Study On Voltage And Reactive Power Control Of Power System

With the realization of the future Chinese interconnected power systems, the power network becomes larger and voltage becomes higher. Problems occurred recently make the researcher and operator to reconsider the var/voltage-control problem and its influence to the power systems.All sorts of algorithm in solving optimal reactive power is studied and analyzed and their advantage and disadvantage is pointed out. The problem of reactive power optimization is infeasible in some cases, which leads to the volatilization in iteration of primal-dual interior point method in the problem. This homogeneous interior-point method is used to solve the reactive power optimization. The proposed method can detect the infeasible problem easily and it is almost as efficient as primal –dual interior point method. The calculating results of IEEE 30-node standard system are displayed and it shows that this method can be used in practice.The voltage stability problem is also studied. There is stiff problem and discontinuity problem when we use integration function during simulating the voltage stability in power systems. Variable-step integration method is used to solve the problem of short-step and long time span and reduce the connection error. The method to solve the power flow in simulation of voltage stability is different. The iteration direction is given out when the Jacobi matrix is singularity using trust-region method. The factors to cause voltage collapse are pointed out after simulating a certain system.