Driving control system applied to silicon carbide MOS tube

Abstract

The invention discloses a driving control system applied to a silicon carbide MOS tube, which comprises a negative voltage module and a driving control module, and is characterized in that the negative voltage module is used for converting a first input voltage into a negative voltage to be output; the driving control module is used for converting the negative voltage output into negative voltage driving output to the silicon carbide MOS tube, the driving control module comprises a driving enhancement unit, and the driving enhancement unit is used for amplifying the negative voltage driving. Through negative voltage output generated by the negative voltage module, the problem of misconduction caused by grid charge residue is eliminated, serious consequences such as current out-of-control, device overheating and even machine explosion caused by accidental conduction of the grid are avoided, the reliability of the system is improved, and the service life of the silicon carbide MOS tube is prolonged. Meanwhile, a driving enhancement unit in the driving control module performs waveform optimization and enhancement on the driving signal, so that the silicon carbide MOS tube can respond to the driving signal more quickly in the switching process, the switching loss is reduced, and the switching efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of MOS tube driving, and more specifically, to a driving control system applied to silicon carbide MOS tubes. Background Art

[0002] With the development of science and technology, people's demand for electricity is increasing, and power supplies are becoming more and more high-voltage and high-power density, which also leads to smaller and smaller power supplies, while the power is getting higher and higher. In order to meet these needs, people usually choose silicon carbide MOS tubes as switch tubes because of their excellent characteristics of high withstand voltage, low on-resistance and faster switching speed. However, compared with traditional power devices, the faster switching speed dv / dt of silicon carbide MOS tubes also means an increased risk of gate mis-conduction, which can easily cause problems such as explosion.

[0003] The above shortcomings need to be improved. Summary of the invention

[0004] In order to solve or alleviate the problem in the prior art that the gate of a silicon carbide MOS tube is easily mis-turned on, the present invention provides a drive control system applied to a silicon carbide MOS tube.

[0005] The technical solution of the present invention is as follows:

[0006] A drive control system applied to a silicon carbide MOS tube, comprising:

[0007] A negative pressure module, the negative pressure module is used to convert a first input voltage into a negative pressure output;

[0008] A drive control module, the drive control module is used to convert the negative voltage output into a negative voltage drive output to the silicon carbide MOS tube, the drive control module includes a drive enhancement unit, and the drive enhancement unit is used to amplify the negative voltage drive.

[0009] Further, the negative pressure module includes a negative pressure generating unit, which includes a first transformer winding T1-C and a second transformer winding, the first end of the first transformer winding T1-C is connected to the first input voltage and the positive electrode of the first diode, the negative electrode of the first diode is connected to the second input voltage, the first end of the first capacitor and the first end of the second capacitor, the second end of the first capacitor and the second end of the second capacitor are connected to the ground and the first end of the third capacitor, the second end of the first transformer winding T1-C and the first end of the second transformer winding are connected, and the second end of the first transformer winding T1-C and the first end of the second transformer winding are grounded, the second end of the second transformer winding is connected to the negative electrode of the second diode, the positive electrode of the second diode is connected to the first end of the first resistor, and the first end of the first resistor is connected to the second end of the third capacitor and the negative voltage output.

[0010] Furthermore, the negative voltage module includes a first voltage stabilizing circuit, the first voltage stabilizing circuit includes a voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the second end of the first capacitor, and the anode of the voltage stabilizing diode is connected to the negative voltage output.

[0011] Further, the drive control module includes a drive wave simulation unit, the drive wave simulation unit includes a comparator, the positive input end of the comparator is connected to the PWM wave generating chip, the reverse input end of the comparator is connected to the reference voltage, the power supply end of the comparator is connected to the power supply and the first end of the second capacitor, the second end of the second capacitor is connected to the comparator ground end and the negative voltage output, the output end of the comparator is connected to the drive enhancement unit, and a second resistor is connected between the positive input end and the output end of the comparator.

[0012] Furthermore, the drive control module includes a first filtering unit, the first filtering unit includes an RC filtering circuit composed of a third resistor and a third capacitor, and the first filtering unit is connected between the positive input terminal of the comparator and the PWM wave generating chip.

[0013] Furthermore, the drive control module includes a first voltage divider unit, the first voltage divider unit includes a fourth resistor and a fifth resistor, a fourth capacitor is connected in parallel across the fifth resistor, and the first voltage divider unit is connected to the reference voltage and the inverting input terminal of the comparator.

[0014] Further, the driving control module includes a second voltage dividing unit, the second voltage dividing unit is connected between the driving wave simulation unit and the driving enhancement unit, the second voltage dividing unit includes a sixth resistor and a seventh resistor, and a first end of the sixth resistor is connected to a power supply.

