Practical Control Design for a Power Supply with Saturable Magnetics

This study presents a control design procedure useful for power supplies featuring saturable magnetics. The paper addresses load identification, analysis limitations, and experimental evaluation. The system is described by a nonlinear state-space representation that is converted to a linearized time-varying system, which in turn is sampled to provide a discrete-time representation. We discuss some continuous versus discrete-time issues. Power supplies based on the ferroresonant transformer have been reported to be incompatible with loads that feature negative input resistance such as certain power factor corrected loads. This often causes instability in the controlled variable. The study proposes a procedure that leads to a feedback controller that stabilizes such systems. The suggested method is expected to be useful for ferroresonant power supplies and load interaction studies. This type of power supply is frequently encountered in telecommunication applications