Abstract: A sealed induction motor for a chiller assembly is provided. The induction motor includes a stator, a rotor, and a shaft with a first end and a second end. The rotor and the shaft are configured to rotate relative to the stator. The induction motor further includes a first magnetic bearing assembly located proximate the first end of the shaft and a second magnetic bearing assembly located proximate the second end of the shaft. The first and the second magnetic bearing assemblies are configured to support the shaft. The shaft is coupled to a centrifugal compressor using a direct drive connection.

Abstract: A sealed induction motor for a chiller assembly is provided. The induction motor includes a stator, a rotor, and a shaft with a first end and a second end. The rotor and the shaft are configured to rotate relative to the stator. The induction motor further includes a first magnetic bearing assembly located proximate the first end of the shaft and a second magnetic bearing assembly located proximate the second end of the shaft. The first and the second magnetic bearing assemblies are configured to support the shaft. The shaft is coupled to a centrifugal compressor using a direct drive connection.

Abstract: A sealed induction motor for a chiller assembly is provided. The induction motor includes a stator, a rotor, and a shaft with a first end and a second end. The rotor and the shaft are configured to rotate relative to the stator. The induction motor further includes a first magnetic bearing assembly located proximate the first end of the shaft and a second magnetic bearing assembly located proximate the second end of the shaft. The first and the second magnetic bearing assemblies are configured to support the shaft. The shaft is coupled to a centrifugal compressor using a direct drive connection.

Abstract: A sealed induction motor for a chiller assembly is provided. The induction motor includes a stator, a rotor, and a shaft with a first end and a second end. The rotor and the shaft are configured to rotate relative to the stator. The induction motor further includes a first magnetic bearing assembly located proximate the first end of the shaft and a second magnetic bearing assembly located proximate the second end of the shaft. The first and the second magnetic bearing assemblies are configured to support the shaft. The shaft is coupled to a centrifugal compressor using a direct drive connection.

Abstract: There is provided a system and method for controlling an electronic device. An exemplary method comprises employing a look-up table to derive waveform value data for a multi-phase reference waveform. The exemplary method also comprises employing the look-up table to derive waveform value data corresponding to harmonic data for the multi-phase reference waveform. Harmonic data is injected into the multi-phase reference waveform to produce a harmonic reference waveform. The exemplary method additionally comprises generating a plurality of control signals from the harmonic reference waveform.

Abstract: An exemplary control method includes a step of employing a look-up table to derive first waveform value data for a multi-phase reference waveform. The exemplary method also includes a step of deriving second waveform value data corresponding to modifier data for the multi-phase reference waveform. The modifier data is added into the reference waveform to produce a modified reference waveform. The exemplary method additionally includes a step of generating a plurality of control signals from the modified reference waveform and controlling one or more electronic devices based on the control signals.

Abstract: There is provided a system and method for controlling an electronic device. An exemplary method comprises employing a look-up table to derive waveform value data for a multi-phase reference waveform. The exemplary method also comprises employing the look-up table to derive waveform value data corresponding to harmonic data for the multi-phase reference waveform. Harmonic data is injected into the multi-phase reference waveform to produce a harmonic reference waveform. The exemplary method additionally comprises generating a plurality of control signals from the harmonic reference waveform.

Abstract: A method for driving a DC motor includes generating a first voltage pulse, based on a pre-determined speed input and duty cycle, and configured to generate motor current of reference current value sufficient to achieve a desired speed according to the speed input. Subsequent pulses of the voltage are generated to maintain the current substantially within a range of the reference current. Another method includes sensing and comparing motor current to reference current value and generating an error signal therebetween, which is integrated over time to generate an integrated current error, which is compared with a reference pulse. Thereafter generating applied voltage pulses configured to: switch at each instance of the integrated current error exceeding or becoming less than the reference pulse value; generate a motor current sufficient to achieve a desired speed according to a pre-determined speed input; and having substantially zero average variation from the reference current.

Abstract: A method for reducing negative torque in a brushless single phase DC motor, the method includes initiating the motor in a normal mode of operation and activating an ON time control to cut off a voltage supply to the motor. The ON time control is applied after a predetermined time delay, the delay being defined by the motor parameters.

Abstract: A method of reducing torque ripple and noise for an brushless DC machine comprising: determining a control frequency for the electric machine, the control frequency indicative of an existing current command to and a rotational velocity of the electric machine; multiplying the control frequency by a selected multiple and forming a modulating signal responsive thereto; and formulating a modified command profile. The method also includes: correlating and synchronizing the modified command profile with the existing current command and a rotor position for the electric machine; and generating a modulated current command to the electric machine.

Abstract: A method of reducing torque ripple and noise for an brushless DC machine comprising: determining a control frequency for the electric machine, the control frequency indicative of an existing current command to and a rotational velocity of the electric machine; multiplying the control frequency by a selected multiple and forming a modulating signal responsive thereto; and formulating a modified command profile. The method also includes: correlating and synchronizing the modified command profile with the existing current command and a rotor position for the electric machine; and generating a modulated current command to the electric machine.