Short-circuit protection driving circuit, method and equipment
By designing a short-circuit protection driving circuit for half-bridge circuit, the gate voltage of the silicon carbide MOS module is controlled by using the current sensor and the driving circuit, the circuit short-circuit problem caused by the gate loss of SiC power module is solved, and the uniform sharing of short-circuit impact power and effective protection of the circuit are achieved.
Patent Information
- Application Number
- CN202311653489.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-04
- Publication Date
- 2025-06-06
AI Technical Summary
The circuit short circuit problem in the half-bridge circuit caused by the loss of gate of the SiC power module, especially the electromagnetic coupling and capacitive coupling caused by changes in high-speed current, resulting in signal crosstalk and short circuit.
A short-circuit protection driving circuit is designed, including the first and second silicon carbide MOS modules, driving circuits and current sensors, and the load current signal is detected through the current sensor, and the gate voltage of the two MOS modules is controlled by the driving circuit to reduce the short-circuit impact power received by each module individually, so as to achieve uniform sharing of the short-circuit impact power.
By controlling the gate voltage of the MOS module, the short-circuit impact power received by any module is reduced, ensuring that the short-circuit impact power sharing of the two modules is more even, and the circuit short-circuit protection is achieved.
Smart Images
Figure CN120110143A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of protection circuits, and specifically relates to a short-circuit protection driving circuit, method and device. Background Art
[0002] In the field of power electronic conversion, Si-based IGBT (Insulated Gate Bipolar Transistor: Insulated Gate Bipolar Transistor) is generally used as a high-speed switching element. Two power switching devices can form a half-bridge circuit to achieve power switch control and power conversion. Based on the half-bridge circuit, a power conversion circuit can be formed to achieve power conversion such as DC to AC, AC to DC, DC to DC and AC to AC. It is widely used in new energy fields such as electric vehicles, wind power generation, and photovoltaic power generation. In recent years, with the rapid development of power electronic conversion technology towards high frequency, high efficiency and high power density, power electronic conversion devices that replace Si-based IGBT and low-loss SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor: Metal-Insulator-Semiconductor Field Effect Transistor) are gradually becoming popular, and correspondingly, the driving technology of SiC-MOSFET power modules is being promoted.
[0003] Compared with IGBT power modules made of Si-based materials, SiC power modules have the advantages of low on-resistance and high switching speed, and their applications are characterized by high frequency, high temperature, and strong interference. High frequency and high switching speed have also caused new application problems. When the SiC power module switches, high-speed current changes will cause electromagnetic coupling and capacitive coupling, resulting in mutual interference between adjacent modules. This interference can be transmitted through electromagnetic coupling (inductance) and capacitive coupling (capacitance), resulting in signal crosstalk, which is also called crosstalk problem. Crosstalk problems can easily cause the gates of the two SiC power modules in the half-bridge circuit to lose control, which in turn causes the SiC power module to connect to the positive and negative ends of the DC capacitor to form a short circuit. Summary of the invention
[0004] The present application provides a short-circuit protection driving circuit, method and device to solve the circuit short-circuit problem caused by the gate loss of control of the power module in a half-bridge circuit.
[0005] In a first aspect, the present application provides a short-circuit protection drive circuit, comprising a first silicon carbide MOS module, a second silicon carbide MOS module, a first drive circuit, a second drive circuit and a current sensor S1, wherein the first silicon carbide MOS module and the second silicon carbide MOS module are connected in series to a load main circuit to form a half-bridge circuit, the current sensor S1 is connected to the load main circuit, and the current sensor S1 is used to detect a current signal between the first silicon carbide MOS module and the second silicon carbide MOS module in the load main circuit, the first drive circuit and the second drive circuit are both connected to the current sensor S1, the first drive circuit is connected to the first silicon carbide MOS module, and the first drive circuit is used to control the gate voltage of the first silicon carbide MOS module according to the current signal, the second drive circuit is connected to the second silicon carbide MOS module, and the second drive circuit is used to control the gate voltage of the second silicon carbide MOS module according to the current signal.
[0006] Optionally, the first silicon carbide MOS module and the second silicon carbide MOS module are both silicon carbide NMOS tubes.
[0007] Optionally, the first silicon carbide MOS module and the second silicon carbide MOS module are both connected in parallel with diodes for sharing current.
