KR101731564B1

KR101731564B1 - Motor Driving Apparatus

Info

Publication number: KR101731564B1
Application number: KR1020150108287A
Authority: KR
Inventors: 이병상; 손홍엽
Original assignee: 주식회사 레보텍
Priority date: 2015-07-30
Filing date: 2015-07-30
Publication date: 2017-05-11
Also published as: KR20170014621A; WO2017018832A1

Abstract

The present invention relates to a motor driving apparatus, comprising: a control unit for generating a gate control signal with a pulse width modulation signal (PWM) necessary for driving a motor; A gate driver for amplifying the gate control signal and outputting a pair of driver signals; And an inverter for driving the motor by generating a driving voltage from an output connection point while the driving transistors are selectively switched in response to the application of the driver signal. An impedance matching unit for removing reflected waves is inserted between the gate driver and the inverter .

Description

[0001] The present invention relates to a motor driving apparatus,

The present invention relates to a motor driving apparatus, and more particularly, to a motor driving apparatus capable of minimizing reflected electromagnetic noise.

The inverter of the motor driving apparatus controls the motor by the pulse width modulation method by the fast switching (ON / OFF) of the power switching semiconductor element. At this time, due to the characteristics of the power switching semiconductor device, the inverter induces electromagnetic noise having a frequency band of several tens of MHz according to the high-speed switching operation. Such electromagnetic noise has a characteristic in which, as the rate of change of voltage (or current) per unit time increases in switching operation of the power switching semiconductor device.

The electromagnetic noise generated from the inverter of such a motor driving device affects peripheral electronic devices, which causes the performance of electronic devices to be impaired. Further, in the automobile, if the electromagnetic noise generated from the inverter of the motor driving apparatus is not suppressed, damage to human life and property due to malfunction of the electronic device can be anticipated. For example, sudden occurrence of an automobile is known as a representative example of malfunction of an electronic device. For this reason, the inverter of the motor driving apparatus must mainly reduce the electromagnetic noise (particularly, the electromagnetic noise in the radio frequency band) due to the high-speed switching operation of the power switching semiconductor device to prevent malfunction of the electronic device due to electromagnetic interference.

Accordingly, conventionally, in order to intensively reduce the electromagnetic noise of a radio frequency band (particularly, AM and FM frequency bands) generated from an inverter in a motor driving apparatus, it is necessary to use a capacitor forming an X- An RC snubber circuit is inserted in the switching device to reduce the frequency of the radio frequency band.

However, such a snubber circuit is configured in such a manner that the snubber circuit is connected between the drain and the source in parallel at the rear end of the pair of switching elements constituting the inverter. That is, conventionally, a separate off-chip device is attached to the rear end of the motor driving device. However, there is an inconvenience that a separate installation space must be provided as well as an additional cost due to the use of off-chip devices.

Published Patent Publication No. 10-2009-0048236, May 23, 2009. open

The present invention provides a motor driving apparatus which does not require the use of a separate off-chip element for eliminating electromagnetic noise.

The motor driving apparatus according to the present invention designs the impedance matching unit for eliminating electromagnetic noise in a single chip type, so that a separate chip off-chip element is not required, and cost and space can be efficiently used.

1 is a circuit diagram showing a motor driving apparatus according to an embodiment of the present invention.
2 is an exemplary diagram of a motor driving apparatus according to the present invention.
3 is a diagram for explaining an example of a waveform change according to an impedance.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

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.

The terms used throughout the specification are defined in consideration of the functions in the embodiments of the present invention and can be sufficiently modified according to the intentions and customs of the user or the operator. It should be based on the contents of.

FIG. 1 is a circuit diagram showing a motor driving apparatus according to an embodiment of the present invention, and FIG. 2 is an exemplary view of a motor driving apparatus according to the present invention.

Referring to FIG. 1, the motor driving apparatus includes a controller 10, a driver 20, and an inverter 30, and applies a driving voltage to the motor 40. The impedance matching unit 100 is inserted between the gate driver 20 and the inverter 30 in order to remove the reflected wave noise generated in the inverter 30 according to an embodiment of the present invention, I have.

The control unit 10 generates the gate control signals HIN and LIN with the pulse width modulation signal PWM necessary for driving the motor.

The gate driver 20 supplies the gate control signals HIN and LIN output from the control unit 10 to the upper and lower driver outputs 41 and 42 which are capable of driving the upper and lower driving transistors 41 and 42 constituting the inverter 30, (HO, LO) and outputs it.

