Approach to Asset Management of Substation Equipment in Japan

IEC white paper “Strategic Asset management of Power Networks” was published in 2015, and TC123 “Management of network assets in power system” is working towards the IEC standardization since 2017. The environment surrounding Japanese utilities is changing, and the need for asset management is increasing. This paper describes the environment surrounding the electric power industry in Japan and the necessity of asset management. And this paper reports example of asset management for substation equipment (Transformers and circuit breakers) by Japanese utilities. First, the environment surrounding the electric power industry in Japan is summarized. The aging of equipment owned by utilities, the decrease in the number of electric power engineers due to the declining birthrate, and a decrease in demand for electric power are some of the problems facing us. Under these circumstances, it is not realistic to replace equipment based on aging due to cost, construction, and network operational constraints. Because many equipment need to be replaced in a short period. Therefore, in order to realize effective investment and equalization of the replacement amount, asset management based on the condition evaluation and evaluation of consequence is important. Next, this paper reports the case of asset management for substation equipment by some Japanese utilities. This paper describes asset management (such as “scoring”, “risk matrix” and other methods) for transformers and circuit breakers, in which condition evaluation of equipment (such as dissolved gas analysis results of transformers and the number of operations of circuit breakers) and evaluation of consequence (such as power system importance and environmental impacts) are evaluated. In addition, important evaluation items in each case are described.