[0008] Optionally, the drain of the first silicon carbide MOS module is connected to the positive electrode of the load main circuit, the gate of the first silicon carbide MOS module is connected to the first drive circuit, the source of the first silicon carbide MOS module is connected to the drain of the second silicon carbide MOS module, the gate of the second silicon carbide MOS module is connected to the second drive circuit, the source of the second silicon carbide MOS module is connected to the negative electrode of the load main circuit, and the current sensor S1 is connected in parallel between the source of the first silicon carbide MOS module and the drain of the second silicon carbide MOS module.
[0009] Optionally, the first driving circuit includes a first control module, a first driving power supply V1, a second driving power supply V2, a third driving power supply V3, a first NMOS tube Q1N, a first PMOS tube Q1P, a second NMOS tube Q2N and a first bypass driving circuit, the power supply voltage of the third driving power supply V3 is less than the power supply voltage of the first driving power supply V1, the first control module is connected to the current sensor S1, the first control module is respectively connected to the gates of the first NMOS tube Q1N, the first PMOS tube Q1P and the second NMOS tube Q2N, the drain of the first NMOS tube Q1N is connected to the positive electrode of the first driving power supply V1, and the The drain of the second NMOS tube Q2N is connected to the positive electrode of the third driving power supply V3, the source of the first PMOS tube Q1P is connected to the negative electrode of the second driving power supply V2, the negative electrode of the first driving power supply V1, the positive electrode of the second driving power supply V2 and the negative electrode of the third driving power supply V3 are all connected in parallel to the source of the first silicon carbide MOS module, the source of the second NMOS tube Q2N is connected in series to the gate of the first silicon carbide MOS module through the first bypass driving circuit, and the source of the first NMOS tube Q1N and the drain of the first PMOS tube Q1P are connected in parallel to the gate of the first silicon carbide MOS module through the first bypass driving circuit.
[0010] Optionally, the first bypass drive circuit includes a first turn-off diode D1, a first drive resistor R1 and a second drive resistor R2, the second drive resistor R2 is connected in series between the source of the second NMOS tube Q2N and the gate of the first silicon carbide MOS module, and the first turn-off diode D1 and the first drive resistor R1 are connected in parallel at both ends of the second drive resistor R2.
[0011] Optionally, the second driving circuit includes a second control module, a fourth driving power supply V4, a fifth driving power supply V5, a sixth driving power supply V6, a third NMOS tube Q3N, a second PMOS tube Q2P, a fourth NMOS tube Q4N and a second bypass driving circuit, the power supply voltage of the sixth driving power supply V6 is less than the power supply voltage of the fourth driving power supply V4 and the power supply voltage of the first driving power supply V1, the power supply voltage of the third driving power supply V3 is less than the power supply voltage of the fourth driving power supply V4, the second control module is connected to the current sensor S1, the second control module is respectively connected to the gates of the third NMOS tube Q3N, the second PMOS tube Q2P and the fourth NMOS tube Q4N, the third NMOS The drain of the transistor Q3N is connected to the positive electrode of the fourth driving power supply V4, the drain of the fourth NMOS transistor Q4N is connected to the positive electrode of the sixth driving power supply V6, the source of the second PMOS transistor Q2P is connected to the negative electrode of the fifth driving power supply V5, the negative electrode of the fourth driving power supply V4, the positive electrode of the fifth driving power supply V5 and the negative electrode of the sixth driving power supply V6 are all connected in parallel to the source of the first silicon carbide MOS module, the source of the fourth NMOS transistor Q4N is connected in series to the gate of the first silicon carbide MOS module through the second bypass driving circuit, and the source of the third NMOS transistor Q3N and the drain of the second PMOS transistor Q2P are connected in parallel to the gate of the first silicon carbide MOS module through the second bypass driving circuit.
[0012] Optionally, the second bypass drive circuit includes a second turn-off diode D2, a third drive resistor R3 and a fourth drive resistor R4, the fourth drive resistor R4 is connected in series between the source of the fourth NMOS tube Q4N and the gate of the second silicon carbide MOS module, and the second turn-off diode D2 and the third drive resistor R3 are connected in parallel at both ends of the fourth drive resistor R4.
