Control method for improving fault-tolerant capability of power electronic transformer

Abstract

The invention discloses a control method for improving the fault-tolerant capability of a power electronic transformer, and belongs to the technical field of power electronic transformer control. According to the technical scheme, the method comprises the steps of detecting and comparing output voltage of each CHB module, voltage of a secondary side of a DC-DC module transformer and DC bus voltagein real time, and if the former is greater than 1.2 times of a rated value and the absolute value of the latter is less than 0.8 times of the DC bus voltage, considering that an open-circuit fault occurs in a DC-DC preceding stage; meanwhile, judging whether the device has a short-circuit fault or not through the voltage in the front-stage series resistor of the device. When it is judged that theDC-DC module device has an open-circuit fault or a short-circuit fault, the fault-tolerant capability of the equipment for the open-circuit fault and the short-circuit fault of the DC-DC module device is improved by reasonably changing the active power instruction transmitted by the power electronic transformer and the operation state of each DC-DC module. The method is applied to reliable operation of the power electronic transformer, solves the fault tolerance problem, and has the effects of improving the fault tolerance capability and improving the equipment reliability.

Description

technical field [0001] The invention relates to the technical field of power electronic transformer control, in particular to a control method for improving the fault tolerance capability of a power electronic transformer. Background technique [0002] A control method for improving the fault tolerance capability of a power electronic transformer is mainly applied to a new power electronic transformer control scheme. Compared with traditional power transformers, power electronic transformers can not only realize functions such as voltage level transformation, electrical isolation and energy transfer, but also realize additional functions such as power flow control and power quality control. Power electronic transformers including resonant DABs have high operating efficiency and good dynamic performance, but their fault tolerance is much lower than that of most closed-loop DC / DC converters. In the operation of power electronic transformers, device failures may occur due to t...

AI Technical Summary

Problems solved by technology

[0003] The traditional fault-tolerant solution achieves fault-tolerant by adding redundant switches to bypass the faulty module. This solution requires additional hardware, and the number of redundancy is limited, which will increase the cost and volume of the system and reduce the reliability of the system operation.

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