IEEE Transactions on Power Electronics · 2017 · 13 citations · 11 references
EngineeringElectrical EngineeringCircuit TheoryMicroelectronicsPower ElectronicsDc-dc ConversionDc-dc ConvertersFrequency RegulationHigh-frequency Power ConversionResonant CircuitsResonant ConvertersBuck ConvertersCapacitanceEquivalent Circuit AnalysisEquivalent Circuit ModelingEquivalent ResistanceEquivalent Series ResistanceSeries ResistanceVoltage Control
This letter presents a voltage-controlled capacitor that varies from 20% to 100% of the rated capacitance (1 μF) with a control voltage from half of the voltage rating to 0 V. Capacitance, self-resonant frequency, and equivalent series resistance were measured with respect to the control voltage. An equivalent circuit and a nonlinear model derived from relationship between permittivity and electric field were created and implemented in SPICE. A buck converter with input of 12 V, output of 5 V, and switching frequency of 500 kHz was built to demonstrate the change from 85% to 40% of the rated capacitance of the voltage-controlled capacitor. The error between the simulation and experiment was limited within 10%, which verifies the model.
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