Arbitration of day-ahead real power market clearing under the influence of voltage dependent load models

Social welfare maximization is used as an objective function to clear day-ahead real power electricity markets with elastic loads. The conventional way is to model loads as voltage independent. This paper investigates behaviour of day-ahead market clearing in the presence of voltage dependent load models at different loading conditions. In a multi-objective framework, different objective functions (load served, generation cost, emission and voltage stability enhancement index) are combined with social welfare so as to examine each function’s behaviour. However, it is observed and demonstrated that the objective functions are either in accord or discord with social welfare at different loading conditions. Therefore, Pareto fronts are obtained to decide the most optimal functioning condition subject to all operating and technical constraints for the judgement making authority. The differential evolution algorithm is applied for single and multi-objective optimization purposes. The model is implemented on IEEE 30 bus system for testing and verification.