[0015] Furthermore, the driving enhancement unit includes a driving chip, and a GND pin, an INB pin and a U12 pin of the driving chip are connected to the negative voltage output.

[0016] Furthermore, a driving damping unit is provided between the driving enhancement unit and the silicon carbide MOS tube, and the driving damping unit comprises a first driving resistor and a second driving resistor, and the first driving resistor and the second driving resistor are connected in parallel.

[0017] Furthermore, the first driving resistor and the second driving resistor are connected in parallel with a discharge unit, and the discharge unit includes a third diode and a discharge resistor connected in series, the cathode of the third diode is connected to the OUTA pin of the driving chip, the anode of the third diode is connected to the first end of the discharge resistor, and the second end of the discharge resistor is connected to the gate of the silicon carbide MOS tube.

[0018] The beneficial effect of the present invention according to the above scheme is that the present invention effectively eliminates the problem of mis-conduction caused by residual gate charge through the negative pressure output generated by the negative pressure module, thereby avoiding serious consequences such as current loss of control, device overheating and even explosion caused by accidental gate conduction, which not only improves the reliability of the system, but also extends the service life of the silicon carbide MOS tube. At the same time, the drive enhancement unit in the drive control module optimizes and enhances the waveform of the drive signal, so that the silicon carbide MOS tube can respond to the drive signal faster during the switching process, reducing switching losses and improving switching efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 Schematic diagram of the circuit structure of the medium negative pressure module of the present invention;

[0021] Figure 2 It is a schematic diagram of the circuit structure of the driving control module of the present invention. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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.

[0023] It should be noted that when a component is referred to as being "fixed" or "set" or "connected" to another component, it may be located directly or indirectly on the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and should not be construed as limitations on the present technical solution. The terms "first", "second", etc. are only used for the convenience of description and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0024] like Figure 1 and Figure 2As shown, a drive control system applied to a silicon carbide MOS tube described in one embodiment of the present invention includes a negative pressure module and a drive control module. The negative pressure module is used to convert a first input voltage into a negative pressure output; the drive control module is used to convert the negative pressure output into a negative pressure drive output to the silicon carbide MOS tube, and the drive control module includes a drive enhancement unit, which is used to amplify the negative pressure drive.

[0025] When working, the first input voltage (positive voltage) is input into the negative voltage module, and the first input voltage is converted into a negative voltage output through the conversion of the negative voltage module. The negative voltage output is used as the reference ground of the drive control module to ensure that the voltage between the gate and the source is always kept within a safe range, that is, lower than the gate's conduction voltage threshold, effectively eliminating the problem of misconduction caused by residual gate charge. The drive control module processes the negative voltage output of the negative voltage module, amplifies the negative voltage signal through the drive enhancement unit, and optimizes its waveform. The drive enhancement unit enhances the amplitude of the drive signal to ensure the rapid response and stability of the signal and enhance the drive capability of the silicon carbide MOS tube.

[0026] In this embodiment, by setting a negative pressure module and a drive control module, the stability and safety of the silicon carbide MOS tube when used in a high voltage and high power density environment are ensured. The negative pressure output generated by the negative pressure module effectively eliminates the problem of misconduction caused by residual gate charge, thereby avoiding serious consequences such as current runaway, device overheating, and even machine explosion caused by accidental gate conduction, which not only improves the reliability of the system, but also extends the service life of the silicon carbide MOS tube. At the same time, the drive enhancement unit in the drive control module optimizes and enhances the waveform of the drive signal, so that the silicon carbide MOS tube can respond to the drive signal faster during the switching process, reducing switching losses and improving switching efficiency.

[0027] like Figure 1 As shown, in a preferred embodiment, the negative pressure module includes a negative pressure generating unit, which includes a first transformer winding T1-C and a second transformer winding T1-B, a first end of the first transformer winding T1-C is connected to a first input voltage VC and a positive electrode of a first diode D14, a negative electrode of the first diode D14 is connected to a second input voltage VCC 13V, a first end of a first capacitor C6 and a first end of a second capacitor C82, a second end of the first capacitor C6 and a second end of the second capacitor C82 are connected to ground and a first end of a third capacitor C30, a second end of the first transformer winding T1-C is connected to a first end of a second transformer winding T1-B, and a second end of the first transformer winding T1-C and a first end of the second transformer winding T1-B are grounded, a second end of the second transformer winding T1-B is connected to a negative electrode of a second diode D5, a positive electrode of the second diode D5 is connected to a first end of a first resistor R28, and a first end of the first resistor R28 is connected to a second end of the third capacitor C30 and a negative pressure output (-4V).

