扩展c_1～c_(12)模型及SVC阻尼特性再认识

Extended c_1～c_(12) model for study of SVC damping characteristics

基于扩展Phillips-Heffron k1～k6模型的研究认为静止无功补偿器(SVC)在有功轻载工况下可能向电力系统提供负阻尼。为更加全面地认识SVC的阻尼作用,建立了考虑发电机阻尼绕组作用的单机-SVC-无穷大系统线性化直观模型(扩展c1～c12模型)。基于该模型,给出了SVC提供的阻尼转矩解析式,分析了不同工况和自动电压调节器(AVR)增益下的SVC阻尼特性。研究认为,SVC的阻尼作用随有功负荷的增大而增大,随AVR增益的增大而减小,在有功轻载且AVR高增益时SVC阻尼作用最弱,但不会向系统提供负阻尼,不存在所谓的"阻尼失灵点",这深化了关于SVC阻尼特性的认识。大扰动下的系统非线性仿真验证了上述结论。

The study of the extended Phillips-Hefferon k1-k6 model points out that,the SVC（Static Var Compensator） is likely to provide negative damping to power system under low active load conditions. In order to study the damping effectiveness of SVC more comprehensively,the linearized models of the single-machine-SVC- infinite-bus system is established with the effect of damper windings of synchronous machine,extended c1-c12 model,is established,based on which,the expression of SVC damping torque is given and its damping characteristics under different operating conditions or with different AVR（Automatic Voltage Regulator） gains are analyzed. The research deems that, the damping effectiveness of SVC increases along with the increase of active load,while decreases along with the increase of AVR gain. When active load is low and AVR gain is high,the damping effectiveness is the weakest,but not negative. There is no ＂ineffective-point＂ in SVC damping control, which deepens the understanding of SVC damping characteristics. The non-linear simulation under large disturbance verifies these conclusions.