Solving the Multi-Frequency AC Power Flow Using Bus Injection Model with Fixed-Point Iteration

A novel approach to long-distance bulk-power transmission has emerged, known as the low-frequency high-voltage ac (LF-HVac) system. It combines the strengths of both HVac and HVdc systems. The LF-HVac scheme offers high bulk-power transmission capacity over long distances and power flow control using low frequency transmission and back-to-back converters. This paper introduces a power flow calculation method based on bus injection model for multi-frequency ac systems interconnected via LF-HVac tie lines. The power flow formulation, employing a fixed-point iteration approach, facilitates the analysis of asynchronous power system power flow and is suitable for application in large-scale power systems. The results demonstrate that the proposed multi-frequency power flow, implemented in Python, exhibits negligible discrepancies when compared with time-domain simulation results using PSCAD/EMTDC.