A Novel Constrained Load Flow Model and Algorithm for New-Type Power System Based on the Levenberg-Marquardt Method

Load flow computation faces increasing challenges with the rapid development of new-type power system, particularly the widespread integration of renewable energy sources such as photovoltaic and wind power. Traditional load flow algorithms urgently require enhancement to address the evolving demands of new-type power system. This paper introduces a constrained load flow (CLF) model for new-type power system based on the Levenberg-Marquardt (LM) method to address the operational uncertainties inherent in such system. Firstly, Transform the traditional load flow (TLF) model's nonlinear equations into nonlinear inequalities and equalities by relaxing generator outputs and bus voltages, forming a CLF model that broadens the solution space for load flow computations. Further, the inequalities in the constrained load flow model are converted into equalities, transforming the problem into a bounded constrained least-squares problem, which is solved using the Levenberg-Marquardt method. Finally, a case study on the IEEE 30-bus system with integrated renewable energy units validates the effectiveness and practicality of the proposed approach. Results indicate that the method effectively addresses the challenges posed by the fluctuating outputs and voltage variations of renewable energy units, providing theoretical support for the planning and operation of new-type power system.