Abstract: An electric motor, including a motor assembly having a rotor and a stator, and a switching assembly adapted to switch the motor assembly between a wye configuration, a delta configuration, and a neutral configuration. The switching assembly may include a plurality of actuators configured to move at least two movable contact members so as to select which configuration of the motor assembly is active.

Abstract: A vehicle such as a riding lawn mower may have at least one electric drive motor configured to drive at least one wheel, at least one electric blade motor configured to drive at least one cutting blade, and a battery module connected to the drive and blade motors. According to some embodiments, a method of controlling the vehicle may include: operating the blade motor according to a blade target speed; monitoring a blade current load for the blade motor; comparing the blade current load to a light load low threshold for the blade motor; and if the blade current load is less than the light load low threshold, decreasing the blade target speed.

Abstract: An electric motor, including a motor assembly having a rotor and a stator, and a switching assembly adapted to switch the motor assembly between a wye configuration, a delta configuration, and a neutral configuration. The switching assembly may include a plurality of actuators configured to move at least two movable contact members so as to select which configuration of the motor assembly is active.

Abstract: A method of operating an electric motor having a motor assembly that includes a rotor and a stator. The method includes providing the electric motor in a neutral state, and from the neutral state, determining whether to operate the electric motor in a wye configuration or a delta configuration and then operating the motor in that state. In some embodiments, if the electric motor is to be operated in the wye configuration, then putting at least one first actuator into a first state and then powering the stator, and if the electric motor is to be operated in the delta configuration, then putting at least one second actuator into a first state and then powering the stator.

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: Systems and methods are described for controlling power factor in motor drives having a switching rectifier providing a DC link current to an inverter in which the rectifier gain is increased to provide additional DC link current to correct the drive power factor based on current drawn by capacitors of the AC drive power input, and the inverter gain is decreased by introducing bypass states in the inverter switching control scheme or by reducing the motor flux to accommodate the increased DC link current.

Abstract: Systems and methods are described for controlling power factor in motor drives having a switching rectifier providing a DC link current to an inverter in which the rectifier gain is increased to provide additional DC link current to correct the drive power factor based on current drawn by capacitors of the AC drive power input, and the inverter gain is decreased by introducing bypass states in the inverter switching control scheme or by reducing the motor flux to accommodate the increased DC link current.

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.