Simulation Analysis on Heating of Metal Structure in Leakage Magnetic Field of Arm Inductor in Converter Station

The Modular Multilevel Converters (MMC) based Voltage Source Converter High Voltage DC (VSC-HVDC) power transmission technology has been widely used worldwide. The arm inductor in the MMC plays a role of controlling power transmission, filtering, and suppressing AC side current fluctuations. The dry-type air-core reactor used by MMC generates an alternating magnetic field under the excitation of the AC at 50 Hz, which may induce a current in the metal structure forming a loop in the arm inductor room. When contact resistance appears in the metal loop, significant heating may occur. This paper built simulation models based on the actual size of the arm inductor of a converter station and simulated the partial heating phenomenon caused by the contact resistance and the limited heat dissipation ability, reproduced the observed temperature rise phenomenon under the actual operation condition of the converter station. This work confirmed the feasibility of measures to reduce the temperature rise and has certain guiding significance for future HVDC projects.