基于虚拟电阻的电动汽车负荷虚拟同步机调频性能优化策略  

Optimization strategy of frequency regulation performance of load-side virtual synchronous machine for electric vehicle based on virtual resistance

作　　者：芮月晨 肖国春[1] 何玉瑞 高子鹏 RUI Yuechen;XIAO Guochun;HE Yurui;GAO Zipeng(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,陕西西安710049

出　　处：《电力自动化设备》2022年第10期210-217,共8页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51277146)。

摘　　要：负荷虚拟同步机(LVSM)技术可使电动汽车(EV)充电桩等负荷主动参与电网调频,但在EV两级式充电结构中,基于比例积分(PI)控制的后级DC/DC变换器的特性会削弱LVSM的调频性能。为此,提出一种虚拟电阻(VR)控制策略,通过重塑后级DC/DC变换器的输入阻抗为阻性,优化了LVSM的调频性能,充分发挥了LVSM的网荷互动能力。从理论上对比了采用传统PI控制和所提出的VR控制时,负荷扰动后电网频率偏差、各台LVSM直流母线电压和充电电流变化量的响应过程,结果表明VR控制通过充电电流调节过程使电网频率稳定性有所提升,且未对LVSM直流母线电压的稳定性造成不良影响。最后,通过仿真和实验验证了理论分析的正确性和所提控制方法的有效性。LVSM(Load-side Virtual Synchronous Machine) technology enables EV(Electric Vehicle) charging piles and other loads to actively participate in grid frequency regulation,but in the EV two-stage charging structure,the characteristics of the post-stage DC/DC converter based on PI(Proportion Integration) control weaken the frequency regulation performance of LVSM. Therefore,a VR(Virtual Resistance) control strategy is proposed,which optimizes the frequency regulation performance of LVSM by reshaping the input impedance of the post-stage DC/DC converter as resistive,and the grid-load interaction ability of LVSM is fully utilized.The responses of grid frequency variation,DC-link voltage variation and charging current variation of each LVSM after load disturbance when using traditional PI control and the proposed VR control are theoretically compared.The results show that VR control can stabilize the grid frequency through charging current regulation process,without adversely affecting the stability of DC-link voltage of LVSM.Finally,the correctness of the theoretical analysis and the effectiveness of the proposed control method are verified by simulation and experiment.

关 键 词：电动汽车 负荷虚拟同步机 惯量 调频 虚拟电阻 

分 类 号：TM461[电气工程—电器] U469.72[机械工程—车辆工程]