A magnet temperature estimating device for a motor including a rotor having magnets and configured to output a rotational motive force, and a stator having a plurality of coils opposing the rotor with a gap therebetween, is provided. The device includes a sensor configured to detect an induced voltage induced by rotation of the rotor, and a controller configured to control the motor by supplying power to the plurality of coils in response to an input of a detection signal from the sensor. Gaps adjacent to each magnet in a rotation direction of the rotor are formed in the rotor. The controller estimates a temperature of the magnet based on the induced voltage detected when the magnet opposes any one of the plurality of coils, according to the rotation of the rotor.

The invention relates to a method and device for operating an electric machine (10) for outputting a predefined torque and a predefined rotational speed, comprising the following steps: providing (420) a first and a second operating mode for the operation of the electric machine (10); detecting (430) a temperature of the electric machine (10); and operating the electric machine (10) in the first operating mode (440) if the detected temperature falls below a threshold value, and operating the electric machine (10) in the second operating mode (450) if the detected temperature corresponds with the threshold value or exceeds same. During the operation of the electric machine (10) in the second operating mode (450), with the resulting output of the predefined torque and the predefined rotational speed, the magnetic stator flux of the electric machine (10) is reduced compared with the magnetic stator flux of the electric machine (10) during the operation of the electric machine (10) in the first operating mode (440), with the resulting output of the predefined torque and the predefined rotational speed.

A head-mountable device can effectively manage heat with a motor assembly that efficiently and accurately senses a temperature of a motor. A temperature sensor can be provided on an outer surface (e.g., case) of the motor. A flex circuit can be operably connect both the motor and the temperature sensor to a controller of the head-mountable device. The flex circuit can have a first side coupled to the outer surface of the case, a second side supporting the temperature sensor, and thermally conductive vias extending from the first side to the second side to conduct heat from the case to the sensor. The flex circuit can further include a memory comprising calibration data of the temperature sensor and a connector for outputting temperature data based on the temperature sensor and the calibration data of the memory.

The present disclosure pertains to systems and methods configured to monitor and protect an electric motor during startup using a motor model. The motor model parameters may be calculated using measurements taken during a calibration start of the electric motor. The measurements may include slip, stator current, stator voltage, frequency, and/or other electrical or physical parameters. In some embodiments, the motor model parameters may be calculated by minimizing the difference between a measured slip and a calculated slip. The motor model may comprise a variety of parameters used to determine operation parameters of the motor during the startup. In one specific embodiment, the motor model may determine a thermal capacity used (TCU). The TCU may be compared to a threshold value to determine whether protective action is necessary.

A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit generates a control signal to control the switch circuit. The motor controller determines a non-excitation time. When the motor is in a locked state, the motor controller enables the non-excitation time to be a variable value. The motor controller utilizes the non-excitation time to achieve a lock protection function. The motor controller determines whether the motor is in the locked state by detecting a rotor speed or a rotor temperature. Moreover, the motor controller further comprises a driving signal, where the driving signal has the non-excitation time.

A magnet temperature estimating device for a motor provided with a rotor having magnets and configured to output a rotational motive force, and a stator having a plurality of coils opposing the rotor with an aperture therebetween, is provided. The device includes a sensor configured to detect an induced voltage induced by rotation of the rotor, and a controller configured to control the motor by supplying power to the plurality of coils in response to an input of a detection signal from the sensor. The controller estimates a temperature of one of the magnets based on an amplitude of a frequency spectrum corresponding to a given frequency, among frequency components constituting the induced voltage.

In a rotating electrical machine, in particular a generator, different components, such as, for example, rotor, stator rod and end zone, are cooled as required by associated external fans, whereby the cooling power requirement is reduced. The method for cooling includes a plurality of cooling fans arranged for cooling different components of the machine, wherein a cooling fan is individually controlled in its cooling performance in accordance with the temperature of the associated component.

In a rotating electrical machine, in particular a generator, different components, such as, for example, rotor, stator rod and end zone, are cooled as required by associated external fans, whereby the cooling power requirement is reduced. The method for cooling includes a plurality of cooling fans arranged for cooling different components of the machine, wherein a cooling fan is individually controlled in its cooling performance in accordance with the temperature of the associated component.

Disclosed is a traction battery self-heating control method and a device. Acquiring a second temperature of a rotor at a current sampling time according to system parameters and a first temperature of the rotor at a previous sampling time, and estimating a third temperature of the rotor at a next sampling time according to the first temperature and the second temperature, and stopping the self-heating of the traction battery when the third temperature reaches a demagnetization temperature of the rotor. Whether to stop the self-heating of the traction battery is determined by estimating a rotor temperature under the self-heating condition, and comparing the rotor temperature with the demagnetization temperature of the rotor, and thus the self-heating control of the traction battery is realized.

Methods and apparatuses for determining a rotor temperature of a permanent magnet synchronous machine (PSM) of an electrically driven vehicle are described.