KR20170005910A - Operation control circuit for motor of electronic power steering - Google Patents

Operation control circuit for motor of electronic power steering Download PDF

Info

Publication number
KR20170005910A
KR20170005910A KR1020150095673A KR20150095673A KR20170005910A KR 20170005910 A KR20170005910 A KR 20170005910A KR 1020150095673 A KR1020150095673 A KR 1020150095673A KR 20150095673 A KR20150095673 A KR 20150095673A KR 20170005910 A KR20170005910 A KR 20170005910A
Authority
KR
South Korea
Prior art keywords
switch
relay
switches
motor
voltage difference
Prior art date
Application number
KR1020150095673A
Other languages
Korean (ko)
Inventor
이광형
금기섭
Original Assignee
주식회사 만도
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 만도 filed Critical 주식회사 만도
Priority to KR1020150095673A priority Critical patent/KR20170005910A/en
Publication of KR20170005910A publication Critical patent/KR20170005910A/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
    • B62D5/0481—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such monitoring the steering system, e.g. failures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
    • B62D5/046—Controlling the motor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W50/02—Ensuring safety in case of control system failures, e.g. by diagnosing, circumventing or fixing failures
    • B60W50/0205—Diagnosing or detecting failures; Failure detection models
    • B60W2050/021—Means for detecting failure or malfunction

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)
  • Control Of Electric Motors In General (AREA)

Abstract

The present invention relates to a motor drive control circuit of an electric power steering apparatus, and more particularly, to a motor drive control circuit of a motor-driven steering apparatus, comprising: a relay connected in series with a battery and controlling a power supply provided from a battery; At least one pair of switches connected between the battery and the motor, the pair of switches being arranged in pairs relative to each phase of the motor; A switch monitoring unit for monitoring a voltage difference between both ends of at least one pair of switches; A relay monitoring unit monitoring a voltage difference between both ends of the relay; And a power control part for determining that at least one of the switches is abnormal if a voltage difference between both ends of at least one of the switches and a voltage difference between both ends of the relay are out of a predetermined range. As a result, the state of the shoot through state of the switch can be accurately determined. Therefore, when the motor is not in the shoot through state, it is possible to prevent the driver from stopping the drive, thereby minimizing the inconvenience of the driver.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a motor drive control circuit for an electric power steering apparatus,

[0001] The present invention relates to a motor drive control circuit of an electric steering system, and more particularly, to a motor drive control circuit for an electric steering system, which detects three pairs of switches connected to respective phases of a motor and a voltage flowing through the relays, The present invention relates to a motor drive control circuit for an electric steering system.

Generally, a vehicle is provided with an electronic power steering (EPS) to easily steer the steering wheel, and EPS assists the steering force of the driver by using the rotational force of the motor.

This EPS controls driving of the motor according to the torque and the steering angle sensed when the steering wheel rotates, and the motor receives power from the battery.

The motor can be configured as a three-phase motor with three phases of U, V, W phases connected to a common molded connection point. As the motor has three phases, a pair of switches is connected to each phase of the motor to intermittently supply power supplied from the battery. That is, three-phase motors are connected to three pairs of switches, and three pairs of switches are alternately turned on and off so that the motors can be driven.

Of these three pairs of switches, three switches connected to the positive electrode of the battery are called upper switches, and three switches connected to the negative electrode of the battery are called lower switches. One upper switch and one lower switch are turned on at the same time for driving the motor, and the upper switch and the lower switch must be connected to each other on a different phase. If the upper switch connected to one phase and the lower switch are turned on at the same time, a short circuit may occur in the motor and the circuit, and the motor and the circuit may be damaged.

On the other hand, when one of the upper switch and the lower switch is short-circuited, when the upper switch and the lower switch are alternately turned on, a shoot-through occurs in which the upper switch and the lower switch connected to one phase are turned on at the same time . Accordingly, it is necessary to accurately detect a short between the upper switch and the lower switch.

The present invention proposes a motor drive control circuit of an electric steering system which can determine whether or not three switches connected to respective phases of a motor are shot-off.

