基于改进下垂控制的多模块谐振变换器均衡控制策略研究OA北大核心CSTPCD

Due to the rapid development of power elec-tronics technology,medium-voltage DC transmission has attracted more and more attention in DC confluence occasions of photovoltaic,offshore wind power and other new energy stations due to its suitability for long-distance transmission.In the case of low-voltage input and medium-voltage confluence output of new energy power generation,in order to increase the DC transmission voltage and further reduce device stress,the input-parallel output-series(IPOS)structure is often used.Although this modular series-parallel structure has many advantages,due to the device parameter error between modules,there is a problem of unbalanced voltage and current in each module,which affects the stable operation of the entire power conversion system.For this reason,this paper proposes an IPOS multi-module improved droop control equalization method for medium-voltage DC confluence applications.It can realize the complete balance of output voltage and power of each module without adding communication between modules,which improves the traditional droop control the problem that the voltage does not match the reference value,and further improve the dynamic response performance of the system.Based on this control method,a three-way modular IPOS system prototype is built,and the equilibrium effect of the proposed droop control method on the IPOS system is verified through experiments.