Adaptive Observer for Dynamic Voltage Restorer with Optimized Proportional Integral Gains

An algorithm based on a sliding-mode adaptive observer is proposed for the effective control of dynamic voltage restorers (DVRs). Three single-phase voltage source converter-based topologies are implemented for the DVR. In this control, frequency adaption is considered for estimating the phase angle, system frequency, and fundamental component of the disturbed input voltage signals. The estimated fundamental component of the supply voltage is used to generate the DVR reference load voltage. The phase jump in the supply voltage is also considered for DVR compensation studies along with voltage sag, swell, and voltage distortions. For this purpose, the gains of the proportional integral (PI) controllers used in this control algorithm are estimated using a nature-inspired optimization approach for the desired response. A moth flame optimization algorithm is implemented for PI controller gain tuning owing to the advantage of finding the best solution by each moth's search and updating it. Through Matlab simulation and hardware testing, the performance of the DVR with an adaptive observer is found to be satisfactory for supply voltage sag, swell, phase jump, and voltage distortions.