多机系统发电机时滞反馈励磁与STATCOM的非线性鲁棒协调控制

广域反馈信号的时滞性使得包含广域信号的电力系统变成时滞动力系统。利用Pade近似逼近时滞环节,将时滞影响隐含在系统动态方程的系数中,静止同步补偿器(STATCOM)的动态特性用一阶微分方程形式的可控无功电流源表示,推导了含多台STATCOM的多机系统的电磁功率表达式。基于伪广义Hamilton系统理论,将包含STATCOM和时滞反馈励磁的多机系统表示成伪广义耗散Hamilton系统形式。利用L2干扰抑制控制方法得到考虑广域信号时滞性及转移电导的发电机励磁和STATCOM的协调控制策略。4机2区域系统的仿真结果表明,与传统的分散控制器相比,所提考虑时滞影响的非线性鲁棒协调控制器能够有效地抑制系统振荡,且具有一定的时滞不敏感性。

Nonlinear robust coordinated control of time-delay feedback excitation and STATCOM for multi-machine power system

The power system with wide-area signals becomes a time-delay dynamic system due to the time-delay of wide-area feedback signals. Pade approximation is adopted to implicate the effect of time-delay section in the coefficients of system dynamic equations and a first-order differential equation is applied to express the dynamic characteristics of STATCOM(STATic synchronous COMpensator) as a controllable current source, based on which, the electromagnetic power expressions of multi-machine power system with multiple STATCOMs are derived. Based on the pseudo-generalized Hamilton theory, a multi-machine power system with STATCOM and time-delay feedback excitation is represented as a pseudo-generalized dissipation Hamilton system. L2 disturbance attenuation control method is used to design a coordinated control strategy of STATCOM and generator excitation, which considers the time-delay of wide-area signals and the transfer conductance. Results of the simulation for a four-machine two-area system show that, compared with traditional decentralized controller, the proposed nonlinear robust coordinated controller with the consideration of time-delay effect restrains the power system oscillation more effectively and is insensitive to time-delay to a certain degree.