Research on Evaluation of Dispersed Generations Installed in Distribution Systems

在本研究中，为评估太阳能电池和燃料电池等分散式发电机安装在配电系统中的效果，建立了以下研究结果。供电可靠性评估方法的研究：提出了一种分散发电机组在故障状态下利用分布式电源提高供电可靠性的策略分配方法。在该方法中，用停电费用来评估供电可靠性。也就是说，分散发电机(DG)的最具成本效益的分配是根据DG的安装和供电可靠性来确定的。在求解算法中，采用禁忌搜索算法。算法的外环采用禁忌搜索算法确定分布式电源的大小和位置，内环采用禁忌搜索算法确定每个故障情况下分布式电源的最优运行方式。为了减少计算负担，还采用了停电费用的敏感度或停电费用的近似计算。通过数值算例与模拟退火法进行了比较，验证了该方法的有效性。建立了配电网分布式电源优化配置的降损评估方法，确定了分布式电源的最优配置和容量，使配电网网损最小。该算法是基于上述禁忌搜索的。在此基础上，提出了在需求侧安装分布式电源时使配电网网损最小的配电网重构方法。该算法是基于分支交换法的。利用多个系统模型对所提出的算法进行了测试。从这些算法中发现各种信息可以减少分配损失。上述研究成果被介绍在日本IEE交易和相关技术国际会议等交易和会议上。

In this research, the followings research results are established for evaluating the effects of such dispersed generators as solar cells and fuel cells installed in distribution systems.1. Development of evaluation method for power supply reliability:A dispersed generator's strategic allocation method for enhancing power supply reliability by using DGs in a fault state is developed. In the method, the power interruption cost is used to evaluate the power supply reliability. That is, the most cost-effective allocation of the dispersed generators (DGs) is determined from both DGs installation and power supply reliability. In the solution algorithm, tabu search is employed. The tabu search is used in the outer loop of the algorithm to determine the size and location of DGs, and is used in the inner loop to determine the optimal operation of DGs for each fault case. In order to reduce the computational burden, the sensitivity of the power interruption cost or approximate calculation of the power interruption cost is also employed. The method is tested through the numerical examples by comparing with the simulated annealing method.2. Development of evaluation method for loss reductionA method for loss reduction by optimally allocating DGs in distribution system is developed which determine the optimal allocation and capacities of DGs for minimizing the distribution system loss. The algorithm is based on the tabu search as above. Further, distribution systems reconfiguration method to minimize distribution losses when DGs are installed in the demand side is developed. The algorithm is based on the branch exchange method. The developed algorithms are tested by using several system models. From these algorithms, various information is found to reduce distribution losses.The above research results are presented in such transactions and conferences proceedings as the transaction of IEE of Japan and international conferences on the relating technology.