Electrothermal Coupling Model Based on Thyristor Voltage-Current Characteristics

This research develops the electro-thermal coupling model of the thyristor valve, encompassing the electrical model and the thermal network model, based on the relationship between the electrical properties of the thyristor and the temperature. Based on the characteristics of the thyristor characteristic curve, the electrical model analyzes the link between on-state voltage drop, current, and junction temperature, and then constructs a thyristor loss model that takes current and temperature fluctuations into account. The steady-state thermal resistance of the thyristor and its water-cooled heatsink is computed using the physical composition and material characteristics of the thyristor and the water-cooled heatsink in the thermal network model. The structure of the water-cooled heat dissipation loop of the converter valve assembly is analyzed, and the converter valve thermal network model considering the water-cooled heat dissipation loop is constructed. Based on the relationship between the electrical characteristics of thyristors and temperature, an iterative electro-thermal coupling model of junction temperature is proposed, which combines the information of device current, conduction communication signal and shell temperature. Finally, the effectiveness of the proposed loss model is verified by simulation.