A Dynamic Voltage Restorer With Selective Harmonic Compensation Based On Resonant Controller

As the growing consumption of electricity in modern society, the load of power system increases rapidly. When there are more and more impacting and nonlinear loads, power system has some problems such as voltage aberration, flicker and imbalance. Dynamic Voltage Restorer is equipment which can solve voltage drop problem. It is being one if the most serious imperil to many countries.As voltage drop happens rarely in power system, Dynamic Voltage Restorer always keeps a stand by condition which is a big waste of resource. To increase the efficiency of DVR, this paper proposes a resonant controller to add a harmonic compensation to DVR without affecting the voltage drop mechanism.The existing harmonic detection method mainly base on the Instantaneous Reactive Power Theory. These methods takes two times transform from stationary coordinate to synchronous rotate coordinate, which is very complicated to realize. At the same time it can't be use in single phase system. This paper analyzes the transformation between stationary coordinate and synchronous rotate coordinate and proposes a resonant controller to detect selective harmonic voltage. It has the same frequency response as the PI regulator under synchronous rotate coordinate. This controller decrease calculation amount and can be use in single phase, so it is more flexible. Multiple controllers can be used for many harmonics, and it has little influence on the voltage drop mechanism.The DC side energy maintenance of DVR is the key problem of long time...