Research On Optimization Allocation Of Distributed Generation Considered Time-Varying Properties

Reasonable choice of integration type, integration position and capacity for distributed generation can reduce the power losses of distribution network, and improve voltage quality. The output characteristics of wind power and photovoltaic power generation mainly decided by the climate of it’s location, but the uncertainty of climate result in the uncertainty of output. At the same time, load of each nod in the distribution network varies at any time. So it’s important to taking the time-varying properties of distributed generation and load into account when optimal the al ocation.Optimization of the location and capacity of wind power and photovoltaic power is mainly studied in this paper when integrating into distribution network.Firstly, Various DGs are analyzed and then the corresponding models are discussed combined with power flow calculations in this paper. By introducing the sensitivity impedance matrix correction method and updating the reactive power injection of PV nodes, combined with the charac teristics of the radial distribution network, a layer-by-layer back/forward power flow calculation based on the sensitivity impedance matrix correction method is proposed. The proposed method solves the problem that the traditional back/forward power flow calculation is failure for dealing with PV nodes, or dealing with the distribution network contained various DGs; Secondly, based on the probability model of wind generator, photovoltaic power and load, the derivation process of two-point estimate method is given; Thirdly, calculation steps of active power losses algorithm with transposed jacobian matrix is deduced. solution of active power losses algorithm which considering the time-varying characteristics of the load combined whit the two-point estimate method is proposed. Finally, the basic principles and steps of standard particle swarm optimization are introduced, and a dimensionality reduction method is proposed by using the expectation of active power losses algorithm to guide the optimal location and capacity of the distributed generation. By taking the annual integrated economic benefit as objective function, and taking the capacity constraints of the distributed generation as well as the probability constraints of the node voltage and the branch current as constrains, the optimal distributed generation configuration of typical system is calculated by using MATLAB and the effectiveness of the proposed method is verified.