POWER QUALITY ANALYSIS IN DISTRIBUTED GENERATION SYSTEM AND IMPROVING THE STABILITY USING UNIFIED POWER QUALITY CONDITIONER BASED ON INTELLECTUAL POWER OPTIMIZING TECHNIQUE

In the distribution system, power quality is a major issue and it is defined as an electricity quality. The concept of the system is used to transfer quality energy. However, many problems with the power network due to power quality, e.g., the transmission voltage is drop, voltage swell, imbalanced current and voltage, harmonics is produced voltage and current flickers and it causes power supply disturbance in the distribution system. In heavy loads the UPQC is the most powerful power electronics and it requires control system with proper PWM pulse with the reactive power to compensate the heavy loads. The UPQC has combined shunt and series converter which is more flexible compare with the other single converter. The UPQC system is optimize the imbalance disturbances of the current and supply voltage of the distribution system. The UPQC compensators contain two Voltage Source Inverters (VSI), one is shunt APF and another series APF which is connected to a common DC link. The shunt converter load is connected in parallel. It provides compensation for the load voltage control using series converter and provides uniform currents using shunt converter. Whenever the voltage drops, the series converter produces a suitable reactive power to overcome the Fluctuations. Thus, UPQC improves the power quality and also maintain the unity power factor of the system. The series inverter with the advanced control scheme is create the reactive power with the help actual DC link voltage for compensating sag and swell voltage present in the system .The shunt inverter and its control system analyse the load current values based on the gain the a necessary reactive power is produced and compensate the fluctuations.