Topologies and Control Strategies Implicated in Dynamic Voltage Restorer (DVR) for Power Quality Improvement

Controlled and improved power quality is one of the fundamental and essential needs in any industry driven by electric power for optimal exploitation of resources. However, in power quality, some crucial problems have been recognized as harmonic distortion, interruption, sag, swell and transient. Out of these, sag and swell are predominantly seen and cause stern impact on the electrical devices or machines and therefore require to be mitigated at an earliest to protect from any failure or mal-operation. As an ultimate key to crack these problems, some custom power devices such as distribution STATCOM (DSTATCOM), dynamic voltage restorer (DVR) and unified power quality conditioner are unanimously procured. A prominent custom power device DVR is apparently suggested in the literature for the mitigation of voltage sag and swells, with the benefit of active or/and reactive power control. The DVR is reported as being a high-performance solution to compensate voltage disturbances, since it provides both a cost-effective solution and very fast dynamics. In recent years, a bulk amount of the literature accounts for DVR on different configurations of its power circuit and various control techniques employed in it. This review article presents a detailed study on DVR with the different possible configurations of its power circuit and control techniques encircling major power quality issues. The informative object covered in the paper, articulate choice of control strategy and power circuit ensuring optimal recital of DVR in satisfying a required quality. This paper also furnishes the valued information for the investigator in this field.