Optimal energy management of distributed generation in micro-grid to control the voltage and frequency based on PSO-adaptive virtual impedance method

Line impedance varies between distributed generation and load feeders due to the existence of different distances and the micro-grids complexity. Therefore, conventional droop control methods do not have the desired efficiency in the power distribution between DG units. Generally, due to simplification, the impedance of the lines is considered non-complex. The stated conditions greatly reduce the accuracy and dynamic response of the control system. In this paper, the voltage and frequency control of the micro-grid is presented by an adaptive virtual impedance control method based on the multi-objective particle swarm optimization (MOPSO) algorithm for the purpose of proportional power distribution. The control unit operation is based on the control of virtual resistance and inductance. The central control and the optimization unit are responsible for controlling the proportional power distribution by using the information of the local controllers. In the proposed method, in order to improve the stability and optimal operation of the micro-grid the reduction of the deviation related to active power, reactive power, voltage and frequency are presented. The proposed method has optimal performance in different operating conditions. Finally, the results are presented along with stability and sensitivity analysis based on the Bode diagram and Root locus.