Ensure stable output in the presence of disturbance. In case of sudden emergency, the protection can be automatically triggered to stop running, so that the main circuit is not damaged, and can automatically run at the next start. Satisfy a certain control strategy, and can automatically adjust when reaching the maximum limit that the converter can bear. For example, in the high temperature environment, the heat dissipation is poor, which will make the junction temperature of IGBT too high, and if it is too high, it may damage IGBT. At this time, it is necessary to derate the converter and reduce the output power to ensure that it is not damaged