The Study On Reactive Power Compensation Methods For Power Distribution Network Planning

Power distribution network planning is a task involving many things, which mainly includes: power load forecasting, transformer substation location, distribution network planning, distribution network power flow calculation, reactive power compensation planning, power network automation, reliability analysis in fault and normal state. The thesis is a part of power distribution network planning project of Jia County. My studies mainly focus on distribution network power flow calculation and reaction power compensation planning. These methods are applied to Hengyang City's project, and got satisfactory result.Reactive power compensation planning is based on distribution network power flow calculation. Due to some distinctive differences between distribution network and transmit network, there are some problems in precision and convergence when using Newton-Raphson'method. The thesis analyzes the illness reason of Jacobin Matrix. A fast-decoupled load flow method is introduced, and applied to real problems, the convergence and the precision are increased.With the rapid development of economy, and reconstruction of urban power network, Hengyang urban power network, whether on power source or network structure, is strengthened step by step. The active power planning in Hengyang, taking fall consideration of the network structure change after the load increased, have been completed with a lot of calculations and analysis to ensure that over-load at any kinds of load levels wouldn't appear in the network. To further improve supply quality, decrease loss and improve voltage level, it is necessary to study reactive power distribution in detail to make sure that reactive power facilities is optimally installed when the existing reactive power facility is taken into account.The key issue to the reactive power compensation is to determine optimal compensation capacity and compensation position based on a given rational objective function. A mathematical model with maximum economical efficiency that considers compensation capacitors price, installation cost, running cost and etc. is proposed. An improved adaptive genetic algorithms is suggested to obtain the optimal reactive power compensation scheme, where the reactive power compensation capacity sensitivity is used in creating the initial population.Based on the proposed algorithm, carried out the study of theoptimal allocation of reactive power in hengyang power grid. The paper proposes some question that need to further research in the optimal allocation of reactive power. And it is a preparation both in theory and practice to the specific implementation for the optimal allocation of reactive power, it also is positive guidance to the optimal allocation of reactive power compensation equipment.