A novel control algorithm for static series compensators by use of PQR instantaneous power theory

This paper describes an algorithm and the related implementations to control static series compensators (SSCs). Directly sensed three-phase voltages are transformed to p-q-r coordinates without time delay, then the reference voltages in p-q-r coordinates become very simple form: single dc value. The controller in p-q-r coordinates is very simple and clear, has better steady state and dynamic performance. The controlled variables in p-q-r coordinates are then inversely transformed to the original a-b-c coordinates without time delay, generating control signals to SSCs. The control algorithm can be used for various kinds of SSCs such as dynamic voltage restorer (DVRs), series active filters (SAFs), synchronous static series compensators (SSSCs), bootstrap variable inductances (BVIs). The control algorithm was applied to a DVR system. The experimental results verified the performance of the proposed control algorithm.