Design of economic X̄ chart for monitoring electric power loss through transmission and distribution system

This article presents a model for the optimisation design of the (Formula presented.) chart based on Duncan’s model for identifying unusual power loss through transmission and distribution system so that an immediate action can be taken to maintain the power network stability. The model optimises the chart parameters in order to minimise the mean cost of power loss (MLC) under random process shifts (e.g. mean shifts), and ensures that the false alarm probability of the control chart will not exceed the allowable level and extra inspection resources (e.g. operators and measurement instruments) will be avoided. A comparative study based on fractional factorial experiment shows that, from an overall viewpoint, the optimal (Formula presented.) chart reduces the MLC by about 40% compared to the traditional (Formula presented.) chart. The effects of design specifications on the charting parameters and optimal MLC of the proposed chart are also investigated through sensitivity analysis. Finally, the design and application of the proposed chart is illustrated through an example. In general, this article will help reduce the cost of power loss and broaden the literature on the application of control chart in the service organisations.