Abstract: An apparatus for controlling a microturbine, the apparatus comprising: a rectifier adapted for converting at least one generated voltage from the microturbine to a DC link voltage; an inverter adapted for converting the DC link voltage to at least one inverter output voltage, the at least one inverter output voltage being electrically coupled to an external power bus; a starter drive adapted for converting at least one starter input voltage to at least one starter output voltage, the at least one starter input voltage being electrically coupled to the external power bus, the at least one starter output voltage being electrically coupled to the microturbine.

Abstract: A method and system are described for providing a direct current (DC) uninterruptible power supply with the method including, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.

Abstract: A method for predicting zero crossings of fault currents in a multi-phase power system includes sensing a fault current in each respective phase, estimating parameters of a model of each respective fault current, and independently using the estimated parameters for each respective fault current to predict a zero crossing of the respective fault current.

Abstract: An uninterruptible power supply system has standby and backup modes and can change to backup mode upon detection of a grid fault. In both modes an alternator rotates at synchronous speed so that backup mode capability is ready. An energy storage unit through a DC-AC inverter remains coupled to the grid in standby mode so that it is charged, ready to supply power when changed to backup mode. In standby mode, first and third clutches are disengaged and engaged, transmitting alternator rotary motion to a flywheel but not therefrom to a heat engine. In backup mode, first and third clutch are engaged and disengaged to permit the alternator, via a second clutch, to overrun the flywheel and allow transmitting of flywheel torque to accelerate the heat engine to starting speed for driving the alternator to supply power to the grid after the engine is at operating speed and coupled to the alternator through a locked second clutch and an engaged third clutch.

Abstract: A system and method is provided for establishing a connection between an agent and a user. A request is received from the user requesting contact by an agent. The request includes an identifier associated with the web page being viewed by the user. An agent is selected based on the web page being viewed by the user. The identifier associated with the web page is transmitted to an agent that will contact the user. A connection is then established between the user and the agent.

Abstract: A method and system are described for providing a direct current (DC) uninterruptible power supply with the method comprising, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.

Abstract: An uninterruptible power supply system has standby and backup modes and can change to backup mode upon detection of a grid fault. In both modes an alternator rotates at synchronous-speed so that backup mode capability is ready. An energy storage unit through a DC-AC inverter remains coupled to the grid in standby mode so that it is charged, ready to supply power when changed to backup mode. In standby mode, first and third clutches are disengaged and engaged, transmitting alternator rotary motion to a flywheel but not therefrom to a heat engine. In backup mode, first and third clutch are engaged and disengaged to permit the alternator, via a second clutch, to overrun the flywheel and allow transmitting of flywheel torque to accelerate the heat engine to starting speed for driving the alternator to supply power to the grid after the engine is at operating speed and coupled to the alternator through a locked second clutch and an engaged third clutch.

Abstract: An uninterruptible power supply system has standby and backup modes and can change to backup mode upon detection of a grid fault. In both modes an alternator rotates at synchronous speed so that backup mode capability is ready. An energy storage unit through a DC-AC inverter remains coupled to the grid in standby mode so that it is charged, ready to supply power when changed to backup mode. In standby mode, first and third clutches are disengaged and engaged, transmitting alternator rotary motion to a flywheel but not therefrom to a heat engine. In backup mode, first and third clutch are engaged and disengaged to permit the alternator, via a second clutch, to overrun the flywheel and allow transmitting of flywheel torque to accelerate the heat engine to starting speed for driving the alternator to supply power to the grid after the engine is at operating speed and coupled to the alternator through a locked second clutch and an engaged third clutch.

Abstract: A delegated authority system allows an account holder to delegate authority to one or more individuals, such as financial advisors through a third party service. An individual receives authority to access financial accounts and/or access aggregated financial data. The individual may then retrieve account information from the individual accounts or from the aggregated financial data. In on exemplary system, the account information is accessed via the Internet or another data communication network.

Abstract: The field ground fault detector of the present invention detects a ground fault that occurs in the field circuit and in any associated circuits galvanically connected to the field. The field ground fault detector discerns the ground resistance so that it can be monitored to detect gradual degradation of the ground resistance. The detector estimates the resistance of the ground fault and the location of the ground fault. The detector is able to estimate the location of the ground fault during system operation and during periods of non-operation. The invention utilizes a low frequency square wave oscillator to permit measurement of the ground fault resistance when field voltage is not applied, to insure that there are no blind spots when the field is energized, and to provide a method for estimating the ground fault resistance. The field ground detector can differentiate between ground faults that occur on the AC side form those on the DC side of the Thyristor Bridge.

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.

Abstract: A control system for controlling power flow in a power bus generally powered by a reformer-based fuel cell system (FCS) is provided. The control system comprises an energy storage device (ESD); a power interface unit coupled to selectively and bi-directionally pass power between the energy storage device and the power bus; and a controller coupled to the power bus to receive one or more signals indicative of the instantaneous power delivered by the fuel cell system. The controller may be configured so that the energy storage device may supply power to the power bus at least during transient conditions when the instantaneous power delivered by the fuel cell system drops below a (FCS) power command signal.

Abstract: A system is provided for establishing a connection between a telephone agent and a computer user. A request is received from the user requesting a return call by an agent. The request is received through a web server and includes an identifier associated with the web page being viewed by the user. The identifier associated with the web page is transmitted to an agent that will contact the user. This allows the agent to view the web page that was being viewed by the user when the request was entered. A telephone connection is then established between the user and the agent. An agent can be selected based on the content of the web page being viewed by the user at the time the request for agent contact is entered. Additionally, for an incoming call, a web page can be generated that contains information about the incoming call. An identifier associated with the generated web page is transmitted to an agent that will answer the call. The agent then accesses the web page using the received identifier.

Abstract: A power electrical system is disclosed to connect a microturbine and an electrical machine to electrical power sources and a load. The invention permits the microturbine to be started using an external DC power source and/or an external AC power source. DC power is converted to AC power by means of a buck-boost chopper, DC bus and a DC-to-AC converter. AC power, from the AC power source, is converted to frequencies and voltages suitable to start a microturbine by a pair of DC-to-AC converters and the DC bus. The frequency and voltage levels of the AC power are gradually increased to accelerate the microturbine to startup speed. Once the microturbine is started, the external power sources are disconnected, and the DC bus and the DC-to-AC converters produce output AC power at a voltage level and frequency to match an electrical load.

Abstract: A multilevel inverter system having four or more levels of output voltage on each inverter output line. The voltage across each of three or more series connected DC bus capacitors is provided to an inverter which is formed to have redundant switching states, such as a plurality of controlled switching devices and diodes connected in a diode-clamped multilevel inverter configuration. The switching of the switching devices is controlled to provide a selected output voltage waveform utilizing redundant switching states, when such states are available on each voltage transition, by selecting a one of the available switching states that serves to provide the desired phase-to-phase voltages and to tend to equalize the voltages across the DC bus capacitors. Active or passive rectifiers may be used to provide the DC voltage across the DC bus lines and across the DC bus capacitors.