Design And Implementation Of Central Controller Of Microgrid In The Park

The rapid development of the world economy leads to the depletion of traditional fossil energy and the deterioration of the ecological environment.The development of renewable energy becomes a global energy strategy.As the most effective means to solve the problem of distributed generation and grid connection,microgrid is extensively researched in countries all over the world.At present,the energy demand space of various industrial and commercial parks in China is very large.Promoting the construction of the microgrid in the park and making the microgrid transition from demonstration to commercialization is of great significance for integrating the advantages of distributed PV and weakening the negative impact on the distribution network.At first,this paper studies two typical PV and energy-storage microgrid system topologies in industrial and commercial park based on single energy-storage system and multiple energy-storage systems and a three-layer control architecture based on local layer,control layer and scheduling layer.The design requirements of the central controller of microgrid in the park is refined by summarizing the current microgrid related standards.The hardware and software frameworks of the central controller are designed by these requirements,and the hardware units and software modules are introduced in detail.Secondly,this paper proposes the on-grid energy management control strategy of the microgrid in the park with engineering value and park characteristics,which considering the input-output and economic benefits of enterprise users in industrial and commercial parks,including energy transfer strategy,tie line control strategy,demand management strategy,and the demand forecast based on the three exponential smoothing method and the maximum demand control process in the demand management strategy are specifically introduced.Two on-grid and off-grid switching control strategies of microgrid in the park based on sequential control and seamless way are proposed.The enterprise users in the park can consider and select it comprehensively combining power supply requirement and economic perspective to ensure the on-grid and off-grid switching process can be carried out methodically.The off-grid running control strategy of the microgrid in the park is proposed.The PV system and the energy-storage system are coordinated to the load swiching to ensure power balance and reliable power supply in off-grid mode.Finally,the hardware and software design of the central controller and feasibility of on-grid and off-grid running and swiching control strategy of the microgrid in the park are verified by various tests and building a physical experiment platform.This controller is applied in actual engineering.