Evaluation of Power Capacity Availability at Load Bus in a Composite Power System

The evaluation of reliability of a composite power system is essential for the modern power system to assess the capacity to supply continuous power to the consumers. The power system network is affected by various uncertainties such as equipment failures and random variations in power generation and load demand. All these factors and complex network topology with a large number of equipment components lead to difficulties in the assessment of reliability in a composite power system. In this paper, reliability evaluation is carried out to estimate the power capacity availability at load bus in a composite power system. The composite power system considered here is a microgrid consisting of a conventional power generating unit, power transformer, wind farm, and four loads. New simplified predictive models have been suggested for the estimation of ambient temperature and wind velocity and validated with the actual weather data collected from Meteorological and Oceanographic Satellite Data Archival Centre, India. Using these models, wind velocity and ambient temperatures are predicted one day ahead to estimate the transformer tank temperature, from which the transformer derating factor and the power injected into the microgrid are computed. The proposed methodology is aimed to obtain the power capacity availability at load bus, the limits on the available power capacity variation, and corresponding confidence limits.

I. Introduction

The electrical energy plays a vital role in our day-to-day life to meet the needs of modern society. The reliability evaluation of the electrical system is important to assess the quality of power system. The power system operators must aim to provide continuous power supply to the consumers at a reasonable cost. The reliability and probability evaluation methods for the power system are developed in [1]–[3]. The reliability assessment based on probability of available power capacity at load bus in an interconnected system is quite difficult due to the large number of equipment components, network topology, and constraints on its generation capacity [4]–[7].