Real-time energy coordinated and balance control strategies for microgrid with photovoltaic generators

A typical microgrid system comprises photovoltaic generator which usually operates at both grid-connected and intentionally islanding operation modes. In terms of such operation characteristics of the microgrid, this paper proposes an active power control strategy dynamically to balance the energy output and consumption in the microgrid. By the control strategy, the photovoltaic generators may actively curtail their output energy instead of maximum output power by MPPT when the total microgrid system has surplus energy specifically at intentionally islanding operation mode. In order to ensure the stability of the voltage amplitude and frequency at PCC and achieve energy real-time coordinated and balance control, a method by real-time calculating the change of load power according to P-f and Q-V drooping relationship, then assigning to each micro-source by energy dispatching layer is proposed. The simulation results prove that proposed active power control strategy and coordinated method operates effectively to dynamically manage energy of the microgrid.