The object of the present invention can be achieved by a battery charger comprising: a relay connected in series with a battery and controlling a power supply provided from the battery; At least a pair of switches connected between the battery and the motor, the pair of switches being arranged in pairs relative to each phase of the motor; A switch monitoring unit monitoring a voltage difference between both ends of each of the at least one pair of switches; A relay monitoring unit monitoring a voltage difference between both ends of the relay; And a power controller for determining that the at least one switch is abnormal when a voltage difference between both ends of at least one of the switches and a voltage difference between both ends of the relay are out of a predetermined range, Can be achieved by a motor drive control circuit of the apparatus.

According to the present invention, the voltage difference between the both ends of the upper switch and the lower switch can be used as a primary difference, and the voltage difference between the ends of the relay can be used as a secondary to accurately determine the state of a shoot through. That is, it is possible to more accurately determine the shoot through state by double checking. Therefore, it is possible to prevent the driver from stopping the motor despite the non-shoot through state, thereby minimizing the driver's inconvenience. In addition, since the shoot through can be accurately determined, it is possible to reduce the risk of accidents by stopping the drive of the motor in the shoot through state.

1 is a block diagram of a motor drive control circuit of an electric power steering apparatus according to the present invention,
FIG. 2 is a flowchart showing a process of judging and controlling a shoot through of the upper switch and the lower switch in the motor drive control circuit of FIG. 1;

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

1 is a motor drive control circuit of an electric steering system according to the present invention.

The motor drive control circuit can detect a short-circuit between each switch connected to the motor 5 and a voltage flowing through the relay.

The motor 5 controlled by this motor drive control circuit is a three-phase motor having three phases of U phase, V phase and W phase connected to a common molded connection point.

This motor drive control circuit includes three pairs of switches 21, 22, 23, 31, 32, and 33 for providing power from the battery 10 to each phase of the three-phase motor, three pairs of batteries 10, A relay 40 connected between the switches 21, 22, 23, 31, 32 and 33 of the battery 10 to supply power from the battery 10 to the motor 5, A relay monitoring unit 45 for detecting a voltage flowing through the relay 40, and a pair of switches 21, 22, 23, 31, 32, and 33).

Three pairs of switches 21, 22, 23, 31, 32, and 33 connected to respective phases of the three-phase motor can be operated so that power is sequentially supplied to each phase under the control of the power source control unit 50 . Three switches, one end of which is connected to the positive side of the battery 10 power source and the other end which is connected to the U phase, V phase and W phase of the motor 5 is referred to as an upper switch, and each of the upper switches 21 22, and 23 are connected to the U-phase, V-phase, and W-phase, respectively, with the first upper switch 21, the second upper switch 22, the third upper switch 23 ).

One end of each pair of switches is connected to the cathode side of the battery 10 power source, and the other end is connected to each phase of the motor 5 as a lower switch, and each of the U, V, and W phases The switches 31, 32, and 33 are referred to as a first lower switch 31, a second lower switch 32, and a third lower switch 33, respectively.

The upper switches 21, 22 and 23 and the lower switches 31, 32 and 33 are alternately turned on to supply power to each phase of the three-phase motor 5, And the lower switch are simultaneously turned on or short-circuited, a shoot through occurs and a short circuit occurs in the power supply control circuit. For example, when the first upper switch 21 and the first lower switch 31 are simultaneously turned on or short-circuited, a short circuit occurs in the power supply control circuit.

The upper switches 21, 22 and 23 and the lower switches 31, 32 and 33 maintain the turn-off state when the motor 5 is not operated and can be constituted by a field effect transistor have.

The relay 40 is connected between the positive side of the power source of the battery 10 and the upper switches 21, 22 and 23 and controls the power supplied from the battery 10 to the motor 5. [ When the motor 5 is operated, the relay 40 is turned on by the on / off state of the upper switches 21, 22, 23 and the lower switches 31, The power from the battery 10 is supplied to each phase of the battery 5.

The switch monitoring unit 35 detects the voltage state of the first to third upper switches 21, 22 and 23 and the first to third lower switches 31, 32 and 33, Off state, or a short state.

