The invention relates to a method for determining a rotor temperature of an electric motor, in particular an asynchronous motor, the rotor temperature being determined at least in accordance with reactive powers and/or in accordance with losses of the electric motor. A first rotor temperature is determined in accordance with the reactive powers and, depending on an operating range of the electric motor, plausibility-checked or replaced by a second rotor temperature, which is determined in accordance with the losses.

The invention relates to a method for determining the temperature in an electronic controller of a motor vehicle, the controller having at least one electrical winding, characterized in that the electrical resistance of the winding is determined in a defined operating state and based thereon the temperature is determined.

A power tool is provided, including a housing; a brushless DC (BLDC) motor arranged within the housing, the motor including a stator and a rotor rotatably disposed within the stator; a power module electrically disposed between the motor and a power supply, the power module including power switches; an actuator engageable by a user; and a control module configured to control a switching operation of the power switches to begin supply power to the motor when the actuator is engaged. The control module monitors engagement and disengagement events of the actuator, and ignores a subsequent engagement of the actuator if at least one of number of actuator engagement events and/or number of actuator disengagement events exceeds a predetermined threshold value within a predetermined time.

A power tool is provided, including a housing; a brushless DC (BLDC) motor arranged within the housing, the motor including a stator and a rotor rotatably disposed within the stator; a power module electrically disposed between the motor and a power supply, the power module including power switches; an actuator engageable by a user; and a control module configured to control a switching operation of the power switches to begin supply power to the motor when the actuator is engaged. The control module monitors engagement and disengagement events of the actuator, and ignores a subsequent engagement of the actuator if at least one of number of actuator engagement events and/or number of actuator disengagement events exceeds a predetermined threshold value within a predetermined time.

The invention relates to a device for controlling an alternator of the type that controls a DC voltage (B+A) generated by the alternator (11) according to a predetermined set voltage (U.sub.0) by monitoring the intensity of an energizing current (I.sub.EXC) flowing through an energizing circuit of the alternator. According to the invention, the device includes a voltage-control loop (7) and a temperature-control loop (17) which comprises a temperature sensor supplying a current temperature (T) of components of the alternator, a subtracter (19) supplying a temperature error (.sub.t) between the current temperature (T) and a maximum acceptable temperature (T.sub.max) and a control module (20) supplying a maximum admissible energizing percentage (r.sub.max) in accordance with the temperature error according to a predetermined control law.

A field current limiting section includes a field current limitation instructing section for, when a field current limitation determining section determines that a determination value has reached a predetermined determination threshold value, generating a field current limiting instruction to a field current control section so as to limit field current to be equal to or smaller than a predetermined permissible value during a predetermined field current limitation time T.sub.lim. A field current limitation releasing section outputs a field current limitation releasing instruction to the field current limiting section so as to release limitation of the field current during a predetermined field current limitation release time T.sub.C. When having received the field current limitation releasing instruction from the field current limitation releasing section, the field current limiting section releases limitation of the field current during the predetermined field current limitation release time.

A rotating electrical machine for a motor vehicle comprising a rotor (2) supplied with an excitation current (ie), a stator (3) comprising a polyphase winding and coupled to the rotor (2), a thermal protection module (4) suitable for evaluating at least one temperature (T1, T2, T3) in the machine and for comparing the temperature with an associated thermal protection threshold (Th), a control device (5) supplying the excitation current (ie) depending on an operation mode command (RQ) and the temperature comparison, so as to operate the rotating electrical machine (1) according to a mode of operation chosen from a nominal generator mode in which the machine is configured to deliver a first maximum power or at least one extended generator mode in which the machine is configured to deliver a second maximum power greater than said first maximum power.

The invention relates to a method for determining a rotor temperature of an electric motor, in particular an asynchronous motor, the rotor temperature being determined at least in accordance with reactive powers and/or in accordance with losses of the electric motor. A first rotor temperature is determined in accordance with the reactive powers and, depending on an operating range of the electric motor, plausibility-checked or replaced by a second rotor temperature, which is determined in accordance with the losses.