Brushless direct current electric motor driving control method and system of electrical water pump

• US 10,447,188 B2
• Filed: 12/08/2017
• Issued: 10/15/2019
• Est. Priority Date: 12/14/2016
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group), Kia Motors Corporation (Kia Corp.), Myung Hwa Ind Co., Ltd.
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Shim, Dong Soo, Kim, Yeon Ho, Choi, Byoung Hoon, Yi, Jae Shin, Song, Hyeong Geun, Dong, Geun Oh
• Primary Examiner(s): Islam, Muhammad S
• Application Number:
  US15/836,522
• Publication Number:
  US 20180167005A1
• Time in Patent Office: 676 Days
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F04B 2203/0201 Current
• CPC Class Codes: F04B 2203/0203 Magnetic flux
• CPC Class Codes: F04B 2203/0207 Torque
• CPC Class Codes: F04B 2203/0209 Rotational speed
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: F04B 49/20 by changing the driving speed
• CPC Class Codes: F05B 2270/101 to control rotational speed (n)
• CPC Class Codes: H02P 21/24 Vector control not involving the use of rotor position or rotor speed sensors
• CPC Class Codes: H02P 7/0094 wherein the position is detected using the ripple of the current caused by the commutator
• CPC Class Codes: H02P 7/34 using Ward-Leonard arrangements

Abstract

A method and system of controlling driving of a brushless DC electric motor (BLDC) of an electric water pump are provided. The method includes estimating an initial position of a rotor using a magnitude of a current detected in a three-phase coil wound on a stator and converting a current magnitude that reflects a rotational angle of the rotor with respect to the initial position into two direct currents based on the three-phase current. The converted direct currents are output and a rotational angle, a speed, a flux and a torque of the rotor are acquired based on values of the three-phase current, a voltage generated according to flow of the three-phase current, a predetermined coil resistance, and an inductance input. A speed of the motor is then adjusted based on the acquired rotational angle, speed, flux, and torque of the rotor.

Claims

1. A method for controlling driving of a brushless direct current electric motor (BLDC) of an electric water pump, comprising the steps of:

estimating, by a controller, an initial position of a rotor based on a magnitude of a current detected in a three-phase coil wound on a stator;

converting, by the controller, a current magnitude that reflects a rotational angle of the rotor with respect to the initial position into two direct currents based on a three-phase current, and outputting the converted direct currents;

acquiring, by the controller, the rotational angle, a speed, a flux and a torque of the rotor based on values of the three-phase current, a voltage generated based on flow of the three-phase current, a predetermined coil resistance, and an inductance input; and

adjusting, by the controller, a speed of the motor based on the acquired rotational angle, speed, flux, and torque of the rotor,

wherein the acquiring step further comprises;

acquiring, by the controller, the speed of the rotor based on a change in the rotational angle of the rotor with respect to the initial position; and

acquiring, by the controller, the torque of the rotor based on the rotational angle of the rotor and the speed of the rotor.

2. The method of claim 1, further comprising:

comparing, by the controller, the acquired speed, flux and torque of the rotor based on the rotational angle of the rotor with a predetermined speed, flux, and torque based on a change in rotational angle of the rotor.

3. The method of claim 1, wherein the converting step further comprises:

converting, by the controller, the three-phase current into the magnitude of the current generated in the three-phase coil of the stator and a magnitude of a current generated in a magnet of the rotor and outputting the magnitudes.

4. The method of claim 1, wherein the acquiring step further comprises:

adding, by the controller, the voltage generated based on the flow of the three-phase current to the speed of the rotor and acquiring the flux of the rotor.

5. A system for controlling driving of a brushless direct current electric motor (BLDC) of an electric water pump, comprising:

a memory configured to store program instructions; and

a processor configured to execute the program instructions, the program instructions when executed configured to;

estimate an initial position of a rotor based on a magnitude of a current detected in a three-phase coil wound on a stator;

convert a current magnitude that reflects a rotational angle of the rotor with respect to the initial position into two direct currents based on a three-phase current, and output the converted direct currents;

acquire a rotational angle, a speed, a flux and a torque of the rotor based on values of the three-phase current, a voltage generated based on flow of the three-phase current, a predetermined coil resistance, and an inductance input; and

adjust a speed of the motor based on the acquired rotational angle, speed, flux, and torque of the rotor,

wherein the program instructions that, when executed, acquire the rotational angle, the speed, the flux and the torque of the rotor are further configured to;

acquire the speed of the rotor based on a change in the rotational angle of the rotor with respect to the initial position; and

acquire the torque of the rotor based on the rotational angle of the rotor and the speed of the rotor.

6. The system of claim 5, wherein the program instructions when executed are further configured to:

compare the acquired speed, flux and torque of the rotor based on the rotational angle of the rotor with a predetermined speed, flux, and torque based on a change in rotational angle of the rotor.

7. The system of claim 5, wherein the program instructions when executed are further configured to:

convert the three-phase current into the magnitude of the current generated in the three-phase coil of the stator and a magnitude of a current generated in a magnet of the rotor and outputting the magnitudes.

8. The system of claim 5, wherein the program instructions when executed are further configured to:

add the voltage generated based on the flow of the three-phase current to the speed of the rotor and acquiring the flux of the rotor.

9. A method for controlling driving of a brushless direct current electric motor (BLDC) of an electric water pump, comprising the steps of:

estimating, by a controller, an initial position of a rotor based on a current magnitude detected in a three-phase coil wound on a stator;

converting, by the controller, a current magnitude that reflects a rotational angle of the rotor with respect to the initial position into two direct currents based on a three-phase current, and outputting the converted direct currents;

acquiring, by the controller, the rotational angle, a speed, a flux and a torque of the rotor based on values of the three-phase current, a voltage generated based on flow of the three-phase current, a predetermined coil resistance, and an inductance input; and

adjusting, by the controller, a speed of the motor based on the acquired rotational angle, speed, flux, and torque of the rotor,

wherein the current magnitude generated in the three-phase coil wound on the stator and the current magnitude generated in a magnet of the rotor are converted, by a controller, into output signals of a DC waveform based on the three-phase current.