Control apparatus of motor

Patent metadata

Field	Value
Publication number	US-9906184-B2
Application number	US-201514956795-A
Country	US
Kind code	B2
Filing date	Dec 2, 2015
Priority date	Dec 2, 2014
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A temperature detection element that detects a temperature of a detector is provided in a detector that detects a rotational position and/or a rotational speed of a rotor of a motor. An estimated value of a change of a wiring temperature is calculated based on a current supplied to the wiring of the motor. An estimated value of a change of the detector temperature is calculated based on the estimated value of the change of the wiring temperature. A difference between the detector temperature detected by the temperature detection element and the estimated value of the change of the detector temperature is set as an environmental temperature. The environmental temperature is added to the estimated value of the change of the wiring temperature, to estimate an absolute value of the wiring temperature. The wiring temperature is monitored based on the estimated absolute value of the wiring temperature.

First claim

What is claimed is:

1. A control apparatus of a motor, comprising:
a detector that detects a rotational position and/or a rotational speed of a rotor of a motor, and that has a temperature detection element that detects a temperature of the detector;
a circuit that estimates a change of a wiring temperature, to calculate an estimated value of the change of the wiring temperature;
a circuit that estimates a change of a detector temperature based on the estimated value of the change of the wiring temperature, to calculate an estimated value of the change of the detector temperature;
a circuit that subtracts the estimated value of the change of the detector temperature from an absolute value of the detector temperature detected by the temperature detection element, to calculate an environmental temperature; and
a circuit that adds the obtained environmental temperature to the estimated value of the change of the wiring temperature, to calculate an estimated value of an absolute value of the wiring temperature.

2. The control apparatus of motor according to claim 1 , wherein
the circuit that calculates the estimated value of the change of the wiring temperature is a circuit that calculates, based on an estimated value of the change of the wiring temperature at a certain detection period and a value related to a current supplied to the motor, an estimated value of the change of the wiring temperature at a next detection period, and
the circuit that calculates the estimated value of the change of the detector temperature is a circuit that calculates, based on an estimated value of the change of the detector temperature at a certain detection period and an estimated value of the change of the wiring temperature at a next detection period, an estimated value of the change of the detector temperature at the next detection period.

3. The control apparatus of motor according to claim 2 , wherein
the circuit that calculates the estimated value of the change of the wiring temperature calculates the estimated value of the change of the wiring temperature based on an equation:
ΔT′ (n) =β×{(α× T in) 2 −ΔT′ (n-1) }+ΔT′ (n-1)

wherein:
ΔT′ represents the estimated value of the change of the wiring temperature;
α represents a coefficient that determines a saturated value of the estimated value of the change of the wiring temperature;
β represents a coefficient that determines a time constant of the estimated value of the change of the wiring temperature;
Tin represents a command value or a detected value of a current, or a torque command value; and
an index (n) represents a number of detection periods, and
the circuit that obtains the estimated value of the change of the detector temperature calculates the estimated value of the change of the detector temperature based on an equation:
ΔTe′ (n) =βe× (α e×ΔT′ (n) −ΔTe′ (n-1) ) +ΔTe′ (n-1)

wherein:
ΔTe′ represents the estimated value of the change of the detector temperature;
αe represents a coefficient that determines a saturated value of the estimated value of the change of the detector temperature;
βe represents a coefficient that determines a time constant of the estimated value of the change of the detector temperature; and
an index (n) represents a number of detection periods.

Assignees

• Okuma Machinery Works Ltd

Inventors

• Yato Takahiko

Classifications

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title

• G01K7/00

  Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat (giving results other than momentary value of temperature G01K3/00) {; Power supply therefor, e.g. using thermoelectric elements} · CPC title

• H02P29/0055 Primary

  Electricity · mapped topic

• H02P29/64 Primary

  Controlling or determining the temperature of the winding · CPC title