Research On Reactive Power Optimization Of Distribution Network With Distributed Generation

At present,large-capacity unit power generation,ultra-high voltage long-distance transmission and cross-regional large power grid parallel are the main power system production,transportation and distribution.With the rapid development of the technology and social economy,the demand for the quality and reliability of electric power is increasing.The scale of the distribution network is expanding and its structure is becoming more and more complex.The reactive power optimization of the distribution network has the following advantages:changing the power quality,adjusting the voltage of each node of the distribution network and reducing the active loss of the system.In recent years,with the problem of global wanning and environmental pollution becoming more and more serious,the distributed generation technology with renewable energy generation is been paid more attention by the whole society.Compared with the traditional large-scale centralized power generation,distributed generation has the advantages of low cost,high energy utilization,less environmental pollution,and can improve the reliability and flexibility of the distribution network.In the actual application,distributed power generation is required to input active and reactive power to the distribution network.Because of its intennittent and random power supply.The size and direction of power flow in the distribution on network will change,which results in the distribution network voltage line,increase the network loss,reduce the reliability and so on.Therefore,through the reactive power optimization of distribution network,reducing the impact of distributed generation on distribution network,the power quality and reliability of distribution network will be ensured.This paper mainly studies the subject that it is the reactive power optimization in distribution network with DGs.Firstly,the calculation method and its process of distribution network power flow is described in detail.Secondly,through the comparison of the influence on the distribution network voltage and power loss,which is from the different number,the location and capacity of distributed generation;the paper verified that distributed generation can reduce the power loss,effectively prevent the ability of local distribution network node voltage over the line.Finally,the paper puts forward a hybrid algorithm combing particle swarm algorithm and ant colony algorithm.On account of the local optimization problem of particle swarm and in order to improve the long-time optimization disadvantages of ant colony algorithm,this method mixes the above two algorithms utilizing the advantages of particle swarm algorithm which are simple structure and less parameter setting and the advantages of ant colony algorithm which has strong global search capability.Combining with the interior penalty method the algorithm constructs reactive power optimization mathematical model and proposes the hybrid PSO-ACO method.Taking IEEE-33 node distribution system for example,the simulation shows that the hybrid algorithm has good convergence and stability.