Risk Assessment of Distribution Systems with Distributed Generation

Based on risk assessment theory and "N-1" safety criteria, aiming at the situation of fault and power recovery in distribution system with distributed generation (DG), load bus loss and line overload and they comprehensive risk index are proposed to assess the risk degree of system, and find the vulnerable nodes and lines through statistical analysis. At the same time based on the heuristic algorithm, the fault restoration scheme of power distribution system is proposed, which use the tie line to transfer load at first and then through DG islanding to restore power supply. Finally, taking IEEE 33 bus distribution system for example, calculation results in different conditions prove that these evaluation indexes can accurately reflect the risk degree of DG distribution network, and the scheme of failure recovery can effectively reduce the system risk, which can be regarded as reference for distribution network planning and risk prevention. Keywords-distribution network; risk assessment; fault recovery; distributed generation; "N-1" security criterion; island classification; heuristic algorithm