Multiple-input soft-switching power converters
View Patent ↗A multiple-input power converter transferring energy from multiple input sources to a load comprises a plurality of voltage inputs. The power converter implements soft-switching techniques thereby reducing the converter switching losses and increasing the converter efficiency while using fewer components than presently designed multiple-input power converters. Such a power converter may include multiple input sources, where serially connected switches are coupled to one of the multiple input sources in an input leg. A voltage blocking capacitor is inserted between these input legs. Furthermore, the power converter includes a transformer for isolating the load from the multiple input sources, where the voltage blocking capacitor is connected to the primary winding of the transformer.
1. A multiple-input power converter transferring energy from multiple input sources to a load, the multiple-input power converter comprising:
a plurality of voltage inputs;
a first plurality of serially connected switches coupled to a first voltage input of said plurality of voltage inputs in a first input leg;
a second plurality of serially connected switches coupled to a second voltage input of said plurality of voltage inputs in a second input leg;
a first capacitor inserted between said first input leg and said second input leg;
a load;
a transformer isolating said load from said plurality of voltage inputs, wherein said first capacitor is coupled to a primary winding of said transformer;
a second capacitor connected in parallel to said load;
a third plurality of serially connected switches connected in parallel to said load; and
a fourth plurality of serially connected switches connected in parallel to said load;
wherein a terminal of a first switch of said third plurality of serially connected switches is connected to a secondary winding of said transformer, wherein a terminal of a first switch of said fourth plurality of serially connected switches is connected to said secondary winding of said transformer.
2. A multiple-input power converter transferring energy from multiple input sources to a load, the multiple-input power converter comprising:
a plurality of voltage inputs;
a first plurality of serially connected switches coupled to a first voltage input of said plurality of voltage inputs in a first input leg;
a second plurality of serially connected switches coupled to a second voltage input of said plurality of voltage inputs in a second input leg;
a first capacitor inserted between said first input leg and said second input leg;
a load;
a transformer isolating said load from said plurality of voltage inputs, wherein said first capacitor is coupled to a primary winding of said transformer;
a leakage inductor coupled in series to said first capacitor, wherein said leakage inductor is connected to said primary winding of said transformer; and
a magnetizing inductor coupled in series with said leakage inductor.
3. The multiple-input power converter as recited in claim 2 , wherein said first capacitor is configured to maintain a voltage balance of said magnetizing inductor in response to a duty cycle of said first and second plurality of serially connected switches not being symmetric.
4. The multiple-input power converter as recited in claim 2 further comprising:
a first and a second diode connected to a first and a second secondary windings of said transformer, respectively; and
a second capacitor in parallel with said load and said first and second diodes.
5. The multiple-input power converter as recited in claim 4 further comprising:
a first inductor serially connected to said first diode and to said second capacitor in parallel with said load.
6. The multiple-input power converter as recited in claim 2 further comprising:
a first and a second diode serially connected; and
a third and a fourth diode serially connected;
wherein said first and second diodes are in parallel to said load, wherein said third and fourth diodes are in parallel with said load and in parallel with said first and second diodes.
7. The multiple-input power converter as recited in claim 6 further comprising:
a second capacitor in parallel with said load.
8. The multiple-input power converter as recited in claim 7 further comprising:
a first inductor in series with said second capacitor.
9. A multiple-input power converter transferring energy from multiple input sources to a load, the multiple-input power converter comprising:
a plurality of voltage inputs;
a first plurality of serially connected switches coupled to a first voltage input of said plurality of voltage inputs in a first input leg;
a second plurality of serially connected switches coupled to a second voltage input of said plurality of voltage inputs in a second input leg;
a first capacitor inserted between said first input leg and said second input leg;
a load;
a transformer isolating said load from said plurality of voltage inputs, wherein said first capacitor is coupled to a primary winding of said transformer;
a second and a third capacitor serially connected; and
a first and a second diode serially connected;
wherein said second and third capacitors are in parallel with said load, wherein said first and second diodes are in parallel with said load, wherein a cathode of said first diode is connected to a secondary winding of said transformer, wherein a terminal of said third capacitor is connected to said secondary winding of said transformer.
10. The multiple-input power converter as recited in claim 9 further comprising:
a first inductor connected in series with said second capacitor and said first diode; and
a second inductor connected in series with said third capacitor and said second diode.
11. A multiple-input power converter transferring energy from multiple input sources to a load, the multiple-input power converter comprising:
a plurality of voltage inputs;
a first inductor coupled to a first voltage input of said plurality of voltage inputs in a first input leg;
a second inductor coupled to a second voltage input of said plurality of voltage inputs in a second input leg;
a first capacitor inserted between said first input leg and said second input leg;
a load; and
a transformer isolating said load from said plurality of voltage inputs, wherein said capacitor is coupled to a primary winding of said transformer.
12. The multiple-input power converter as recited in claim 11 further comprising:
a first switch serially connected to said first inductor; and
a second switch serially connected to said second inductor;
wherein a terminal of said first capacitor is connected to a terminal of said first inductor.
13. The multiple-input power converter as recited in claim 11 further comprising:
a second and a third capacitor serially connected; and
a first and a second diode serially connected;
wherein said second and third capacitors are in parallel with said load, wherein said first and second diodes are in parallel with said load, wherein a cathode of said first diode is connected to a secondary winding of said transformer, wherein a terminal of said third capacitor is connected to said secondary winding of said transformer.
14. The multiple-input power converter as recited in claim 13 further comprising:
a magnetizing inductor coupled in parallel to a fourth capacitor, wherein said magnetizing inductor and said fourth capacitor are connected across said secondary winding of said transformer.
15. The multiple-input power converter as recited in claim 11 further comprising:
a second capacitor in parallel with said load;
a third and a fourth capacitor serially connected, wherein said third and fourth capacitors are in parallel with said second capacitor;
a first diode connected in parallel with said second capacitor and said load and connected in series with said third capacitor; and
a second diode in series with said fourth capacitor;
wherein a cathode of said first diode is connected to a first secondary winding of said transformer, wherein a cathode of said second diode is connected to a second secondary winding of said transformer.