Integration of UPQC for Power Quality improvement in distributed generation network - a review <s> A. (DG -UPQC) DC-linked <s> This paper describes analysis results of a combined operation of the unified power quality conditioner with the distributed generation. The proposed system consists of a series inverter, a shunt inverter, and a distributed generator connected in the dc link through a rectifier. The proposed system can compensate voltage sag and swell, voltage interruption, harmonics, and reactive power in both interconnected mode and islanding mode. The performance of proposed system was analyzed using simulations with power system computer aided design/electromagnetic transients dc analysis program, and experimental results with the hardware prototype. The proposed system can improve the power quality at the point of installation on power distribution systems or industrial power systems. <s> BIB001 </s> Integration of UPQC for Power Quality improvement in distributed generation network - a review <s> A. (DG -UPQC) DC-linked <s> The use of Dispersed or Distributed Generation (DG) has been increased in recent years to fill the gap between supply and demand of energy, as the sources of conventional power generation are depleting fast. DGs through static compensators are also used for improving the power quality of distribution systems like mitigation of voltage dips and compensation of harmonics. Shunt, series, and series-shunt type of configuration of static compensators combined with DG have been proposed in the literature. This paper presents a feasibility analysis of DGSC-UPQC (Distributed Generation based Static Compensator as Unified Power Quality Conditioner), a series-shunt type of static compensator with DG. The analysis has been carried from technical and economical aspects when the device i.e. DGSC-UPQC is used for compensation of unbalance in source voltages and load currents and power factor improvement. Simulation results show the capability of the DGSC-UPQC to compensate the unbalance in source voltages and load currents satisfactorily. <s> BIB002
A structure has been proposed in BIB001    BIB002 , as shown in Figure  2 , where DG sources are connected to a DC link in the UPQC as an energy source. This configuration works both in interconnected and islanded mode (shown in Figure 3) . In Interconnected mode, DG provides power to the source and loads whereas in islanded mode DG (within its power rating) supplies the power to the load only. In Addition, UPQC has the ability to inject power using DG to sensitive loads during source voltage interruption. The advantage of this system is voltage interruption compensation and active power injection to the grid in addition to the other normal UPQC abilities. The system's functionality may be compromised if the DG resources are not sufficient during the voltage interruption conditions. Economical operation of the system can also be achieved by proper controlling of the active power transfer between the supply and DG source through a series APF BIB002 . The proposed system can also reduce the investment cost by nearly one fifth if the UPQC and DG are used separately  . 