Design of a highly stable electromagnet power supply

A method for designing a highly stable electromagnet power supply combining the 12-pulse phase-controlled rectifier (PCR), passive filter, and transformed active filter is investigated. The PCR system is analyzed, and passive filter parameters are designed from this analysis. A phase-locked voltage control circuit with a fast dynamic characteristic is analyzed, and an optimal constant proportional-integral and measurable variable feedback plus feedforward (PIMF) current controller is designed using a time-weighted quadratic performance index. It is shown via experimental results that the proposed design method gives good performance