A Novel Method of Voltage and Frequency Control in Isolated Micro grids using Improved Droop Controller

This paper presents a new method for optimal frequency and voltage control in micro grids (MG) considering the mutual effect of line parameters on power transfer. An MG consists of a number of distributed generation (DG) sources that are linked to the main grid with voltage source inverters. In MGs each DG has its special droop characteristics. When a load consumption change occurs in the MG, an imbalance between generation and consumption rises, thus a change occurs in the voltage and frequency of DGs according to their droop characteristics. In order to minimize oscillations of voltage and frequency, we have used optimal droop controller which is based on considering the mutual effects of transfer parameters on active and reactive powers. Since line parameters heavily affect the droop characteristics, these parameters are obtained optimally by the frog algorithm such that oscillations in voltage and frequency are minimized. In order to enhance the controlling scheme, effects of line resistance on reactive power changes and effects of line reactance on active power changes are also considered. The obtained results show satisfactory voltage and frequency control in various load level. In this paper, MGs are studied and simulated in an isolated state

کلیدواژه ها:

micro grids ، frog optimization algorithm ، droop control ، voltage and frequency control ، isolated network