A dispatch strategy for remote independent power producers connected to radial feeders

Abstract

This thesis presents a cost-optimized dispatch strategy for distributed generators (DGs) in radial distribution feeders using the open-source power system analysis toolbox, PyPSA. The study addresses the operational condition where the cumulative DG generation exceeds local load demand, leading to power export toward the grid substation. A control methodology is proposed to allocate DG dispatch levels such that the sum of the dynamic generation cost and associated line loss cost remains below the marginal cost defined by the utility. The dynamic generation cost is evaluated for each DG based on its tariff rate and the cost of power losses incurred during transmission to the grid. A four-stage algorithm is developed to identify the optimal output of each DG while ensuring compliance with predefined operational limits. The algorithm iteratively reduces the output of high-cost DGs and finalizes dispatch levels based on economic feasibility and system constraints. The methodology is implemented and validated using PyPSA, with comparative analysis against ETAP simulations to verify model accuracy. The results demonstrate that the proposed approach effectively minimizes operational costs by prioritizing lower-cost DGs and managing surplus capacity without compromising system reliability. This work contributes a practical framework for utility-oriented DG dispatch planning and offers insights for integrating dynamic cost control mechanisms into Power Purchase Agreements (PPAs).