Research On The Reactive Power And Voltage Of Shaoguan Distribution Systems Effected By Hydropower Plants

Vigorous development of small hydropower has not only alleviated the shortage of ruralpower supply in China’s region with abundant hydropower resources, but also promoted thedevelopment of the local economy. However, due to the long distance between smallhydropower plants and the load center and small wire diameters, the system voltage isunreasonable and the distribution of reactive power presents an obvious seasonal variation.The voltage of10kV distribution line could reach up to13kV. It not simply would causedamage of equipments in consumer side, but also makes main network voltage regulation agreat challenge. On the other side, it leads to overtension of generator voltage and imperils thesecurity of generators. In addition, the insert of small hydropower makes the structure ofdistribution network more complicated. Great majority of hydropower are run-off river plantswith obsolete equipment. Their operations are not controlled by the dispatch department. Thedispatch center can hardly monitor the output of hydropower plants.The power equality and reliability in consumer side are important contents of theconstruction of smart grids. It is an important issue that must be solved to reduce the adverseeffect of distributed small hydropower plants and ensure the safety, high quality andeconomic operation of power grid. It is also a very important project of smart power gridconstruction. At present, domestic experts and scholars have started research on the influenceon transmission loss and power flow caused by small hydropower as well as reactive powerand voltage management measures in this area. Nonetheless, the study on the impact of smallhydropower plants to the reactive power and voltage is relatively deficient.This dissertation analyses the influence on reactive power and voltage of smallhydropower plants in mechanism. Through the simulation on the lanterns series model ofsmall hydropower plants, this thesis presents the improvement measures of distribution linereplacement, voltage regulation in the substation and so on. These measures are validated onthe actual distribution lines of Shaoguan and the satisfactory results are obtained. This workcan provide a reference for small hydropower planning in other areas.