基于分散控制理论的多机系统低频振荡抑制

常规的电力系统低频振荡抑制措施是在发电机励磁系统中加装电力系统稳定器(PSS),然而它在多机电力系统中的应用并没有充分的理论研究.将大系统分散控制原理应用于多机电力系统低频振荡抑制问题,只要分散阻尼控制器(DDC)的阶数足够高,分散闭环控制系统的低频振荡模态总可以在复平面内任意配置.分析了PSS与DDC的关系,论证了PSS是DDC的一种特殊形式,因而从理论上说明了DDC比PSS优越.将DDC的优化配置表示为一个带不等式约束的非光滑优化问题并用遗传算法求解.以新英格兰测试系统和我国西北电网为算例的计算结果表明,在发电机励磁系统中加装DDC是一种有效的低频振荡抑制新措施.

Low-frequency oscillation damping for multi-machine systems by using decentralized control theory

The conventional power system low-frequency oscillation damping measure is to install power system stabilizers(PSSs) in the excitation systems of generators.However,adopting of the measure for multi-machine systems is not sufficiently studied theoretically.Decentralized control theory for large systems was used for multi-machine power system low-frequency oscillation damping,and the low-frequency oscillation modes of decentralized close-loop control systems can be unlimitedly set in the complex plane as long as the order of decentralized damping controllers(DDCs) is high enough.The relationship between PSS and DDC is studied,and it is proved that PSS is a special type of DDC,so it is shown in theory that DDC is more ascendant than PSS.The optimal configuration of DDC was expressed as a non-smooth optimization problem with inequality constraints and was solved by genetic algorithm.The calculation results of New England Test System and that of Northwest China Power Grid show that installing DDCs in the excitation systems of generators is an effective measure for low-frequency oscillation damping.