基于多环虚拟同步发电机的功率控制

Power Control Based on Multi-loop Virtual Synchronous Generator

在传统下垂控制中,由于缺乏惯性和过度下垂特性的限制,微电网电压、频率在负荷变化过程中会出现波动过快以及偏差越限现象。针对这一问题,提出一种多环虚拟同步发电机(virtual synchronous generator,VSG)功率控制策略。首先,在有功-频率下垂控制中引入虚拟惯性和一次调频控制器,抑制频率振荡并解决有功负荷突增引起的频率偏差越限问题;其次,在无功-电压下垂控制中引入虚拟励磁和一次调压控制器,抑制电压幅值振荡并解决无功负荷突增引起的电压偏差越限问题;最后,结合电压、电流双闭环控制,可以有效保证VSG供电电能质量。应用M ATLAB/Simulink软件搭建了微电网仿真模型进行仿真,结果验证了该控制策略的可行性与有效性。

In traditional drop control,voltage and frequency of the micro-grid may fluctuate too fast and offset more during load change due to restriction of lack of inertial and excessive drop characteristic.Therefore,this paper proposes a kind of power control strategy for the multi-loop virtual synchronous generator(VSG)which firstly introduces virtual inertial and primary frequency modulation controller in active power-frequency drop control so as to restrain frequency oscillation and solve the problem of frequency offset caused by sudden increase of active power load.Secondly,by introducing virtual excitation and primary voltage modulation controller in reactive power-frequency drop control,this strategy could restrain voltage oscillation and solve the problem of voltage offset caused by sudden increase of reactive power load.Finally,by combining double closed loop control of voltage and current,the strategy could effectively ensure power supply quality of VSG.The paper also uses MATLAB/Simulink software to establish a micro-grid simulation model to verify feasibility and effectiveness of this control strategy.