Starting system and method for a microturbine power generation unit
First Claim
1. A method for starting a turbine coupled to an electric machine for supplying power to a load through a DC bus the method comprising, during a startup phase:
- a. gradually increasing a voltage level of the DC bus;
b. converting DC power from the DC bus to AC power such that the frequency of the AC power increases in proportion to the gradually increasing voltage level of the DC bus;
c. applying the AC power to drive electric machine, which machine in turn drives the turbine to a starting speed.
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Accused Products
Abstract
A power electrical system is disclosed for a microturbine power generator. The invention permits the microturbine to be started using an external DC power source. The DC voltage is converted to a variable DC voltage by means of a bi-directional buck-boost circuit, DC bus and a DC-to-AC converter. The DC-to-AC converter produces at its output a fixed voltage pattern whose frequency is gradually increased in concert with the DC voltage, to accelerate the microturbine from standstill to startup speed. Once the microturbine is started, the excitation is discontinued, and the DC bus and DC-to-AC are used to produce output AC power at a voltage level and frequency to match an electrical load.
42 Citations
17 Claims
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1. A method for starting a turbine coupled to an electric machine for supplying power to a load through a DC bus the method comprising, during a startup phase:
- a. gradually increasing a voltage level of the DC bus;
b. converting DC power from the DC bus to AC power such that the frequency of the AC power increases in proportion to the gradually increasing voltage level of the DC bus;
c. applying the AC power to drive electric machine, which machine in turn drives the turbine to a starting speed. - View Dependent Claims (2)
- a. gradually increasing a voltage level of the DC bus;
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3. A method for starting a turbine coupled to an electrical machine which in turn is driven by a power circuit including a buck-boost chopper circuit, a DC bus and a DC-to-AC converter, wherein the method comprises the steps of:
- a. gradually charging the DC bus by gradually increasing a voltage level output of the buck boost chopper;
b. during step (a), converting DC power from the DC bus to AC power using the DC-to-AC converter, where the frequency of the AC power increases in proportion to the gradually increasing voltage level output from the buck boost chopper;
c. applying the AC power from the DC-to-AC converter to drive electrical machine which drives the turbine during a startup phase. - View Dependent Claims (4, 5, 6, 7, 8, 9)
- a. gradually charging the DC bus by gradually increasing a voltage level output of the buck boost chopper;
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10. A system for starting a turbine coupled to an electrical machine which in turn is driven by a power circuit, wherein the power circuit comprises:
- a buck-boost chopper having a DC power output, where DC power is output at a gradually increasing DC voltage level;
a DC bus charged by the gradually increasing DC voltage level;
a DC-to-AC converter powered by the DC bus and converting the gradually increasing DC voltage level to AC power, wherein the AC power is applied to drive an electrical machine which drives the turbine during a startup phase. - View Dependent Claims (11, 12, 13, 14)
- a buck-boost chopper having a DC power output, where DC power is output at a gradually increasing DC voltage level;
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15. A system for starting a turbine coupled to an electric machine for supplying power to a load through a DC bus the system comprising:
- a buck-boost chopper for gradually increasing a voltage level of the DC bus during a startup phase;
an AC-to-DC converter for converting generated AC power from the electric machine to DC power and applying the DC power to the DC bus after the startup phase;
a DC-to-AC converter for converting DC power from the DC bus to AC power;
at least one switch for, during the startup phase, applying the AC power from the DC-to-AC converter to drive electric machine, which machine in turn drives the turbine to a starting speed, and, after the startup phase, applying AC power from the DC-to-AC converter to the load.
- a buck-boost chopper for gradually increasing a voltage level of the DC bus during a startup phase;
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16. A system for starting a turbine coupled to an electric machine for supplying power to a load through a DC bus the system comprising, during a startup phase:
- means for gradually increasing a voltage level of the DC bus;
means for converting DC power from the DC bus to AC power;
means for applying the AC power to drive electric machine, which machine in turn drives the turbine to a starting speed. - View Dependent Claims (17)
- means for gradually increasing a voltage level of the DC bus;
Specification