Energy Management Strategy For Microgrid Under Planned Island

As a key part of the smart grid, The microgrid which integrates the distributed generation equipment, load, energy storage and control devices into the medium and low voltage distribution system organically, has become an effective way to realize the comprehensive utilization of renewable energy. At the same time, microgrid energy management system as one of the core technologies of microgrid has become a research hotspot.Based on the planning of microgrid experimental platform, this paper focuses on the multi-time scale microgrid energy management strategy based on demand side response under planned island conditions.Firstly,the system structure, working principle and control system structure of photovoltaic grid connected system and energy storage system are studied. And a island microgrid simulation model that contain Droop control as master control and PQ control as slave control is establishedbased on the Matlab/Simulink software platform.Then the simulation verification is carried out under different conditions to ensure that the island microgrid system can be adjusted in different conditions according to its control principle so that the island microgrid can work stably.Secondly, based on the classification of load resources, a multi-time scale microgrid energy management strategy based on demand side response which starting from the perspective of multiple time scales, considering the balance between supply and demand of electricity and power in microgrid system, and combined with the demand side response technology is designed. The strategy includes day-ahead scheduling layer, rolling scheduling layer based on energy storage surplus energy and real-time scheduling layer. The day-ahead layer would pre-determine the operation schedule of each period of future microgrid by using particle swarm algorithm according to the micro grid operation optimization and the corresponding constraints; The rolling scheduling layer collects the real-time data to calculate the remaining energy of the energy storage, and makes a correction to the day-ahead scheduling; the real-time scheduling layer is used for real-time monitoring and real-time regulation of voltage and frequency.Finally, the designed multi-time scale microgrid energy management strategy based on demand side response is programmed. And then it is implemented in real-time simulation platform of microgrid. The numerical examples show that the microgrid system optimized by the energy management strategy designed in this paper can run smoothly in the planned island operation period under different working conditions, improve the utilization of renewable energy power generation to some extent, and ensure the reliability of power supply at all levels.