An electric motor control method for controlling an electric motor by voltage phase control performed based on a voltage norm command value representing a magnitude of a voltage to be supplied to the electric motor and a voltage phase command value representing a phase of the voltage. The method including: acquiring a required time required for calculating a final command value of a voltage applied to the electric motor by the voltage phase control according to a command value calculation model for calculation by using a rotation speed parameter related to a rotation speed of the electric motor; detecting the rotation speed parameter; changing the detected rotation speed parameter based on the required time; and calculating the final command value by using the changed rotation speed parameter according to the command value calculation model.

The present invention includes: a control initiation-stop determiner which receives an initiation-stop request signal for controlling initiation and stop of a motor and information on the number of revolutions of the motor and which outputs a state signal for switching a state of a drive voltage among three states of control stop, control initiation, and control start; and a drive voltage controller which gradually increases a phase current supplied to the motor by using a PWM signal while the state signal causes the state of the drive voltage to transition from control stop to the control initiation and then to the control start.

The present invention includes: a control initiation-stop determiner which receives an initiation-stop request signal for controlling initiation and stop of a motor and information on the number of revolutions of the motor and which outputs a state signal for switching a state of a drive voltage among three states of control stop, control initiation, and control start; and a drive voltage controller which gradually increases a phase current supplied to the motor by using a PWM signal while the state signal causes the state of the drive voltage to transition from control stop to the control initiation and then to the control start.

A system and method are provided for saving energy for an electric motor having periodic load variations by reducing the supply voltage to the motor during an open loop mode. The motor and system will speed up, allowing the natural kinetic energy of the cyclic motion to perform part of the pumping action. A closed loop controller computes information from the observed phase angle between the voltage and current supplied to the motor. By reducing the supply voltage to the motor, the observed phase angle may be reduced to a target phase angle value. By allowing some current flow, primarily of a reactive nature, an observable feedback parameter may be used in the closed loop control system as an indication of the load condition, to which the closed loop motor controller may react, supplying power when needed, such as in the energy consumption mode.

A system and method are provided for saving energy for an electric motor having periodic load variations by reducing the supply voltage to the motor during an open loop mode. The motor and system will speed up, allowing the natural kinetic energy of the cyclic motion to perform part of the pumping action. A closed loop controller computes information from the observed phase angle between the voltage and current supplied to the motor. By reducing the supply voltage to the motor, the observed phase angle may be reduced to a target phase angle value. By allowing some current flow, primarily of a reactive nature, an observable feedback parameter may be used in the closed loop control system as an indication of the load condition, to which the closed loop motor controller may react, supplying power when needed, such as in the energy consumption mode.

The present invention relates to a system for controlling rotational speed on a rotating process machine, which for example is a turbine or a propeller, where the rotating process machine is connected to at least one motor and arranged to rotate with a given rotational speed given by the motor, the motor is connected to a control system and the rotational speed of the motor is arranged to be controlled by a control system. The rotating process machine comprises a load control arranged to be adaptable, the control system is connected to the rotating process machine. With the invention, one achieves soft transitions between several selectable rotational speeds and lower energy consumption by step by step adjusting the size and the rotational speed of the motor to varying energy requirement.

The present invention relates to a system for controlling rotational speed on a rotating process machine, which for example is a turbine or a propeller, where the rotating process machine is connected to at least one motor and arranged to rotate with a given rotational speed given by the motor, the motor is connected to a control system and the rotational speed of the motor is arranged to be controlled by a control system. The rotating process machine comprises a load control arranged to be adaptable, the control system is connected to the rotating process machine. With the invention, one achieves soft transitions between several selectable rotational speeds and lower energy consumption by step by step adjusting the size and the rotational speed of the motor to varying energy requirement.

Conventional internal combustion engine technology has been around for decades and historically has been the primary power source for virtually all industrial equipment. It relies on carbon-based fuels, is loud, polluting, and the machines it powers are expensive to operate and maintain. A self-contained, rechargeable battery system is provided that possesses improved power than comparable diesel and gas engines and it generates zero emissions, is virtually maintenance free, is quiet, and recharges overnight via a standard electrical outlet. The rechargeable battery power system can be installed in new and used construction equipment and may be used wherever a source of power is required including smart grid application. It can be safely used indoors, in neighborhoods and other locations sensitive to the side effects of internal combustion engines. There is a battery management system that controls sequential shutdown system and a power reserve system to control operation of the battery.

At least one example embodiment discloses a method of generating an output variable voltage. The method includes obtaining a selected mode of operation, the selected mode of operation being one of an voltage control mode and a frequency mode, determining an input voltage command based on the selected mode of operation, determining an input frequency command based on the selected mode of operation, adjusting at least one of the input frequency command and the input voltage command based on the selected mode of operation, generating a pulse width modulation reference based on the adjusted at least one of the input frequency command and the input voltage command and generating the output variable voltage based on the pulse width modulation reference.

At least one example embodiment discloses a method of generating an output variable voltage. The method includes obtaining a selected mode of operation, the selected mode of operation being one of an voltage control mode and a frequency mode, determining an input voltage command based on the selected mode of operation, determining an input frequency command based on the selected mode of operation, adjusting at least one of the input frequency command and the input voltage command based on the selected mode of operation, generating a pulse width modulation reference based on the adjusted at least one of the input frequency command and the input voltage command and generating the output variable voltage based on the pulse width modulation reference.