Protection circuit for detecting drain-source voltage of SicMOSFET based on high-speed isolation operational amplifier

Abstract

The invention discloses a protection circuit for detecting drain-source voltage of a SicMOSFET based on a high-speed isolation operational amplifier, which is applied to a motor driver of a motor and comprises an impact suppression circuit arranged in an electric driver circuit, the input end of the impact suppression circuit is connected with a capacitor and an inverter bridge in parallel, the impact suppression circuit is provided with a SicMOSFET tube, and the SicMOSFET tube is connected with the inverter bridge in parallel. The output end of the SicMOSFET is connected with a high-speed isolation operational amplifier conditioning circuit, the high-speed isolation operational amplifier conditioning circuit is used for detecting drain-source voltage of the SicMOSFET, and the output end of the high-speed isolation operational amplifier conditioning circuit is connected with a DSP controller. According to the invention, the drain-source voltage of the SicMOSFET tube can be monitored in real time, the DSP controller is matched to drive the motor to work in different states according to the value of the drain-source voltage, the current passing through the SicMOSFET tube is reduced, the SicMOSFET tube is protected from being damaged due to overheating, and the use reliability of the impact suppression circuit of the motor driver is improved.

Description

Technical Field

[0001] This invention relates to the field of voltage protection circuits for aerospace motor drivers, specifically a protection circuit based on high-speed isolation operational amplifier detection of SiCMOSFET drain-source voltage. Background Technology

[0002] In traditional aerospace motor drives, SiS MOSFETs are typically used to suppress the charging current of capacitors during instantaneous power-up to prevent excessive charging current from adversely affecting the entire power supply system.

[0003] However, power outages or power transitions may damage the SiS MOSFET. This is mainly because the motor does not stop immediately during power outages or transitions. When the power returns to a steady state, the SiS MOSFET in the surge suppression circuit will re-enter the saturation region. At this time, the SiS MOSFET will inevitably pass through the variable resistance region. Since the motor is still running, current will flow through the SiS MOSFET. The on-resistance of the SiS MOSFET is relatively high, which can cause the SiS MOSFET to overheat and be damaged, leading to the failure of the surge suppression circuit or the product's functionality. To address this, a protection circuit based on high-speed isolation operational amplifier detection of SiCMOSFET drain-source voltage is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a protection circuit based on high-speed isolation operational amplifier detection of SiCMOSFET drain-source voltage, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a protection circuit based on high-speed isolated operational amplifier detection of SiCMOSFET drain-source voltage, applied in a motor driver for an electric motor, including a surge suppression circuit disposed in the motor driver circuit. The input terminal of the surge suppression circuit is connected in parallel with a capacitor and an inverter bridge. The surge suppression circuit has a SiCMOSFET, and the output terminal of the SiCMOSFET is connected to a high-speed isolated operational amplifier conditioning circuit. The high-speed isolated operational amplifier conditioning circuit is used to detect the drain-source voltage of the SiCMOSFET. The output terminal of the high-speed isolated operational amplifier conditioning circuit is connected to a DSP controller used to determine the operating region of the SiCMOSFET. The output terminal of the DSP controller is connected to the inverter bridge, and the output terminal of the inverter bridge is connected to the motor.

[0006] Furthermore, the input terminal of the surge suppression circuit is connected to a power supply module, which is 270VDC.

[0007] Furthermore, a control and drive circuit is provided between the input terminal of the inverter bridge and the output terminal of the DSP controller.

[0008] The beneficial effects of this invention are: This invention uses a high-speed isolated operational amplifier conditioning circuit to monitor the drain-source voltage of the SiCMOSFET in real time, and works with a DSP controller to drive the motor to operate in different states according to the value of the drain-source voltage, thereby reducing the current through the SiCMOSFET, protecting the SiCMOSFET from overheating and damage, improving the reliability of the motor driver's surge suppression circuit, and solving the problem that the SiCMOSFET in the surge suppression circuit is easily damaged when the power supply changes or is interrupted. Attached Figure Description

[0009] Figure 1 This is a block diagram illustrating the principle of the voltage protection circuit of the present invention.

