Study On Modeling And Appliance Of Optimal Dispatch For Distribution Network With Distributed Generation

With economy and society develop rapidly, the problem of energy shortage and environment pollution appears gradually. As an important solution, distributed generations will have a bright future and play an important role at the end of power grid. However, distributed generations are mostly renewable generations whose power supply are unpredicted and uncontrollable. Therefore, an optimal dispatch model for distribution network with distributed generations is to be found. The research purpose of this paper is to present a reasonable optimal dispatch model and demonstrate its effectiveness with a real case.This paper proposes a new dispatch model to control the output of distributed generations which are integrated in distribution network by micro-grids to realize new energy power absorbed level by level. Firstly, total power load and total new energy power supply is predicted. Then depending on consumer psychology curve, electricity price arrangement in24hours is calculated to transfer related power load and to realize "peak load shifting" in different new energy output conditions. The results indicates that the "quasi real-time pricing" model proposed in this paper can adapt different new energy output conditions, and have both electric power company and consumers make a profit. Secondly, according to the established electricity price arrangement, the economic operation mode of a micro-grid is studied to investigate the power sold or bought by a micro-grid in one day. This procedure is to pave the way for calculating the final operation state of distribution network. At last, the micro-grid output is dispatched at the level of distribution network. Minimum operation cost, minimum gas pollution cost and best voltage quality are set as objective functions. An interactive multi-objective decision-making method based on evaluation function is proposed for solving the problem that different objective functions conflict each other. Then the particle swarm optimization is used for case study, and the final operation state of the distribution network is determined. IEEE33-bus system and typical micro-grid data are used as case in this paper to certify the effectiveness of this dispatch model. Result shows that the optimal dispatch model with distributed generations proposed in this paper is well suitable to solve the problem that power supply of distributed generations is unpredicted and uncontrollable. This optimal dispatch model can give some advice for electric power companies in the area where distributed generations are in use greatly.