2, the gate driver 20 includes a VCC terminal, a HIN terminal, a LIN terminal, a GND terminal, a BS terminal, an HO terminal, a VS terminal, and an LO terminal. Also, a bootstrap resistor Rboot and a diode Dboot may be connected between the VCC terminal and the VS terminal, and a bootstrap capacitor CB may be connected between the BS terminal and the VS terminal. Here, as the internal power supply, for example, 15 V may be supplied to the VCC terminal.

The PWM signal is input from the control unit 10 to the HIN terminal and the LIN terminal. For example, a square wave voltage of 5 V is applied to the HIN terminal and a square wave voltage of 5 V is applied to the LIN terminal. Here, the square wave voltage inputted to the HIN terminal and the rectangular wave voltage inputted to the LIN terminal are approximately 180 degrees in phase difference. The 5V square wave signal applied to the HIN terminal is shifted and outputted so as to have a level similar to the level of the external power supply. The HO terminal is connected to the gate electrode of the upper driving transistor Q1, and the LO terminal is connected to the gate electrode of the lower driving transistor Q2.

The inverter 30 is configured so that the upper driving transistor Q1 31 and the lower driving transistor Q2 32 each form an output circuit connected to the motor 40 between the supply voltage VDD and the ground, (Q1) 31 are respectively connected to the drains of the lower driving transistors Q2 and 32, and an output signal for the motor 40 is generated from the connection point. Here, the driving transistors Q1 and Q2 are formed of an n-type power MOS FET that operates as a switching element. Between the drain and the source of the driving transistors Q1 and Q2, Diodes D1 and D2 for freewheeling the back electromotive force are connected in the reverse direction. The resistors R1 and R2 connected between the gate and the source of the driving transistors Q1 and Q2 are high capacity resistors and prevent the FET from malfunctioning due to the charges charged in the parasitic capacitors formed between the gate and the source of the FET So that the charges charged in the parasitic capacitor are discharged. These resistors R1 and R2 may be omitted.

The impedance matching unit 100 may be designed such that the impedance of the driver 20 constituting the signal source impedance Zin and the impedance of the load 20 constituting the signal source impedance Zin are different from each other. Is designed to match the impedances of the inverter (30) and the motor (40) constituting the impedance (ZL). The impedance matching unit 100 includes an upper filter 110 inserted between the gate driver 20 and the upper driving transistor 31 and a lower filter 120 inserted between the gate driver and the lower driving transistor 32, .

2 shows an example of a filter circuit in which a capacitor C and an inductor L are connected in parallel and one end is connected to the gate terminal of the gate driver 20 and the gate terminals of the driving transistors 31 and 32 And the other end is connected to the source terminals of the driving transistors 31 and 32 to remove the noise of the signal corresponding to the reflected noise.

Here, the load impedance ZL can be obtained through the information provided by the manufacturer with the impedance value of the drive transistors 31 and 32 and the impedance value of the motor 40, or can be measured by the LCR meter. Further, the signal source impedance Zin can be obtained through information provided by a manufacturer as a gate driver output value or can be obtained by measurement. Then, using the input terminal impedance Zin and the output terminal impedance ZL obtained as described above, the reflection coefficient (

) Is close to 0, the matching impedance Zo is selected. At this time, the matching impedance Zo is selected in consideration of the maximum error of 10%.

&Quot; (1) "

3 is a diagram for explaining an example of a waveform change according to an impedance.

Referring to FIG. 3, when the signal source impedance Z and the load impedance Z do not match, undesired signals such as a change in edge rate, ringing, EMI, and crosstalk are generated in the waveform at the load . However, when the signal source impedance Z and the load impedance Z are matched to the impedance matching impedance Zo, it can be seen that no noise signal is generated in the waveform at the load.

Claims

A control unit for generating a gate control signal with a pulse width modulation signal (PWM) necessary for motor driving;
A gate driver for amplifying the gate control signal and outputting a pair of driver signals; And
And an inverter for driving the motor by generating a driving voltage from an output connection point while one of the upper driving transistor and the lower driving transistor is selectively switched as the driver signal is applied,
An impedance matching unit for removing reflected waves between the gate driver and the inverter is inserted and designed in the form of one chip with the control unit, the driver and the inverter,
The impedance matching unit
An upper filter inserted between the gate driver and the upper driving transistor, and a lower filter inserted between the gate driver and the lower driving transistor,
Each of the upper and lower filters
And a capacitor and an inductor are connected to each other.

The apparatus of claim 1, wherein the impedance matching unit
Wherein the signal source impedance corresponding to the gate driver is designed to match the load impedance corresponding to the inverter and the motor.

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