Abstract: A power converter includes a PWM active rectifier and controller that minimize harmonic ripple currents on the DC link during an engine start mode (first stage) in which power is provided to an AC starter motor. The PWM active rectifier and controller also minimize harmonic currents on AC input lines during a second stage (active filter mode). The power converter also includes a PWM inverter and corresponding inverter controller that controls the performance of the AC starter motor during the first stage based on mode selection input received. The power converter system further includes pre-charge circuitry that charges a DC link capacitor located within the power converter system to a desired level prior to providing the power converter system with AC power.

Abstract: An electronic power converter for a generator under test that emulates resistive and inductive-capacitive (LC) loads and regenerates energy from the generator back to a utility grid.

Abstract: An electric start system (20) includes a controller (40) that controls operation of a motor (22) used to start a device such as a gas turbine engine (24). In one example, the controller (40) determines when an acceleration rate of the motor (22) is outside of a desired range and dynamically controls the acceleration rate. In another example, the controller (40) determines when the motor (22) is disengaged from the engine (24) and controls a torque reference value to facilitate smoother reengagement. In another example, the controller (40) provides an initial starting torque value that allows for soft starting capabilities of the motor (22).

Abstract: An electric motor control strategy includes using a low resolution position sensor that provides a square wave output signal. The position sensor information is converted into sinusoidal commutation signals for motor control that reduces torque ripple. In one disclosed example, square wave commutation is used at low motor speeds and a controller switches to sinusoidal commutation once a selected threshold speed of the motor is reached. In another disclosed example, sinusoidal commutation is used at all motor speeds with two different techniques for converting the square wave sensor signal into a sinusoidal commutation signal, depending on the motor speed.

Abstract: A turbine engine inspection arrangement utilizes a motor that is otherwise utilized for starting the engine. An inspection interface allows for communicating with a motor controller to operate the motor in an inspection mode. During inspection, the motor moves the components of the engine very slowly or in an incremental fashion to facilitate visual inspection of the engine components, such as the turbine blades.

Abstract: An electric engine starting system includes a permanent magnet motor that is used to start the engine and then to generate power for powering a load while the engine is running. A disclosed system includes a first phase controlled rectifier in series with a power converter and a second phase controlled rectifier. During an engine starting operation, the first phase controlled rectifier is switched to couple the permanent magnet motor to a power source for starting the engine. Once the engine is running, the first phase controlled rectifier is switched off and the second phase controlled rectifier is switched on. The second phase control rectifier converts variable AC power from the motor into DC power. The power converter converts the DC power into an appropriate power for driving the load. One disclosed example includes a filter between the power converter and the load to ensure that the load receives a selected quality of power.