Research On Distributed Generation Access Technologyand Reactive Power Flow Optimization Method

Energy shortage and power shortage has become a major issue in the development of thesociety. Therefore, the development and the utilization of new energy is an effective way tosolve energy problems. In the electric industry, distributed generation (DG) which takesadvantages of renewable energy rises as a key to ease the demand of power. But the radicaldistribution mode of power flow will change with the access to DG, and the randomness andvolatility resulting from the utility of natural resources can threaten grid safety and economicoperation.Problems on system frequency, voltage stability and reactive power control with the accessto DG have been studied further. Deviations between actual power output and predicted poweroutput of DG, actual power output and planned power output are added in ACE calculationmodel, in which the fuzzy PI control is adopted to adjust the output of generators and keepsystem frequency stable. In the process of system partition, power output fluctuating with windspeed is discretized into n scenes which are partitioned according to probabilities. Then systemvoltage is kept over stable range by adjusting generator excitation and reactive compensationdevice with fuzzy logic control. On the precise of stable system frequency and voltage, powerflow calculation aiming for the minimization of network loss and voltage excursion iscomputed with particle swarm optimization.Control strategy proposed in this paper is tested in Matlab/Simulink simulationenvironment. Results show that system frequency and voltage get smaller fluctuation rangesand more useful optimization with improved AGC and AVE control strategy.