Electric power system cost/loss optimization using Dynamic Thermal Rating and linear programming

Abstract

Electric power systems consist of generation, transmission, and distribution components. As the demand for electricity grows seemingly endless, it is expected that a number of constraints, such as environmental, regulatory and economic, prevent the construction of new power plants and transmission lines. Finding improved ways to utilize the capacity supplied by existing power generation facilities and power transmission infrastructure is the problem that engineers, equipment manufacturers, and regulatory agencies are now facing. This paper introduces an optimization method using Dynamical Thermal Rating (DTR) and linear programming (LP) to minimize generation costs or transmission losses. DTR values are derived from a spatially resolved thermal model of the transmission system based on actual weather conditions along the line. This allows determination of line ampacity based on thermal bottlenecks that can exist at different locations along the line. The thermal model can also account for power losses more accurately, by considering actual distribution of temperature-dependent conductor resistance along the line. The model is used in a case study involving a simplified power transmission system with two types of generators, and a single load center. The simulation results show that more energy from hydro power plant can be transmitted to the load center, instead of using more expensive and polluting thermal generation.