US 2020/0287472 A1 · VOLTAGE CONVERSION CIRCUIT AND CONTROL METHOD THEREOF

Abstract

The present disclosure provides a control method of a voltage conversion circuit. The voltage conversion circuit includes a DC voltage input terminal, a primary side switch unit, a resonant inductance, a transformer, a secondary side switch unit and a DC voltage output terminal which are electrically coupled. The resonant inductance is connected to the transformer in series. The voltage conversion circuit also includes a resonant capacitance which resonates with the resonant inductance. The control method includes: controlling switch elements in the primary side switch unit and the secondary side switch unit, so that a range of a ratio Ton/Tr of a total conduction time Ton to a resonant period Tr of the voltage conversion circuit is (0, 1.8)U(2.7, 3.7)U(4.8, 5.5), and a quality factor Q of the voltage conversion circuit is less than or equal to 5, that is, Q≤5. The control method provided by the embodiment of the present disclosure can reduce the conduction loss and the switching loss of the voltage conversion circuit, thereby improving the efficiency and reducing the cost.

Claims20

Dependent claims

A control method of a voltage conversion circuit, wherein the voltage conversion circuit comprises a DC voltage input terminal, a primary side switch unit, a resonant inductance, a resonant capacitance, a transformer, a secondary side switch unit and a DC voltage output terminal, the resonant inductance being connected to the transformer in series, wherein the control method comprises:

controlling switch elements of the primary side switch unit and the secondary side switch unit, so that a range of a ratio Ton/Tr of a total conduction time Ton to a resonant period Tr of the voltage conversion circuit is (0, 1.8)U(2.7, 3.7)U(4.8, 5.5), and a quality factor Q of the voltage conversion circuit is less than or equal to 5, wherein Q=SQRT(Lr_eqv/Cr_eqv)/Ro, where Lr_eqv is an equivalent resonant inductance of the voltage conversion circuit, Cr_eqv is an equivalent resonant capacitance of the voltage conversion circuit, and Ro is an internal resistance of the voltage conversion circuit;
wherein the resonant capacitance is provided between the DC voltage input terminal and the primary side switch unit or between the DC voltage output terminal and the secondary side switch unit.

A voltage conversion circuit comprising:

a DC voltage input terminal, a primary side switch unit, a transformer, a secondary side switch unit and a DC voltage output terminal which are electrically coupled;
a resonant inductance and a resonant capacitance, the resonant inductance being connected to a primary winding or a secondary winding of the transformer in series, the resonant capacitance being disposed between the DC voltage input terminal and the primary side switch unit or between the DC voltage output terminal and the secondary side switch unit, and a quality factor Q of the voltage conversion circuit being less than or equal to 5;
and
a controller coupled to the primary side switch unit and the secondary side switch unit for controlling switch elements of the primary side switch unit and the secondary side switch unit, so that a range of a ratio Ton/Tr of a total conduction time Ton to a resonant period Tr of the voltage conversion circuit is (0, 1.8)U(2.7, 3.7)U(4.8, 5.5).

1 more element

A voltage conversion circuit comprising:

a DC voltage input terminal, a primary side switch unit, a transformer, a secondary side switch unit and a DC voltage output terminal, which are electrically coupled;
a resonant inductance and a resonant capacitance, the resonant inductance being connected to a primary winding or a secondary winding of the transformer in series, the resonant capacitance being disposed between the DC voltage input terminal and the primary side switch unit or between the DC voltage output terminal and the secondary side switch unit, and a quality factor Q of the conversion circuit is smaller than or equal to 2;
and
a controller coupled to the primary side switch unit and the secondary side switch unit for controlling switch elements of the primary side switch unit and the secondary side switch unit, so that a range of a ratio Ton/Tr of a total conduction time Ton to a resonant period Tr of the voltage conversion circuit is less than or equal to 5.5.

1 more element

Dependencies are inferred from the claim text.

Voltage conversion circuit and control method thereof

Life of this patent

Voltage conversion circuit and control method thereof

Life of this patent

Abstract

Claims20