A power tool is provided including a housing, a brushless direct-current (BLDC) electric motor disposed inside the housing, power switches disposed between a power supply and the electric motor and including high-side switches and low-side switches, and a control unit configured to control a switching operation of the power switches to operate the electric motor and electronically brake the motor by simultaneously activating the high-side switches or the low-side switches to stop the rotation of the motor upon detection of a condition prompting the braking of the motor. The control unit is configured to detect the condition that prompts the braking of the electric motor, set a braking profile for braking the electric motor based on the detected condition, and execute braking of the electric motor using the braking profile.

At least one example embodiment discloses a method of controlling an alternating current (ac) machine. The method includes determining or retrieving a current limit for the ac machine, determining a characterized peak current value based on a voltage-to-speed ratio of the ac machine, determining current command values for the ac machine based on at least one of the torque command limit and a torque command for the ac machine, determining current command values for the ac machine based on the torque command limit and controlling the ac machine based on the current command values.

An electric motor system having substantially independent hardware-based and software-based pathways for detecting and initiating responses to fault conditions, such as over-current conditions, in an electric motor which is powered by a power inverter which is controlled by a power module and a microprocessor. Each pathway involves comparing a voltage, which is representative of an electric current flowing to the motor, to a predetermined maximum voltage, and if the former exceeds the latter using hardware or software to initiate shutting off the motor, such as by shutting off the power inverter. When one pathway detects a fault condition it may notify the other pathway, and the notified pathway may also initiate shutting off the motor.

An electric motor system having substantially independent hardware-based and software-based pathways for detecting and initiating responses to fault conditions, such as over-current conditions, in an electric motor which is powered by a power inverter which is controlled by a power module and a microprocessor. Each pathway involves comparing a voltage, which is representative of an electric current flowing to the motor, to a predetermined maximum voltage, and if the former exceeds the latter using hardware or software to initiate shutting off the motor, such as by shutting off the power inverter. When one pathway detects a fault condition it may notify the other pathway, and the notified pathway may also initiate shutting off the motor.

A vehicle brake control system includes an inverter configured to convert direct current (DC) into an alternating current (AC) for a motor of a vehicle. The inverter includes switches configured to convert the DC to the AC, as well as a resistor and a bypass switch disposed in series with each other. A controller is communicatively coupled with the inverter switches and the bypass switch. The controller opens the bypass switch so that the DC is conducted through and converted into the AC for the motor during a motoring mode. The controller closes the bypass switch so that regenerated current from the motor is conducted through the resistor of the inverter for partial dissipation of the regenerated current during a dynamic braking mode.

A vehicle brake control system includes an inverter configured to convert direct current (DC) into an alternating current (AC) for a motor of a vehicle. The inverter includes switches configured to convert the DC to the AC, as well as a resistor and a bypass switch disposed in series with each other. A controller is communicatively coupled with the inverter switches and the bypass switch. The controller opens the bypass switch so that the DC is conducted through and converted into the AC for the motor during a motoring mode. The controller closes the bypass switch so that regenerated current from the motor is conducted through the resistor of the inverter for partial dissipation of the regenerated current during a dynamic braking mode.

A motor driving system includes a controller, motors and motor drivers. In the normal supplying state of a power supply, the controller controls the motor drivers. The motor drivers output driving signals for driving the motors respectively. In an abnormal state or a power-off state of the power supply, one of the motor drivers is set to be a master driver and the others are set to be slave driver. The master driver activates a deceleration energy backup (DEB) function, powers the slave drivers through a common-DC-bus structure, controls the slave drivers, and during deceleration maintains a ratio between frequencies of the driving signals, until all of the motors are decelerated to stop at the same time.

There is provided an electric motor comprising a rotor, a stator and a motor controller. The stator comprises a substantially cylindrical body, a plurality of teeth extending from the substantially cylindrical body in a radial direction, one or more first sets of electrical windings that are wound around said teeth and configured to drive the rotor, and one or more second sets of electrical windings electrically separate from the first set of electrical windings. The second set of electrical windings on the stator are electrically connected to the motor controller such that energy produced by the electric motor during a regenerative mode of operation in use is diverted to the second set of electrical windings on the stator for dissipating the energy produced in the regenerative mode.

A motor control device includes a power-consumption calculator that calculates a power loss L according to a motor current I or according to the motor current I and a motor velocity v, and calculates a motor output W from a product of the motor velocity v and a torque τ or thrust force, to determine whether a regenerative resistance is in an energized state. When the regenerative resistance is in an energized state, if a total value W+L of the power loss L and the motor output W is equal to or greater than 0 (W+L≧0), the power-consumption calculator calculates a power consumption P as W+L, and if a total value W+L of the power loss L and the motor output W is less than 0 (W+L<0), the power-consumption calculator calculates the power consumption P=0.

A motor control device includes a power-consumption calculator that calculates a power loss L according to a motor current I or according to the motor current I and a motor velocity v, and calculates a motor output W from a product of the motor velocity v and a torque τ or thrust force, to determine whether a regenerative resistance is in an energized state. When the regenerative resistance is in an energized state, if a total value W+L of the power loss L and the motor output W is equal to or greater than 0 (W+L≧0), the power-consumption calculator calculates a power consumption P as W+L, and if a total value W+L of the power loss L and the motor output W is less than 0 (W+L<0), the power-consumption calculator calculates the power consumption P=0.