When the switch is on, the voltage difference between both ends of the switch is detected to be close to zero. When the switch is off, a voltage difference across the switch is detected adjacent to the voltage provided by the battery. On the other hand, when the switch is in the short state, since the amount of the current flowing through the switch increases, the voltage across the switch increases and the voltage difference across the switch increases. Therefore, the voltage difference between both ends detected when the switch is in the short state is much smaller than when the switch is in the off state, but a larger value is detected than when the switch is in the on state.

In order to detect the short state of such a switch, the switch monitoring unit 35 may use a preset switch threshold voltage value, and the switch threshold voltage value is set to a value larger than the voltage difference across the switches flowing when the switch is in the ON state And is set to a value smaller than the voltage difference across the switch when the switch is in the OFF state.

The switch monitoring unit 35 can determine that the switch is short-circuited if the voltage difference across the switch is greater than the switch threshold voltage value and less than the voltage difference across the switch where the switch is detected to be off.

The switching monitoring unit 35 may compare the voltage difference between the both ends of the switch with the threshold voltage value only when the switch is in the ON state in accordance with the switch control command to determine whether a switch short occurs. For example, the switch short state in which the voltage difference increases due to abnormal transient currents and the switch off state in which the steady voltage difference is large (for example, battery voltage level) may not be distinguished using only the voltage difference. Therefore, the switch monitoring unit 35 determines whether or not the switch is short-circuited by using the voltage difference and the threshold voltage at both ends of the switch only when the switch control command is switched on (for example, Gate input voltage level = 1) .

If the switch monitoring unit 35 determines that the threshold voltage value is greater than the switch threshold voltage value at both ends of the switch, the switch monitoring unit 35 can provide the determination result to the power control unit 50. [

On the other hand, sometimes the AC component noise occurs at the time of on-off due to the characteristics of the FET, and the switch monitoring unit 35 can determine that the switch is in a short state even though the switch is not in the short state due to noise. When the switch monitoring unit 35 determines that the vehicle is in the short state and cuts off the power supplied to the motor 5, the driver does not receive the auxiliary steering force of the steering wheel. do.

In the present invention, the voltage difference across the relay 40 is monitored in order to prevent a case where the short state is erroneously determined, and the short state is doubly determined.

The relay monitoring unit 45 can judge whether or not a pair of the upper switch and the lower switch connected to the same phase are in the turned-on shoot-through state by monitoring the voltage difference across the relay 40. [

Since the relay 40 is always turned on, an excessive current flows to the drive control circuit and an excessive current flows to the relay 40 when the switch 40 is in the shoot through state. Accordingly, since the voltage value flowing through the relay 40 increases, the voltage difference across the relay 40 becomes large.

Accordingly, the relay monitoring unit 45 can determine that an excessive voltage flows to the drive control circuit when the voltage difference across the relay 40 exceeds a preset relay threshold voltage value V reth . Even if it is determined that an excessive voltage flows in the drive control circuit, the switch monitoring unit 35 can detect at least one of the first to third upper switches 21, 22, 23 and the first to third lower switches 31, Only when it is determined that one has been short-circuited.

The relay threshold voltage value used in the relay monitoring unit 45 is calculated by the following equation (1).

[Equation 1]

V reth = (I max * R relay ) + V tol

Here, I max represents a maximum voltage flowing through the relay 40, and R relay represents a resistance value when the relay 40 is on. And V tol represents a margin voltage considering micro-variations of the voltage flowing through the relay 40. Fig.

The relay monitoring unit 45 can transmit the result to the power control unit 50 when the voltage difference across the relay 40 exceeds the relay threshold voltage value V reth .

The power supply control unit 50 controls the voltage supplied to the motor 5 in accordance with a control signal from the ECU and controls the relay 40, the first to third upper switches 21, 22, The operation of the third lower switch 31, 32, 33 can be controlled.

In addition, the power control unit 50 determines whether or not a shoot-through has occurred according to the results detected by the switch monitoring unit 35 and the relay monitoring unit 45, and can take appropriate measures in case of a shoot through.

