The disclosure relates to a redundant electric machine for driving a propulsion means with increased operational safety. The machine may include two systems, with each system including a stator winding system and a rotor assigned thereto with permanent magnets, wherein the rotors are fastened on a common shaft for driving the propulsion means. If a fault occurs in one of the stator winding systems, the rotor, which continues to rotate, has to be prevented from inducing electric voltages in the stator winding system because this may lead to a fire in the machine. A demagnetization apparatus is therefore provided which, in a targeted manner, demagnetizes the permanent magnets of the rotor assigned to the faulty stator winding system such that the inducing of electric voltages is prevented.

A motor temperature and torque estimation device comprises: a temperature sensor; a losses estimation circuitry to estimate an iron loss; a first temperature estimation circuitry to estimate a first magnet temperature from the estimated iron loss and a sensor's detected temperature; a second temperature estimation circuitry, to input into a magnet's magnetic flux calculator thereinside motor's modified inductance, to estimate a second magnet temperature from magnet's magnetic flux calculated through voltage equations; a magnet-temperature estimation circuitry to estimate a motor's magnet temperature from the first and second magnet temperatures; a magnet's magnetic estimation circuitry to estimate magnetic flux based on the calculated/modified one, the motor's estimated magnet temperature and temperature characteristics, and to output the estimated magnetic flux into the losses estimator; and a torque estimation circuitry to estimate torque based on the estimated magnetic flux and iron loss, wherein a motor's magnet temperature(s) and torque are estimated.

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.

Parameters relating to rotation of a motor (2) measured every constant time are acquired and the moving average of each constant interval of the parameters is calculated. The calculated moving averages are input to a training model trained so as to output a temperature of magnets attached to a rotor (7) of the motor (2) when the moving averages of the parameters relating to rotation of the motor (2) are input, and an estimated value of the magnet temperature output from the model is acquired. Next, the acquired estimated value of the magnet temperature is output.

A motor control apparatus excites an excitation phase targeted for excitation among a plurality of excitation phases of a motor. The motor control apparatus, in a state in which a rotor of the motor is stopped, excites an excitation phase corresponding to a stop position of the rotor among the plurality of the excitation phases, and measures a physical quantity which changes in accordance with an inductance of at least one of a plurality of coils configuring the plurality of excitation phases. The motor control apparatus estimates a temperature of the rotor from a measurement value of the measured physical quantity, and decides a parameter value for control of the motor based on the estimated temperature.

A controller for a rotary electric machine may include: at least one memory that stores a temperature prediction data in which a relationship among a rotational speed of a rotary electric machine, a torque information of the rotary electric machine, a temperature of the rotary electric machine at a reference time point, and a temperature of the rotary electric machine after an estimation calculation period elapses from the reference time point, and at least one processor that, at every estimation calculation period, sets the last calculation time before the estimation calculation period as the reference time point, and, by referring to the temperature prediction data, calculates an estimation value of temperature of the rotary electric machine after the estimation calculation period elapses from the last calculation time.

Given a first intersection point of the surface of a rotor and a straight line that joins a central point of a permanent magnet on a stator side and a tooth tip section closest to the central point of the permanent magnet on the stator side, a flange is formed outward of an arc having, as the radius thereof, a distance from a second intersection point of the inner peripheral face of the stator and a straight line that joins the rotation axis of the rotor and the first intersection point, up to the tooth tip section.

A motor includes a magnet and a coil. α2=[{(Br2−Br1)/Br1}/(T2−T1)]×100≧−0.10 and α3=[{(Br3−Br1)/Br1}/(T3−T1)]×100≦−0.12 are satisfied. In the magnet, Br1 (mT) is a residual magnetic flux density at T1 (° C.), Br2 (mT) is a residual magnetic flux density at T2 (° C.), and Br3 (mT) is a residual magnetic flux density at T3 (° C.), and α2 (%/° C.) is a temperature coefficient at a target temperature of T2 (° C.) with respect to a reference temperature of T1 (° C.), and α3 (%/° C.) is a temperature coefficient at a target temperature of T3 (° C.) with respect to a reference temperature of T1 (° C.) in conditions of T1=23, T2=60, and T3=180.

A rotor temperature monitoring method and system for a permanent magnet synchronous motor are provided. According to the method and system, an a-phase line current and a b-phase line current of a stator of a permanent magnet synchronous motor are obtained as a first line current and a second line current; further, a line voltage between the a-phase and the b-phase of the stator is obtained and a rotating speed of the rotor of the permanent magnet synchronous motor is obtained; and then, the first line current, the second line current, the line voltage, the rotating speed of the rotor, an inductance parameter of the permanent magnet synchronous motor and a temperature characteristic equation of a permanent magnet of the rotor are substituted into a preset rotor permanent magnet temperature expression to calculate and obtain the temperature of the rotor.

A temperature estimating apparatus for a synchronous motor comprises: a voltage command generating unit for controlling d-phase current by increasing or decreasing d-phase and q-phase voltages; a voltage acquiring unit for d-phase and q-phase voltages when the d-phase current is varied; a rotating speed detecting unit for the synchronous motor; a current detecting unit for the d-phase and q-phase currents; a winding temperature acquiring unit; a winding resistance converting unit for winding resistance from winding temperature; an inductance calculating unit for d-axis inductance based on the variation of the d-phase current and the q-phase voltage and on the rotating speed; a counter electromotive voltage constant calculating unit from the q-phase voltage, the varied d-phase current, the rotating speed, the q-phase current, the winding resistance, and the d-axis inductance; and a magnet temperature estimating unit for estimating magnet temperature based on the counter electromotive voltage constant.