中文摘要：

在电网电压不平衡条件下,以网侧各相单位功率因数为补偿控制目标,提出了基于虚拟导纳的静止同步补偿器（STATCOM）无源控制方法,可保证输电线路有功损耗最小。在dq同步旋转坐标系下,建立了不平衡条件下STATCOM的数学模型,构造出相互独立的正负序双电流环系统,以便于控制系统设计。基于无源性理论,利用能量成形和阻尼注入方法,分别对正负序电流环设计了控制器。给出了STATCOM直流侧电压与虚拟导纳的数学关系式,阐明了虚拟导纳电流控制的合理性和可行性,并设计了直流电压外环比例积分控制器。仿真实验结果表明,所提控制策略可实现电网电压不平衡条件下STATCOM对无功负荷的快速补偿,同时可保证网侧各相均实现单位功率因数控制。

英文摘要：

With the unity power factor of each phase at grid side as the objective,the passivity-based control is put forward for the STATCOM（STATic synchronous COMpensator） based on virtual admittance to ensure the least active power loss of power transmission lines under unbalanced grid voltage condition.The STATCOM model in dq synchronous reference frame is established to construct the independent dual-loop control system of positive and negative sequence currents for easy control system design.Based on the passivity theory and with the energy shaping and damping injection method,the controllers are designed for positive and negative sequence current loops respectively.The mathematical relationship between DC-side voltage and virtual admittance is presented to illustrate the reasonability and feasibility of virtual-admittance-based current control.The proportional plus integral controller for DC-side voltage is designed.Simulative and experimental results show that the proposed STATCOM control system compensates the reactive load rapidly under unbalanced condition and ensures the realization of unity power factor control for each phase at grid side.