The power supply control unit 50 controls the switch monitoring unit 35 so that the voltage between both ends of at least one of the first to third upper switches 21, 22, 23 and the first to third lower switches 31, If it is detected that the vehicle exceeds the switch threshold voltage value, the relay monitoring unit 45 can check the detected result to determine whether the vehicle is in a shoot-through state. That is, the power supply control unit 50 determines whether the voltage difference between both ends of the switches of the first to third upper switches 21, 22, and 23 and the first to third lower switches 31, 32, And when the voltage difference between both ends of the relay 40 in the relay monitoring unit 45 exceeds the relay threshold voltage value V reth , the upper switch connected to one phase and the lower switch are both shorted to the short- throw state It can be judged.

The power control unit 50 can protect the drive control circuit by turning off the relay 40 and stopping the driving of the motor 5 when the power control unit 50 determines that it is in the shoot through state. In addition, when the driving of the motor 5 is stopped, the driver directly operates the steering wheel without assistance of the motor 5, so that an accident caused by the driving error of the motor 5 can be prevented.

A process of judging and controlling the shoot through of the upper switch and the lower switch in the motor drive control circuit of the electric type steering apparatus having such a configuration will be described with reference to FIG.

When the vehicle is started, the power supply control unit 50 turns on the relay 40 and turns on the first to third upper switches 21, 22, and 23 connected to the motor 5 in accordance with an instruction from the ECU, The third lower switches 31, 32, and 33 are turned on and off.

When the vehicle is started as described above, the switch monitoring unit 35 monitors the voltage difference between the first to third upper switches 21, 22, 23 and the first to third lower switches 31, 32, 33 , And the relay monitoring unit 45 monitors the voltage difference between the terminals of the relay 40.

The switch monitoring unit 35 detects that the voltage difference between both ends of at least one of the first to third upper switches 21, 22 and 23 and the first to third lower switches 31, 32 and 33 is greater than the switch threshold voltage value The switch monitoring unit 35 transmits the detection result to the power control unit 50. [

Then, the power supply control unit 50 checks whether the voltage difference between the terminals of the relay 40 is larger than the relay threshold voltage value V reth in the relay monitoring unit 45.

If the voltage difference across the relay 40 is greater than the relay threshold voltage value V reth , the power supply control unit 50 determines that it is in the shoot-through state. Then, the power supply control unit 50 turns off the relay 40 and cuts off the power supplied to the motor 5. [

As described above, according to the motor drive control circuit of the electric power steering apparatus according to the present invention, the first to third upper switches 21, 22, and 23 and the first to third lower switches 31, A short circuit is firstly determined using the voltage difference between the ends of the switch and a short circuit state of the switch is secondarily determined using the voltage difference across the relay 40 in a state where at least one switch is determined to be short, It can be judged accurately. That is, it is possible to more accurately determine the shoot through state by double checking, so that it is possible to prevent the drive of the motor 5 from being stopped despite the non-shoot through state. Therefore, the inconvenience of the driver due to the stop of the driving of the motor 5 can be minimized. In addition, since the shoot through can be accurately determined, the driving of the motor 5 can be stopped in the shoot through state, thereby reducing the risk of accidents.

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and portions of the standard documents are added to or contained in the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

5: Motor 10: Battery
21: first upper switch 22: second upper switch
23: third upper switch 31: first lower switch
32: second lower switch 33: third lower switch
35: Switch monitoring section 40: Relay
45: Relay monitoring unit 50: Power control unit

Claims (6)

