Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.

Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.

Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.

Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.

A method and a control device for regulating a drive device includes an electric motor with a motor shaft and a converter for supplying power to the electric motor. To this end, measured values of measured variables, which characterize a power loss of the drive device, are detected and a converter output voltage is adjusted depending on the detected measured values in such a way that the power loss decreases.

A method and a control device for regulating a drive device includes an electric motor with a motor shaft and a converter for supplying power to the electric motor. To this end, measured values of measured variables, which characterize a power loss of the drive device, are detected and a converter output voltage is adjusted depending on the detected measured values in such a way that the power loss decreases.

Methods and systems of optimizing efficiency of a motor drive or generator are provided. The methods include measuring data corresponding to input power and output power of a motor drive or generator at a control parameter and different load values. The methods include generating a three-dimensional surface model based on the measured data. The three-dimensional surface model can estimate an efficiency of the motor drive or generator at the control parameter and at unmeasured load values. The methods can include determining optimal efficiency of the motor drive or generator at the different load values and the unmeasured load values based on the three-dimensional surface model.

Disclosed is a dual motor unit for a flywheel mass accumulator, with at least two electric machines coupled to a common rotary body; wherein the electric machines have different power characteristics and the dual motor unit is adapted to provide a total operating power in an operating speed range (Ω) by an interaction of the electric machines. The power characteristic (P.sub.max) is non-linearly dependent on a rotational speed (ω) of the common rotary body.

An electric working machine according to one aspect of the present disclosure includes a motor, a current detector, a voltage detector, and a load state determination unit. The current detector is configured to detect a current flowing through the motor during drive of the motor. The voltage detector is configured to detect an input voltage supplied to the motor during drive of the motor. The load state determination unit is configured to determine whether the motor is in a no-load operation state based on the detected current, the detected input voltage and an output voltage from an electric power source.

An electric working machine according to one aspect of the present disclosure includes a motor, a current detector, a voltage detector, and a load state determination unit. The current detector is configured to detect a current flowing through the motor during drive of the motor. The voltage detector is configured to detect an input voltage supplied to the motor during drive of the motor. The load state determination unit is configured to determine whether the motor is in a no-load operation state based on the detected current, the detected input voltage and an output voltage from an electric power source.