A method is used to identify impending or previously occurring condensation on/in electric motors, in particular on/in electric motors as a component of fans or fan groups. It includes the following method steps: Determining component temperatures, preferably surface temperatures on the electronics, on/in the motor, on/in the fan, or on/in fan groups; Determining the dew point temperature or individual dew point temperatures on the electronics, in/on the motor, fan, or on/in fan groups; Comparing the respective component temperature with the respective dew point temperature and concluding a formation of condensation has already taken place or is imminent when the component temperature approaches the dew point temperature or when the dew point temperature is undershot. A further method serves to prevent the formation of condensate and/or to eliminate/remove condensate on/in electric motors, in particular on/in electric motors as a component of fans or fan groups. It includes the following method steps: Detecting an impending and/or previously occurring formation of condensate on or in the motor; and Initiating measures to prevent the formation of condensate and/or to eliminate/remove the condensate by means of passive or active measures.

A method is used to identify impending or previously occurring condensation on/in electric motors, in particular on/in electric motors as a component of fans or fan groups. It includes the following method steps: Determining component temperatures, preferably surface temperatures on the electronics, on/in the motor, on/in the fan, or on/in fan groups; Determining the dew point temperature or individual dew point temperatures on the electronics, in/on the motor, fan, or on/in fan groups; Comparing the respective component temperature with the respective dew point temperature and concluding a formation of condensation has already taken place or is imminent when the component temperature approaches the dew point temperature or when the dew point temperature is undershot. A further method serves to prevent the formation of condensate and/or to eliminate/remove condensate on/in electric motors, in particular on/in electric motors as a component of fans or fan groups. It includes the following method steps: Detecting an impending and/or previously occurring formation of condensate on or in the motor; and Initiating measures to prevent the formation of condensate and/or to eliminate/remove the condensate by means of passive or active measures.

An electric motor includes a case, a stator having stator windings, a rotor having a rotor shaft, and at least one main rotor bearing coupling the rotor shaft to the case. Common mode charge builds up on the rotor due to imbalances of the stator. The at least one main rotor bearing has a first electrical resistance between the rotor shaft and the case. The electric motor further includes a rotor discharge bearing coupling the rotor shaft to the case. The rotor discharge bearing has a second electrical resistance between the rotor shaft and the case that is less than the first electrical resistance, causing the common mode charge to discharge through the rotor discharge bearing. In a differing embodiment, a rotor discharge brush coupled between the case and the rotor shaft along the longitudinal axis of the rotor shaft discharges the common mode charge.

An inverter device is provided which is capable of more quickly raising an internal temperature of an electrolytic capacitor within a permissible range of a ripple voltage to shorten a non-operating time. The inverter device includes an electrolytic capacitor, an inverter circuit, a temperature sensor, and a control device. When the ambient temperature of the electrolytic capacitor detected by the temperature sensor is lower than a predetermined temperature, the control device on-drives specific switching elements of the inverter circuit before the start of a normal operation of a motor, and executes a warming up operation of allowing a current capable of controlling a ripple voltage of a DC voltage within a permissible range to flow through the motor at a predetermined rate of increase while keeping the motor stopped.

A vehicle includes an electric machine, a battery, an inverter, and a controller. The controller switches the inverter at a switching frequency selected to generate an AC current to heat the battery, adjusts a d-axis current of the electric machine to increase a battery heating power, and adjusts a q-axis current of the electric machine according to the adjusted d-axis current.

A linear actuator and a method for heating a linear actuator. An electric motor is configured to generate rotational motion in a first operating mode of the linear actuator. A transmission mechanism is configured to convert the rotational motion generated by the electric motor into translational motion. The linear actuator is further configured to generate heat in a second operating mode.

A linear actuator and a method for heating a linear actuator. An electric motor is configured to generate rotational motion in a first operating mode of the linear actuator. A transmission mechanism is configured to convert the rotational motion generated by the electric motor into translational motion. The linear actuator is further configured to generate heat in a second operating mode.

A control method for an electric drive system of a vehicle, includes: acquiring a shaft torque of the electric motor and a present operating point of the vehicle in response to a vehicle heating demand signal; acquiring a present heat generation power of the electric drive system accordingly; determining a current adjustment amplitude accordingly; acquiring a three-phase current value and a position value of the electric motor, and a present direct axis current value and a present quadrature axis current value of the electric motor at the present operating point accordingly; controlling the present direct axis current value to oscillate at a change frequency and the current adjustment amplitude to obtain a target direct axis current value; acquiring a target quadrature axis current value accordingly; acquiring an electric motor drive signal accordingly.

A control method for an electric drive system of a vehicle, includes: acquiring a shaft torque of the electric motor and a present operating point of the vehicle in response to a vehicle heating demand signal; acquiring a present heat generation power of the electric drive system accordingly; determining a current adjustment amplitude accordingly; acquiring a three-phase current value and a position value of the electric motor, and a present direct axis current value and a present quadrature axis current value of the electric motor at the present operating point accordingly; controlling the present direct axis current value to oscillate at a change frequency and the current adjustment amplitude to obtain a target direct axis current value; acquiring a target quadrature axis current value accordingly; acquiring an electric motor drive signal accordingly.

The present invention provides a stage driving apparatus for driving a stage, comprising: a linear motor including a stator which includes a coil array obtained by alternately arraying first phase coils and second phase coils, and a movable element placed on the stage; and a control unit configured to control the linear motor by controlling an energization state of the coil array, wherein in a stopping period during which the stage is stopped in a predetermined position, the control unit holds a position of the stage in the predetermined position by turning on the first phase coil among the coil array, and generates heat by turning on the second phase coil arranged in a position where no thrust is given to the movable element among the coil array.