An optimized compensation strategy of DVR for micro-grid voltage sag

Abstract

Introduction: This paper uses a dynamic voltage restorer (DVR) to improve the voltage quality from voltage sags. It is difficult to satisfy various of compensation quality and time of the voltage sag by using single compensation method. Furthermore, high-power consumption of the phase jump compensation increases the size and cost of a dynamic voltage restorer (DVR). Methods & Results:In order to improve the compensating efficiency of DVR, an optimized compensation strategy is proposed for voltage sag of micro-grid caused by interconnection and sensitive loads. The proposed compensation strategy increases the supporting time for long voltage sags. Discussion: Firstly, the power flow and the maximum compensation time of DVR are analyzed using three basic compensation strategies. Then, the phase jump is corrected by pre-sag compensation. And a quadratic transition curve, which involves the injected voltage phases of pre-sag strategy and minimum energy strategy, is used to transform pre-sag compensation to minimum energy compensation of DVR.

Power Quality in Microgrids Including Supraharmonics: Issues, Standards, and Mitigations

“…However, some limitations in terms of LVRT still exist. Therefore, [112] used an optimization technique to enhance the performance of the DVR in solving the sag problem in the MG system. The fuzzy logic-based DVR is used to overcome the sag and swell in an MG connected grid.…”

High-voltage Ride Through Strategy for DFIG Considering Converter Blocking of HVDC System

“…The principle of DFIG de-loading is given in Fig. 3, in which initially DFIG is at the operation point a of MPPT, and then it actively traces some de-loading curves defined in (9) to point b so that part of available wind energy can be stored in form of rotating kinetic energy [28], [29]. In Fig.…”

“…Fortunately, many efforts have been devoted to relieve the above transient overvoltage problem on wind farm side, which can be approximately classified into three categories. The first one can be attributed into a type of external RPC control methods, in which additional RPCs or their combination on the stator side are equipped and RPC control schemes are designed accordingly, e.g., a combination scheme of static synchronous compensator and dynamic voltage restorer is proposed to achieve fault ride through of DFIG in [8], [9]; a superconducting fault current limiter and a transient voltage controller are jointly used to improve the system transient voltage stability in [10], [11]. The second one is a type of rotor-side converter (RSC) supplementary circuit control methods, where protection circuits are added in the rotor or DC circuit to attenuate the rotor overcurrent or DC overvoltage, e. g., a series dynamic braking resistor based crowbar in rotor circuit is proposed to limit current surge in [12]; a DC series chopper circuit is proposed to maintain a constant DC voltage in [13]; a DC series storage protection circuit is proposed to store excess energy during voltage surge in [14].…”

Self‐tuned fuzzy‐proportional–integral compensated zero/minimum active power algorithm based dynamic voltage restorer

“…Therefore, the total expenditure of DVR may get increased. The energy optimised DVR control technique has been analysed in [13,14]. Nielsen et al [15] have proposed the implication of DVR at a low and medium voltage level.…”