【摘要】 一种基于虚拟异步机的并网逆变器实现方法被提出,通过建立并模拟异步电动机电磁及机械暂态模型,使并网逆变电源电压及电流特性等效为实际异步电动机及其负载。在功率控制模式下,通过设定发电转矩阈值使其工作于回馈制动模式,并向电网注入有功功率;配合无功复合控制,可使电网电压运行于单位功率因素,且当有功功率变化时,电网与系统均没有无功交换。模拟转子串联电阻分级起动模式,可有效降低并网电流,且无需锁相环和预同步环节,提高了并网的可靠性与安全性。仿真结果验证了所提方案的可行性和有效性。更多还原

【Abstract】 An implementation method of grid-connected inverters based on virtual asynchronous machine is presented, the voltage and current characteristics of the grid-connected inverters are equivalent to the actual asynchronous machine and its load by simulating its electromagnetic and mechanical transient model. Under the power control mode, the generating torque threshold is set to make it work in the feedback braking mode, and the active power is injected into the grid. The grid voltage can be operated at the unit power factor through the cooperation of the reactive compound control, and when the active power changes, there is no reactive power exchange between the grid and the system. Step-by-step starting by the simulation of the series resistance on the rotor can effectively reduce the grid-connected current, which improve the reliability and security of grid connection without phase-locked loops and pre-synchronization. Simulation results verify the feasibility and effectiveness of the presented scheme.更多还原