Аннотация:This paper illustrates the application of value-based reliability planning (VBRP) methods to the problem of distribution substation capacity enhancement. The traditional approach is to consider relative investment and operating costs of various alternatives. VBRP enhances the traditional approach with the addition of reliability valuation. This includes a detailed representation of performance during transformer failures and the accelerated aging from increased stress on remaining transformers, as well as the cost of customer interruptions. The addition of a transformer is compared with various distributed resource options, and also the option of doing nothing and incurring more frequent interruptions and greater stress. This paper illustrates the usefulness of VBRP techniques for the planner who must consider customer value in planning decisions.