A Novel Reduced-Rule Fuzzy Logic Based Self-Supported Dynamic Voltage Restorer for Mitigating Diverse Power Quality Problems

Abstract

For shielding voltage sensitive loads from diverse power quality problems (Voltage harmonic distortion and voltage sag/swell) a wide variety of custom power devices are used. Dynamic voltage restorer (DVR) is one of the important custom power device presently used for mitigation of above mentioned power quality problems. In this paper, reduced-rule fuzzy logic controller based on synchronous reference frame theory for controlling of self-supported dynamic voltage restorer (DVR) is proposed. As a result of the proposed controller, the mathematical model of plant is not at all needed and the control signals required by the DVR are thoroughly provided during various types of power quality problems at the source side. The performance of this technique is better than the other existing techniques and it is very simple to implement, less complex, very flexible and robust in nature. For the same system parameters, the fuzzy logic based controller uses the less amount of reactive power to mitigate the various disturbances at source side compared to PI based controller, which results into reduced rating of IGBTs and consequently leading to lowering of the overall cost. DVR is simulated for mitigation of various power quality problems (voltage harmonic distortion, balanced voltage sag/swell, unbalanced voltage sag/swell, balanced voltage sag/swell with harmonic distortion and unbalanced voltage sag/swell with harmonic distortion) and the simulation results verified by experimental results are presented displaying the workability of proposed controller.

Dynamic Voltage Restorer as a Solution to Voltage Problems in Power Systems: Focus on Sags, Swells and Steady Fluctuations

“…For mitigation of balanced and unbalanced voltage sag/swell as well as balanced and unbalanced voltage sag/swell with harmonic distortion, Singh et al [62] introduced a selfsupported DVR utilising a reduced-rule fuzzy logic controller based on SRF theory. Notably, this controller does not require a mathematical model of the plant and adequately provides control signals from the source side, resulting in a controller with superior performance compared to some existing techniques, simple implementation, lower complexity, high flexibility and robustness.…”