Bridgeless single-stage AC/DC converter
First Claim
1. An apparatus comprising:
- a transformer comprising a primary winding and a secondary winding, the primary winding comprising a first end and a second end of the primary winding, and the secondary winding comprising a first end and a second end of the secondary winding;
a first AC voltage source input connectable to a first AC input line;
a second AC voltage source input connectable to a second AC input line;
a first inductor connected between the first AC voltage source input and a central node;
a first switch connected between the central node and a first rail node, the first rail node connected to the second end of the primary winding;
a first diode oriented to pass current from the first rail node to the central node;
a second switch connected between the central node and a second rail node;
a second diode oriented to pass current from the central node to the second rail node;
a first input rectifier connected between the first rail node and the second AC voltage source input and oriented to pass current from the first rail node to the second AC voltage source input;
a second input rectifier connected between the second rail node and the second AC voltage source input and oriented to pass current from the second AC voltage source input to the second rail node;
a second inductor connected between the central node and the first end of the primary winding of the transformer;
a first capacitor connected between the second rail node and the second end of the primary winding of the transformer; and
an output rectifier circuit connected between the secondary winding of the transformer and a load, wherein, in operation, the apparatus delivers a DC current to the load via the output rectifier circuit.
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Accused Products
Abstract
A single-stage AC/DC converter includes a boost PFC AC/DC converter and a half-bridge split-capacitor DC/DC converter. The boost PFC AC/DC converter includes a boost inductor, and the half-bridge split-capacitor DC/DC converter includes an inductor in series with a primary winding of a transformer. A method of operation of a single-stage AC/DC converter that includes a boost PFC AC/DC converter and a half-bridge split-capacitor DC/DC converter includes modulating a switching frequency of at least one switch. The method may further include maintaining a constant duty cycle, for example a duty cycle of 0.5. An implementation of the boost inductor in a boost PFC AC/DC converter of a single-stage AC/DC converter includes a variable boost inductor, such as two inductors of approximately equal inductance, and a boost inductor switching circuit, such as two single-pole, double-throw relays.
70 Citations
21 Claims
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1. An apparatus comprising:
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a transformer comprising a primary winding and a secondary winding, the primary winding comprising a first end and a second end of the primary winding, and the secondary winding comprising a first end and a second end of the secondary winding; a first AC voltage source input connectable to a first AC input line; a second AC voltage source input connectable to a second AC input line; a first inductor connected between the first AC voltage source input and a central node; a first switch connected between the central node and a first rail node, the first rail node connected to the second end of the primary winding; a first diode oriented to pass current from the first rail node to the central node; a second switch connected between the central node and a second rail node; a second diode oriented to pass current from the central node to the second rail node; a first input rectifier connected between the first rail node and the second AC voltage source input and oriented to pass current from the first rail node to the second AC voltage source input; a second input rectifier connected between the second rail node and the second AC voltage source input and oriented to pass current from the second AC voltage source input to the second rail node; a second inductor connected between the central node and the first end of the primary winding of the transformer; a first capacitor connected between the second rail node and the second end of the primary winding of the transformer; and an output rectifier circuit connected between the secondary winding of the transformer and a load, wherein, in operation, the apparatus delivers a DC current to the load via the output rectifier circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of controlling a single-stage AC/DC converter, the AC/DC converter comprising a boost PFC AC/DC converter and a half-bridge DC/DC converter, the boost PFC AC/DC converter and the half-bridge DC/DC converter sharing a pair of switches, wherein a boost inductor of the boost PFC AC/DC converter has a selectively variable inductance, the method comprising:
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modulating a respective switching frequency of each of the pair of switches; and selectively varying the inductance of the boost inductor based at least in part on a voltage of an AC input line.
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21. A method of controlling a single-stage AC/DC converter, the AC/DC converter comprising a boost PFC AC/DC converter and a half-bridge DC/DC converter, the boost PFC AC/DC converter and the half-bridge DC/DC converter sharing a pair of switches, wherein a boost inductor of the boost PFC AC/DC converter comprises two inductors, and the boost PFC AC/DC converter comprises a boost inductor switching circuit operatively coupled to the two inductors, the method comprising:
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modulating a respective switching frequency of each of the pair of switches; and controlling the boost inductor switching circuit to cause the boost inductor switching circuit to couple the two inductors in a parallel configuration or a series configuration based at least in part on a voltage of an AC input line connected to the AC/DC converter.
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Specification