Abstract:

Aiming at the requirements of high-power IGBT drive circuit of Tokamak’s pulse step modulation (PSM) module, an active clamp flyback converter is selected as the main circuit of the design, and the design method of the main components of the circuit is introduced in detail. Research on the zero-voltage turn-on of the main switch of the circuit and the implementation scheme based on the LM5025 feedforward control. For the ITER radio frequency heating system, a driving power supply with a switching frequency of 480 kHz is designed. The experimental results show that the zero-voltage turn-on and feedforward control of the main switch of the circuit are realized within the allowable input voltage range, which reduces the switching loss and improves the reliability of the circuit operation.

Key words: Pulse step modulation, feedforward control, zero voltage turn-on, flyback converter, active clamp