Search

The aim of this paper is to study the stability of linear multiloop control of quasiresonant converters (QRC). It is shown that a P-current feedback, plus an I-voltage feedback suffices to stabilize a QRC. A systematic procedure of control synthesis is presented and stability conditions for the control parameters are derived from nonlinear systems theory. Performance of the proposed controller is verified through an experimental application in a boost type QRC. Index Terms--Current mode control, multiloop control, Quasiresonant converters.

This brief addresses the problem of designing a robust tracking controller for a nonlinear Chua's circuit involving plant uncertainties and external disturbances. Given a bounded desired trajectory, a robust tracking controller, which is based on modeling-error compensation is developed such that all the states and signals of the closed-loop system are bounded and the tracking error can be made as small as desired. In contrast to the previous proposed controllers for tracking control of Chua's circuit, the controller developed here is linear and equivalent to a traditional PI compensator. Index Terms--Chua's circuit, modeling-error compensation, tracking.

The aim of this letter is to improve operation of a class of resonant converters and take quasi-resonant converters (QRCs) as a benchmark to realize this aim. In particular, a variable pulsewidth control scheme is proposed that ensures soft-switching conditions and reduces conduction losses. The control scheme has the feature of significant improvement of efficiency and wider voltage conversion ratio. The proposed controller modifies the pulsewidth of the square driving signal without modifying its frequency. This fact makes it able to be used as a complementary control action to voltage regulators. Results are illustrated via experimental work for the case of a boost-type zero-voltage-switching QRC. Index Terms--Control, efficiency improvement, quasi-resonant converters (QRCs), soft switching.

The stability of boost and buck-boost dc-dc power converters under proportional plus integral (PI) control is discussed in this paper. A novel PI control configuration is proposed, which reveals the effect that the right-hand -side zero has on PI control stability. Tuning rules in terms of the converter parameters are derived and illustrated via numerical and experimental simulations. Index Terms--DC-DC power conversion, proportional plus integral control, tuning rules.