【作者】 周晖；

【导师】 谈顺涛；

【作者基本信息】 武汉大学 ， 电力系统及其自动化， 2004， 硕士

【摘要】 无功／电压优化控制是保证电力系统安全、经济运行的一项有效手段，是提高电压质量的重要措施，因此研究地区电网的电压／无功控制策略，既具有理论意义，又具有实际应用价值。 在无功电压优化中，在追求网损目标最小及较高电压质量的同时，通常并未考虑限制每个调度周期内设备的动作次数，因此，可能会造成某些设备频繁动作，同时每个时间段的优化中，动作设备数可能会过多，这样对于电网运行的质量，如网损的减少、设备的寿命、系统的扰动等，综合来看并不是最优。本文提出了一种考虑设备动作成本和限制设备次数的新的无功电压优化方法，从而能对电网运行的网损、设备寿命和动作次数进行综合优化。 借助于负荷预测的结果，可以对全天(例如24个时间点，即24次优化)按照传统的无功电压优化方法进行预优化。在预优化中，可以同时算出每个时间点的动作设备数以及全天的动作总数。因而可以在实时控制中，对那些全天动作过频繁的设备引入惰性因子。利用该惰性因子，不仅可以避免设备动作次数越限，同时可以将设备动作合理地分布到全天的各个时段。 采用的混合优化算法并进行了如下改进：引入灵敏度指导优化进程，减少搜索的盲目性；根据不同设备的调节范围，采用不同二进制长度进行编码，以减少无效搜索；采用可变交叉、变异率，以适应搜索进程的需要；种群大小根据搜索进程动态改变，在保证搜索质量的同时提高速度；在目标函数中引入模糊逻辑中的隶属度来计及负荷的轻重，以实现逆调压的目标等。 将本文所提出的算法应用于某地区电网实时电压无功控制，体现出了较好的实用性，较高的适应性及实时性。更多还原

【Abstract】 In voltage-reactive power optimization, with the pursuit of the minimization of system losses and higher electric power quality, the restrict of the equipment operations number during a specific time period is often not considered, so some equipment may be operated frequently and the number of operated equipment in each optimization can be quite high. The equipment duration and system operation quality are not comprehensively optimized in this manner.In this paper, a new voltage-reactive power optimization method, which considers the equipment operational cost and confines the number of operated equipment in each optimization, is introduced. The system losses, endurance of equipment and operated times could be calculated optimally and comprehensively.By the result of load forecasting, the pre-optimization is made for a whole day (e.g. 24 time-points, i.e. 24 optimizations) in conventional voltage-reactive power optimization method . In the pre-optimization, not only the number of equipment operation at one point of time but also the number of operations during a whole day can be calculated. So in real-time control, inertia factors are introduced when equipment are operated too frequenctly within a whole day. With the utilization of such factors, the number of operations can be reasonably distributed among the whole day, and the violation of operating limits can be avoided.Furthermore, the hybrid optimal strategy is introduced and improved: introducing sensitivity to guide the searching course, in order to reduce the blindness of search; coding based on range of value corresponding equipment operation, to avoid invalid search; adopting variable cross over and mutation rate, to adapt it to the requirement of the searching progress; making dynamic variation of searching population, to ensure the optimization quality while accelerate the searching course; adopting the membership degree of fuzzy logic to objective function, to take into account the load status and to realize the counter voltage adjustment.The proposed algorithm has been used in real-time control of voltage-reactive power in a regional power network system and are of high practicability, good adaptability and fast speed.更多还原