Optimal control for electromagnet power supply

A method for designing an electromagnet power supply using the concepts of state-variable feedback control theory is investigated. Step and ramp responses for experimental models designed as type-one optimal servosystems are examined. These models exhibit properties as good as or better than those of supplies designed on the basis of classical control theory. A type-one servosystem combined with an active filter is proposed to reconcile two opposing requirements, that, high-speed response and low ripple current, which seem to be incompatible in a usual power-supply system with a passive filter. Although the type-one servosystem and active filter in the combined system are designed independently, neglecting the interaction between them, satisfactory control performance can be achieved.<>