected to capacitor C37, and the bottom of the capacitor is connected to GND. These resistors and capacitors of the input signal form a second-order low-pass filter to filter the input signal. Then, after being inverted by the ACT14 logic chip, the signal is input to the cathode of the isolation optocoupler ACPL332J.

[0055] In this implementation example, diodes D69 and D68 are used to establish the power supply level for VDD1 and VDD1-VDD. A third filter circuit is provided between the isolation optocoupler and the rectifier and voltage regulator circuit. C12, C64, C93, C89, and C88 are connected to VDD1 and VDD1-VDD at the top and to AE1 and IGBT_AE1 at the bottom. AE1 and IGBT_AE1 are separated by a 0R resistor R136, essentially forming a network. C16, C69, C90, C91, and C92 are connected in parallel, with the bottom connected to the power supply VEE1 and the top connected to AE1 and IGBT_AE1. Three capacitors, C28, C60, and C61, are connected in parallel, with the top connected to VDD1 and the bottom connected to VEE1. These numerous capacitors form the third filter circuit.

[0056] The VCE detection circuit includes resistors R98, R129, and R133, and diodes D31, D35, D43, and D27. The anode of the isolation optocoupler is connected to a 5V power supply via R109. VCC1 and VEE are the chip's power supply and ground, respectively. Pin 3 (Fault pin) of the isolation optocoupler is ground-active. Resistor R98 is connected to the right side of pin 14 of the isolation optocoupler. From the right side of this resistor, R133 connects to VDD1, and R129 connects to D31 and D35, which in turn connect to P+ (IGBT_AC1). A rectifier diode D43 and a Zener diode D27 are connected to R133, and the tops of these two diodes are connected to IGBT_AE1.

[0057] The amplifier circuit for recommendation-free operation includes resistors R144, R145, and R151, and transistors Q7 and Q12. The signal output pin of the isolation optocoupler is connected to one end of resistors R144, R145, and R151 respectively. The other ends of resistors R144 and R145 are connected to the base of transistors Q7 and Q12 and the VDD1 pin of the isolation optocoupler. Resistor R151 is connected in parallel with the base and collector of transistor Q12 and is also connected to the VEE1 pin of the isolation optocoupler. The collector of transistor Q7 is connected to the VDD1 pin of the isolation optocoupler, and the emitters of transistors Q7 and Q12 are connected to IGBT_AG1. Pin 11 of the isolation optocoupler is the signal isolation output, connected to the left side of R144 and R145. R151 is connected in parallel between pins B and C of transistor Q12 to prevent interference and mis-conduction when the transistor is in a static state. Two high-power transistors, Q7 and Q12, form a push-pull circuit to amplify the drive level of the optocoupler output and output it to the IGBT. Pin 1 of D38 is connected to pin 1 of D7, the delta of D7 is connected to NPN transistor Q17, and pin 2 of D7 is connected to PNP transistor Q16. D38 is a 15V Zener diode. When VDD1-VDD is not greater than 15V, pins 1, 2, and 3 of D7 are all low, Q17 is cut off, Q16 is turned on, and IGBT_AE1 and VEE1 are connected. However, if VDD1-VDD exceeds 15V, the Zener diode turns on, pins 1, 2, and 3 of D7 are all high, Q17 is turned on, Q16 is cut off, and VDD1-VDD is pulled down for discharge. This part of the circuit clamps the drive power supply to +15V to ensure stable and normal operation of the IGBT.

