Simplified Algorithm of Voltage Security Correction Based on Sensitivity Analysis Method

Voltage stability is a crucial factor in power system operation. When bus voltage exceeds the operation limits because of change of the operation mode, load in the network or the environmental factors, appropriate control actions should be taken to guarantee a secure system operation, avoiding emergency situations or voltage collapse. Development and improvement of the algorithm for voltage security correction is a significant subject. This paper makes several improvements on the usual voltage security correction algorithms, and a new simplified algorithm based on sensitivity analysis is proposed. Emphasize is placed on the reduction of calculation scale in the selection of the control devices, fast calculation of the sensitivities and the calculation of the adjustment quantities. With only a few buses involved in the calculation, the simplified correction algorithm can guarantee high-speed and accuracy in most cases and is especially useful for online applications. An example of the New England 39 buses system is used to verify the effectiveness of the simplified algorithm.