Abstract: Under a condition that rotor rotation speeds ?es are equal, winding wire currents Id, Iq are equal, and winding wire inductances Ld, Lq are equal in first and second electric motors (1, 2), a magnet temperature anomaly detector (30) provided in a microcomputer (5) calculates a change ratio d(|?ml??mr|)/dt of a magnetic flux difference between the first and second electric motors (1, 2) based on the difference Vql*?Vqr* between a q-axis voltage command value Vql* corresponding to the first electric motor (1) and a q-axis voltage command value Vqr corresponding to the second electric motor (2), and then when the change ratio d(|?ml??mr|)/dt of the magnetic flux difference is more than a predetermined threshold Sh1, it is determined that a permanent magnet of at least any one of the electric motors (1, 2) has a temperature anomaly.

Abstract: A motor control apparatus has a start control section. When the motor control apparatus receives a motor start command from a host control unit when a motor is in a stop state or a low-speed rotating state where a sensorless control cannot be applied, the control section starts the motor that rotates a vehicle fan by a forced commutation which supplies a pseudo sinusoidal drive signal caused by a complementary PWM control. Thereafter, the motor control apparatus switches over to a sensorless control using a rectangular wave drive signal at an energization angle of lower than 180°.

Abstract: An apparatus, system, and method are disclosed for fault tolerant cooling in a redundant power system. The apparatus receives power from a common power bus to power one or more power supply fans. The apparatus detects a non-functioning redundant power supply. The apparatus receives a fan control signal within a non-functioning redundant power supply. In addition, the apparatus uses the received fan control signal to synchronize a fan speed of a power supply fan within the non-functioning redundant power supply. The fan speed is synchronized with at least one fan control signal of a power supply fan within a functioning redundant power supply. Thus, the power supply fans of a non-functioning power supply continue to operate and are synchronized with power supply fans in functioning power supplies.

Abstract: Presented in an apparatus for controlling a brushless DC motor with a permanent magnet arranged on a rotor and a stator with windings. The apparatus includes an observer that is adapted to determine an estimated temperature of the permanent magnet as a function of the temperature of the windings, and determine at least one actuating signal for controlling the DC motor as a function of the estimated temperature of the permanent magnet.

Abstract: A motor control apparatus has a start control section. When the motor control apparatus receives a motor start command from a host control unit when a motor is in a stop state or a low-speed rotating state where a sensorless control cannot be applied, the control section starts the motor that rotates a vehicle fan by a forced commutation which supplies a pseudo sinusoidal drive signal caused by a complementary PWM control. Thereafter, the motor control apparatus switches over to a sensorless control using a rectangular wave drive signal at an energization angle of lower than 180°.

Abstract: It is the objective of the present invention to provide a sensorless vector control method and a control apparatus, for an alternating-current motor, that can smoothly restart an alternating-current motor in the free running state. According to the present invention, when a current that flows in an alternating-current motor (2) at a restart time 7 the alternating-current motor (2) continuously flows at a designated current level or higher for a designated period of time, it is determined that the rotational direction or the velocity of the alternating-current motor (2) is incorrectly estimated, and a direct current or a direct-current voltage is again applied to again estimate the rotational direction and the velocity.

Abstract: In the control of a synchronous motor having a permanent magnet, an alternating current power supply voltage that is input to a power amplifier or a direct current link voltage of which input voltage is rectified is measured. A reactive current (a d-axis current) or a current control phase advance is changed, according to this power supply voltage. With this arrangement, reactive current control or current phase control can be carried out directly according to a change in the input power supply voltage. A motor control device includes a voltage measuring unit that measures a voltage supplied to a driving amplifier, and a current control unit that controls a current passed to a synchronous motor based on the measured voltage. The voltage measuring unit measures a voltage supplied to the amplifier. The current control unit controls a current that is passed to the synchronous motor, according to the measured voltage.

Abstract: An electric motor system includes an electric motor, a temperature sensor mounted therein capable of measuring a local temperature and generating a temperature related signal, and a processor configured to calculate an actual temperature of a rotor magnet from the temperature related signal, and an actual output torque from the actual rotor magnet temperature. A method for determining the actual output torque of a motor includes sensing a temperature within the motor, calculating a rotor magnet temperature from the sensed temperature, and calculating the actual output mechanical torciue from the rotor magnet temperature.

Abstract: A method and system for estimating a temperature of an electric machine comprising obtaining a temperature value responsive to a temperature signal from a temperature sensor, the temperature sensor is operatively connected to and transmitting the temperature signal corresponding to a measured temperature to a controller. The controller executes a temperature estimation process; and is operatively connected to a switching device, where the switching device is operatively connected between the electric machine and a power source, the switching device being responsive to the controller. Also disclosed is a storage medium encoded with a machine-readable computer program code for estimating an operating temperature of an electric machine. The storage medium includes instructions for causing controller to implement method for estimating an operating temperature of an electric machine as described above.

Abstract: The present invention relates to an electronic device (10) for controlling a discharge pump, driven by a synchronous electric motor with a permanent-magnet rotor (3) and of the type comprising at least a controller (1) receiving at its input a synchronizing signal (5) of the motor supply voltage (V) and at least a second signal (7) being proportional to the current absorbed by the motor, to drive at its output a switch (6) being series-connected to one of the motor windings. Advantageously, the switch (6) is a bidirectional switch (11) comprising a diode bridge and it can be manufactured in an integrated way. In a preferred embodiment the bidirectional switch (11) is of the SCR type.

Abstract: For a method of operating of a synchronous compensator comprising a rotating electric machine comprising rotor (46) and stator (2) with at least one winding with a solid insulation enclosing the electric field, relevant parameters for the temperature conditions in the rotor are determined, and during over-excited operation in order to temporarily enlarge the field of operation of the synchronous compensator, the cooling of the rotor is forced depending on a rotor temperature value (TR) determined from said parameters. Such a synchronous compensator comprises measuring means for measuring parameters relevant for the temperature conditions of the rotor. Means (36, 38) are also provided to force the cooling of the rotor (46) depending on rotor temperature values (TR) determined from said parameters during over-excited operation of the electric machine.

Abstract: This invention relates to a system for protecting an amortisseur winding during the starting of a synchronous motor. The system compares the actual slip frequency of the accelerating motor with predetermined slip frequencies. These predetermined slip frequencies are each associated with a timer which measures successive time segments. Each timer is stopped when the actual slip frequency, which decreases as rotor speed increases, is less than the associated predetermined slip frequency. When the timer is stopped a successive timer is started. In this manner the acceleration of the motor is broken up into time segments. The initial timer is started when the motor starts. The final timer is stopped when the rotor field current is applied to bring the motor into synchronism. Should any timer be permitted to have its timed segment expire before being stopped, the motor is shut down. There is also provided a thermal memory which receives information from the expired timer as to its associated slip frequency.