Research on Optimization of Multifunction Control Using Energy Storage Systems

本研究旨在利用分散储能系统作为未来电力系统的主控制器，实现现有设施难以实现的良好的质量控制。研究了分散储能系统负荷频率控制、电压和无功控制、电力系统稳定控制和负荷均衡等多重功能的优化方法。对于分散储能系统的频率和实际功率控制，我们建立了基本的负荷频率控制模型，并通过PID控制器对其进行了改进。通过计算机模拟对其进行了评价。在此基础上实现了一种负载均衡模式，并对其特性进行了研究。得到了储能系统与现有发电机组合作时的最优负荷频率控制准则。同样，研究了分散储能系统的电压和无功控制。考虑到与实际功率控制的配合以及交直流变换器和存储能量的限制，通过与现有VQC或SVC的比较，对其控制性能进行了检验。结果表明，储能系统的无功功率，交直流变流器容量。存储的能量和P: Q比受电力系统特性的影响，如无储能系统的母线电压特性。此外，我们还从预防控制的角度研究了分散储能系统对电力系统暂态稳定的控制。因此，人们认识到在短暂的稳定效果和预防性控制的费用之间存在一种权衡关系。然而，分散储能系统的使用也拓宽了运营商在电力系统运行中的选择。

This research aimed at realization of good quality control by using dispersed energy storage systems as main controllers in future power systems, which was difficult to realize by existing facilities only. The optimization methods for plural functions expected to dispersed energy storage systems, such as load frequency control, voltage and reactive power control, and power system stabilizing control, as well as load leveling, were investigated.As regards frequency and real power control using dispersed energy storage systems, we have constructed basic load frequency control model, and have improved it by PID controller. It was evaluated by computer simulation. Then a load leveling mode was realized based on the model, and its characteristics were investigated. As a result, we have obtained guidelines for the optimal load frequency control where energy storage systems have cooperated with existing generators.Similarly, voltage and reactive power control using dispersed energy storage systems was investigated. And then the control performance was examined by comparing with existing VQC or SVC considering cooperation with real power control and limits of ac-dc converter and stored energy. As a result, it was revealed that the reactive power of energy storage system, ac-dc converter capacity.stored energy and P : Q ratio are influenced by power system characteristics such as voltage characteristics of the buses with no energy storage system.Moreover, we have investigated the power system stabilizing control using dispersed energy storage systems from the viewpoint of preventive control to improve transient stability. As a result it was recognized that there was a trade-off relationship between the transient stabilizing effect and the cost for preventive control. However, it was also revealed that operators choices in power system operation were widened by using dispersed energy storage systems.