[0013] In a second aspect, the present application further provides a short-circuit protection driving device, comprising the short-circuit protection driving circuit as described in the first aspect.
[0014] In a third aspect, the present application further provides a short-circuit protection driving method, which is applied to the short-circuit protection driving circuit described in the first aspect, wherein the first silicon carbide MOS module is connected to the positive electrode of the load main circuit, and the second silicon carbide MOS module is connected to the negative electrode of the load main circuit, and the method comprises the following steps:
[0015] The current sensor S1 is used to collect the current signal of the load current in the load main circuit;
[0016] Analyzing the current signal using a phase-locked loop analysis method to determine the current direction and current magnitude of the load current;
[0017] Determining whether a short circuit occurs in the load main circuit according to the current magnitude;
[0018] If a short circuit occurs in the load main circuit, judging whether the load current is a positive current or a negative current according to the current direction;
[0019] If the load current is a forward current, the gate voltage of the first silicon carbide MOS module is controlled to be a first gate voltage through a first driving circuit, and the gate voltage of the second silicon carbide MOS module is controlled to be a second gate voltage through a second driving circuit, and the first gate voltage is greater than the second gate voltage;
[0020] If the load current is a negative current, the gate voltage of the first silicon carbide MOS module is controlled to be a first gate voltage through a first driving circuit, and the gate voltage of the second silicon carbide MOS module is controlled to be a second gate voltage through a second driving circuit, and the first gate voltage is less than the second gate voltage.
[0021] The beneficial effects of this application are:
[0022] In a half-bridge circuit, the lower the gate voltage of the MOS module, the greater the equivalent resistance, so the silicon carbide MOS module with a low gate voltage will divide a higher intermediate voltage. According to this principle, when the MOS module has a crosstalk problem that causes the gate to be out of control, which in turn causes a short circuit in the load main circuit, the gate voltage of the first silicon carbide MOS module can be controlled by the first drive circuit, and the gate voltage of the second silicon carbide MOS module can be controlled by the second drive circuit. By controlling the gate voltage of the two silicon carbide MOS modules, the short-circuit impact power of any silicon carbide MOS module can be reduced, and the short-circuit impact power of the two silicon carbide MOS modules can be shared more evenly, thereby achieving the purpose of circuit short-circuit protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a circuit structure diagram of the short-circuit protection driving circuit in this application.
[0024] Figure 2 Schematic diagram of the waveform of the positive load current in this application.
[0025] Figure 3 It is a waveform diagram of a negative load current in this application.
[0026] Figure 4 This is a schematic diagram of current flow when a bridge arm short circuit occurs in the upper and lower bridge arms and the load current is positive in this application.
[0027] Figure 5This is a schematic diagram of current flow when a bridge arm short circuit occurs in the upper and lower bridge arms and the load current is negative in this application.
[0028] Figure 6 It is a flow chart of the short-circuit protection driving method in this application.
[0029] Description of reference numerals:
[0030] 1. First silicon carbide MOS module; 2. Second silicon carbide MOS module; 3. First drive circuit; 31. First bypass drive circuit; 4. Second drive circuit; 41. Second bypass drive circuit. DETAILED DESCRIPTION
[0031] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.
[0032] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.
[0033] The present application discloses a short circuit protection driving circuit, referring to Figure 1 The short-circuit protection driving circuit includes a first silicon carbide MOS module, a second silicon carbide MOS module, a first driving circuit, a second driving circuit and a current sensor S1. The first silicon carbide MOS module and the second silicon carbide MOS module are connected in series with the load main circuit to form a half-bridge circuit. The current sensor S1 is connected to the load main circuit. The current sensor S1 is used to detect the current signal between the first silicon carbide MOS module and the second silicon carbide MOS module in the load main circuit. The first driving circuit and the second driving circuit are both connected to the current sensor S1. Specifically, the control module in the driving circuit can be communicated with the current sensor S1. The first driving circuit is connected to the first silicon carbide MOS module. The first driving circuit is used to control the gate voltage of the first silicon carbide MOS module according to the current signal. The second driving circuit is connected to the second silicon carbide MOS module. The second driving circuit is used to control the gate voltage of the second silicon carbide MOS module according to the current signal.
