| Microgrid is one of the most active branches of smart grid technology.It is proposed to solve the problem of near-balanced distribution of power supply and improvement of the quality of power supply service.Its potential advantages are low power consumption,low investment,high reliability of power supply,and small impact on the environment.However,when the microgrid part icipates in the distribution network power transaction,the distribution channel of its output power that can be used are reduced,and the power output peaks of the same type of microgrid are likely to overlap in time sequence,thereby causing the problem of distribution network congestion.In order to effectively alleviate distribution network congestion,this paper considered both the temporal and spacial distribution characteristic of the output power of the microgrid.By introducing a reasonable distribution path competition mechanism,the static and dynamic congestion management model of the microgrid integrated distribution network were established,respectively.In order to reduce the influence of deviation energy on the interests of distribution network,microgrid and users,the optimal tracking problem of the time-sharing error of the microgrid was studied and disscussed.Firstly,this paper studied the problem of static congestion management for microgrid integrated distribuiton network.By clarifying market participants and establishing a reasonable market mechanism and pricing mechanism,a static congestion management model for distribution networks was proposed to determine the congestion price at a certain time.Utilizing the theory of optimization,the electricity price can be iteratively optimized between the distribution network and microgrid,thereby obtaining the reasonable congestion price.The case analysis and calculation were given for this static congestion management model,w hich verified the correctness and practicability of the congestion management strategy.Compared with the traditional congestion management method,it shows that this method is more applicable to the actual operation of the grid and can reasonably optimize the resource allocation.Secondly,based on the analysis of static congestion management strategy for microgrid integrated distribution network,considering the practical operating conditions of the distribution network and the microgrid and the various micro sources that may appear in the microgrid,a dynamic congestion management model for the distribution network was established.In this model,the interests of the distribution network and the microgrid were maximized respectively,and the actual operating conditions of the power grid were taken as constraints.Based on the optimization theory,the prices of the distribution network and the microgrid were alternatively optimized to determine the congestion price for a certain period of time.Through the test of simple system and complex system,it is shown that the proposed method can better solve the dynamic congestion management problem of the distribution network with the microgrid participating in the transaction when the distribution channel is limited.Finally,the optimal tracking problem of time-sharing deviation energy of the microgrid was analysed.Taking into account the power generation cost and output power of the microgrid,an optimized tracking model for deviation power under unconstrained conditions was established.On the basis of this model,considering the constraints brought about by the actual operation of the power grid,the optimal tracking model of the time-sharing unbalanced power of the microgrid with constraints was designed.Through the analysis of the examples,the designed biased energy tracking model can make good use of the adjustment resources of the microgrid to reduce the deviation power to the allowable range,effectively avoiding the possible intraday congestion and facilitating the orderly and healthy development of the power market. |
