Frequency Adaptive Circular Limit Cycle Oscillator-Based Control and Operation of Dynamic Voltage Restorer

This paper proposed a circular limit cycle oscillatorbased control algorithm for dynamic voltage restorer to mitigate power quality issues. Dynamic voltage restorer is an affordable device to safeguard sensitive/critical loads from distortion, sag, swell, and supply voltage unbalance. The conventional synchronous reference frame phase locked loop-based control algorithm has limitation under unbalance/distorted grid condition. This limitation is addressed in this paper by extracting the fundamental sequence components from the distorted/unbalanced grid signals using circular limit cycle oscillator frequency locked loop. It offers distinct advantages such as simple, robust, and almost asymptotic stable. MATLAB simulation is employed to implement the proposed control algorithm. The results demonstrated the suggested control algorithm provides satisfactory solution to the above problems.