[0034] exist Figure 1 In the illustrated embodiment, the first silicon carbide MOS module is the upper arm of the half-bridge circuit, and the second silicon carbide MOS module is the lower arm of the half-bridge circuit. When the first silicon carbide MOS module and the second silicon carbide MOS module have crosstalk problems, resulting in gate loss of control, a bridge arm direct short circuit occurs in the upper and lower bridge arms. Assuming that the first silicon carbide MOS module and the second silicon carbide MOS module have the same gate voltage, the DC voltage VDC in the load main circuit (DC voltage VDC = (VDC+) - (VDC-)) will be evenly divided by the first silicon carbide MOS module and the second silicon carbide MOS module, and each will bear VDC / 2. If the gate voltages of the first silicon carbide MOS module and the second silicon carbide MOS module are different, although the DC voltage VDC in the load main circuit is still borne by the first silicon carbide MOS module and the second silicon carbide MOS module together, the specific amount of voltage borne is related to the corresponding gate voltage. For example, when the gate voltage of the first SiC MOS module is +15V and the gate voltage of the second SiC MOS module is +10V, the first SiC MOS module bears a lower DC voltage, and the second SiC MOS module bears a higher DC voltage, which is determined by the characteristics of the SiC MOS module itself. The lower the gate voltage of the SiC MOS module, the greater the equivalent resistance of the SiC MOS module, so the SiC MOS module with a low gate voltage will share a higher DC voltage.
[0035] In one embodiment, the first silicon carbide MOS module and the second silicon carbide MOS module are both silicon carbide NMOS tubes. The first silicon carbide MOS module and the second silicon carbide MOS module are both connected in parallel with a diode for sharing current. Figure 2 , assuming that the current flowing from the midpoint of the half-bridge circuit to the load is positive, such as Figure 2 As shown, when the load current works in the upper half of the quasi-sinusoidal waveform, the load current is positive. If the first silicon carbide MOS module is turned on, the current flows from the positive pole of the load main circuit through the first silicon carbide MOS module; if the first silicon carbide MOS module is turned off, the current flows through the second silicon carbide MOS module, and at this time, the second silicon carbide MOS module and the diode connected in parallel share the current flowing through. Figure 3 When the load current works in the lower half of the quasi-sinusoidal waveform, the load current is negative, and the current flows from the load to the midpoint of the half-bridge circuit. At this time, if the first silicon carbide MOS module is turned on, the current flows from the load through the first silicon carbide MOS module, and the first silicon carbide MOS module and the diode connected in parallel share the current; if the first silicon carbide MOS module is turned off and the second silicon carbide MOS module is turned on, the current flows from the load through the second silicon carbide MOS module.
[0036] therefore Figure 1The circuit principle of the short-circuit protection drive circuit shown is: when the load current operates in the lower half of the quasi-sinusoidal waveform, the load current is negative. If the first silicon carbide MOS module is turned on, the current flows from the load through the first silicon carbide MOS module; if the first silicon carbide MOS module is turned off and the second silicon carbide MOS module is turned on, the current flows from the load through the second silicon carbide MOS module. Therefore, when the load current is negative, if a short circuit occurs, the gate voltage of the first silicon carbide MOS module can be controlled by the first drive circuit, and the gate voltage of the second silicon carbide MOS module can be controlled by the second drive circuit. By controlling the gate voltages of the two silicon carbide MOS modules, the short-circuit impact power received by any one of the silicon carbide MOS modules can be reduced, and the short-circuit impact power of the two silicon carbide MOS modules can be shared more evenly, thereby achieving the purpose of circuit short-circuit protection. Therefore Figure 1 The short-circuit protection driving circuit shown is used to solve the short-circuit problem formed between the first silicon carbide MOS module and the second silicon carbide MOS module caused by gate loss of control.
