Abstract: In a permanent magnet synchronous motor drive system, phase currents can be used to calculate a current that produces no shaft torque and only motor losses and a current that only produces shaft torque. These currents can be controlled to be resupplied into the motor drive system to a desired amount on a continuous basis to maintain a DC energy storage device voltage at a desired safe level. The calculated currents are resupplied to the motor drive system such that voltage levels within the DC energy storage device that approach a voltage maximum limit are transferred to the motor in the form of current that is dissipated by the motor without losing efficiency and control of driving a load with the motor.

Abstract: In a permanent magnet synchronous motor drive system, phase currents can be used to calculate a current that produces no shaft torque and only motor losses and a current that only produces shaft torque. These currents can be controlled to be resupplied into the motor drive system to a desired amount on a continuous basis to maintain a DC energy storage device voltage at a desired safe level. The calculated currents are resupplied to the motor drive system such that voltage levels within the DC energy storage device that approach a voltage maximum limit are transferred to the motor in the form of current that is dissipated by the motor without losing efficiency and control of driving a load with the motor.

Abstract: A motor drive for driving two-phase motors using a three-phase bridge output stage, and a method of operating the drive. The driven two-phase motor can be a two-phase bipolar motor (such as a hybrid stepping motor). The drive can also be configured so that a single output stage can be used to drive either two-phase or three-phase motors, with or without a feedback sensor. A reference return is provided from one of the three half-bridge output stages with each of the motor phase windings connected between the reference return and one of the other half-bridge outputs. The switches of each half-bridge are modulated so that current can be controlled in each of the two motor phase windings.

Abstract: A motor drive for driving two-phase motors using a three-phase bridge output stage, and a method of operating the drive. The driven two-phase motor can be a two-phase bipolar motor (such as a hybrid stepping motor). The drive can also be configured so that a single output stage can be used to drive either two-phase or three-phase motors, with or without a feedback sensor. A reference return is provided from one of the three half-bridge output stages with each of the motor phase windings connected between the reference return and one of the other half-bridge outputs. The switches of each half-bridge are modulated so that current can be controlled in each of the two motor phase windings.