Optimal Comprehensive Control Of Prevention And Emergency Based On Dsr And Probabilistic Insecurity Measurement

Preventive control is executed before the accidents occur. The cost, which should not be too high, will always be paid whenever the accidents occur or not. Emergency control, which cost is high, is executed after the accident is detected. Emergency controls are followed with restoration control. Therefore, preventive control, emergency control, and restoration control followed with emergency control should be considered synthetically, and some random factors of the fault have effects on DSR which is used to deal with transient stability constraints.1)Large amounts of simulations show that there is an approximately exponential relationship between the constant variable in the linear expression of DSR boundary hyperplane and the fault location with given fault duration time and fault resistance. This relationship can be used to the fast calculation of DSRs when fault location changes in the same transmission line, so to facilitate the computing off-line and application online of DSRs. 2) The probability insecurity measurement, which is more sensitive with the changes of the control amount than the safety margin, is taken as the effectiveness criterion of emergency control. 3)An optimal comprehensive control model of prevention and emergency based on DSR and probability insecurity measurement is established, by taking the minimum cost of preventive control, emergency control, and the following restorative control with the system stability ensured as the objective function. 4)The optimal operating point of the system is obtained by using the improved genetic algorithm in the preventive control and the emergency control, and using optimal recovery strategy in the restorative control, which forming a three-level optimal process. 5)The feasibility of the model and optimization strategy are verified by the case of the IEEE 4-genarator 11-nodes test system. Simulating results show that the cost of comprehensive control of prevention and emergency , when considering the random factors of defaults, is obviously less than that without the random factors.