[0028] The negative voltage module includes a first voltage stabilizing circuit, which includes a voltage stabilizing diode Z3, a cathode of the voltage stabilizing diode Z3 connected to the second end of the first capacitor C6, and an anode of the voltage stabilizing diode Z3 connected to the negative voltage output.

[0029] The 6th pin of the first transformer winding T1-C is grounded to 0V, and the 5th pin is connected to the 12V VC. The number of turns of the first transformer winding T1-C is 5, and the number of turns of the second transformer winding T1-B is 2. According to the turn ratio conversion, the voltage of the 4th pin is 12 / 5*2=4.8V, and the 4th and 6th pins are the same-name terminals of the transformer winding, both of which are low-potential terminals, so the actual voltage of the 4th pin is -4.8V, plus the voltage drop of the second diode D5 of 0.7V, at this time the voltage of the negative voltage output is -4.1V, and the negative voltage output is provided to the comparator U35-A and the driver chip U12 as a reference ground. A 6.2V voltage regulator diode Z3 is connected between the negative voltage output and the ground to prevent voltage mutation.

[0030] like Figure 2 As shown, in a preferred embodiment, the drive control module includes a drive wave simulation unit, which includes a comparator U35-A, the positive input terminal of the comparator U35-A is connected to the PWM wave generating chip, the reverse input terminal of the comparator U35-A is connected to the reference voltage +5V, the power supply terminal of the comparator U35-A is connected to the power supply VCC and the first terminal of the second capacitor C12, the second terminal of the second capacitor C11 is connected to the ground terminal and the negative voltage output of the comparator U35-A, the output terminal of the comparator U35-A is connected to the drive enhancement unit, and a second resistor R30 is connected between the positive input terminal and the output terminal of the comparator U35-A.

[0031] The drive control module includes a first filter unit, which includes an RC filter circuit composed of a third resistor R38 and a third capacitor C11. The first filter unit is connected between the positive input terminal of the comparator U35-A and the PWM wave generating chip.

[0032] The drive control module includes a first voltage divider unit, which includes a fourth resistor R45 and a fifth resistor R43, and a fourth capacitor C24 is connected in parallel at both ends of the fifth resistor R43. The first voltage divider unit is connected to the reference voltage +5V and the reverse input terminal of the comparator U35-A. The voltage is reduced to a suitable value of the reverse input terminal of the comparator U35-A to prevent voltage overstress and chip damage.

[0033] The driving control module includes a second voltage dividing unit, which is connected between the driving wave simulation unit and the driving enhancement unit. The second voltage dividing unit includes a sixth resistor R23 and a seventh resistor R113, and a first end of the sixth resistor R23 is connected to the power supply VCC. The voltage is reduced to a suitable value of the input pin of the driving chip U12 to prevent voltage overstress and chip damage.

[0034] The driving enhancement unit includes a driving chip U12, and a GND pin, an INB pin and a U12 pin of the driving chip U12 are connected to a negative voltage output.

[0035] The driving wave BPWM emitted by the PWM wave chip is sent to the 3rd pin of the comparator U35-A through the resistor R38, and the reference voltage +5V is sent to the 2nd pin of the comparator U35-A after the voltage is divided by the fourth resistor R45 and the fifth resistor R43. After the comparator U35-A compares the signals of the 2nd and 3rd pins, when the voltage of the 3rd pin is higher than the voltage of the 2nd pin, the 1st pin outputs high impedance, and the power supply VCC provides a high level through the voltage division of the sixth resistor R23 and the seventh resistor R113; when the voltage of the 3rd pin is lower than the voltage of the 2nd pin, the 1st pin chip is grounded internally, which is equivalent to outputting a low level. By continuously comparing the high and low levels, a signal similar to the driving wave is simulated. At this time, the reference ground of the driving wave signal becomes -4V of the comparator and is transmitted to the 2nd pin of the driving chip U12. The specific model of the driving chip U12 can be MD18624GAE.

[0036] like Figure 2 As shown, in a preferred embodiment, a driving damping unit is provided between the driving enhancement unit and the silicon carbide MOS tube, and the driving damping unit includes a first driving resistor R95 and a second driving resistor R236, and the first driving resistor R95 and the second driving resistor R236 are connected in parallel.

[0037] The first driving resistor R95 and the second driving resistor R236 are connected in parallel with a discharge unit, and the discharge unit includes a third diode D12 and a discharge resistor R194 connected in series, the cathode of the third diode D12 is connected to the OUTA pin of the driving chip, the anode of the third diode D12 is connected to the first end of the discharge resistor R194, and the second end of the discharge resistor R194 is connected to the gate of the silicon carbide MOS tube Q4.