[0037] In one embodiment, Figure 1 As shown, the first driving circuit includes a first control module, a first driving power supply V1, a second driving power supply V2, a third driving power supply V3, a first NMOS tube Q1N, a first PMOS tube Q1P, a second NMOS tube Q2N and a first bypass driving circuit, the power supply voltage of the third driving power supply V3 is less than the power supply voltage of the first driving power supply V1, the first control module is connected to the current sensor S1, the first control module is respectively connected to the gates of the first NMOS tube Q1N, the first PMOS tube Q1P and the second NMOS tube Q2N, the drain of the first NMOS tube Q1N is connected to the positive electrode of the first driving power supply V1 The drain of the second NMOS tube Q2N is connected to the positive electrode of the third driving power supply V3, the source of the first PMOS tube Q1P is connected to the negative electrode of the second driving power supply V2, the negative electrode of the first driving power supply V1, the positive electrode of the second driving power supply V2 and the negative electrode of the third driving power supply V3 are all connected in parallel to the source of the first silicon carbide MOS module, the source of the second NMOS tube Q2N is connected in series to the gate of the first silicon carbide MOS module through the first bypass driving circuit, and the source of the first NMOS tube Q1N and the drain of the first PMOS tube Q1P are connected in parallel to the gate of the first silicon carbide MOS module through the first bypass driving circuit.
[0038] In this embodiment, the first control module can be a device such as a comparator, a trigger, a logic gate, etc. The first bypass drive circuit includes a first turn-off diode D1, a first drive resistor R1 and a second drive resistor R2, the second drive resistor R2 is connected in series between the source of the second NMOS tube Q2N and the gate of the first silicon carbide MOS module, and the first turn-off diode D1 and the first drive resistor R1 are connected in parallel to the two ends of the second drive resistor R2. In another embodiment, the first control module can also be a microcontroller such as an FPGA chip, a CPLD chip, etc.
[0039] In one embodiment, the second driving circuit includes a second control module, a fourth driving power supply V4, a fifth driving power supply V5, a sixth driving power supply V6, a third NMOS tube Q3N, a second PMOS tube Q2P, a fourth NMOS tube Q4N and a second bypass driving circuit, the power supply voltage of the sixth driving power supply V6 is less than the power supply voltage of the fourth driving power supply V4 and the power supply voltage of the first driving power supply V1, the power supply voltage of the third driving power supply V3 is less than the power supply voltage of the fourth driving power supply V4, the second control module is connected to the current sensor S1, and the second control module is respectively connected to the gates of the third NMOS tube Q3N, the second PMOS tube Q2P and the fourth NMOS tube Q4N, The drain of the third NMOS tube Q3N is connected to the positive electrode of the fourth driving power supply V4, the drain of the fourth NMOS tube Q4N is connected to the positive electrode of the sixth driving power supply V6, the source of the second PMOS tube Q2P is connected to the negative electrode of the fifth driving power supply V5, the negative electrode of the fourth driving power supply V4, the positive electrode of the fifth driving power supply V5 and the negative electrode of the sixth driving power supply V6 are all connected in parallel to the source of the first silicon carbide MOS module, the source of the fourth NMOS tube Q4N is connected in series to the gate of the first silicon carbide MOS module through the second bypass driving circuit, and the source of the third NMOS tube Q3N and the drain of the second PMOS tube Q2P are connected in parallel to the gate of the first silicon carbide MOS module through the second bypass driving circuit.
[0040] In this embodiment, the first control module can be a device such as a comparator, a trigger, a logic gate, etc. The second bypass drive circuit includes a second turn-off diode D2, a third drive resistor R3 and a fourth drive resistor R4, the fourth drive resistor R4 is connected in series between the source of the fourth NMOS tube Q4N and the gate of the second silicon carbide MOS module, and the second turn-off diode D2 and the third drive resistor R3 are connected in parallel to both ends of the fourth drive resistor R4. In another embodiment, the first control module can also be a microcontroller such as an FPGA chip, a CPLD chip, etc.
