A Compensation Method of Dynamic Voltage Sag Based on SMES

In order to reduce the DVR manufacturing cost, we had better expand the range of the DVR compensation as far as possible in a certain energy storage capacity under the restricted condition of maximum output compensation voltage of the device. This paper adopted a fast- detection method in which the single-phase voltage is delayed 60ºso as to structure the virtual three-phase voltage, and ensured the minimum energy output of DVR based on the phasor diagram of the pre-sag load voltage. The characteristics of the fast response and the high conversion of the super conductor magnetic energy storage (SMES) are made full use of. Finally, through simulating MATLAB, this compensation method is proved to be capable of effectively reducing the active power output of DVR, fast compensating the voltage sag, as well as enlarging the compensation scope of DVR.