Simulation analysis on magnetic core loss characteristic of valve reactor in UHVDC system

Valve reactors (VR) with multiple magnetic cores are important electrical components in ultra-high voltage direct current systems. The impact current and high-order harmonics during their operation can lead to additional losses and temperature rise in the valve reactors, posing a threat to insulation aging, and even causing serious incidents such as combustion and explosions. Therefore, it is necessary to accurately quantify and analyze the loss characteristics of valve reactors under different magnetic materials. This article first theoretically analyzes the electromagnetic and temperature characteristics during the actual operation of VR; then, it analyzes and calculates the magnetic field distribution and electromagnetic losses of a single magnetic core. Finally, it establishes a three-dimensional equivalent model of VR and conducts transient electromagnetic-thermal coupled finite element simulation to reveal the magnitude and spatial distribution of VR temperature changes.