VSG限流控制的光储并网系统故障穿越策略OA北大核心CSTPCD

The VSG-controlled voltage source converter effectively supports the PCC point voltage during grid faults.However,it is prone to overcurrent phenomenon,which seriously affects the safe operation of the system.This paper takes the PV-ES system as an example and conducts research on the VSG current limiting control method during the fault period,in which the PV system adopts the grid-following type of control,and the ES system adopts the VSG control.First,the topology and control strategy of the PV-ES system are analyzed,and the mathematical model of the VSG control strategy is built to study the mechanism of providing voltage support for the system.Second,the transient current characteristics and power angle characteristics of the VSG converter are analyzed during the grid voltage drop.Our results show during the fault period,the VSG converter outputs a large short-circuit current.Meanwhile,there is a transient oscillation in the virtual rotor speed of VSG,and if the duration of the fault is longer,there is a transient oscillation in the virtual rotor speed of VSG oscillation,which may lead to system instability if the fault lasts for a long time.Again,a fault ride-through strategy based on VSG current limiting control is realized by combining the PV system voltage support strategy,virtual impedance technology,and dynamic power regulation method.Finally,the effectiveness of the proposed control strategy is verified in PSCAD/EMTDC electromagnetic transient simulation software,and the ability of the method to support the voltage at the PCC point and limit the overcurrent of VSG is investigated.The fault ride-through method proposed in this paper not only realizes the effective support of the PCC voltage in the PV-ES system,but also suppresses the overcurrent problem of the VSG converter.