Elliott Energy Systems, Inc.

Perfect Electric Power, Inc.

Rte Deltec Corporation

Suresh Gupta

J Michael Teets

Jon William Teets

Douglas R Burnham

Anuag Chandra

A combination controller incorporates features of a classic controller and a state space controller to function as a hybrid controller unit. The PID portion of the classic controller regulates the steady state error and is separated from the pulse width modulated constant frequency signal generator that also comprises part of the classic controller. The PID portion is coupled with a state space controller such that the output of the PID controller, i.e., the steady state error correction, is input to the state space controller. The state space controller further receives as input variables a reference sinusoidal signal, the load current, the current across a pre-load filter capacitor, and the output voltage. From these inputs, the state space controller employs principles of differential calculus to generate a transient error correction that is fed to a PWM signal generator for generating a sinusoidal output voltage signal with both steady state and transient error correction. The sinusoidal output voltage signal is directed to a power amplifier and filtered for delivery to a connected load. The combination controller is thusly incorporated into an electrical feedback system such as a frequency converter, a power conditioner, and an uninterruptible power supply (UPS).

Combination feedback controller and power regulator using same

An electrical system and method for a turbine/alternator comprising a gas driven turbine and a permanent magnet alternator rotating on a common shaft includes an inverter circuit connectable either to an output circuit or the stator winding of the alternator. A control circuit during a start-up mode switches the inverter circuit to the stator winding of the alternator and during a power out mode switches the inverter circuit to the output circuit. During the power out mode, current data is sensed and is used for current limit and/or power balancing.

Method and apparatus for controlling output current of turbine/alternator on common shaft

An electrical system for a turbine/alternator comprising a gas driven turbine and a permanent magnet alternator rotating on a common shaft includes an inverter circuit connectable either to an AC output circuit or the stator winding of the alternator. A control circuit during a startup mode switches the inverter circuit to the stator winding of the alternator and during a power out mode switches the inverter circuit to the AC output circuit. Thus, during the startup mode, the alternator functions as a motor to raise the speed of the turbine to a safe ignition speed and in the power out mode the electrical system outputs the AC output circuit, electrical power having a frequency unrelated to the rotation speed of the alternator.

Electrical system for turbine/alternator on common shaft

An electrical system and method for a turbine/alternator comprising a gas driven turbine and a permanent magnet alternator rotating on a common shaft includes an inverter circuit connectable either to an output circuit or the stator winding of the alternator. A control circuit during a start-up mode switches the inverter circuit to the stator winding of the alternator and during a power out mode switches the inverter circuit to the output circuit and power line. During the power output mode the power line is monitored and the output voltage, frequency and/or phase is matched or synchronized to the power line.

Method and apparatus for controlling output voltages and frequencies of turbine/alternator on common shaft

An electrical system for a turbine/alternator comprising a gas driven turbine and a permanent magnet alternator rotating on a common shaft includes an inverter circuit connectable either to an output circuit or the stator winding of the alternator. A control circuit during a start-up mode switches the inverter circuit to the stator winding of the alternator and during a power out mode switches the inverter circuit to the output circuit. During start-up the frequency and voltage of the electrical power to the inverter is controlled as a function of the time and/or rotation speed.

Method and apparatus for turbine/alternator on common shaft during start-up

An electrical system and method for a turbine/alternator comprising a gas driven turbine and a permanent magnet alternator rotating on a common shaft includes an inverter circuit connectable either to an output circuit or the stator winding of the alternator. A control circuit during a start-up mode switches the inverter circuit to the stator winding of the alternator and during a power out mode switches the inverter circuit to the output circuit. During the power out mode, output voltage is continuously measured and the inverter circuit is controlled to compensate for output voltage fluctuations.

Method and apparatus for compensating output voltage fluctuations of turbine/alternator on common shaft

An electrical system and apparatus for a turbine/alternator comprising a gas driven turbine and a permanent magnet alternator rotating on a common shaft includes an inverter circuit connectable either to an output circuit or the stator winding of the alternator. A control circuit during a start-up mode switches the inverter circuit to the stator winding of the alternator and during a power out mode switches the inverter circuit to the output circuit. The operating parameters of the turbine are monitored during start-up and/or the power out mode.

Method and apparatus for monitoring turbine parameters of turbine/alternator on common shaft

An electrical system for a turbine/alternator comprising a gas driven turbine and permanent magnet alternator rotating on a common shaft comprises an inverter circuit connectable either to an AC output circuit or the stator winding of the alternator. A control circuit during a startup mode switches the inverter circuit to the stator winding of the alternator and during a power out mode switches the inverter circuit to the AC output circuit. Thus, during the startup mode, the alternator functions as a motor to raise the speed of the turbine to a safe ignition speed and in the power out mode the electrical system outputs to the AC output circuit, electrical power having a frequency unrelated to the rotational speed of the alternator.

An uninterruptible power supply comprising a regulating transformer including output circuitry for connection to a load, first input circuitry for coupling a reserve AC voltage source to the regulating transformer and second input circuitry for coupling a primary AC voltage source to the regulating transformer, the second input circuitry comprising a plurality of winding taps, with each of the taps including a tap switch coupled to the primary AC voltage source. The uninterruptible power supply also includes a voltage control monitor for monitoring the voltage of the primary source and, if the voltage is outside a predetermined maximum allowable range, opening all of said tap switches to isolate the primary source from said transformer, and, if said voltage is within said predetermined maximum allowable range, selectively closing one of said tap switches so that the voltage at the load is held within a predetermined range.

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Los Alamitos, CA, United States of America

Suresh Gupta