I. Introduction Renewable energy resources such as wind turbines, hydrogen turbines and photovoltaic arrays are environmental friendly. This type of generations rapidly increasing around the world because they can increasing the demand of electric power and to decrease the green house gases. Penetration of wind power generation and PV power generation into distribution systems is expected to increase dramatically, which raises concerns about system impact by the intermittent power generation of

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... DG [1]- [3] . Compared to large-scale wind power and conventional bulk generation, the generation cost of a PV system is relatively higher However, many countries offer significant financial subsidies to encourage customers to install PV systems. To achieve the goal of 1000 MW PV installed capacity by 2025, the Taiwan government has launched a promotion program to subsidize 50% of the PV installation cost and has increased the selling price of PV generation to 40¢/kWh [4]. Considerable efforts have been proposed in the previous works to solve the loading balance of distribution systems. The distribution static compensator (DSTATCOM) was considered for compensation of loading unbalance caused by stochastic load demand in distribution systems [6] . The control algorithm for static var compensation (SVC) has been developed for loading balance at any given power factor [7] . Fuzzy multi objective and Tabu search have been used to optimize the on/off patterns of tie switches and sectionalizing switches to achieve feeder loading balance in distribution systems with distributed generators [8] . A heuristicexpert system approach for network reconfiguration to enhance current balance among distribution feeders was presented by Reddy and Sydulu [9] . A Petri-Net algorithm has also been proposed for loading balance of distribution systems with open loop configuration by identifying open-tie switches [10] . For the distribution system with large capacity of PV installation, the feeder loading will be varied dramatically because the power injection by PV generation is varied with the intensity of solar radiation. The load transfer between feeders with an open-tie switch must be adaptively adjusted according to PV power generation. Due to the intermittent power generation by PV systems, it becomes very difficult to achieve loading balance with conventional network reconfiguration methods by changing the status of line switches. With the advancement of power electronics, the back-to-back (BTB) converters can be applied to replace the open-tie switch for better control of real power and reactive power load transfer by changing the voltage ratio and phase shift between two feeders according to the power unbalance at any time instant [11] . For the distribution system with high penetration of renewable energy sources, voltage profiles and loading balance have to be enhanced by improving the power exchange capability between feeders. This study pro-poses a loop power controller (LPC) [12], [13] to replace the conventional open-tie switch so that loading balance of distribution feeders can be obtained by power flow control in a more active manner. A transformer less converter with snubberless insulated gate bipolar transistor (IGBT) is applied to the proposed LPC using an active-gate-control (AGC) scheme. The AGC scheme can balance the collector ABSTRACT: Now a day's solar power plants are more reliable, because no fuel and reduced CO2 emission. But the solar power generation system do not work in all weather conditions, it is power generated only solar radiation time .To overcome this problem by using (pv)). In fuel cell power generation there will be no problems, where as in fuel cell power distribution systems have some problems like overloading the distribution feeders. In this project to overcome this overloading by using Loop Power Controller (LPC).The loop power controller to control real power and reactive power flow by adjusting voltage ratio and phase shift. Daily loading unbalance is determined by analyzing (pv) power generation recording by using SCADA system and load profile based on Data Automation System (DAS).The loop power controller can improve controllability, operational flexibility and reduce power loss of the distribution system. The Loop Power Controller (LPC) is based on the MATLAB/ SIMULINK.