IP Library Granted Patent US 10,090,790
Granted Patent B2
US 10,090,790 · App. 15/520,746 · Granted Oct 2, 2018

Motor control device

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Quick Facts
Patent No.
US 10,090,790
App. No.
15/520,746
Granted
Oct 2, 2018
Kind
B2
Abstract

The occurrence of torque in the motor due to an unintentional flow of the q-axis current in the motor during discharging of the smoothing capacitor is reduced. A motor control device according to the present invention controls a system including an inverter including a smoothing capacitor connected to a power source via a relay, a motor connected to the inverter, and a current sensor configured to detect a current flowing through the motor, the motor control device including: an electric discharge control unit configured to discharge, in the motor via the inverter, an electric charge accumulated in the smoothing capacitor; and a current sensor calibration unit configured to calibrate the current sensor in a state where no current in the motor flows during a time period from when the relay is cut off to when discharge control by the electric discharge control unit is started, wherein the electric discharge control unit performs discharge by controlling the current in the motor based on a value of the current sensor calibrated by the current sensor calibration unit.

Claims (5)

1. A motor control device that controls a system, the system including an inverter including a smoothing capacitor connected to a power source via a relay, a motor connected to the inverter, and a current sensor configured to detect a current flowing through the motor, the motor control device comprising:

an electric discharge control unit configured to discharge, in the motor via the inverter, an electric charge accumulated in the smoothing capacitor; and

a current sensor calibration unit configured to calibrate the current sensor in a state where no current in the motor flows during a time period from when the relay is cut off to when discharge control by the electric discharge control unit is started,

wherein the electric discharge control unit performs discharge by controlling the current in the motor based on a value of the current sensor calibrated by the current sensor calibration unit.

2. The motor control device according to claim 1 , wherein the current sensor calibration unit detects a state in which no current flows to the motor by determining a voltage change of the smoothing capacitor.

Assignments (2)
CHANGE OF NAME Recorded Mar 25, 2021
From: HITACHI AUTOMOTIVE SYSTEMS, LTD.
To: HITACHI ASTEMO, LTD.
Reel/Frame 056299/0447 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 12, 2017
From: SAMBONSUGE, HIROKAZU; MYOEN, KOHEI; OYAMA, KAZUTO
To: HITACHI AUTOMOTIVE SYSTEMS, LTD.
Reel/Frame 042353/0801 →