Abstract:
Micro grid (MG) in the electrical distribution system ensures reliability in terms of availability of electrical power for specific loads, even then the concerns of power quality for loads exist due to faults and sudden transients. Interruption free electricity with standardized Power Quality (PQ) is an ideal case for customers. For this purpose, an improved control strategy based Unified Power Quality Conditioner (UPQC) is presented in this research to use within microgrid system. Proposed UPQC consist of series and shunt compensators, which can work individually or simultaneously to compensate power quality problems. The Control strategy of UPQC depends on two separate controls, a novel 3DI controller based internal control which works in Synchronous Reference Frame (SRF) environment and fuzzy logic based external control for intelligent switching (on/off) of compensators. The internal control of UPQC efficiently compensates power quality problems in very less time. On the other hand, external control of UPQC produces sensibility in the device so it detects power quality problems in power line and does the switching of compensators of UPQC. Both controls together make UPQC an ideal power quality compensation device. Using proposed control strategy the series and shunt compensators of UPQC compensates power quality problems for loads including voltage sag/swell, sudden transients, current harmonics and current unbalances. The Performance comparison of UPQC with proposed control strategy and conventional Proportional Integral (PI) controller based control strategy is presented in terms of better compensation of power quality problems. In presence of UPQC with MG system, the associated loads are secure in term of the uninterrupted power supply and standardized power quality delivery. Matlab/Simulink is used as a simulation environment to design the whole system and to test the effectiveness of the proposed control strategy for UPQC to compensate power quality problems. It is established with help of presented results that performance of the UPQC with proposed control strategy is efficient in terms of compensation of power quality problems in less time, in an accurate way, and with a fast response when it compares to the performance of UPQC with conventional PI controller based control.