[0058] The second IGBT driver circuit is as follows: Figure 5As shown: In this circuit, the cathode of D45 is connected to VDD2, the anode is connected to the cathode of D53, the anode of D53 is connected to VEE2, the midpoint of D45 and D53 is connected to the secondary output of the isolation transformer, C76 and C3 are connected in parallel, the top of the parallel connection of C76 and C3 is connected to VDD2, C77 and C4 are connected in parallel, the bottom of the parallel connection of C77 and C4 is connected to VEE2, and the midpoint of the four capacitors is connected to the other secondary output of the isolation transformer. The high-frequency power supply is rectified by the diode and regulated by the capacitor, thus generating an isolated power supply. The capacitors C11, C63, C95, C85, and C84 are connected to VDD2 and VDD2-VDD at the top and to AE2 and IGBT_AE2 at the bottom. AE2 and IGBT_AE2 are separated by a 0R resistor R135, essentially forming a network. This is a reserved design element. The capacitors C15, C68, C86, C87, and C94 are connected in parallel, with the bottom connected to the power supply's VEE2 and the top connected to AE2 and IGBT_AE2. The three capacitors C24, C58, and C59 are connected in parallel, with the top connected to VDD2 and the bottom connected to VEE2. These numerous capacitors form the filtering circuit for the isolated power supply. PWM_AG2 is the signal input for the first PWM channel. The PWM signal is connected to the left side of R86, and the right side is connected to R92. The right side of R92 is connected to diode D12 and resistor R94. R94 is connected in series with GND through capacitor C44. The midpoint of R86 and R92 is connected to capacitor C40, and the bottom of the capacitor is connected to GND. These resistors and capacitors form a second-order low-pass filter to filter the input signal. Then, after being inverted by the ACT14 logic chip, the signal is input to the cathode of the isolation optocoupler ACPL332J. The anode of the isolation optocoupler is connected to the 5V power supply through R107. VCC2 and VEE are the power supply and ground of the chip, respectively. The second IGBT driver does not have IGBT VCE detection, so pin 3 of the isolation optocoupler is directly connected to the 5V power supply. Pin 3 is active low, and connecting it to 5V directly shields the fault function. Pin 14 of the isolation optocoupler is directly connected to VE2 of pin 16 of the isolation optocoupler. Pin 11 of the optocoupler is for signal isolation output, connected to the left side of R143 and R142. R152 is connected in parallel between the B and C pins of transistor Q11 to prevent interference and mis-conduction when the transistor is in a static state. Two high-power transistors, Q8 and Q11, form a push-pull circuit to amplify the drive level of the optocoupler output and output it to the IGBT. Diodes D71 and D70 connect VDD2 and VDD2-VDD together, forming a power supply level.Pin 1 of D37 is connected to pin 1 of D8. Pin 3 of D8 is connected to NPN transistor Q18, and pin 2 of D8 is connected to PNP transistor Q15. D37 is a 15V Zener diode. When VDD2-VDD is not greater than 15V, pins 1, 2, and 3 of D8 are all low, Q18 is cut off, Q15 is turned on, and IGBT_AE2 and VEE2 are connected. However, if VDD2-VDD exceeds 15V, the Zener diode turns on, pins 1, 2, and 3 of D8 are all high, Q18 is turned on, Q15 is cut off, and VDD2-VDD is pulled down for discharge. This part of the circuit clamps the power supply of the drive to +15V to ensure that the drive IGBT can operate stably and normally.

[0059] The third IGBT driver circuit is as follows: Figure 6As shown: In this circuit, the cathode of D46 is connected to VDD2, the anode is connected to the cathode of D55, the anode of D55 is connected to VEE3, the midpoint of D46 and D55 is connected to the secondary output of the isolation transformer, C78 and C5 are connected in parallel, the top of the parallel connection of C78 and C5 is connected to VDD3, C79 and C6 are connected in parallel, the bottom of the parallel connection of C79 and C6 is connected to VEE3, and the midpoint of the four capacitors is connected to the other secondary output of the isolation transformer. The high-frequency power supply is rectified by the diode and regulated by the capacitor, thus generating an isolated power supply. The capacitors C10, C62, C109, C108, and C99 are connected to VDD3 and VDD3-VDD at the top and to AEE3 and IGBT_AE3 at the bottom. AE3 and IGBT_AE3 are separated by a 0R resistor R134, essentially forming a network. This is a reserved design element. The capacitors C14, C67, C82, C83, and C98 are connected in parallel, with the bottom connected to VEE3 of the power supply and the top connected to AE3 and IGBT_AE3. The three capacitors C20, C56, and C57 are connected in parallel, with the top connected to VDD3 and the bottom connected to VEE3. These numerous capacitors form the filter circuit for the isolated power supply. PWM_AG3 is the signal input for the first PWM channel. The PWM signal is connected to the left side of R87, and the right side is connected to R90. The right side of R90 is connected to diode D13 and resistor R100. R100 is connected in series with GND through capacitor C43. The midpoint of R87 and R90 is connected to capacitor C39, and the bottom of the capacitor is connected to GND. These resistors and capacitors form a second-order low-pass filter to filter the input signal. The signal is then inverted by the ACT14 logic chip and input to the cathode of the isolation optocoupler ACPL332J. The anode of the isolation optocoupler is connected to a 5V power supply through R105. VCC3 and VEE3 are the power supply and ground of the chip, respectively. The third IGBT driver does not have IGBT VCE detection, so pin 3 of the isolation optocoupler is directly connected to a 5V power supply. Pin 3 is active low, and connecting it to 5V directly shields the fault function. Pin 14 of the isolation optocoupler is directly connected to pin 16 (AE3). Pin 11 of the optocoupler is for signal isolation output, connected to the left side of R141 and R140. R153 is connected in parallel between the B and C pins of transistor Q10 to prevent interference and mis-conduction when the transistor is in a static state. Two high-power transistors, Q6 and Q10, form a push-pull circuit to amplify the drive level of the optocoupler output and output it to the IGBT. Diodes D73 and D72 connect VDD3 and VDD3-VDD together, forming a power supply level.Pin 1 of D39 is connected to pin 1 of D9, pin 3 of D9 is connected to NPN transistor Q19, and pin 2 of D8 is connected to PNP transistor Q13. D39 is a 15V Zener diode. When VDD3-VDD is not greater than 15V, pins 1, 2, and 3 of D9 are all low, Q19 is cut off, Q13 is turned on, and IGBT_AE3 and VEE3 are connected. However, if VDD3-VDD exceeds 15V, the Zener diode turns on, pins 1, 2, and 3 of D9 are all high, Q19 is turned on, Q13 is cut off, and VDD3-VDD is pulled down for discharge. This part of the circuit clamps the drive power supply to +15V to ensure that the drive IGBT can operate stably and normally.

