Boost power conversion circuit
A boost power conversion circuit includes an inductor, a first switch module, a second switch module, a first unilateral conduction component, a second unilateral conduction component, a flying capacitor, an upper bus capacitor, a lower bus capacitor, and a third unilateral conduction component. The power supply, the inductor, the first switch module, and the second switch module are connected in series to form a loop. The first unilateral conduction component, the second unilateral conduction component, the upper bus capacitor and the lower bus capacitor are connected in series. The flying capacitor is electrically connected between a reverse cut-off end of the first unilateral conduction component and a forward conduction end of the second unilateral conduction component. The third unilateral conduction component is configured to clamp a voltage stress of the second switch module to a lower-bus voltage.
1. A boost power conversion circuit, comprising:
a power supply;
an inductor;
a first switch module;
a second switch module;
a first unilateral conduction component;
a second unilateral conduction component;
a flying capacitor;
an upper bus capacitor;
a lower bus capacitor;
a third unilateral conduction component; and
a fourth unilateral conduction component,
wherein
the power supply, the inductor, the first switch module, and the second switch module are connected in series to form a loop,
the first unilateral conduction component, the second unilateral conduction component, the upper bus capacitor and the lower bus capacitor are connected in series,
a forward conduction end of the first unilateral conduction component is electrically connected to a positive end of the first switch module,
a positive end of the flying capacitor is electrically connected between a reverse cut-off end of the first unilateral conduction component and a forward conduction end of the second unilateral conduction component,
a negative end of the flying capacitor is electrically connected to a forward conduction end of the third unilateral conduction component,
a reverse cut-off end of the third unilateral conduction component is electrically connected to a junction point between the upper bus capacitor and the lower bus capacitor,
a forward conduction end of the fourth unilateral conduction component is electrically connected to the forward conduction end of the first unilateral conduction component between the inductor and the first unilateral conduction component,
a reverse cut-off end of the fourth unilateral conduction component is electrically connected to a reverse cut-off end of the second unilateral conduction component, and
the third unilateral conduction component is configured to clamp a voltage stress of the second switch module to a lower-bus voltage.
2. The boost power conversion circuit according to claim 1 , further comprising:
a third switch module,
wherein a first end of the third switch module is electrically connected to the negative end of the flying capacitor, and a second end of the third switch module is electrically connected to a common point between the first switch module and the second switch module.
3. The boost power conversion circuit according to claim 2 , wherein the third switch module is in an off state before the boost power conversion circuit operates, and the third switch module is in an on state after the boost power conversion circuit operates.
4. The boost power conversion circuit according to claim 3 , further comprising:
a bus, comprising the upper bus capacitor and the lower bus capacitor,
wherein
the third switch module is configured to be in the off state if the power supply is not powered on, but a bus voltage has been established on the bus and a voltage stress of the second unilateral conduction component is less than the bus voltage, and
with the third switch module is in the off state, the bus voltage is applied to both ends of the first unilateral conduction component and the second unilateral conduction component, and the bus voltage is a sum of an upper bus voltage and the lower-bus voltage.
5. The boost power conversion circuit according to claim 4 , wherein the boost power conversion circuit causes the bus voltage to jump and a voltage of the flying capacitor to jump in a manner corresponding to the bus voltage in operation.
6. The boost power conversion circuit according to claim 2 , further comprising:
an upper bus comprising the upper bus capacitor; and
a lower bus comprising the lower bus capacitor,
wherein the flying capacitor is pre-charged by powering on the power supply such that an output current of the power supply in the boost power conversion circuit flows through a positive end of the power supply, the inductor, the first unilateral conduction component, the flying capacitor, the third unilateral conduction component, the lower bus, and back to a negative end of the power supply.
7. The boost power conversion circuit according to claim 1 , wherein
a forward conduction voltage drop of the fourth unilateral conduction component is lower than a forward conduction voltage drop of the first unilateral conduction component and the second unilateral conduction component connected in series, and
a withstand voltage of the fourth unilateral conduction component is greater than the bus voltage.
8. The boost power conversion circuit according to claim 7 , wherein in a phase in which the boost power conversion circuit operates, and both the first switch module and the second switch module are turned off, a freewheeling current of the inductor freewheels into the bus through the fourth unilateral conduction component.
9. The boost power conversion circuit according to claim 1 , wherein the power supply, the inductor, the first switch module, and the second switch module are sequentially connected in series to form the loop.
10. The boost power conversion circuit according to claim 9 , wherein the first unilateral conduction component, the second unilateral conduction component, the upper bus capacitor and the lower bus capacitor are sequentially connected in series.