METHOD FOR EVALUATING SECURITY OF CLOSED-LOOP OPERATION OF MEDIUM-VOLTAGE DISTRIBUTION NETWORK

摘要

Disclosed is a method for evaluating the security of a closed-loop operation of a medium-voltage distribution network. The method includes: on the basis of acquired topological structures and device parameters of a closed-loop network, and acquired real-time running data before loop closing of the closed-loop network, estimating a state of a high-voltage distribution network to obtain voltage amplitude values and phase angles of 10kV buses at head ends of closed-loop feeders; selecting a ratio of an active load of each load point on each of the closed-loop feeders to the active power at the head end of the feeder and a ratio of a reactive load of each load point on the closed-loop feeder to the reactive power at the head end of the feeder as input variables, and calculating, on the basis of historical load data of each load point, a multi-order semi-invariant of each of the input variables; calculating a certainty power flow and closed-loop currents; calculating multi-order semi-invariants of the closed-loop currents; obtaining the cumulative probability distribution of the closed-loop currents; and calculating the limit violation probability of each of the closed-loop currents, and determining that a closed-loop operation has security insofar as the multiple limit violation probabilities are all less than a pre-set threshold value.