A method for estimating the temperature of a stator coil of a magnetic suspension bearing of a rotor that is connected by connection wires to circuits for servo-controlling the position of the rotor includes the following steps: measuring the electric voltage at the terminals of the connection wires of the stator coil; measuring the intensity of the current passing through the stator coil; estimating the electric resistance of the stator coil and of the connection wires on the basis of an adaptive filter, the measured electric voltage and the intensity of the measured current; and estimating the temperature of the coil on the basis of the value of the estimated resistance.

A method for estimating the temperature of a stator coil of a magnetic suspension bearing of a rotor that is connected by connection wires to circuits for servo-controlling the position of the rotor includes the following steps: measuring the electric voltage at the terminals of the connection wires of the stator coil; measuring the intensity of the current passing through the stator coil; estimating the electric resistance of the stator coil and of the connection wires on the basis of an adaptive filter, the measured electric voltage and the intensity of the measured current; and estimating the temperature of the coil on the basis of the value of the estimated resistance.

In described examples, a measurement circuit includes an isolated power supply that generates an output signal in response to an input signal. A signal processing circuit is coupled to the isolated power supply and generates a first signal in response to a sense signal. A load manipulator circuit is coupled to the signal processing circuit and the isolated power supply. The load manipulator circuit receives the first signal. A detect circuit is coupled to the isolated power supply and generates a second signal in response to the input signal.

In described examples, a measurement circuit includes an isolated power supply that generates an output signal in response to an input signal. A signal processing circuit is coupled to the isolated power supply and generates a first signal in response to a sense signal. A load manipulator circuit is coupled to the signal processing circuit and the isolated power supply. The load manipulator circuit receives the first signal. A detect circuit is coupled to the isolated power supply and generates a second signal in response to the input signal.

Provided is an electric drive device which controls a current supplied to coils during normal operation so as to be less than a current limit value when normal, which is determined from heat generating properties and heat radiating properties of a thermally coupled body that includes the coils and an inverter circuit. When an abnormality in each group or each phase of the coils and the inverter circuit is detected, the supply of current to all phases of a group suffering an abnormality in the coils, or to a phase that is not capable of continuous operation, is stopped or reduced; and the limit value of the current supplied to a coil that is capable of continuous operation is reset to a current limit value in the event of abnormality, which is larger than the current limit value when normal, within the range of improvement of the heat generating properties of the thermally coupled body due to the stopping or reduction of the supply of current.

Provided is an electric drive device which controls a current supplied to coils during normal operation so as to be less than a current limit value when normal, which is determined from heat generating properties and heat radiating properties of a thermally coupled body that includes the coils and an inverter circuit. When an abnormality in each group or each phase of the coils and the inverter circuit is detected, the supply of current to all phases of a group suffering an abnormality in the coils, or to a phase that is not capable of continuous operation, is stopped or reduced; and the limit value of the current supplied to a coil that is capable of continuous operation is reset to a current limit value in the event of abnormality, which is larger than the current limit value when normal, within the range of improvement of the heat generating properties of the thermally coupled body due to the stopping or reduction of the supply of current.

A motor control system includes a three-phase motor winding; and a thermistor that measures a temperature of any one or two of coils of the three-phase motor winding, the motor control system including a coil temperature estimation unit that calculates an estimated temperature of each of the three-phase coils based on a value of a current flowing through the three-phase motor winding. The motor is controlled based on the estimated temperature of the three-phase motor winding when a difference between the estimated temperatures of the three-phase motor winding is larger than a predetermined value. The motor is controlled based on a measured value of the thermistor when the difference between the estimated temperatures of the three-phase motor winding is equal to or less than the predetermined value.

A motor control system includes a three-phase motor winding; and a thermistor that measures a temperature of any one or two of coils of the three-phase motor winding, the motor control system including a coil temperature estimation unit that calculates an estimated temperature of each of the three-phase coils based on a value of a current flowing through the three-phase motor winding. The motor is controlled based on the estimated temperature of the three-phase motor winding when a difference between the estimated temperatures of the three-phase motor winding is larger than a predetermined value. The motor is controlled based on a measured value of the thermistor when the difference between the estimated temperatures of the three-phase motor winding is equal to or less than the predetermined value.

A motor control device controls a driving of a motor having a motor winding. The motor control device includes a motor control unit and a parameter setting unit. The motor control unit controls the driving of the motor. The parameter setting unit sets a control parameter related to a driving control of the motor such that at least one of a motor torque and a motor speed is variable according to a system temperature.

A motor control device controls a driving of a motor having a motor winding. The motor control device includes a motor control unit and a parameter setting unit. The motor control unit controls the driving of the motor. The parameter setting unit sets a control parameter related to a driving control of the motor such that at least one of a motor torque and a motor speed is variable according to a system temperature.