The generating mechanism and optimal control of power quality in micro-grids

As an important component of distribution network, micro-grid is the necessarily development trend for future. Micro-grid has greatly improved the random problems of distributed generation (DG). However, DGs, the power electronic equipments inevitably bring about power quality problems, especially voltage flicker and harmonics. This paper tries to study the operating regulations of micro-grid in order to find out the generating mechanism and propagation characteristic of power quality problems. Taking the photovoltaic (PV) system for an example, the micro-grid simulation model has been set up. The experiments show that an appropriate control strategy coordinating every part can improve the power quality of micro-grid greatly. This paper finds out the factors affecting power quality and their harm degrees, explaining the reasons of power quality problems. Coordinating every unit, this paper set up an optimal control strategy and proper parameter settings, trying to improve power quality of micro-grid to the largest extent.