[0060] The fourth IGBT drive circuit is as follows Figure 7As shown: In this circuit, the cathode of D47 is connected to VDD4, and the anode is connected to the cathode of D52. The anode of D52 is connected to VEE4. The midpoint between D47 and D52 is connected to the secondary output of the isolation transformer. Simultaneously, C7 and C80 are connected in parallel, with the top of this parallel connection connected to VDD4. C8 and C81 are connected in parallel, with the bottom of this parallel connection connected to VEE4. The midpoint of the four capacitors is connected to the other secondary output of the isolation transformer. The high-frequency power supply is rectified by the diodes and regulated by the capacitors, thus generating an isolated power supply. The top of C9, C65, C104, C97, and C105 are connected to VDD4 and VDD4-VDD, and the bottom is connected to AE4 and IGBT_AE4. AE4 and IGBT_AE4 are separated by a 0R resistor R137, essentially forming a network. The capacitors C13, C66, C96, C106, and C107, connected in parallel, are connected to VEE4 of the power supply at the bottom and to AE4 and IGBT_AE4 at the top. The three capacitors C17, C54, and C55, connected in parallel, are connected to VDD4 at the top and to VEE4 at the bottom. These numerous capacitors form the filtering circuit for the isolated power supply. PWM_AG4 is the signal input for the first PWM channel. The PWM signal is connected to the left side of R85, and the right side is connected to R93. The right side of R93 is connected to diode D11 and resistor R99. R99 is connected in series with GND through capacitor C42. The midpoint between R85 ​​and R93 is connected to capacitor C38, which is connected to GND at the bottom. These input signal resistors and capacitors form a second-order low-pass filter to filter the input signal. The signal is then inverted by the ACT14 logic chip and input to the cathode of the isolation optocoupler ACPL332J. The anode of the isolation optocoupler is connected to a 5V power supply via R103. VCC4 and VEE4 are the chip's power and ground, respectively. Pin 3 (Fault pin) of the isolation optocoupler is ground-active. Pin 14 of the isolation optocoupler is connected to resistor R95 on the right. To the right of this resistor, it is connected to VDD1 via R130, and then to IGBT_AC4 via R126, D28, and D32. A rectifier diode D40 and a Zener diode D24 are connected to R130, and the tops of these two diodes are connected to IGBT_AE4. Pin 11 of the isolation optocoupler is the signal isolation output, connected to the left side of R139 and R138. R150 is connected in parallel between the B and C terminals of transistor Q9 to prevent interference and mis-conduction when the transistor is in a static state. High-power transistors Q5 and Q9 form a push-pull circuit to amplify the drive level of the optocoupler output and output it to the IGBT. Diodes D67 and D66 connect VDD4 and VDD4-VDD together, forming a power supply level.Pin 1 of D36 is connected to pin 1 of D10, pin 3 of D7 is connected to NPN transistor Q20, and pin 2 of D10 is connected to PNP transistor Q14. D36 is a 15V Zener diode. When VDD4-VDD is not greater than 15V, pins 1, 2, and 3 of D10 are all low, Q20 is cut off, Q14 is turned on, and IGBT_AE4 and VEE4 are connected. However, if VDD4-VDD exceeds 15V, the Zener diode turns on, pins 1, 2, and 3 of D10 are all high, Q20 is turned on, Q14 is cut off, and VDD4-VDD is pulled down for discharge. This part of the circuit clamps the power supply of the drive to +15V to ensure that the drive IGBT can operate stably and normally.

