Research On The Optimal Allocation Of Distributed Generations In Micro-grid

With the increasing serious energy crisis and environmental pressure, the development and utilization of renewable energy is the developmental trend of new energy strategy. Micro-grid which combined dispersed and different types of distributed generations is an effective way to give rein to the effectiveness of distributed generations and to solve the problem of grid connected distributed generation system. However, facing the gradual access to the distributed generations in the grid, the reasonable allocation of type and capacity for distributed generations has the important significance in ensuring the reliability of the micro-grid, reducing its construction and planning costs, and improving the environmental friendliness of micro-grid. For this reason, based on the domestic and foreign relevant theory of capacity allocation for distributed generations, and combined with the operating characteristics of the micro-grid, the main works of this dissertation are as follows:(1) For the structure of stand-alone micro-grid, the key factors that influence type selection and capacity allocation are analyzed. The optimal objective is to minimize the total net present cost (NPC) of the system, which includes capital cost and operating cost. In addition, Homer software is used to optimize the types and capacity allocation of the system, and the sensitivities of influencing factors are simulated. The validity of the analysis is verified.(2) For the stand-alone micro-grid, the optimal allocation of distributed generations is studied. Considering the economy, reliability and environmental friendliness of the system, the effects of different optimal models for optimal allocation of distributed generations are analysed. The annual minimum cost of the system is the optimal objective, which considers the different combinational modes of capital cost, operating cost, fuel cost, environmental cost and reliability cost. Different optimal models of optimal allocation are established. Based on the adaptive weight particle swarm optimization algorithm, the optimal allocations of different optimal models are simulated by using the programmable function of Matlab software. The balance of power demand is also verified under them. The validity and feasibilityof the models are verified.(3) For the grid-connected micro-grid, also considering the economy, reliability and environmental friendliness of the system, the effects of different generating dispatch strategies for optimal allocation of distributed generations are analysed. The annual minimum cost of the system is the optimal objective, which includes capital cost, operating cost, fuel cost and transactional cost of electrical energy with the main grid. The optimal model of optimal allocation is established. Also based on the adaptive weight particle swarm optimization algorithm, the optimal allocations of different generating dispatch strategies are simulated by using the programmable function of Matlab software. The balance of power demand is also verified under them. In addition, pollution fines of pollutant emissions are used as environmental indicator, the environment performance of the allocation results are calculated and analysed. The significance of generating dispatch strategies which can improve the environment performance of the system are pointed out. Through the analysis of the example, the validity and feasibilityof generating dispatch strategies are verified.