High efficiency voltage converter
First Claim
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1. A DC-DC voltage converter comprising:
- a voltage source;
inverter means connected to said voltage source, said inverter means including a first, second, third, and fourth switching means;
transformer means connected to said inverter means, said transformer means including a primary winding and a secondary winding;
rectifier means connected to the secondary winding of said transformer means for supplying a DC output voltage;
capacitance means connected to said inverter, said capacitance mans including a second capacitor in parallel across the second switching means and a fourth capacitor in parallel across the fourth switching means; and
control means for regulating the output voltage, said control means supplying fixed pulse width control signals to the first and third switching means and pulse width modulation control signals to the second and fourth switching means in an operating cycle in which (1) the first and the fourth switching means are turned on while the second and the third switching means remain off, (2) the fourth switching means in turned off such that the voltage rise across the fourth switching means is limited by said capacitor means to facilitate zero voltage switching of the fourth switching means, (3) the fourth capacitor is charged to a voltage greater than the voltage source such that a current through the primary winding is driven to zero, (4) the first switching means is turned off after the current through the primary winding reaches zero to facilitate zero current switching of the first switching means, (5) the second and the third switching means are turned on while the first and the fourth switching means remain off, (6) the second switching means is turned off such that the voltage rise across the second switching means is limited by said capacitor means to facilitate zero voltage switching of the second switching means, (7) the second capacitor is charged to a voltage greater than the voltage source such that the current through the primary winding is driven to zero, and (8) the third switching means is turned off after the current through the primary winding reaches zero to facilitate zero current switching of the third switching means.
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Abstract
A full bridge DC to DC converter which provides zero voltage switching (ZVS) for one leg of the bridge and zero current switching (ZCS) for the other leg of the bridge is described. ZVS is achieved with parallel capacitors, while ZCS is achieved by using the reverse breakdown characteristics of the various diode and switching devices. This technique provides a significant reduction in the switching losses of the switching devices, which allows for higher power and frequency combinations.
67 Citations
20 Claims
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1. A DC-DC voltage converter comprising:
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a voltage source; inverter means connected to said voltage source, said inverter means including a first, second, third, and fourth switching means; transformer means connected to said inverter means, said transformer means including a primary winding and a secondary winding; rectifier means connected to the secondary winding of said transformer means for supplying a DC output voltage; capacitance means connected to said inverter, said capacitance mans including a second capacitor in parallel across the second switching means and a fourth capacitor in parallel across the fourth switching means; and control means for regulating the output voltage, said control means supplying fixed pulse width control signals to the first and third switching means and pulse width modulation control signals to the second and fourth switching means in an operating cycle in which (1) the first and the fourth switching means are turned on while the second and the third switching means remain off, (2) the fourth switching means in turned off such that the voltage rise across the fourth switching means is limited by said capacitor means to facilitate zero voltage switching of the fourth switching means, (3) the fourth capacitor is charged to a voltage greater than the voltage source such that a current through the primary winding is driven to zero, (4) the first switching means is turned off after the current through the primary winding reaches zero to facilitate zero current switching of the first switching means, (5) the second and the third switching means are turned on while the first and the fourth switching means remain off, (6) the second switching means is turned off such that the voltage rise across the second switching means is limited by said capacitor means to facilitate zero voltage switching of the second switching means, (7) the second capacitor is charged to a voltage greater than the voltage source such that the current through the primary winding is driven to zero, and (8) the third switching means is turned off after the current through the primary winding reaches zero to facilitate zero current switching of the third switching means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A DC-DC voltage converter comprising:
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inverter means for receiving a DC input voltage, including a first, a second, a third, and a fourth insulated gate bipolar transistor, the second and fourth insulated gate bipolar transistors being connected in series to form a leading leg, the first and third insulated gate bipolar transistors being connected in series to form a trailing leg, and the leading leg and trailing leg being connected in parallel; a DC voltage source connected in parallel to the leading leg and the trailing leg; a first and second capacitor connected in parallel across the second and fourth insulated gate bipolar transistors, respectively; a first, second, third, and fourth controlled avalanche diode connected in series to the first, second, third, and fourth insulated gate bipolar transistors, respectively; transformer means connected between the junction of the first and third insulated gate bipolar transistors and the junction of the second and fourth insulated gate bipolar transistors, said transformer means including a primary winding and a secondary winding; rectifier means connected to the secondary winding of said transformer means for converting an AC voltage of said transformer means into a DC output voltage; and control means for supplying control signals to the first, second, third, and fourth insulated gate bipolar transistors to provide for zero voltage switching of the second and fourth insulated gate bipolar transistors and for zero current switching of the first and third insulated gate bipolar transistors, said control means generating a fixed pulse width signal to selectively energize the first and third insulated gate bipolar transistors to an on state and an off state and a pulse width modulation signal to selectively energize the second and fourth insulated gate bipolar transistors to an on state and an off state such that the first and fourth insulated gate bipolar transistors are selectively energized to an on state during a first half cycle of aid control means and the second and third insulated gate bipolar transistors are selectively energized to an on state during the second half cycle of said control means. - View Dependent Claims (20)
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Specification