The Research Of Non-communication Energy Management For Islanded Microgrids

Due to the pressure of energy crisis, environmental pollution, and sustainable development, clean and renewable resources get rapid development in recent years. Microgrid acting as a new grid structure attracts widespread attention, which provides a necessary condition for developing clean and renewable resources. How to address coordinated control problem for multiple microsources, maintain power supply and demand balance, and ensure system stability within microgrid are now imperative questions. In this paper, a study on non-communication energy management for islanded microgrid is presented.The microgrid system that will be studied is firstly described, and the necessity of wireless energy management is also pointed out. On the basis of analyzing the droop-control-based and frequency-based energy management strategies, the relationship between active power and frequency bus-signaling as well as the contact between microsource and microgrid are established by droop control and frequency bus-signaling, respectively. Based on droop control and frequency bus-signaling, the wireless energy management can be achieved.Secondly, based on the frequency bus-signaling, two kinds of energy management strategies, namely, adaptive reference power energy management strategy and adaptive droop coefficient energy management strategy are proposed. The application range, operation principle, and stability analysis for both the strategies are presented in detail. Simulation and experimental results validate the effectiveness and advantages of the proposed strategies.Thirdly, a common control architecture for droop-control-based microgrid energy management is proposed by means of analyzing frequency-based control strategies. With the consideration of different microsource characteristics, eleven energy management solutions that belong in two types are explained in detail.Finally, a three-phase inverter prototype platform for islanded application is built and the hardware and software design scheme is also presented. The hardwire design follows module design principle, mainly including drive protection circuit, control circuit, and auxiliary power supply circuit. In the software design aspects, the influences of sampling, filtering, computing, and transmission delay on the inverter model are analyzed and the software design process is also described. The correctness of the hardware and software design is validated through the experiment.