[0038] The output end of the driver chip U12 integrates a totem pole circuit, which further enhances the current driving capability of the input signal, and transmits it to the gate of the silicon carbide MOS tube Q4 through the first drive resistor R95 and the second drive resistor R236 through pin 7. The drive damping unit provides sufficient damping in the drive circuit to damp the oscillation of the drive current when the silicon carbide MOS tube Q4 is turned on. At the same time, it prevents the silicon carbide MOS tube Q4 from being turned on again by mistake due to a large dv / dt when the silicon carbide MOS tube Q4 is turned off. The source of the silicon carbide MOS tube Q4 is connected to the 0V ground, and the gate is connected to the -4V reference ground. When the drive signal is low, that is, the silicon carbide MOS tube Q4 is turned off, there is a -4V voltage difference between the gate and the source, and the silicon carbide MOS tube Q4 is completely turned off, realizing the negative voltage drive function of the silicon carbide MOS tube.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A drive control system applied to a silicon carbide MOS tube, characterized in that: include: A negative pressure module, the negative pressure module is used to convert the first input voltage into a negative pressure output; A drive control module, the drive control module is used to convert the negative voltage output into a negative voltage drive output to the silicon carbide MOS tube, the drive control module includes a drive enhancement unit, and the drive enhancement unit is used to amplify the negative voltage drive.

2. A drive control system for silicon carbide MOS tube according to claim 1, characterized in that: The negative voltage module includes a negative voltage generating unit, which includes a first transformer winding T1-C and a second transformer winding, the first end of the first transformer winding T1-C is connected to the first input voltage and the positive electrode of the first diode, the negative electrode of the first diode is connected to the second input voltage, the first end of the first capacitor and the first end of the second capacitor, the second end of the first capacitor and the second end of the second capacitor are connected to the ground and the first end of the third capacitor, the second end of the first transformer winding T1-C and the first end of the second transformer winding are connected, and the second end of the first transformer winding T1-C and the first end of the second transformer winding are grounded, the second end of the second transformer winding is connected to the negative electrode of the second diode, the positive electrode of the second diode is connected to the first end of the first resistor, and the first end of the first resistor is connected to the second end of the third capacitor and the negative voltage output.

3. A drive control system for silicon carbide MOS tube according to claim 2, characterized in that: The negative voltage module includes a first voltage stabilizing circuit, the first voltage stabilizing circuit includes a voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the second end of the first capacitor, and the anode of the voltage stabilizing diode is connected to the negative voltage output.

4. A drive control system for silicon carbide MOS tube according to claim 2, characterized in that: The driving control module includes a driving wave simulation unit, which includes a comparator. The positive input end of the comparator is connected to the PWM wave generating chip, the negative input end of the comparator is connected to the reference voltage, the power supply end of the comparator is connected to the power supply and the first end of the second capacitor, the second end of the second capacitor is connected to the ground end of the comparator and the negative voltage output, the output end of the comparator is connected to the driving enhancement unit, and a second resistor is connected between the positive input end and the output end of the comparator.

5. A drive control system for silicon carbide MOS tube according to claim 4, characterized in that: The driving control module includes a first filtering unit, which includes an RC filtering circuit composed of a third resistor and a third capacitor. The first filtering unit is connected between the positive input terminal of the comparator and the PWM wave generating chip.

6. A driving control system for silicon carbide MOS tube according to claim 4, characterized in that: The driving control module includes a first voltage dividing unit, which includes a fourth resistor and a fifth resistor. A fourth capacitor is connected in parallel at both ends of the fifth resistor. The first voltage dividing unit is connected to the reference voltage and the inverting input end of the comparator.

7. A drive control system for silicon carbide MOS tube according to claim 4, characterized in that: The driving control module includes a second voltage dividing unit connected between the driving wave simulation unit and the driving enhancement unit. The second voltage dividing unit includes a sixth resistor and a seventh resistor. A first end of the sixth resistor is connected to a power supply.

8. A driving control system for silicon carbide MOS tube according to claim 1, characterized in that: The driving enhancement unit comprises a driving chip, and a GND pin, an INB pin and a U12 pin of the driving chip are connected to the negative voltage output.

9. A driving control system for silicon carbide MOS tube according to claim 8, characterized in that: A driving damping unit is arranged between the driving enhancement unit and the silicon carbide MOS tube. The driving damping unit includes a first driving resistor and a second driving resistor. The first driving resistor and the second driving resistor are connected in parallel.

10. A driving control system for silicon carbide MOS tube according to claim 9, characterized in that: The first driving resistor and the second driving resistor are connected in parallel with a discharge unit, and the discharge unit includes a third diode and a discharge resistor connected in series, the cathode of the third diode is connected to the OUTA pin of the driving chip, the anode of the third diode is connected to the first end of the discharge resistor, and the second end of the discharge resistor is connected to the gate of the silicon carbide MOS tube.

Images