NON-ISOLATED DC/AC INVERTER
A method and apparatus for converting DC power comprising: a boost circuit comprising two switches and a capacitor where the two switches are serially connected and coupled in parallel to the capacitor, a voltage source inverter (VSI) comprising at least four switches in an H-bridge configuration, and a controller coupled to the boost circuit and VSI for selectively energizing the switches wherein no more than two switches are toggling in a time period for operating the apparatus in either the buck mode or boost mode.
1 . An apparatus for converting DC power comprising:
a boost circuit comprising two switches and a capacitor where the two switches are serially connected and coupled in parallel to the capacitor;
a voltage source inverter (VSI) comprising at least four switches in an H-bridge configuration; and
a controller coupled to the boost circuit and VSI for selectively energizing the switches wherein no more than two switches are toggling in a time period for operating the apparatus in either the buck mode or boost mode.
2 . The apparatus of claim 1 , wherein selection of the at least two switches for toggling is based on a comparison of an input voltage to the boost circuit and output voltage from the VSI.
3 . The apparatus of claim 1 , wherein the two toggling switches are energized using at least one of: pulse width modulation, predictive control, or hysteretic control.
4 . The apparatus of claim 1 , wherein the remaining switches are not toggling and held at either a closed or open position.
5 . The apparatus of claim 1 , further comprising a DC input port for receiving DC power for conversion to AC power.
6 . The apparatus of claim 5 , further comprising a low pass filter circuit at the DC input port.
7 . The apparatus of claim 5 , wherein when the apparatus is in a buck mode, no more than two active switches are active, and located within the inverter circuit.
8 . The apparatus of claim 5 , wherein when the apparatus is in the boost mode, no more than two active switches are active, and located within the boost circuit.
9 . The apparatus of claim 1 , wherein the apparatus is capable of outputting multiphase power.
10 . The apparatus of claim 9 , wherein outputting multiphase power further comprises three output legs.
11 . A method for converting DC power using a converter comprising:
selectively operating two switches of a boost circuit to control charging a capacitor of a boost circuit when DC input power is greater than AC output power;
coupling power from the boost circuit to a voltage source inverter (VSI) comprising four switches in an H-bridge configuration; and
operating the boost circuit and VSI with a controller, wherein no more than two switches are toggling in a time period for operating the apparatus in either the buck mode or boost mode.
12 . The method of claim 11 , wherein selection of the at least two switches for toggling is based on a comparison of an input voltage to the boost circuit and output voltage from the VSI.
13 . The method of claim 11 , wherein the two toggling switches are energized using at least one of: pulse width modulation, predictive control, or hysteretic control.
14 . The method of claim 11 , wherein the remaining switches are not toggling and held at either a closed or open position.
15 . The method of claim 11 , wherein the method further comprising receiving DC input power for conversion to AC output power.
16 . The method of claim 13 , wherein the DC input power is received at a DC input port further comprising a low pass filter.
17 . The method of claim 15 , further comprising when operating in a buck mode, no more than two switches actively toggling are located within the inverter circuit.
18 . The method of claim 15 , further comprising when operating in a boost mode, no more than two switches actively toggling are located within the boost circuit.
19 . The method of claim 11 , wherein the VSI is capable of outputting multiphase power.
20 . The method of claim 19 , wherein outputting multiphase power includes outputting to three output legs.