Abstract: A method for determining rotor characteristic of an alternating current (AC) electrical machine includes obtaining a reference voltage signal, one or more phase currents, and rotor data. The method includes determining orthogonal components of an extended back electromotive force (BEMF) model of the AC electrical machine based on the reference voltage signal, the one or more phase current characteristics, and the rotor data. The method includes determining a product of the orthogonal components of the extended BEMF model. The method includes determining a squared-magnitude of the orthogonal components of the extended BEMF mode. The method includes determining the rotor characteristic of the AC electrical machine based on the product of the orthogonal components and the squared-magnitude of the orthogonal components.

Abstract: A method for controlling an electric motor is described herein. The method comprises setting a current limit, a speed limit and a torque limit. The method also comprises sensing a DC link current, comparing the sensed DC link current with the current limit and adjusting the torque limit based on the comparison with the current limit to provide an adjusted torque limit. The method also comprises sensing the speed of the electric motor, comparing the speed with the speed limit and further adjusting the adjusted torque limit based on the comparison with the speed limit.

Abstract: A method for controlling an electric motor is described herein. The method includes setting a current limit, a speed limit and a torque limit. The method also includes sensing a DC link current, comparing the sensed DC link current with the current limit and adjusting the torque limit based on the comparison with the current limit to provide an adjusted torque limit. The method also includes sensing the speed of the electric motor, comparing the speed with the speed limit and further adjusting the adjusted torque limit based on the comparison with the speed limit.

Abstract: A method for determining rotor characteristic of an alternating current (AC) electrical machine includes obtaining a reference voltage signal, one or more phase currents, and rotor data. The method includes determining orthogonal components of an extended back electromotive force (BEMF) model of the AC electrical machine based on the reference voltage signal, the one or more phase current characteristics, and the rotor data. The method includes determining a product of the orthogonal components of the extended BEMF model. The method includes determining a squared-magnitude of the orthogonal components of the extended BEMF mode. The method includes determining the rotor characteristic of the AC electrical machine based on the product of the orthogonal components and the squared-magnitude of the orthogonal components.

Abstract: A method for commissioning a synchronous or asynchronous electric motor having a stator and a rotor in which electrical power is applied to the motor when the rotor is stationary. The electric power is applied in two stages. The first stage utilizes a DC power that ramps in voltage over the duration of the first test to produce a current response that is employed to determine at least a first motor parameter. The second stage uses relatively high frequency AC power to generate one or more current responses that are employed to determine second and third motor parameters. A related electric motor drive system is also provided.

Abstract: A method for commissioning a synchronous or asynchronous electric motor having a stator and a rotor in which electrical power is applied to the motor when the rotor is stationary. The electric power is applied in two stages. The first stage utilizes a DC power that ramps in voltage over the duration of the first test to produce a current response that is employed to determine at least a first motor parameter. The second stage uses relatively high frequency AC power to generate one or more current responses that are employed to determine second and third motor parameters. A related electric motor drive system is also provided.

Abstract: A method for controlling an electric motor is described herein. The method includes setting a current limit, a speed limit and a torque limit. The method also includes sensing a DC link current, comparing the sensed DC link current with the current limit and adjusting the torque limit based on the comparison with the current limit to provide an adjusted torque limit. The method also includes sensing the speed of the electric motor, comparing the speed with the speed limit and further adjusting the adjusted torque limit based on the comparison with the speed limit.

Abstract: A protection scheme to protect pulse width modulated drives is described. The scheme is implantable in both hardware and software and combinations thereof. The semiconductor devices of the drive are protected from transient signals such as power line spikes and loss of line. The present scheme uses an adaptive technique to determine the normal or steady state distortion (transients and harmonics) value in an unfiltered power signal. The present distortion value is compared to the normal distortion. If the present distortion exceeds the steady state value by a given amount, then the drive is placed in freewheel mode to protect the semiconductor devices in the drive.

Abstract: A protection scheme to protect pulse width modulated drives is described. The scheme is implantable in both hardware and software and combinations thereof. The semiconductor devices of the drive are protected from transient signals such as power line spikes and loss of line. The present scheme uses an adaptive technique to determine the normal or steady state distortion (transients and harmonics) value in an unfiltered power signal. The present distortion value is compared to the normal distortion. If the present distortion exceeds the steady state value by a given amount, then the drive is placed in freewheel mode to protect the semiconductor devices in the drive.

Abstract: A method of operating a power converter in response to an interruption in an input power being provided to the power converter, as well as a power converter capable of performing such method and including a rectifier and an inverter coupled at least indirectly with one another, are disclosed. In at least some embodiments, the method includes (a) operating the rectifier so that energy stored in at least one first component coupled at least indirectly to at least one input terminal of the rectifier is transferred to an intermediate component coupled between the rectifier and the inverter, while the inverter is operated in a first disconnect mode, and (b) subsequently operating the inverter so that at least some of the energy transferred to the intermediate component is transferred to at least one output port of the power converter, while the rectifier is operated in a second disconnect mode.

Abstract: A protection scheme to protect pulse width modulated drives is described. The scheme is implantable in both hardware and software and combinations thereof. The semiconductor devices of the drive are protected from transient signals such as power line spikes and loss of line. The present scheme uses an adaptive technique to determine the normal or steady state distortion (transients and harmonics) value in an unfiltered power signal. The present distortion value is compared to the normal distortion. If the present distortion exceeds the steady state value by a given amount, then the drive is placed in freewheel mode to protect the semiconductor devices in the drive.