Dynamic Operational Risk Assessment For Active Distribution Network

The intermittent and uncertain nature of technologies such as distributed generation,energy storage and flexible demand threaten the operational security of active distribution network.Current risk assessment researches focus on transmission network and traditional distribution network.And the researches lack analysis of risk sources and risk indexes of active distribution network.An approach of uncertainty based on operational risk assessment techniques was presented to assess the security level of active distribution network.Credibility theory was used to handle the uncertainty of active distribution network containing both randomness and fuzziness.Considering the time-connected characteristic of active distribution network,dynamic assessment was applied to evaluate the operational risk of active distribution network during the whole time period.Several risk indexes based on credibility theory were set to evaluate the security level of active distribution network under different scenarios.Loss of wind generation index is proposed to evaluate economic loss of active distribution network due to the error in prediction of wind generation prediction.The proposed approach was applied to an active distribution network modified by the IEEE 33-bus system to demonstrate its effectiveness.The results give us a better understanding of the risk level of active distribution network under different scenarios and economic loss due to the error of wind generation prediction.