Ripple current cancellation circuit
ABSTRACT A ripple current cancellation technique injects AC current into the output voltage bus of a converter that is equal and opposite to the normal converter ripple current. The output current ripple is ideally zero, leading to ultra-low noise converter output voltages. The circuit requires few additional components, no active circuits are required. Only an additional filter inductor winding, an auxiliary inductor, and small capacitor are required. The circuit utilizes leakage inductance of the modified filter inductor as all or part of the required auxiliary inductance. Ripple cancellation is independent of switching frequency, duty cycle, and other converter parameters. The circuit eliminates ripple current in both continuous conduction mode and discontinuous conduction mode. Experimental results provide better than an 80× ripple current reduction.
Conference Proceeding: Improved small-signal analysis for the ZVT converter[show abstract] [hide abstract]
ABSTRACT: A closed form, cycle by cycle analysis forms the basis for a new zero-voltage transition (ZVT) power converter small-signal model. The ZVT converter has an implicit “slew interval,” making the converter dynamics difficult to analyze using traditional averaging techniques. The control to output transfer function for the ZVT converter using voltage-mode control does not exhibit a second order pole associated with the output L-C filter, in direct contrast to existing small-signal models for the ZVT converter. There is a characteristic pole dependent upon switching frequency and inductor values. This characteristic pole is independent of operating conditions and is fundamental to the ZVT converter. The new small-signal model is in excellent agreement with experimental resultsApplied Power Electronics Conference and Exposition, 2001. APEC 2001. Sixteenth Annual IEEE; 02/2001
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ABSTRACT: A steady-state analysis is presented with complete characterization of the converter operation. A small-signal model of the converter is established. The design procedures based on the analysis are presented and the various losses in the circuit assessed. Critical design considerations for a high-power, high-voltage application are analyzed. The results of the analysis are verified using a high-voltage. 2 kW prototypeApplied Power Electronics Conference and Exposition, 1990. APEC '90, Conference Proceedings 1990., Fifth Annual; 04/1990
Conference Proceeding: Input filter design for power factor correction circuits[show abstract] [hide abstract]
ABSTRACT: The issues involved in the design of power factor correction circuit input filters are significantly different than those involved in the design of input filters for DC-DC power converters. So far, there exist no guidelines for high-frequency AC power converter input filter design. This paper addresses these issues and proposes the use of a high order, actively damped filter to achieve the required EMI attenuation and power factor requirements. The new filter topology typically provides 50% filter size reduction over the standard filter designs, and simultaneously minimizes the filter-converter interactionIndustrial Electronics, Control, and Instrumentation, 1993. Proceedings of the IECON '93., International Conference on; 12/1993 · 4.08 Impact Factor