A discrete state event driven simulation based losses analysis for multi-terminal megawatt power electronic transformer

At present, power electronic transformers (PETs) have been widely used in power systems. With the increase of PET capacity to the megawatt level. the problem of increased losses need to be taken seriously. As an important indicator of power electronic device designing, losses have always been the focus of attention. At present, the losses are generally measured through experiments, but it takes a lot of time and is difficult to quantitatively analyze the internal distribution of PET losses. To solve the above problems, this article first qualitatively analyzes the losses of power electronic devices and proposes a loss calculation method based on pure simulation. This method uses the Discrete State Event Driven (DSED) modeling method to solve the problem of slow simulation speed of large-capacity power electronic devices and uses a loss calculation method that considers the operating conditions of the device to improve the calculation accuracy. For the PET prototype in this article, a losses model of the PET is established. The comparison of experimental and simulation results verifies the feasibility of the losses model. Then the losses composition of PET was analyzed to provide reference opinions for actual operation. It can help pre-analyze the losses distribution of PET, thereby providing a potential method for improving system efficiency.