[0041] In the above embodiment, when the load current operates in the upper half of the quasi-sinusoidal waveform, the load current is positive. If a bridge arm short circuit occurs in the upper and lower bridge arms, refer to Figure 4According to Kirchhoff's current law, the sum of the upper arm current I1, the lower arm current I3 and the load current I2 is 0, so I1=I2+I3, so I1>I3. Because the lower the gate voltage of the silicon carbide MOS module, the greater the equivalent resistance of the silicon carbide MOS module, the silicon carbide MOS module with a low gate voltage will divide a higher intermediate voltage. According to this principle, when the second control module detects a short circuit and a positive load current through the current sensor S1, the second control module outputs a high level to the fourth NMOS tube Q4N. After the fourth NMOS tube Q4N is turned on, the power supply low voltage of the sixth driving power supply V6 is output to the second silicon carbide MOS module. At this time, the gate voltage VGS2 of the second silicon carbide MOS module is V6. Since the first control module also detects the occurrence of a short circuit and the load current is positive through the current sensor S1, the first control module keeps the first NMOS tube Q1N turned on, and the first driving power supply V1 outputs the power supply voltage to the first silicon carbide MOS module through the first NMOS tube Q1N. At this time, the gate voltage VGS2 of the first silicon carbide MOS module is V1, and since V6 is less than V1, the gate voltage of the second silicon carbide MOS module is less than the gate voltage of the first silicon carbide MOS module. Therefore, the shared voltage of the second silicon carbide MOS module will increase, and the shared voltage of the first silicon carbide MOS module will decrease, thereby reducing the short-circuit impact power received by the first silicon carbide MOS module, so as to ensure that the short-circuit impact power of the upper and lower bridge arms is shared more evenly, so as to achieve the purpose of enhancing the short-circuit capability and allow the control module to have more time for protection.
[0042] When the load current is operating in the lower half of the quasi-sinusoidal waveform, the load current is negative. If the upper and lower bridge arms are short-circuited, refer to Figure 5According to Kirchhoff's current law, the sum of the upper arm current I1, the lower arm current I3 and the load current I2 is 0, so I3 = I1 + I2, so I3>I1. When the first control module detects a short circuit and a negative load current through the current sensor S1, the first control module outputs a high level to the second NMOS tube Q2N. After the second NMOS tube Q2N is turned on, the third driving power supply V3 is connected to the first silicon carbide MOS module. At this time, the gate voltage VGS1 of the first silicon carbide MOS module is V3. Since the second control module also detects the occurrence of a short circuit and the load current is negative through the current sensor S1, the second control module keeps the third NMOS tube Q3N turned on, and the fourth driving power supply V4 outputs the power supply voltage to the second silicon carbide MOS module through the third NMOS tube Q3N. At this time, the gate voltage VGS2 of the second silicon carbide MOS module is V4, and since V3 is less than V4, the gate voltage of the first silicon carbide MOS module is less than the gate voltage of the second silicon carbide MOS module. Therefore, the shared voltage of the first silicon carbide MOS module will increase, and the shared voltage of the second silicon carbide MOS module will decrease, thereby reducing the short-circuit impact power received by the second silicon carbide MOS module, so as to ensure that the short-circuit impact power of the upper and lower bridge arms is shared more evenly, so as to achieve the purpose of enhancing the short-circuit capability and allow the control module to have more time for protection.
[0043] The present application also discloses a short-circuit protection driving device, which includes a short-circuit protection driving circuit as described in any one of the above embodiments.
[0044] The present application also discloses a short-circuit protection driving method, which is applied to the short-circuit protection driving circuit described in any one of the above embodiments, such as Figure 1 As shown, the first silicon carbide MOS module is connected to the positive electrode of the load main circuit, and the second silicon carbide MOS module is connected to the negative electrode of the load main circuit. Figure 6 , the short-circuit protection driving method specifically includes the following steps:
[0045] S101. Collect the current signal of the load current in the load main circuit through the current sensor S1.
[0046] S102. Analyze the current signal using a phase-locked loop analysis method to determine the current direction and magnitude of the load current.
[0047] Among them, the current sensor can feed back the current signal to the control module in the first drive circuit or the second drive circuit, and the control module can be programmed with software to identify the size and angular frequency of the current signal, thereby identifying whether the current is the positive half-wave or negative half-wave of the sine wave to determine the current direction and current size.
[0048] S103. Determine whether a short circuit occurs in the load main circuit according to the current size. If a short circuit occurs in the load main circuit, execute step S104.
[0049] If there is no short circuit in the main line of the load, the current signal continues to be detected.
[0050] S104. Determine whether the load current is a positive current or a negative current according to the current direction. If the load current is a positive current, execute step S105; if the load current is a negative current, execute step S106.
[0051] S105. Control the gate voltage of the first silicon carbide MOS module to a first gate voltage through the first driving circuit, and control the gate voltage of the second silicon carbide MOS module to a second gate voltage through the second driving circuit, wherein the first gate voltage is greater than the second gate voltage.
