A Novel Dynamic Voltage Restorer with Outage Handling Capability Using Fuzzy Logic Controller


This paper presents a novel dynamic voltage restorer (DVR) capable of handling deep sags including outage on a low voltage distribution system. The DVR recovers sags up to 10% of nominal voltage; otherwise, it will operate as an uninterruptible power supply (UPS). A transformer is connected in series with the load when restoring sags, and is reconfigured into parallel connection using switches when handling outages. The controller uses a Fuzzy Logic with 3 inputs to maintain the load voltage through d-q transformation. Preliminary results from laboratory tests are also presented in this paper.





Fig. 1. Block diagram of the proposed DVR



(a) Grid Voltage

(b) Load Voltage

(c) Inverter Voltage

Figure 2. The grid, load and inverter voltages under 3-phase fault

Figure 3. Grid and load voltages during 1-phase to ground fault



A dynamic voltage restorer using Fuzzy Logic controller was demonstrated to remedy sags and outage voltages. Phase jumps and unbalanced conditions due to single phase-to-ground fault can also be compensated by the DVR. In the event of outage, where the voltage drops below 10%, the DVR restore the voltage into the normal. Thus, the load voltage is unaffected by the disturbances including sags and outages.



  • T Wunderlin, P. Dahler, D. Amhof, and H. Gruning, “Power Supply quality improvement with a dynamic voltage restorer (DVR)”, proc of EMPD ’98, Mar 3-5.
  • Arora, K. Chan, T. Jauch, A. Kara, and E. Wirth,”Innovative system solutions for power quality enhancement”, ABB Review 3, 1998.
  • Campos and G Joos et al.,”Analysis and design of a series voltage unbalance compensator based on threephase VSI operating with unbalanced switching function”, IEEE Trans. On Power Electronics, vol. 9 no. 3, pp.269-274, May 1994.
  • Haddad and and G. Joos,”Distribution system voltage regulation under fault conditions using static series regulators”, proc of Annual Meeting IEEE Ind. Appl. Soc., 1997. pp. 1383-1389.
  • Ashari, M., C.V. Nayar and S. Islam, “Steady-State Performance of a Grid Interactive Voltage Source Inverter”, proceedings of IEEE PES Summer Meeting, 15-19 July 2001, Vancouver, BC Canada.

Leave a Reply

Your email address will not be published. Required fields are marked *