Online dynamic reactive power reserve optimization for power system with Multi-infeed HVDC systems

It is generally known that sufficient reactive power reserve is critical to maintain power system voltage stability under different operating conditions. A new method to optimize online dynamic reactive power reserve for power system with Multi-infeed HVDC (MI-HVDC) is proposed in this paper. A linear reactive power reserve optimization model is built based on continuation power flow (CPF) and sensitivity analyses to achieve the purpose of the online optimization. The MI-HVDC system is modeled so that its influence on the reactive power reserve optimization is considered. To improve the accuracy of the linear optimization problem, a method considering linear effectiveness interval (LEI) is proposed by limiting the range of control variables. The whole problem is decomposed into two levels to find the final optimal solution by solving the upper and lower sub-problems in turn. The method is tested on a six-bus system and IEEE 118-bus system. Simulation results show effectiveness and accuracy of the method.