A motor control device having a motor temperature sensor for detecting a magnet temperature of the motor, a magnet magnetic flux calculation section that calculates a magnet magnetic flux of the motor corresponding to the magnet temperature of the motor, a current combination candidate calculating section that calculates a d-q axis current combination candidate that minimizes the input current of the inverter within a voltage limit ellipse determined by a value that can be output by a voltage of a power supply of the motor, and a d-q axis current search section that searches the d-q axis current that minimizes the input current of the inverter within the range of the combination candidate of the d-q axis currents when the d-q axis current of the motor moves on a voltage limiting ellipse by automatic weakening flux control.

A permanent-magnet electric motor includes: a rotor; and a rotational-position detection sensor configured to detect a rotational position of the rotor. The rotor includes: a rotating shaft; an annular ferrite magnet disposed on an outer circumferential surface of the rotating shaft; and a rare-earth magnet disposed on an outer circumferential surface of the ferrite magnet, and a length from a center of the ferrite magnet in an axial direction of the ferrite magnet to an end face of the ferrite magnet on a side of the rotational-position detection sensor in the axial direction of the ferrite magnet is longer than a length from a center of the rare-earth magnet in an axial direction of the rare-earth magnet to an end face of the rare-earth magnet on a side of the rotational-position detection sensor in the axial direction of the rare-earth magnet.

A system of calculating temperature may include: a motor including a housing having opened ends, a cover connected to the housing to close at least one of the opened ends, a shaft rotatably disposed in the housing and having one end which penetrates through a center portion of the cover, a rotor fixed on an exterior circumference of the shaft in the housing and the cover, a stator fixed on an interior circumference of the housing, and an air gap formed between an exterior circumference of the rotor and an interior circumference of the stator; an input portion receiving a real time input and a predetermined input; and a control portion establishing a thermal equivalent circuit using the inputs of the input portion and convection or conduction characteristics between constituent elements of the motor, and calculating a temperature of each constituent element using the thermal equivalent circuit.

A system for estimating a temperature of a permanent magnet of a rotor of a motor including a first determination unit configured to determine whether a rotational speed of the rotor is greater than or equal to a reference speed, a second determination unit configured to determine whether a current flowing in a coil included in the motor is less than a reference current, and whether a magnitude of q-axis energy of the motor is less than a reference energy magnitude, when the rotational speed is greater than or equal to the reference speed, a magnetic flux map temperature estimation unit configured to estimate the temperature of the permanent magnet using a d-axis magnetic flux map of the motor responsive to conditions being satisfied, and an energy map temperature estimation unit configured to estimate the temperature responsive to conditions not being satisfied in the second determination unit.

A controller for a permanent magnet synchronous motor includes an estimating portion configured to determine an estimated value of a rotational speed of the rotor and an estimated value of a position of magnetic poles of the rotor based on a value of the current detected by the current detector and a parameter value indicating an interlinkage magnetic flux caused by the permanent magnet across the winding; a control unit configured to control the drive portion to cause the rotating magnetic field based on the estimated value of the rotational speed and the estimated value of the position of the magnetic poles; and a correction portion configured to correct the parameter value indicating the interlinkage magnetic flux based on correction information, the correction information being determined based on a temperature of the winding and a relationship between the temperature of the winding and a temperature of the permanent magnet.

In an example embodiment, a controller includes a memory having computer-readable instructions stored therein and a processor. The processor is configured to execute the computer-readable instructions to determine a first set of inductance values for at least one load machine and second set of inductance values for a generator machine, determine a first set of gains for the at least one load machine based on the first set of inductance values and a regulator bandwidth, determine a second set of gains for the generator machine based on the second set of inductance values and the regulator bandwidth, and generate voltage commands for driving the at least one load machine and the generator machine based on at least the first and second sets of gains.

A magnet temperature estimation device includes: a voltage detector (1) for detecting a voltage at a time when a winding is energized; a high-order component detector (2) for detecting a high-order component of the voltage; a reference database (3) for storing in advance, as a table, a correspondence relationship between the high-order component and two or more parameters, which include a magnet temperature and another one or more parameters, as parameters affecting the voltage from which the high-order component is detected; a parameter value detector (4) for detecting a value of the another one or more parameters; and a magnet temperature estimator (5) for estimating a magnet temperature corresponding to the high-order component detected by the high-order component detector based on the another one or more parameters detected by the parameter value detector and the table stored in the reference database.

A position sensor mounted in an actuator includes a magnetic detecting element for detecting the position of a shaft, and a temperature detecting element for detecting intra-sensor temperature which is used for correction of the temperature characteristics of the magnetic detecting element, the magnetic detecting element and the temperature detecting element being built therein. A control device for the actuator acquires both the temperature-corrected position of the shaft and the intra-sensor temperature from the position sensor, and uses them for control of the actuator.

A controller for a permanent magnet synchronous motor includes an estimating portion configured to determine an estimated value of a rotational speed of the rotor and an estimated value of a position of magnetic poles of the rotor based on a value of the current detected by the current detector and a parameter value indicating an interlinkage magnetic flux caused by the permanent magnet across the winding; a control unit configured to control the drive portion to cause the rotating magnetic field based on the estimated value of the rotational speed and the estimated value of the position of the magnetic poles; and a correction portion configured to correct the parameter value indicating the interlinkage magnetic flux based on correction information, the correction information being determined based on a temperature of the winding and a relationship between the temperature of the winding and a temperature of the permanent magnet.

A controller for a permanent magnet synchronous motor includes an estimating portion configured to determine an estimated value of a rotational speed of the rotor and an estimated value of a position of magnetic poles of the rotor based on a value of the current detected by the current detector and a parameter value indicating an interlinkage magnetic flux caused by the permanent magnet across the winding; a control unit configured to control the drive portion to cause the rotating magnetic field based on the estimated value of the rotational speed and the estimated value of the position of the magnetic poles; and a correction portion configured to correct the parameter value indicating the interlinkage magnetic flux based on correction information, the correction information being determined based on a temperature of the winding and a relationship between the temperature of the winding and a temperature of the permanent magnet.