Microturbine power of generating system including a battery source for supplying startup power

Claim 1

A microturbine power generating system comprising: a compressor including a compressor wheel; a turbine for converting gaseous heat energy into mechanical energy, the turbine including a turbine wheel; an electrical generator for converting the mechanical energy produced by the turbine into electrical energy, the electrical generator including a rotor and a stator, the rotor being mechanically coupled to the turbine wheel and the compressor wheel; a battery source for providing dc power; and a startup circuit including an inverter for converting the dc power to ac power, the inverter selectably connected to the stator; whereby the ac power causes the electrical generator to turn the turbine and compressor wheels during startup; wherein the startup circuit further includes an up chopper for boosting voltage of the battery source, an output of the up chopper providing the dc power to the inverter; and wherein the electrical generator provides ac power during normal operation of the microturbine power generating system, wherein the system further comprises a rectifier for rectifying the ac power generated by the electrical generator; and wherein the startup circuit further includes means for using the rectified power to charge the battery source during the normal operation of the microturbine power generating system.

Claim 13

A method of using a battery source in combination with a microturbine power generating system, the system including an electrical generator, the electrical generator including stator windings, the method comprising the steps of: receiving dc power from the battery source; converting the dc power from the battery source to polyphase ac power during startup of the microturbine power generating system; supplying the polyphase ac power to the stator windings of the electrical generator, wherein the polyphase ac power causes the electrical generator to operate as a starter motor during the startup of the power generating system; boosting the dc power received from the battery source, wherein the boosted battery power is converted to polyphase ac power; rectifying an output of the electrical generator during normal operation of the microturbine power generating system; down chopping at least some of the rectified power during normal operation of the microturbine power generating system; and using the down chopped power to charge the battery source.

Claim 14

A method of using a battery source in combination with a microturbine power generating system, the system including an electrical generator, the electrical generator including stator windings, the method comprising the steps of: receiving dc power from the battery source; converting the dc power from the battery source to polyphase ac power during startup of the microturbine power generating system; supplying the polyphase ac power to the stator windings of the electrical generator, wherein the polyphase ac power causes the electrical generator to operate as a starter motor during the startup of the power generating system; boosting the dc power received from the battery source, wherein the boosted battery power is converted to polyphase ac power; rectifying an output of the electrical generator during normal operation of the microturbine power generating system; down chopping at least some of the rectified power during normal operation of the microturbine power generating system; and using the down chopped power to charge the battery source.