28-08-2014, 10:07 AM
UPQC SIGNAL DETECTION ALGORITHM STUDIES BASED ON PSO-FUZZY
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ABSTRACT:
Distortion of sinusoidal voltage and current waveforms caused by harmonics is one of the major power quality concerns in the electric power industry. Static power converters and other nonlinear loads are the culprits of these distortions. Considerable efforts have been made in recent years to improve the management of harmonic distortion in power systems.
Nowadays, there are a wide range of power electronic applications in utility such as static var compensator (SVC), static synchronous series compensator (SSSC), static compensator (STATCOM), static generator (SG), unified power flow controller (UPFC) and active filter (AF). Considering the current researches makes it possible forecasting much more developments of power electronics utilization in the utility during the 21st century. The unified power quality conditioner (UPQC) is expected to be one of the most important systems to overcome the power quality problems of distribution systems.
Integrating the character of parallel power quality compensator and series power quality compensator, unified power quality conditioner (UPQC) has generally been accepted as a new electric power quality conditioner which has a good development prospect. Towards an excellent performance UPQC device, accurate and real-time signal detection is much important. Instantaneous reactive power theory based on vector transformation is widely applied in active filter. Aiming at the flaw of many times coordinate alternation and precision of low pass filter, signal detection algorithm based on PSOFUZZY for reactive power and harmonic current is proposed in this paper. But its widely adopted harmonic voltage measurements and harmonic current measurements based on instantaneous reactive power theory still have flaws on the algorithm complexity and the accuracy of low pass filters.
A new algorithm of UPQC which abandons original vector transformation and low pass filter aiming at measuring and compensating for voltage flicker, reactive power and harmonic current is proposed in this paper. Fuzzy controller based on particle swarm optimization is discussed for its character of simple computation and high measurement accuracy. Simulation results are shown to verify the effectiveness and superiority of the algorithm