Optimal Dispatching Strategy Of Microgrid Based On Demand Side Response

Entering the 21 st Century,developing renewable energy and ensuring energy security and cleanliness have been the core content of energy sector.In the application of distributed new energy generation technology,micro-grid can effectively reduce the negative impact of intermittent distributed generation on distribution network.Due to the randomness,volatility and unpredictability of distributed generation,such as wind power generation,demand-side resources have been made an important research topic in optimal dispatching of micro-grid.This paper focuses on the application of demand-side resources in optimal dispatching of micro-grid.Firstly,demand-side resources and corresponding scheduling modes in active distribution networks are studied in depth in this paper.Traditional demand-side resources mainly refer to load resources that can respond to price signals or incentive mechanisms.Unlike traditional demand-side resources,generalized demand-side resources include energy storage systems and distributed generation resources besides.Secondly,in order to fully absorb renewable energy and transferring demand side resources in a planned way,a double-deck optimal day-ahead scheduling strategy is proposed.In the upper layer optimal schedule,the improved time-of-use(TOU)price which takes account into the user's satisfaction can express the adjusted loads accurately and the resulting net loads can be treated as a link between upper and lower layer scheduling.The lower level optimal dispatching model takes interruptible load power,charging and discharging power of battery and exchange power between micro-grid and grid as control variables.For the reason of having no precise model of BESS,the lower model for the goal of minimizing the operation cost is solved by action dependent heuristic dynamic programming algorithm that is not relying on the accurate controlled object model.This algorithm is used to obtain integral control strategy.Moreover,due to the uncertainty of renewable energy output,the prediction accuracy errors of renewable energy output in different time scales are appeared,making a great deviation in dispatching of micro-grid.In order to cope with this situation,a multi-time-scale dispatching strategy based on demand-side response for micro-grid is proposed.By classifying the multi-time-scale characteristic demand-side resources,it can be made for participating in the multi-time-scale dispatching of micro-grid reasonably.Then,carbon emissions are included in the objective function of long-time scale scheduling and multi-step dynamic rolling optimization is adopted in intra-day scheduling,solved by the firefly algorithm.After that,in real-time dispatching,the model predictive control is used to reduce the deviation between the predicted value and the actual value of active power output.Ultimately,the economy,stability and environmental protection of micro-grid operation are improved.Finally,the feasibility and effectiveness of the above optimal scheduling strategy are verified by simulation examples.