Evaluating the Effect of Distributed Generation on Power Supply Capacity in Active Distribution System Based on Sensitivity Analysis

Introduction The power supply capacity (PSC) of distribution network is the maximum load that the network can provide on the condition of meeting the branch power and node voltage constraints, which is determined by the operation mode of the distribution network and the growth mode of the load. [...]the PSC is one of the most significant indexes that reflect the reliability and safety of active distribution system (ADS). The possibility of DG real-time adjustment closely affects the assessment of the PSC. [...]the influence on the PSC which is exerted by randomness and volatility of DG output cannot be ignored [10,11,12,13,14]. [...]in the background of ADS, the quantitative study of DG changes on the PSC is significant and indispensable to the accurate assessment. Sensitivity of Evaluation Indexes of PSC to DG type The effects of different types of DG on the PSC upgrading mainly reflect on their corresponding output. [...]the sensitivity of PSC evaluation indexes to DG type can be expressed as below: (1) Sensitivity formula of EPSC to DG type ∂EPSC∂SPV(j)=∂EPSC∂PDG(j)⋅PPV(j )=PPV(j)∑i=1Mp(i)∑n=1N(H^∂PL(i,n)∂δj+N^∂PL(i,n)∂UjUj) ∂EPSC∂SWG(j)=∂EPSC∂PDG(j)⋅PWG(j )=PWG(j)∑i=1Mp(i)∑n=1N(H^∂PL(i,n)∂δj+N^∂PL(i,n)∂UjUj) where SPV(j) and SWG(j) are the capacity of photovoltaic (PV) power and wind generation (WG) connected at node j, respectively; PPV(j) and PWG(j) are the output of PV and WG at node j, respectively.