A Study on Newton-Raphson-based AC/DC Integrated System Power Flow Analysis

Abstract

Due to the energy transition towards carbon neutrality, the penetration of DC power-based distributed generation and electric vehicles (EVs) is accelerated. This shift is amplifying the influence of DC-based systems in traditional AC-based power systems. Especially, there is a demand for consideration of the impacts of DC system integration in the fundamental system monitoring technique of power flow analysis, which is essential for stable power system operation. This paper proposes a Newton-Raphson-based power flow analysis technique for AC/DC integrated systems based on the previously proposed AC/DC hybrid network branch flow model. The proposed method is based on the bus injected power model derived from the selected branch model. It selects AC and DC system state variables and performs Newton-Raphson-based power flow analysis using the unified Jacobian matrix obtained by partial differentiation of the model with respect to selected state variables. To evaluate the performance of the proposed technique, case studies on 3 test systems are presented. The power flow analysis results from each case study show that the proposed technique meets convergence criteria and provides valid power flow analysis results for the 3 test systems data.