[0052] S106. Control the gate voltage of the first silicon carbide MOS module to a first gate voltage through the first driving circuit, and control the gate voltage of the second silicon carbide MOS module to a second gate voltage through the second driving circuit, wherein the first gate voltage is less than the second gate voltage.
[0053] The implementation principle of this embodiment is:
[0054] In a half-bridge circuit, the lower the gate voltage of the MOS module, the greater the equivalent resistance, so the silicon carbide MOS module with a low gate voltage will divide a higher intermediate voltage. According to this principle, when the MOS module has a crosstalk problem that causes the gate to be out of control, which in turn causes a short circuit in the load main circuit, the control module in the first drive circuit and the second drive circuit monitors the short-circuit current through the current sensor and determines the current direction of the load current. At this time, the gate voltage of the first silicon carbide MOS module is controlled by the first drive circuit, and the gate voltage of the second silicon carbide MOS module is controlled by the second drive circuit. By controlling the gate voltage of the two silicon carbide MOS modules, the short-circuit impact power of any one silicon carbide MOS module can be reduced, and the short-circuit impact power of the two silicon carbide MOS modules can be shared more evenly, thereby achieving the purpose of circuit short-circuit protection.
[0055] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as above, which are not provided in detail for the sake of simplicity.
[0056] One or more embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.
Claims
1. A short circuit protection drive circuit, It is characterized in that The invention comprises a first silicon carbide MOS module, a second silicon carbide MOS module, a first drive circuit, a second drive circuit and a current sensor S1. The first silicon carbide MOS module and the second silicon carbide MOS module are connected in series with a load main circuit to form a half-bridge circuit. The current sensor S1 is connected to the load main circuit. The current sensor S1 is used to detect a current signal between the first silicon carbide MOS module and the second silicon carbide MOS module in the load main circuit. The first drive circuit and the second drive circuit are both connected to the current sensor S1. The first drive circuit is connected to the first silicon carbide MOS module. The first drive circuit is used to control the gate voltage of the first silicon carbide MOS module according to the current signal. The second drive circuit is connected to the second silicon carbide MOS module. The second drive circuit is used to control the gate voltage of the second silicon carbide MOS module according to the current signal.
2. A short circuit protection driving circuit according to claim 1, It is characterized in that The first silicon carbide MOS module and the second silicon carbide MOS module are both silicon carbide NMOS tubes.
3. A short circuit protection driving circuit according to claim 2, It is characterized in that The first silicon carbide MOS module and the second silicon carbide MOS module are both connected in parallel with diodes for sharing current.
4. A short circuit protection driving circuit according to claim 2, It is characterized in that The drain of the first silicon carbide MOS module is connected to the positive electrode of the load main circuit, the gate of the first silicon carbide MOS module is connected to the first drive circuit, the source of the first silicon carbide MOS module is connected to the drain of the second silicon carbide MOS module, the gate of the second silicon carbide MOS module is connected to the second drive circuit, the source of the second silicon carbide MOS module is connected to the negative electrode of the load main circuit, and the current sensor S1 is connected in parallel between the source of the first silicon carbide MOS module and the drain of the second silicon carbide MOS module.
5. A short circuit protection driving circuit according to claim 4, It is characterized in that The first driving circuit includes a first control module, a first driving power supply V1, a second driving power supply V2, a third driving power supply V3, a first NMOS tube Q1N, a first PMOS tube Q1P, a second NMOS tube Q2N and a first bypass driving circuit, the power supply voltage of the third driving power supply V3 is less than the power supply voltage of the first driving power supply V1, the first control module is connected to the current sensor S1, the first control module is respectively connected to the gates of the first NMOS tube Q1N, the first PMOS tube Q1P and the second NMOS tube Q2N, the drain of the first NMOS tube Q1N is connected to the positive electrode of the first driving power supply V1, and the third PMOS tube Q1P is connected to the positive electrode of the first driving power supply V1. The drain of the second NMOS tube Q2N is connected to the positive electrode of the third driving power supply V3, the source of the first PMOS tube Q1P is connected to the negative electrode of the second driving power supply V2, the negative electrode of the first driving power supply V1, the positive electrode of the second driving power supply V2 and the negative electrode of the third driving power supply V3 are all connected in parallel to the source of the first silicon carbide MOS module, the source of the second NMOS tube Q2N is connected in series to the gate of the first silicon carbide MOS module through the first bypass driving circuit, and the source of the first NMOS tube Q1N and the drain of the first PMOS tube Q1P are connected in parallel to the gate of the first silicon carbide MOS module through the first bypass driving circuit.