A relay connected in series with the battery and controlling the power supply provided from the battery;
At least a pair of switches connected between the battery and the motor, the pair of switches being arranged in pairs relative to each phase of the motor;
A switch monitoring unit monitoring a voltage difference between both ends of each of the at least one pair of switches;
A relay monitoring unit monitoring a voltage difference between both ends of the relay; And
And a power controller for determining that the at least one switch is abnormal if a voltage difference between both ends of at least one switch among the switches and a voltage difference between both ends of the relay are out of a predetermined range, Of the motor drive control circuit. The method according to claim 1,
Wherein the power supply control unit determines that the at least one switch is abnormal only when at least one of the switches out of the preset range is in the on state. The method according to claim 1,
Wherein the power supply control unit determines that a shoot through occurs when a voltage difference between both ends of at least one of the switches exceeds a preset switch threshold voltage value and a voltage difference between both ends of the relay exceeds a preset relay threshold voltage value And the motor drive control circuit of the electric power steering apparatus. The method of claim 3,
Wherein the switch threshold voltage value is formed between a voltage value across the switch when each switch is in an ON state and a voltage across the switch when each switch is in an OFF state. Control circuit. The method of claim 3,
Wherein the relay threshold voltage value is calculated by adding a margin voltage to a value obtained by multiplying a maximum current value flowing through the relay by a resistance value of an ON state of the relay. The method of claim 3,
Wherein the power control unit turns off the relay to shut off power supplied to the motor from the battery when it is determined that the shoot through has occurred.
KR1020150095673A 2015-07-06 2015-07-06 Operation control circuit for motor of electronic power steering KR20170005910A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020150095673A KR20170005910A (en) 2015-07-06 2015-07-06 Operation control circuit for motor of electronic power steering

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020150095673A KR20170005910A (en) 2015-07-06 2015-07-06 Operation control circuit for motor of electronic power steering

Publications (1)

Publication Number Publication Date
KR20170005910A true KR20170005910A (en) 2017-01-17

Family

ID=57990351

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020150095673A KR20170005910A (en) 2015-07-06 2015-07-06 Operation control circuit for motor of electronic power steering

Country Status (1)

Country Link
KR (1) KR20170005910A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019117555A1 (en) * 2017-12-11 2019-06-20 주식회사 엘지화학 Short-circuit prevention device and method
KR20200059858A (en) * 2018-11-22 2020-05-29 현대모비스 주식회사 Apparatus and method for determining relay state of motor driven power steering system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019117555A1 (en) * 2017-12-11 2019-06-20 주식회사 엘지화학 Short-circuit prevention device and method
CN110741521A (en) * 2017-12-11 2020-01-31 株式会社Lg化学 Apparatus and method for preventing short circuit
CN110741521B (en) * 2017-12-11 2021-12-21 株式会社Lg化学 Apparatus and method for preventing short circuit
US11269018B2 (en) 2017-12-11 2022-03-08 Lg Energy Solution, Ltd. Apparatus and method for preventing short circuit
KR20200059858A (en) * 2018-11-22 2020-05-29 현대모비스 주식회사 Apparatus and method for determining relay state of motor driven power steering system

Similar Documents

Publication Publication Date Title
EP3193443B1 (en) Inverter device for driving multi-phase ac motor
US8232752B2 (en) Electric motor control apparatus
EP2662973B1 (en) Motor control device and electric power steering device
US9543857B2 (en) Load driving device with failure detection
WO2010032705A1 (en) Motor controller and electric power steering device
EP3002865B1 (en) Inverter control apparatus, power conversion apparatus, and electric vehicle
CN108123656B (en) Detection and mitigation of inverter errors in steering system motors
US11136062B2 (en) Control for electric power steering
US10829147B2 (en) Power conversion device, motor drive unit, and electric power steering device
CN110231560B (en) Inductive load control device
JP5920171B2 (en) Motor inverter
US10381959B2 (en) Motor control device
KR20170005910A (en) Operation control circuit for motor of electronic power steering
US10014815B2 (en) Control apparatus and control method of AC rotary machine
KR101948109B1 (en) Apparatus for diagnosing motor failure and method thereof
EP3419163A1 (en) Detection apparatus
US10404202B2 (en) Electronic control device and control method thereof
JP2016167971A (en) Motor controller and electrically-driven power steering device having the same
CN111130429A (en) Power conversion device and power conversion system
KR20190106181A (en) Methods for controlling EPS that cuts motor drive power when overcurrent occurs
KR102159110B1 (en) Apparatus for driving motor for a vehicle
CN110622411B (en) Motor driving device and method, electric power steering device, and recording medium
KR100982868B1 (en) Motor control system of electric lift truck with fault detection of line contactor and power line
JP2015226432A (en) Drive device for rotary electric machine
JPWO2023281727A5 (en)