Total Supply Capability Curve And Total Accommodation Capability Curve Of Distribution Network

The future-oriented distribution network will fully realize informationization and automation.It will not only focus on supplying loads,but also accommodating distributed generation(DG)so as to realize the energy exchange between costomers,DGs and transmission networks.It is of great significance to correctly understand and evaluate the capability of a distribution network,which is beneficial for plan and operation of distribution network.The load supply capability of distribution network can be described by total supply capability curve,and the ability to accommodate DG can be described by total accommodation capability curve.Based on the theory of Distribution System Security Region(DSSR),this paper studies the total supply capability curve and total accommodation capability curve of distribution network.The main contents are divided into two aspects:On one hand,aiming at the load supply distribution network without DG,this paper studied the model of total supply capability curve,its decline mechanism and its application in planning.1.Improved the models of strict security boundary and total supply capability curve.2.Observed and summarized the decline mechanism of total supply capability curve,including the backup mechanism and distribution mechanism,which caused the curve decline,and further found the quantitative calculation formula of the effect of back/distribution mechanism.3.Proposed a comprehensive efficiency evaluation method to evaluate connection mode based on load supply capability curve.Several typical connection modes in China are evaluated and their efficiency ranking results are obtained.On the other hand,the total supply capability curve is extended to active distribution network,and the accommodation capability curve of active distribution network is studied under N-0 normal operation constraints.1.Proposed the concept of total accommodation capability curve,which can fully described the accommodation capability of active distribution network.Models of strict security boundary,total supply capability curve and accommodation capability curve are bulit.2.Found the the symmetry of the two capability curve by drawing them together,which showed the duality of the supply capability and the accommodation capability;moreover,the operation area of distribution network can be divided into the safe area and cross-border area,and the total supply/accommodation capability curves are the‘demarcation line’ between different areas.3.Studied the influences of actual configuration on total supply/accommodation capability curve.