Switch overheating protection method based on SiC MOSFET loss model

Abstract

The invention discloses a switch overheating protection method based on a SiC MOSFET loss model, a switch is a SiC MOSFET, and the method comprises the following steps: constructing the loss model of the SiC MOSFET, and estimating the loss of the SiC MOSFET by collecting a sampling electric signal of the SiC MOSFET; based on the device loss and the steady-state thermal network, the junction temperature of the SiC MOSFET is estimated by collecting the surface temperature of a radiator of a switching device on the high-speed/ultra-high-speed motor controller, the junction temperature is compared with a preset protection threshold value, and overheating protection is carried out on the SiC MOSFET according to the comparison result; the system comprises a DSP control chip, a gate driving chip, a three-phase two-level inverter, a signal sampling circuit and a heat dissipation and temperature measurement module, wherein the DSP control chip is used for executing a switch overheating protection method; according to the invention, the device is prevented from failing or even exploding due to overheat, and the safe operation of the system is not harmed.

Description

Technical field [0001] The present application relates to a motor control system, and in particular, a switch overheating protection method based on a SiC MOSFET loss model. Background technique [0002] For high-speed and ultra-high speed motors, it is necessary to achieve good control accuracy requires inverter circuitry at a higher switching frequency, which results in an increase in the loss of switching devices in the inverter circuit. The increase in loss will increase the temperature of the switching device, which causes the device overheating even an explosion when it reaches its threshold, thus hazard the safe operation of the system. [0003] After years of development, the performance of the silicon-based semiconductor power switching device is close to the limit of the application of its material. It is slightly touched in the application of high-speed and ultra-high-speed motors. SiC MOSFET is fast, high temperature resistance, low loss and heat dissipation. More in ...

AI Technical Summary

Problems solved by technology

[0002] For high-speed and ultra-high-speed motors, in order to achieve good control accuracy, the inverter circuit needs to work at a higher switching frequency, which will increase the loss of switching devices in the inverter circuit

The increase in loss will cause the temperature of the switching device to rise continuously, and when it reaches its threshold, it will cause the device to overheat and fail or even explode, thus endangering the safe operation of the system

[0003] After years of development, the performance of silicon-based semiconductor power switching devices is close to the limit of its material application, and it is a little d

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