【摘要】 提出了一种新颖的阻尼联络线低频振荡的UPFC两阶段控制方案。第1阶段是阻尼控制:利用COI之间角速度的正、反向状态控制直流电容器的充、放电,使得联络线总的传输功率相应地减少、增加,从而进一步增加系统阻尼,快速平息振荡。给出了一种利用UPFC安装处的线路功率估算COI之间角速度的方法,估算结果准确。第2阶段是协调控制:第1阶段控制结束后,系统进入了新的稳态。此时利用控制理论中的相对增益矩阵(RGA)方法为UPFC在稳态条件下确定了多个控制通道之间耦合程度最为薄弱的最佳控制方案,使得UPFC潮流控制器、交、直流电压调节器之间实现了协调控制,从而使系统快速运行在所期望的稳态运行点。仿真结果表明,所提出的UPFC两阶段控制方案对阻尼区域模式低频振荡是有效、可行的。更多还原

【Abstract】 This paper proposes a novel two-stage control scheme of UPFC for damping tie-line low frequency oscillation. The first-stage control is damping control: positive and negative states of the angular speed difference between the COIs (center of inertias) are used to control charge and discharge of the DC capacitor, therefore real power of tie lines is decreased and increased correspondingly, the damping of the system is intensified and the oscillation of the system is quickly suppressed. Moreover a method to estimate the angular speed difference between the COIs using locally measurable quantity at the UPFC location is proposed, and the estimation result is quite accurate. The second-stage control is coordinated control: After the first-stage control comes to a close, the system operates at a new steady state operating point. Under the steady-state condition the Relative Gain Array (RGA) method in control theory is used to determine the best control scheme, under which the interactions among UPFC control channels are the most weak. Therefore it is easy to implement the coordinated control among UPFC power flow controller, AC and DC voltage regulators and the system can operates fast at the expected steady-state operating point. Simulation results show that the two-stage control for UPFC is effective and feasible in damping area mode low frequency oscillation.更多还原