Motor control apparatus

Patent metadata

Field	Value
Publication number	US-10199982-B2
Application number	US-201715838125-A
Country	US
Kind code	B2
Filing date	Dec 11, 2017
Priority date	Dec 12, 2016
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

A self-holding termination determination section has an overheat protection map that defines a relationship between a current value and a maximum temperature of a protected portion to which a current value is applied, and sets a limit temperature corresponding to a required current value at next start time based on the map. The self-holding termination determination section calculates, as an evaluation temperature, temperature obtained by adding a performance assurance upper limit temperature, which assures output performance of a motor at the next start time, to the sum of temperature rises. In a next time performance determination process, if the evaluation temperature for all protected portions has fallen below the limit temperature, the self-holding termination determination section determines that a performance assurance condition is met, and terminates power self-holding based on at least the fact that the performance assurance condition is met.

First claim

What is claimed is:

1. A motor control apparatus, comprising:
a drive circuit that drives a motor;
a power supply circuit that has a power self-holding section that holds power for control after supply of drive power to the drive circuit is stopped;
a temperature rise estimation section that estimates at least one temperature rise based on a square value of current flowing through the motor, the drive circuit, or the power supply circuit, or a first-order lag response of a time average of an integrated value of the current;
a detection temperature acquisition section that acquires a detection temperature of at least one protected portion to be protected from being overheated or of a portion having a correlation regarding temperature with the protected portion;
an estimated temperature calculation section that adds the detection temperature to a sum of the at least one temperature rise to calculate estimated temperature of the protected portion;
a current limitation calculation section that calculates a current limiting value for limiting a current command value based on the estimated temperature; and
a self-holding termination determination section that determines termination of power self-holding, wherein
the temperature rise estimation section continues the estimation of the temperature rise while the power self-holding section holds power,
the self-holding termination determination section has an overheat protection map that defines a relationship between a current value and a maximum temperature of the protected portion to which the current value is applied, and sets a limit temperature corresponding to a required current value at next start time based on the overheat protection map,
the self-holding termination determination section calculates, as an evaluation temperature, temperature obtained by adding a performance assurance upper limit temperature, which is an upper limit temperature assuring output performance of the motor at the next start time, to a sum of the at least one temperature rise, and
in a next time performance determination process for comparing the evaluation temperature and the limit temperature, if the evaluation temperature for all of the at least one protected portion has fallen below the limit temperature, the self-holding termination determination section determines that a performance assurance condition is met, and terminates the power self-holding based on at least a fact that the performance assurance condition is met.

2. The motor control apparatus according to claim 1 , wherein
when a predetermined forced termination time has passed from time when the supply of drive power is stopped, the self-holding termination determination section forcibly terminates the power self-holding.

3. The motor control apparatus according to claim 1 , wherein
the self-holding termination determination section has a self-holding addition time map that defines a relationship between the temperature rise and a self-holding addition time, which is added to an elapsed time from the time when the supply of drive power is stopped, to obtain a sum as a self-holding time, and
if it is determined that the performance assurance condition is met in the next time performance determination process, the self-holding termination determination section terminates the power self-holding when the self-holding time based on the self-holding addition time map has passed.

4. The motor control apparatus according to claim 3 , wherein
in the self-holding addition time map, the self-holding addition time is set so as to be shorter as the temperature rise lowers, and to be 0 if the temperature rise is a critical temperature or less.

5. The motor control apparatus according to claim 1 , wherein
temperature information is stored when the power self-holding terminates, and initial current limitation is performed based on the temperature information at the next start time.

Assignees

• Denso Corp

Inventors

• Endoh Go

Classifications

• H02P29/68

  based on the temperature of a drive component or a semiconductor component · CPC title

• H02P29/60

  Controlling or determining the temperature of the motor or of the drive (H02P29/02 takes precedence) · CPC title

• B62D6/00

  Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits (means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00) · CPC title

• B62D5/04

  electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear · CPC title

• H02P31/00 Primary

  Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00 · CPC title