Efficient in-rush current limiting circuit with dual gated bidirectional hemts
View Patent ↗A boost converter in accordance with an embodiment of the present application includes an input rectifying bridge adapted to rectify an input AC voltage, a first inductor connected to the input rectifying bridge, a output capacitor coupled to first inductor for connection to a DC bus, a first bidirectional semiconductor switch coupled between the output capacitor and the first inductor, a second inductor positioned adjacent to the first inductor with a first end connected to a common ground and a second bidirectional semiconductor switch positioned between the second inductor and the output capacitor. An inrush control device may be provided to control the first and second bidirectional semiconductor switches to prevent current inrush.
1. A boost converter comprising:
an input rectifying bridge adapted to rectify an input AC voltage;
a first inductor connected to the input rectifying bridge;
an output capacitor coupled to first inductor for connection to a DC bus;
a first bidirectional semiconductor switch coupled between the output capacitor and the first inductor;
a second inductor magnetically coupled to the first inductor with a first end connected to a common ground;
a second bidirectional semiconductor switch positioned between the second inductor and the output capacitor;
a first control switch connected to the first bidirectional semiconductor switch operable to turn the first bidirectional semiconductor switch on and off;
a second control switch connected to the second bidirectional semiconductor switch operable to turn the second bidirectional semiconductor switch on and off; and
an inrush control device operable to control the first and second control switches.
2. The boost converter circuit of claim 1 , further comprising:
a first switch zener diode connected between a first gate and a first source of the first bidirectional semiconductor switch, wherein the first gate and first source of the first bidirectional semiconductor switch are on the output capacitor side of the first bidirectional semiconductor switch;
a first switch resistor connected between the first gate and the first source of the first bidirectional semiconductor switch in parallel with the first switch zener diode; a first intermediate resistor connected to each of the first gate, the first switch zener diode and the first switch resistor, wherein the first control switch is connected between the first intermediate resistor and a low side rail of the DC bus, such that, when on, it provides a negative voltage to the first gate of the first bidirectional semiconductor switch to turn it off.
3. The boost converter circuit of claim 2 , further comprising:
a second switch zener diode connected between a first gate and a first source of the second bidirectional semiconductor switch, wherein the first gate and the first source of the second bidirectional semiconductor switch are on the output capacitor side of the second bidirectional semiconductor switch;
a second switch resistor connected between the first gate and the first source of the second bidirectional semiconductor switch in parallel with the second switch zener diode;
a second intermediate resistor connected to each of the first gate of the second bidirectional semiconductor switch, the second switch zener diode and the second switch resistor, wherein the second control switch is connected between the second intermediate resistor and the low side rail of the DC bus, such that, when on, it provides a negative voltage to the first gate of the second bidirectional semiconductor switch to turn it off.
4. The boost converter of claim 1 , wherein the inrush control device controls the second control switch to keep the second bidirectional semiconductor device on and controls the first control switch to turn the first bidirectional semiconductor switch on and off as appropriate when the input voltage is larger than the voltage across the output capacitor.
5. The boost converter of claim 1 , wherein the inrush control device controls the second control switch to keep the second bidirectional semiconductor device off and controls the first control switch to keep the first bidirectional semiconductor switch on when the input voltage is less than the voltage across the output capacitor.
6. The boost converter of claim 1 , further comprising:
a power switch connected between a high side rail and the low side rail of the DC bus and positioned between the first inductor and the first bidirectional semiconductor switch; and
a power factor correction control device operable to control the power switch to provide power factor correction for the boost converter.
7. The boost converter of claim 4 , wherein the power switch is a power MOSFET.
8. The boost converter of claim 1 , wherein the first and second bidirectional switches and other parts of the boost converter are fabricated on a single IC.