Voltage stability margin real-time evaluation and optimum control method after grid major failure

Abstract

The invention relates to a voltage stability margin real-time evaluation and optimum control method after a grid major failure, which comprises the following steps: (1) acquiring grid normal rack topological data and current rack state from an energy management system; (2) calculating to obtain an initial operation point under the normal rack; (3) introducing the grid failure, changing the network data and solving the tidal current by a damped Newton method to obtain the solution point; (4) judging the voltage stability of the system after the failure by judging whether the solution point obtained in the previous step is the physical solution or optimum solution; (5) if the voltage is stable after the failure, calculating according to the continuous tidal current to obtain the grid voltage stability margin after the failure; and (6) if the voltage is not stable after the failure, establishing the optimum recovery strategy according to the vector quantity between the optimum solution point and the current operating point. The invention can provide system voltage stability conditions for a dispatcher in time after the grid major failure and provide the optimum recovery strategy aiming at the possible voltage instability condition. The invention has the advantages of high calculation speed, definite physical significance and high accuracy.

Description

technical field [0001] The invention belongs to the field of on-line voltage safety evaluation and control of power grids, and is a method for quickly obtaining post-fault system voltage stability information and an optimal control strategy without depending on expected fault sets. Background technique [0002] At the beginning of 2008, most parts of the southern part of China experienced historically rare extreme weather of continuous low temperature, rain, snow and freezing, which caused severe ice covering of power transmission and transformation facilities, collapsed towers, broken lines and trips of power transmission lines, and large-scale power outages in some areas. This ice disaster has put forward new requirements for the safe and stable operation of the power grid in the future, that is: under severe natural disasters such as ice disasters, if a serious fault occurs in the transmission network (multiple lines, transformers, and generators are out of service), how t...

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Problems solved by technology

However, for severe faults in the transmission network under conditions like ice disasters, the number of faulty equipment is large, far exceeding the conventional N-2 or N-3 faults. In this case, the pre-calculated expected fault set will face the "dimensional Disaster" problem, it is difficult to cover all possible serious failures

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