Active Distribution Network Operation Risk Assessment Considering Control Information Failure

Power system risk refers to the comprehensive measurement of the probability of failure events in the system and the severity of their consequences, which can quantitatively evaluate the safety of the system operation state. The risk considered in this paper is that a certain day-ahead scheduling scheme may have the risk of voltage or power over-limit due to the control failure caused by uncertain factors of information system (random failure of control center software system, communication link failure based on EPON access network and random failure of IED connected to the controlled equipment, etc.); This paper conducts a quantitative assessment of the operation risk of the system under a specific day-ahead scheduling scheme, aiming to prevent control failures caused by information system malfunctions and the subsequent risks. Due to the consideration of the uncertainties of the information system in the day-ahead scheduling, the states of the equipment are random, and the stochastic power flow method is adopted for solving. Therefore, this paper first determines the states of different controllable devices after disconnection, and on this basis, proposes a stochastic power flow calculation method that takes into account the failure of control information. Then, based on the risk assessment theory and the calculation results, it establishes the over-limit risk assessment indicators for day-ahead scheduling. In this way, it can achieve a quantitative assessment of the operation risks of the voltage at each node and the power of each branch in each time period within the scheduling cycle, as well as the overall operation risk of the system, and use this to evaluate the safety of the scheduling scheme. Finally, the specific process of risk assessment and an example analysis are given.