A drive control system for a linear driver may include a power module, a controller, a motor drive module, a motor, and a position control module. The power module may be connected to the controller, the controller may be connected to the motor drive module, and the position control module may be connected in series between the controller and the motor drive module to form a control loop. The power module may be connected to the motor drive module to input power to the motor drive module, and the motor drive module may be connected to the motor to form a drive loop. The control loop may control the work of the drive loop, and the drive loop may directly form a loop in series connection with the motor and the power module through the motor drive module.

An electric tool capable of achieving inhibition of reaction due to braking in good balance with inhibition of voltage jumping due to regenerated energy is provided. A grinder (1) is provided with a motor (6), an inverter circuit (43) for supplying electric current to the motor (6), and a controller (50) for controlling the inverter circuit (43). When generating an electric braking force on a motor (6), the rotation speed of which exceeds a specified rotation speed, the controller (50) performs a first braking control of continuously turning on lower arm-side switching elements (Q4-Q6) of the inverter circuit (43), after which the controller performs a second braking control of repeatedly turning on and off the lower arm-side switching elements (Q4-Q6).

An electric tool capable of achieving inhibition of reaction due to braking in good balance with inhibition of voltage jumping due to regenerated energy is provided. A grinder (1) is provided with a motor (6), an inverter circuit (43) for supplying electric current to the motor (6), and a controller (50) for controlling the inverter circuit (43). When generating an electric braking force on a motor (6), the rotation speed of which exceeds a specified rotation speed, the controller (50) performs a first braking control of continuously turning on lower arm-side switching elements (Q4-Q6) of the inverter circuit (43), after which the controller performs a second braking control of repeatedly turning on and off the lower arm-side switching elements (Q4-Q6).

An active gate driver suitable for activating an electronic switch of an electric motor. The active gate driver includes a pull up branch, a pull down branch and a current and voltage feedback from an output of the active gate driver to at least one input of the active gate driver, wherein the current and voltage feedback is common to both the pull up branch and the pull down branch.

An active gate driver suitable for activating an electronic switch of an electric motor. The active gate driver includes a pull up branch, a pull down branch and a current and voltage feedback from an output of the active gate driver to at least one input of the active gate driver, wherein the current and voltage feedback is common to both the pull up branch and the pull down branch.

A safety device includes a safety module and a safety control module in order to reduce a speed of an unwanted clutch engagement when a malfunction of a motor for a clutch control actuator occurs, such as by the power supply for the motor being interrupted, so that a driver can have more time to react in such situation.

A safety device includes a safety module and a safety control module in order to reduce a speed of an unwanted clutch engagement when a malfunction of a motor for a clutch control actuator occurs, such as by the power supply for the motor being interrupted, so that a driver can have more time to react in such situation.

There is described a method of controlling an inverter supplying power to a permanent magnet AC, PMAC, motor having a plurality of phase windings, The method comprises: selecting a first phase winding of the PMAC motor; electrically connecting the first phase winding to a first DC terminal of a DC link circuit at a first time, and maintaining the connection between the first phase winding and the first DC terminal: determining a flux difference between the first phase winding and a second phase winding of the PMAC motor; selecting a second time to electrically connect the second phase winding to the first DC terminal; electrically connecting the second phase winding to the first DC terminal at the second time; and maintaining the connection between the second phase winding and the first DC terminal. The second time is selected based on the determined flux difference.

A method for controlling the direction of rotation of a fluid machine having an oriented-blade impeller, comprising the following steps:

starting (100) a synchronous electric motor which operates said fluid machine until the synchronous state is reached;

driving (200) said synchronous electric motor at steady state by applying a phase cutting;

applying (300) a phase cutting corresponding to a reference power, wherein said reference power is comprised between a first power required to keep the propeller rotating in a right direction and a second power required to keep the propeller rotating in a wrong direction, which is opposed to the right direction.

A method for controlling the direction of rotation of a fluid machine having an oriented-blade impeller, comprising the following steps:

starting (100) a synchronous electric motor which operates said fluid machine until the synchronous state is reached;

driving (200) said synchronous electric motor at steady state by applying a phase cutting;

applying (300) a phase cutting corresponding to a reference power, wherein said reference power is comprised between a first power required to keep the propeller rotating in a right direction and a second power required to keep the propeller rotating in a wrong direction, which is opposed to the right direction.