High Current Magnet Driver with Pulse Width Modulation Capabilities

EHT developed a power supply capable of switching 40 kA at 100 kHz PWM for driving an inductive load (electromagnet coils). The supply consisted of sixteen IPM-16PPs operating in parallel at 2.5 kA per module for 10 ms. The figure below shows the collector-emitter voltage of the IGBT (Ch2) and the current in the load (Ch3). Midway through the pulse, the pulse width was changed to change the current in the load.

ipm_16parallelpwm

This supply highlights the parallel operation, high current and high frequency capabilities of the IPMs. High switching frequencies and precise pulse width resolution allow for much finer PWM control than other solid-state-based PWM power supplies.