WO2017018832A1

WO2017018832A1 - Motor driving apparatus

Info

Publication number: WO2017018832A1
Application number: PCT/KR2016/008300
Authority: WO
Inventors: 이병상; 손홍엽
Original assignee: 주식회사 레보텍
Priority date: 2015-07-30
Filing date: 2016-07-28
Publication date: 2017-02-02
Also published as: KR101731564B1; KR20170014621A

Abstract

The present invention relates to a motor driving apparatus comprising: a control unit for generating a gate control signal as a pulse width modulation (PWM) signal necessary for driving a motor; a gate driver for outputting a pair of driver signals by means of amplifying the gate control signal; and an inverter for driving the motor by means of generating a driving voltage from an output contact point as the driver signals are applied and drive transistors are selectively switched, wherein an impedance matching unit, for removing reflected waves, is inserted between the gate driver and the inverter.

Description

Motor drive

The present invention relates to a motor drive device, and more particularly to a motor drive device that can minimize the reflected electromagnetic noise.

The inverter of the motor driving device controls the motor by a pulse width modulation method by high speed switching (ON / OFF) of the power switching semiconductor element. In this case, the inverter causes electromagnetic noise having a frequency band of several tens of MHz according to the fast switching operation due to the characteristics of the power switching semiconductor device. The electromagnetic noise has a characteristic of increasing as the rate of change of the voltage (or current) increases during the switching operation of the power switching semiconductor device.

Electromagnetic noise generated from the inverter of the motor driving device affects the peripheral electronic devices and causes disturbances in the performance of the electronic devices. Furthermore, in automobiles, it is possible to anticipate damage to life and property due to malfunction of the electronic device when the electromagnetic noise generated from the inverter of the motor driving device is not suppressed. For example, a sudden start of a vehicle is known as a representative case due to malfunction of the electronic device. For this reason, the inverter of the motor driving apparatus should mainly reduce the electromagnetic noise (especially the electromagnetic noise of the radio frequency band) due to the high-speed switching operation of the power switching semiconductor element to prevent malfunction of the electronic device due to electromagnetic interference.

Accordingly, in order to intensively reduce electromagnetic noise of radio frequency bands (especially, AM and FM frequency bands) generated from an inverter in a motor driving apparatus, each capacitor is based on a capacitor forming an X-cap connected to both ends of a power source. An RC snubber circuit is inserted into the switching element to reduce the frequency of the radio frequency band.

However, the snubber circuit is configured in such a manner that the drain and the source are connected in parallel to the rear ends of the pair of switching elements constituting the inverter. That is, in the related art, an off-chip element is attached to the rear end of the motor driving apparatus. However, the use of such off-chip elements not only incurs additional costs, but also inconvenient that a separate installation space must be provided.

The present invention provides a motor driving apparatus that does not require the use of a separate off-chip device for electromagnetic wave noise removal.

The present invention provides a motor driving apparatus, comprising: a control unit for generating a gate control signal with a pulse width modulation signal PWM required for driving a motor; A gate driver for amplifying the gate control signal and outputting a pair of driver signals; And an inverter configured to drive the motor by generating a driving voltage from an output connection point while the driving transistors are selectively switched as the driver signal is applied, wherein an impedance matching unit is inserted between the gate driver and the inverter to remove the reflected wave. Is designed in the form.

The motor driving apparatus according to the present invention is designed in the form of a single chip impedance matching unit to remove the electromagnetic noise, it is possible to use the cost and space efficiently because there is no need for a separate off-chip device.

1 is a circuit diagram illustrating a motor driving apparatus according to an embodiment of the present invention.

2 is an exemplary view of a motor driving apparatus according to the present invention.

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

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce the present invention.

In the following description of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the gist of the embodiments of the present invention, the detailed description thereof will be omitted.

Terms used throughout the specification are terms defined in consideration of functions in the embodiments of the present invention, and may be sufficiently modified according to the intention, custom, etc. of the user or operator, and the definitions of these terms are used throughout the specification of the present invention. It should be made based on the contents.

1 is a circuit diagram showing a motor driving apparatus according to an embodiment of the present invention, Figure 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 to apply a driving voltage to the motor 40. According to an embodiment of the present invention, in order to remove the reflected wave noise generated in the inverter 30, the impedance matching unit 100 is inserted between the gate driver 20 and the inverter 30 is designed as a one-chip Have

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

The gate driver 20 outputs the gate control signals HIN and LIN output from the controller 10 to drive the upper and lower driver transistors 41 and 42 constituting the inverter 30. Convert to (HO, LO) and output.

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

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

The inverter 30 has an upper drive transistor (Q1) 31 and a lower drive transistor (Q2) 32 so that the upper drive transistors form an output circuit connected to the motor 40 between the power supply VDD and ground, respectively. The sources of (Q1) 21 are respectively connected to the drains of the lower drive transistors (Q2) 32, and an output signal to the motor 40 is generated from the connection point. Here, the driving transistors Q1 and Q2 are formed of n-type power MOS FETs operating as switching elements, and the driving transistors are generated from the motor 40 at the turn-off between the drain and the source of the driving transistors Q1 and Q2. Diodes D1 and D2 for freewheeling the counter electromotive force are connected in the reverse direction. In addition, the resistors R1 and R2 connected between the gate and the source of the driving transistors Q1 and Q2 are high capacitance resistors to prevent the FET from malfunctioning due to the charge charged in the parasitic capacitor formed between the gate and the source of the FET. To discharge the charge charged in the parasitic capacitor. Such resistors R1 and R2 may be omitted.

As described above, in the present invention, the impedance matching unit 100 is designed to be positioned in front of the inverter 30. The impedance matching unit 100 includes the impedance and the load of the driver 20 constituting the signal source impedance Zin. It is designed to match the impedances of the inverter 30 and the motor 40 constituting the impedance ZL. In addition, 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. It includes.

2 shows an example of a filter circuit, in which a capacitor C and an inductor L are connected in parallel, and one end of the filter circuit is connected to a connection point of a gate terminal of the gate driver 20 and the

driving transistors

31 and 32. The other end has a form connected to the source terminals of the

driving transistors

31 and 32 and removes noise of a signal corresponding to reflected wave noise.

Here, the load impedance ZL may be obtained through information provided by a manufacturer as an impedance value of the

driving transistors

31 and 32 and an impedance value of the motor 40, or may be measured by an LCR meter. In addition, the signal source impedance Zin may be obtained through information provided by a manufacturer as a gate driver output value, or may be obtained by measurement. Then, the matching impedance Zo is selected such that the reflection coefficient T ₀ in Equation 1 below is close to zero using the input terminal impedance Zin and the output terminal impedance ZL obtained as described above. do. At this time, the matching impedance Zo is selected in consideration of the maximum error of 10%.

Referring to FIG. 3, when the signal source impedance (Z) and the load impedance (Z) do not match, it can be seen that unwanted signals such as edge rate change, ringing, EMI and crosstalk occur in the waveform at the load. . However, when the signal source impedance Z and the load impedance Z match 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 required for driving the motor;

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 selectively switching the driving transistors as the driver signal is applied.

And an impedance matching part is inserted between the gate driver and the inverter to remove the reflected wave.
The method of claim 1, wherein the impedance matching unit

And a signal source impedance corresponding to the gate driver and load impedances corresponding to the inverter and the motor.
The method of claim 1, wherein the inverter

An upper drive transistor and a lower drive transistor;

The impedance matching unit

And an upper filter inserted between the gate driver and an upper driving transistor, and a lower filter inserted between the gate driver and the lower driving transistor.