[0010] In the diagram: 1. Suppression circuit; 2. High-speed isolation operational amplifier conditioning circuit; 3. DSP controller; 4. Control and drive circuit; 5. Capacitor; 6. Inverter bridge; 7. Motor; 8. Power supply module. Detailed Implementation

[0011] 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, and 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.

[0012] Please see Figure 1 This invention provides a technical solution: a protection circuit based on high-speed isolated operational amplifier detection of SiCMOSFET drain-source voltage, applied in a motor driver of an electric motor 7. It includes a surge suppression circuit 1 in the motor driver circuit. The input terminal of the surge suppression circuit 1 is connected in parallel with a capacitor 5 and an inverter bridge 6. The surge suppression circuit 1 has a SiCMOSFET transistor, and the output terminal of the SiCMOSFET is connected to a high-speed isolated operational amplifier conditioning circuit 2. The high-speed isolated operational amplifier conditioning circuit 2 is used to detect the drain-source voltage of the SiCMOSFET transistor. The output terminal of the high-speed isolated operational amplifier conditioning circuit 2 is connected to a DSP controller 3 used to determine the operating region of the SiCMOSFET transistor. The DSP controller 3 mentioned is, but is not limited to, a TMS320C2000 series controller.

[0013] In this embodiment, the output terminal of the DSP controller 3 is connected to the inverter bridge 6, and the output terminal of the inverter bridge 6 is connected to the motor 7. A control and drive circuit 4 is provided between the input terminal of the inverter bridge 6 and the output terminal of the DSP controller 3. The input terminal of the mentioned surge suppression circuit 1 is connected to a power supply module 8, which is 270VDC. By using the high-speed isolated operational amplifier conditioning circuit 2, the drain-source voltage (DS) of the SiC MOSFET is detected. Based on the value of the drain-source voltage, the motor is made to operate in different states, thereby improving the reliability of the surge suppression circuit 1 and solving the problem that the surge suppression circuit 1 is easily damaged during power supply switching and power interruption in the motor driver.

[0014] In motor drivers used in the aerospace field, a support capacitor 5 is typically used to absorb current ripple. The capacitance of this capacitor 5 is usually several hundred to several thousand microfarads. In this high-speed isolated operational amplifier-based protection circuit for detecting the drain-source voltage of a SiCMOSFET, due to the large capacitance of capacitor 5, a surge suppression circuit 1 is often added to the motor driver to limit the charging current of capacitor 5 at the moment of power-on. Through the high-speed isolated operational amplifier conditioning circuit 2, the drain-source voltage of the SiCMOSFET in the surge suppression circuit 1 can be detected. The DSP controller 3 determines the operating region of the SiCMOSFET and then operates the motor in different operating states, reducing the current through the SiCMOSFET and significantly improving the reliability of the surge suppression circuit 1. The capacitor 5 is labeled C1.

[0015] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0016] The above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be understood that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. In the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a mechanical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Among these, there are various ways of detachable installation, such as by using a combination of plug-in and snap-fit, or by using bolt connections, etc.

[0017] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A protection circuit for detecting the drain-source voltage of a SicMOSFET based on a high speed isolated operational amplifier, characterized by: The application relates to a motor driver circuit, which comprises a shock suppression circuit arranged in an electric drive circuit, the input end of the shock suppression circuit being connected with a capacitor and an inverter bridge, the shock suppression circuit being provided with a SicMOSFET tube, the output end of the SicMOSFET tube being connected with a high-speed isolation operational amplifier conditioning circuit, the high-speed isolation operational amplifier conditioning circuit being used for detecting the drain-source voltage of the SicMOSFET tube, the output end of the high-speed isolation operational amplifier conditioning circuit being connected with a DSP controller used for judging the working area of the SicMOSFET tube, the output end of the DSP controller being connected with the inverter bridge, and the output end of the inverter bridge being connected with a motor.

2. The SicMOSFET drain-source voltage protection circuit based on high speed isolated op-amp detection according to claim 1, characterized in that: The input end of the shock suppression circuit is connected with a power module, and the power module is 270VDC.

3. The high speed isolated op amp based detection SicMOSFET drain to source voltage protection circuit of claim 1, wherein: A control and driving circuit is arranged between the input end of the inverter bridge and the output end of the DSP controller.

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