SNUBBER CIRCUIT, POWER CONVERTER AND METHODS OF OPERATING THE SAME

1 . A snubber circuit for use with a power converter having an input inductor coupled to a winding of a transformer, comprising:

a series-coupled clamp diode and clamp capacitor coupled across said input inductor; and

a clamp switch coupled across and configured to regulate a voltage of said clamp capacitor.

2 . The snubber circuit as recited in claim 1 wherein said clamp capacitor comprises a parallel circuit arrangement of a plurality of capacitors.

3 . The snubber circuit as recited in claim 1 wherein said clamp diode comprises a parallel circuit arrangement of a plurality of diodes.

4 . The snubber circuit as recited in claim 1 wherein a feedback path is coupled to a terminal of said clamp capacitor and a control terminal of said clamp switch.

5 . The snubber circuit as recited in claim 4 wherein said feedback path comprises a resistor divider network.

6 . The snubber circuit as recited in claim 5 wherein a shunt regulator is coupled to said resistor divider network.

7 . The snubber circuit as recited in claim 6 wherein a control switch is configured to disable an operation of said shunt regulator.

8 . The snubber circuit as recited in claim 1 wherein a Zener diode is configured to limit said voltage of said clamp capacitor.

9 . The snubber circuit as recited in claim 1 wherein an input filter capacitor is coupled between said clamp switch and an input power source to said power converter.

10 . The snubber circuit as recited in claim 9 wherein said input power source comprises a photovoltaic panel.

11 . The snubber circuit as recited in claim 1 wherein said clamp switch is operable as a variable linear resistor.

12 . A photovoltaic module, comprising:

a power converter configured to receive a direct current (dc) output voltage from a photovoltaic panel and provide a dc output voltage, said power converter having an input inductor coupled to a winding of a transformer and snubber circuit, comprising:

a series-coupled clamp diode and clamp capacitor coupled across said input inductor; and

a clamp switch coupled across and configured to regulate a voltage of said clamp capacitor; and

an inverter configured to receive said dc output voltage from said power converter and provide an alternating current (ac) output voltage.

13 . The photovoltaic module as recited in claim 12 further comprising a feedback path coupled to a terminal of said clamp capacitor and a control terminal of said clamp switch.

14 . The photovoltaic module as recited in claim 13 wherein said feedback path comprises a resistor divider network.

15 . The photovoltaic module as recited in claim 14 further comprising a shunt regulator coupled to said resistor divider network and a control switch configured to disable an operation thereof.

16 . The photovoltaic module as recited in claim 13 further comprising a Zener diode configured to limit said voltage of said clamp capacitor.

17 . A method of operating a photovoltaic module, comprising:

receiving a direct current (dc) output voltage at a power converter from a photovoltaic panel and providing a dc output voltage, said power converter having an input inductor coupled to a winding of a transformer;

regulating a voltage of a clamp capacitor series-coupled to a clamp diode with a clamp switch of a snubber circuit, said series-coupled clamp capacitor and clamp diode being coupled across said input inductor; and

receiving said dc output voltage from said power converter and providing an alternating current (ac) output voltage.

18 . The method as recited in claim 17 further comprising controlling said clamp switch with a feedback path including a resistor divider network.

19 . The method as recited in claim 18 further comprising discharging said clamp capacitor.

20 . The method as recited in claim 17 further comprising limiting said voltage of said clamp capacitor with a Zener diode.