Voltage-reactive power integrated optimization considering operational cost and equipment endurance

In reactive power optimization (RPO), by pursuing the minimization of system losses and higher electric power quality, the quantity of operated equipment in each optimization can be quite high and some equipment may be operated frequently. A new RPO method is introduced; it considers the equipment regulative cost and confines the number of regulated equipment in each optimization. The system operation quality, such as system losses, endurance of equipment, system disturbances and regulated times, could be optimized comprehensively. By the result of load forecasting, pre-optimization is made for a dispatching period in the conventional RPO method. The quantity of operated equipment at one time and the operating times of equipment during a whole period can be accumulated. In real-time control, inertia factors are introduced to equipment operated too frequently within a period. The number of operations can be reasonably distributed over the whole day. The adopted genetic algorithm (GA) is improved as follows: introducing sensitivity to guide the searching course; coding based on range of values corresponding to equipment operation; making dynamic variation of searching population. The proposed method has been used in real-time control of voltage-reactive power optimization in a regional power system and is of high practicability, good adaptability and fast speed.