SVC在机械投切式并联电感和电容的基础上,采用大容量晶闸管代替断路器而发展起来的。在外特性上,SVC可以视作与系统(负荷)并联的可控容抗或感抗。无功功率对供电系统和负载的运行是十分重要的。早期无功补偿采用同步调相机(同步发电机工作在调相状态),可以根据需要对无功进行动态补偿,但成本较高。后来采用电容来补偿无功, SVC is based on the mechanical shunt parallel inductors and capacitors, developed using high-capacity thyristors instead of circuit breakers. Externally, SVC can be considered as a controlled capacitive reactance or inductive parallel to the system (load). Reactive power is very important for the operation of the power supply system and the load. Early reactive power compensation using synchronous camera (synchronous generator work in the phase modulation state), according to need dynamic compensation of reactive power, but the cost is higher. Later, using capacitors to compensate for reactive power,