6. A short circuit protection driving circuit according to claim 5, It is characterized in that The first bypass drive circuit includes a first turn-off diode D1, a first drive resistor R1 and a second drive resistor R2, the second drive resistor R2 is connected in series between the source of the second NMOS tube Q2N and the gate of the first silicon carbide MOS module, and the first turn-off diode D1 and the first drive resistor R1 are connected in parallel to both ends of the second drive resistor R2.
7. A short circuit protection driving circuit according to claim 5, It is characterized in that The second driving circuit includes a second control module, a fourth driving power supply V4, a fifth driving power supply V5, a sixth driving power supply V6, a third NMOS tube Q3N, a second PMOS tube Q2P, a fourth NMOS tube Q4N and a second bypass driving circuit, the power supply voltage of the sixth driving power supply V6 is less than the power supply voltage of the fourth driving power supply V4 and the power supply voltage of the first driving power supply V1, the power supply voltage of the third driving power supply V3 is less than the power supply voltage of the fourth driving power supply V4, the second control module is connected to the current sensor S1, the second control module is respectively connected to the gates of the third NMOS tube Q3N, the second PMOS tube Q2P and the fourth NMOS tube Q4N, the third NMOS tube Q The drain of the fourth NMOS tube Q3N is connected to the positive electrode of the fourth driving power supply V4, the drain of the fourth NMOS tube Q4N is connected to the positive electrode of the sixth driving power supply V6, the source of the second PMOS tube Q2P is connected to the negative electrode of the fifth driving power supply V5, the negative electrode of the fourth driving power supply V4, the positive electrode of the fifth driving power supply V5 and the negative electrode of the sixth driving power supply V6 are all connected in parallel to the source of the first silicon carbide MOS module, the source of the fourth NMOS tube Q4N is connected in series to the gate of the first silicon carbide MOS module through the second bypass driving circuit, and the source of the third NMOS tube Q3N and the drain of the second PMOS tube Q2P are connected in parallel to the gate of the first silicon carbide MOS module through the second bypass driving circuit.
8. A short circuit protection driving circuit according to claim 7, It is characterized in that The second bypass drive circuit includes a second turn-off diode D2, a third drive resistor R3 and a fourth drive resistor R4, the fourth drive resistor R4 is connected in series between the source of the fourth NMOS tube Q4N and the gate of the second silicon carbide MOS module, and the second turn-off diode D2 and the third drive resistor R3 are connected in parallel to both ends of the fourth drive resistor R4.
9. A short circuit protection driving device, It is characterized in that It comprises the short-circuit protection driving circuit as claimed in any one of claims 1 to 8.
10. A short circuit protection driving method, It is characterized in that Applicable to the short-circuit protection driving circuit according to any one of claims 1 to 8, the first silicon carbide MOS module is connected to the positive electrode of the load main circuit, and the second silicon carbide MOS module is connected to the negative electrode of the load main circuit, and the method comprises the following steps: The current sensor S1 is used to collect the current signal of the load current in the load main circuit; Analyzing the current signal using a phase-locked loop analysis method to determine the current direction and current magnitude of the load current; Determining whether a short circuit occurs in the load main circuit according to the current magnitude; If a short circuit occurs in the load main circuit, judging whether the load current is a positive current or a negative current according to the current direction; If the load current is a forward current, the gate voltage of the first silicon carbide MOS module is controlled to be a first gate voltage through a first driving circuit, and the gate voltage of the second silicon carbide MOS module is controlled to be a second gate voltage through a second driving circuit, and the first gate voltage is greater than the second gate voltage; If the load current is a negative current, the gate voltage of the first silicon carbide MOS module is controlled to be a first gate voltage through a first driving circuit, and the gate voltage of the second silicon carbide MOS module is controlled to be a second gate voltage through a second driving circuit, and the first gate voltage is less than the second gate voltage.