[0061] Fault feedback circuit such as Figure 8 As shown: 5V is connected to the left side of R89. The right side of R89 is connected to the anode of D65 and the top of C125. The bottom of C125 is connected to the right side of GNDR89, which is connected to the input of logic chip U1C. The output, after being inverted, is connected to the left side of R88. The right side of R88 is connected to the left side of R83 and the top of C41. The bottom of C41 is connected to GND. The right side of R83 is connected to the fault feedback signal output.

[0062] Through the above setup, this application uses multiple power inputs to ensure the required input power. Then, by designing filter circuits with different parameters for electrolytic and ceramic capacitors, the stability and cleanliness of the input power supply are fully guaranteed. The isolation power supply circuit also incorporates various types of hardware filtering to ensure low ripple in each isolated power supply path. It uses an IRS27951 high-frequency output power supply, with high and low outputs on separate pins. Two MOSFETs are used for amplification after the output to ensure the power requirements of subsequent power supplies. The power supply also incorporates current detection feedback circuits to ensure circuit stability. A custom isolation transformer is used after the power supply output to ensure complete electrical isolation, providing high and low voltage isolation for subsequent IGBT driving. This circuit has a total of four drive circuits. Each branch IGBT driver uses an ACPL33J isolation optocoupler. The output signal is driven via opto-isolation, ensuring complete isolation between the IGBT's gate (G) and emitter (E) stages and the signal circuit. Furthermore, each isolation optocoupler output utilizes an 8A high-power push-pull circuit to ensure the operating conditions of the high-power IGBT module. The multi-channel drive directly drives a three-level IGBT module, and the output current is relatively large, resulting in strong driving capability. This circuit also utilizes the DESAT detection and fault feedback function of the ACPL332J isolation optocoupler to monitor the IGBT's VCE level in real time while driving the output IGBT. Only with protection can a circuit be considered a qualified and complete IGBT drive circuit, ensuring safer and more stable IGBT operation. In summary, this circuit offers numerous advantages over other IGBT drive circuits, including high drive power, multiple drive channels, and excellent drive protection, thus demonstrating excellent technical performance.

[0063] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-power, multi-channel, protected multi-level IGBT drive circuit, characterized in that, It includes a power supply circuit, an isolated power generation circuit, at least four mutually isolated IGBT drive circuits, and a fault feedback circuit; The power supply circuit includes a through-hole socket and a three-terminal voltage regulator chip. After the external power supply passes through the through-hole socket and the three-terminal voltage regulator chip in sequence, it outputs a +5V power supply. The PWM signal controls different IGBT drive circuits through different pins of the through-hole socket. The isolated power generation circuit includes a switching power supply chip and at least two independent isolation transformers. The power supply pin of the switching power supply chip is connected to an external power supply, and the output pin is connected to one pin of the isolation transformer. The switching power supply chip is also connected to a power soft-start circuit for configuring the output frequency. The other pin of the isolation transformer is connected to an external power supply, so that the isolation transformer generates two sets of isolated DC high-frequency power supplies. The IGBT drive circuit includes a first logic chip and an isolation optocoupler. The DC high-frequency power supply generated by the isolation transformer is connected to the isolation optocoupler. The PWM signal is inverted by the first logic chip and input to the cathode of the isolation optocoupler. The anode of the isolation optocoupler is connected to the +5V power supply. The signal output pin of the isolation optocoupler is connected to the output amplifier circuit. The IGBT driving circuit with at least four mutually isolated IGBTs for driving the external tubes also includes a VCE detection circuit. The VCE detection circuit is connected to the DESAT pin of the isolation optocoupler. When the DESAT pin exceeds the internal 6.5V, the Fault pin of the isolation optocoupler changes from high configuration to logic low and outputs a level signal. The fault feedback circuit includes a second logic chip and a switching diode. The second logic chip and the switching diode perform an "OR" operation on all the level signals. When any of the IGBT drive circuits outputs the level signal, the fault feedback circuit outputs a fault signal and feeds it back to one pin of the through-hole horn socket. A first filter circuit is provided between the straight-in horn socket and the three-terminal voltage regulator chip. The first filter circuit includes four capacitors connected in parallel. The four capacitors include two electrolytic capacitors C128 and C129 and two ceramic capacitors C34 and C124. A second filter circuit is provided between the external power input and the switching power supply chip. The second filter circuit includes ceramic capacitors C101, C103, C35, C119, C120 and resistor R1. Among them, one end of the ceramic capacitors C101 and C103, which are connected in parallel, is connected to the external power supply, and the other end is grounded; one end of the ceramic capacitors C35, C119, and C120, which are connected in parallel, is connected to one end of the resistor R1, and the other end is grounded. The other end of the resistor R1 is connected to the external power supply, and the connection between the resistor R1 and the ceramic capacitors C35, C119, and C120 is also connected to the switching power supply chip.

