Circuit with low DC bias storage capacitors for high density power conversion
OwnerRobert W. Horstinventor
Life of this patent
Estimating the term…
Abstract
A circuit for converting DC to AC power or AC to DC power comprises a storage capacitor, boost and buck inductors and switching elements. The switches are controlled to steer current to and from the storage capacitor to cancel DC input ripple or to provide near unity power factor AC input. The capacitor is alternately charged to high positive or negative voltages with an average DC bias near zero. The circuit is configured to deliver high-efficiency power in applications including industrial equipment, home appliances, mobility devices and electric vehicle applications.
Claims22
A power converter configured to drive an output current from an input current, the power converter comprising:
- a bipolar storage capacitor configured to store energy when an amplitude of the output current is less than an average amplitude of the input current and deliver stored energy to an output when the amplitude of the output current is greater than the average amplitude of the input current, the bipolar storage capacitor arranged in the power converter such that the bipolar storage capacitor is alternately charged to a positive voltage and to a negative voltage;
- a buck circuit;
- and
- a boost circuit,
- wherein the buck circuit is configured to drive the output current from the input current, and
- wherein the boost circuit is configured to drive additional output current from the bipolar storage capacitor when the amplitude of the output current is greater than the average amplitude of the input current.
A power converter configured to drive an output current from an input current, the power converter comprising:
- a bipolar storage capacitor configured to store energy when an amplitude of the output current is less than an average amplitude of the input current and deliver stored energy to the output when the amplitude of the output current is greater than the average amplitude of the input current;
- a first inverter leg having a high side switch segment connected between a first DC node and a first common node and a low side switch segment connected between the first common node and a second DC node;
- a second inverter leg having a high side switch segment connected between the first DC node and a second common node and a low side switch segment connected between the second common node and the second DC node;
- a third inverter leg having a high side switch segment connected between the first DC node and a third common node and a low side switch segment connected between the third common node and the second DC node;
- a boost inductor connected between the first common node and the second common node, wherein the boost inductor is configured to transfer the stored energy of the bipolar storage capacitor to the output;
- and
- a buck inductor connected between the second common node and the third common node,
- wherein the high side switch segment and the low side switch segment of the first inverter leg, the second inverter leg, and the third inverter leg are configured to switch according to a cycle such that a capacitor voltage across the bipolar storage capacitor changes polarity during the cycle.
Dependencies are inferred from the claim text.