Study on Optimal Operation of Multi-Port Cascaded Power Electronic Transformer Cluster

The application of multi-port cascaded power electronic tramsformer (PET) in AC/DC hybrid distribution network is of great significance to solve the problem of high proportion of distributed renewable energy sources and DC loads. By introducing the multi-voltage level four-port PET model, a multi-port PET cluster is proposed to optimize the operation system structure, and a dynamic energy efficiency model of the PET port is established. Combining the PET port control mode, the operation control mode of M N-port PET cluster system is proposed. The optimal operation efficiency optimization model of M N-port PET cluster is established. Based on the typical load data of an industrial park in Dongguan city, two and three 4-port PET cluster operation scenarios and load sharing scenarios were set up to solve the constrained non-linear model. The results show that the efficiency optimization method for PET cluster operation has better system efficiency, and in low load period, the system efficiency is improved. The high load period is more significant, which shows the advantages of PET cluster operation in improving the energy efficiency of key devices in distribution network, and provides theoretical support for the popularization and application of PET.