基于等值单机无穷大系统的多机系统PSS设计

PSS design in a multi-machine system based on equivalent single machine infinite bus power system

多机电力系统PSS的合理设计对于抑制低频振荡至关重要。基于单机无穷大系统的PSS设计方法简单明了,但需要解决等值单机无穷大系统的求取问题。提出了一种直接利用多机系统Phillips-Heffron模型线性化矩阵对角元素形成等值单机无穷大系统Phillips-Heffron模型的新方法,并采用相位补偿法进行PSS设计。与基于发电机间的节点导纳矩阵求取等值单机无穷大系统的方法相比,新方法省去了各机组等值系统参数和线性化系数的计算工作。基于等值单机无穷大系统的PSS设计方法简洁,物理概念清晰,计算量小,便于现场应用。算例比较表明,基于等值单机无穷大系统设计的PSS增强系统阻尼的效果不比一些统一协调设计法的差。

Appropriate design of PSS is very significant to damp system low-frequency oscillation in a multi-machine power system. Though some PSS design methods based on the single machine infinite bus power system are simple and understandable, there is problem in getting the equivalent model. A new approach, forming Phillips-Heffron model for equivalent single machine infinite bus power system directly using the linearization matrix diagonal element of Phillips-Heffron model for multi-machine systems and designing PSS by phase compensation method, is proposed. Compared to the algorithm of getting equivalent single machine infinite bus power system based on bus admittance matrix between generators, it isn＇t needed to calculate the parameters and linearization coefficients of every equivalent single machine infinite bus power system using the proposed approach. The method of PSS design based on equivalent single machine infinite bus power system is brief, with clear physical notion and little computational requirement. Testing computation and comparison show that the effect of enhancing damping by the method of designing PSS based on equivalent single machine infinite bus power system is not poorer than that of some uniform and coordinate methods.