Power System Comprehensive Reactive Power Optimization Based On The Sequential Quadratic Programming Algorithm

With the continuous expansion of grid, in the process of the development of the power grid, the role of the power system reactive power optimization is more and more important. Power system reactive power optimization is the use of reactive equipment to change the system of reactive power current distribution, so as to get better voltage quality and achieve the purpose of effectively reduce the power loss. For urban power grid, this paper is to adjust the cutting of parallel capacitor group and transformer gear. Under the precondition of satisfy all constraints, to solve the objective function optimization.In this paper, with reference to specific urban power grids, for the power system reactive power optimization, which can be interpreted as: to reduce the loss of power is the use of parallel capacitor cutting and to improve the voltage quality is by adjusting the on-load voltage regulating transformer tap position. For comprehensive reactive power optimization, this paper uses the sequential quadratic programming algorithm, and the inequality constraints added to the objective function in the form of penalty function, the day’s overall economic investment minimum as the objective function; at the same time, in each cycle, branch flow and node voltage in network are not fixed, but through the calculation of the last cycle to regain, it can improve the accuracy of the results significantly. First the 24 hours a day is divided into 24 period according to per hour, comprehensive optimization is divided into two processes: static optimization and comprehensive coordination optimization.in the first process, ignoring the mutual influence between all periods, to optimize them one by one; the second process in 24 hours of the static optimization results as the initial value, comprehensive optimize the state of the transformer gear and the group of capacitor within 24 hours, at the same time, the adjustment of reactive power device number is the least as a constraint condition and the day of the total investment cost is the minimum as objective function, finally it gets a whole solution, containing parallel capacitor group’s operation and on-load voltage regulating transformer gear case, and comprehensive investment cost, etc. Results show that the optimization algorithm in this paper can reduce the system of the comprehensive investment, and reduce the number of compensation adjustment of the reactive power device, and reduce the work intensity of operators and save the cost.