2. The high-power multi-channel multi-level IGBT drive circuit with protection as described in claim 1, characterized in that, The power soft-start circuit includes resistors R163 and R162, diode D64 and capacitor C36. One end of each of the resistors R163, R162 and diode D64 is connected to a pin of the switching power supply chip. The other end of the resistor R163 is grounded, and the other ends of the resistor R162 and diode D64 are both grounded through capacitor C36.

3. The high-power multi-channel multi-level IGBT drive circuit with protection as described in claim 2, characterized in that, The isolated power supply generating circuit includes a switching power supply chip, MOSFET Q21, MOSFET Q22, and an isolation transformer. The HO pin of the switching power supply chip is connected to the gate of MOSFET Q21 through a gate resistor, and the LO pin is connected to the gate of MOSFET Q22 through a gate resistor. The switching power supply chip outputs a PWM signal to drive MOSFETs Q21 and Q22 to alternately turn on and off, forming a half-bridge circuit. The output of the half-bridge circuit is connected to the primary side of the isolation transformer, so that the secondary side of the isolation transformer generates two sets of isolated DC high-frequency power supplies.

4. The high-power multi-channel multi-level IGBT drive circuit with protection as described in claim 1, characterized in that, A rectifier and voltage regulator circuit is also provided between the DC high-frequency power supply generated by the isolation transformer and the isolation optocoupler. The rectifier and voltage regulator circuit includes diodes D44 and D45, and capacitors C1, C2, C74, and C75. The midpoints of diodes D44 and D45 are connected to the secondary output of the isolation transformer. Capacitors C1 and C74 are connected in parallel, and capacitors C2 and C75 are connected in parallel. The other secondary output of the isolation transformer is connected to one end of capacitors C1, C2, C74, and C75. The other end of capacitors C1 and C74 is connected to the VDD1 pin of the isolation optocoupler, and the other end of capacitors C2 and C75 is connected to the VEE1 pin of the isolation optocoupler.

5. The high-power multi-channel multi-level IGBT drive circuit with protection as described in claim 4, characterized in that, A third filter circuit is provided between the isolation optocoupler and the rectifier and voltage regulator circuit, and the third filter circuit includes C28, C60, and C61. The capacitors C28, C60, and C61 are connected in parallel to the VDD1 and VEE1 pins of the isolation optocoupler, respectively.

6. The high-power multi-channel multi-level IGBT drive circuit with protection as described in claim 1, characterized in that, The VCE detection circuit includes resistors R98, R129, and R133, and diodes D31, D35, D43, and D27. The DESAT pin of the isolation optocoupler is connected to IGBT_AC1 in sequence through resistors R98 and R129, diodes D31 and D35. The VDD1 pin of the isolation optocoupler is connected to one end of resistor R133. Resistor R133 is connected to one end of resistors R98 and R129 and diodes D43 and D27 connected in parallel. The other end of diodes D43 and D27 is connected to IGBT_AE1.

7. The high-power multi-channel multi-level IGBT drive circuit with protection as described in claim 1, characterized in that, The amplifier circuit for exemption from the requirement includes resistors R144, R145, R151 and transistors Q7 and Q12; The signal output pin of the isolation optocoupler is connected to one end of resistors R144, R145, and R151 respectively. The other ends of resistors R144 and R145 are connected to the base of transistors Q7 and Q12 and the VDD1 pin of the isolation optocoupler. Resistor R151 is connected in parallel with the base and collector of transistor Q12 and is connected to the VEE1 pin of the isolation optocoupler. The collector of transistor Q7 is connected to the VDD1 pin of the isolation optocoupler, and the emitters of transistors Q7 and Q12 are connected to IGBT_AG1.

8. The high-power multi-channel multi-level IGBT drive circuit with protection as described in claim 1, characterized in that, The IGBT drive circuit also includes a signal filtering circuit, which includes resistors R84, R91, R102, capacitors C37 and C45, and diode D6. The PWM signal is connected to one end of resistor R84. The other end of resistor R84 is connected to one end of resistor R91 and one end of capacitor C37. The other end of capacitor C37 is grounded. The other end of resistor R91 is connected to one end of diode D6, one end of resistor R102 and one end of the first logic chip. The other end of diode D6 is connected to the +5V power supply. Resistor R102 is grounded through capacitor C45.

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