Locating And Sizing Method Of SVC Device Based On New Electrical Distance

In recent years,the number of small new energy sources has gradually increased,and it has been connected to the distribution network in the form of distributed power.However,due to the large reactive power demand of the distributed power supply and the rapid change of the reactive power demand,the reactive power generated by the generator alone cannot meet the demand for the reactive power of the power grid.Reactive power compensation devices must be configured.Reactive power evaluation is the basis for grid reactive operation and planning.By summarizing the existing grid reactive power evaluation index system,this paper points out that the existing evaluation indicators only consider the amplitude information of voltage,ignoring the phase angle information of voltage.Morever,active power and reactive power are coupled.Compared with the voltage amplitude alone,the voltage vector and complex power are included in the study.For more complete electrical information,the planning results will be more accurate.It is different that the power obtained from the power supply for different loads.It is also different that the network loss caused by the above transmission process.In this paper,the ratio between the loss in the power transmission process and the load extraction power is called the power transmission complex efficiency.The energy transfer efficiency between the load and the source reflects the tightness of electrical connection between the load and the power source.It is proposed that the power transmission complex efficiency is used to describe the electrical distance between the load and the power source.In this paper,it is found that the power transmission complex efficiency in a single power network can be directly calculated from the voltage vector information.In a multi-supply network,the electrical connection between the load and the power source is multidimensional and does not clearly describe the electrical distance between the load and the power source.In this paper,the concept of power transmission complex efficiency is extended to the multi-power network,the ratio of the sum of the losses corresponding to the power obtained from different power sources to the total power obtained from different power sources is called the power transmission complex efficiency in the multi-power network.A method for dividing reactive area of distribution network based on power transmission complex efficiency is proposed.Different from the traditional reactive power control zone with reactive power supply as the regional center,the reactive area divided by the method is composed of nodes with similar power transmission complex efficiency.The area formed by the load with the lowest power transmission complex efficiency in the network is the area that is the farthest from all the power sources.This area has the weakest connection with the reactive power source,and the most need to install the reactive power compensation device.Taking the IEEE33 node distribution network system as an example,this paper proposes a reactive power area division method for distribution network based on power transmission complex efficiency,which can effectively identify reactive weak areas and improve reactive power planning efficiency.It provides a new theoretical basis for improving the reactive power distribution of the distribution network.The method proposed in this paper is not only applicable to single-power radiant network distribution network,but also applicable in multi-power distribution networks with distributed power supplies.