SVC Control System Based on Instantaneous Reactive Power Theory and Fuzzy PID

Industrial static VAr compensators (SVCs) are typically applied at or near the load center to mitigate voltage fluctuations, flicker, phase unbalance, or other load-related disturbances. In this paper, a phase-to-phase "open + close" control scheme for industrial SVC is proposed. The forward loop is to guarantee short response time, while the feedback loop is to ensure good dynamics and steady characteristics of SVC. The fast compensation algorithm for asymmetric industrial loads based on instantaneous reactive power theory is used in the forward loop, while a fuzzy proportional-integral-differential control strategy is applied to the close loop. The hardware and software of this SVC control system is developed based on SIMATIC-TDC and WinCC; the former is the most modern but well-proven industrial controller, while the latter is the globally used human machine interface system. Many industrial applications show that this kind of control system can meet the strict performance and reliability requirements of industrial SVCs.