KR20180089767A - Power transforming apparatus and air conditioner including the same - Google Patents

Abstract

The present invention relates to a power conversion device. Especially, the present invention relates to a power conversion device including a function for protecting a switching element, and an air conditioning unit including the same. The power conversion device comprises: a rectifying part rectifying an alternating current power; a first switching element connected to the rectifying part, and connected to a ground through sensing resistance; a driving part driving the first switching element; an element protecting part connected to a gate terminal of the first switching element, preventing malfunction of the first switching element; and a control part applying a first driving signal to the first switching element, applying a second driving signal to the element protecting part, and connecting the gate terminal of the first switching element to the ground through the element protecting part when turning off the first switching element.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion apparatus and an air conditioner including the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion apparatus, and more particularly, to a power conversion apparatus including a function of protecting a switching element and an air conditioner including the same.

Generally, a compressor of an air conditioner uses a motor as a driving source. These motors are supplied with AC power from a power conversion device.

Such a power conversion apparatus is generally known to include a rectifying section, a power factor control section, and an inverter.

First, the commercial voltage of the AC output from the commercial power source is rectified by the rectifying part. The voltage rectified in this rectifying part is supplied to a power converting part such as an inverter. At this time, the power converting unit generates AC power for driving the motor by using the voltage output from the rectifying unit.

In some cases, a DC-DC converter for improving the power factor may be provided between the rectification part and the inverter.

Such a converter or inverter is provided with a switching element for switching operation.

Such a switching device may be driven by an on / off operation by a driving signal of a pulse width modulation (PWM) method.

However, in some cases, the switching element may be turned on even in the off period due to noise or other causes. If such a malfunction occurs, the switching element may be damaged by the overvoltage or the peak voltage, and the entire circuit board of the portion connected to the switching element may be damaged.

Therefore, there is a need for a method that can effectively prevent such a malfunction of the switching element.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power conversion apparatus and an air conditioner including the same that can prevent a switching element from being turned on at an off timing.

According to a first aspect of the present invention, there is provided a plasma processing apparatus comprising: a rectifying section for rectifying an AC power source; A first switching device connected to the rectifying part and connected to the ground through a sense resistor; A driving unit for driving the first switching device; A device protection unit connected to a gate terminal of the first switching device to prevent a malfunction of the first switching device; And applying a first driving signal to the first switching device and applying a second driving signal to the device protecting unit to turn off the gate terminal of the first switching device when the first switching device is off, And a control unit connected to the ground through the protection unit.

Here, the device protection unit may include a second switching device having a base end connected to the control unit, a collector end connected to the gate terminal of the first switching device, and an emitter end connected to the ground.

The controller may apply a first driving signal to the first switching element and a second driving signal having a phase difference of 180 degrees with the first driving signal to the second switching element.

Here, the first switching device may be a converter switching device included in the power factor control unit or an inverter switching device included in the inverter.

Here, the device protection unit may prevent the voltage (Vce) at the collector-emitter end of the first switching device from being charged when the first switching device is off.

According to a second aspect of the present invention, there is provided a plasma display apparatus comprising: a rectifying section for rectifying an AC power source; A power conversion unit connected to the rectification unit and including a first switching device connected to the ground through a sense resistor; A driving unit for driving the first switching device; A control unit for applying a first driving signal to the driving unit; And a device protection unit connected between the control unit and the first switching device to prevent the voltage Vce of the collector-emitter terminal of the first switching device from being charged when the first switching device is off, And the like.

Here, the control unit applies a second driving signal to the device protection unit to connect the gate end of the first switching device to the ground through the device protection unit when the first switching device is off.

The device protection unit may include a second switching device having a base end connected to the control unit, a collector end connected to the gate terminal of the switching device, and an emitter terminal connected to the ground.

The controller may apply a first driving signal to the first switching element and a second driving signal having a phase difference of 180 degrees with the first driving signal to the second switching element.

According to a second aspect of the present invention, there is provided an air conditioner including the power conversion device.

The present invention has the following effects.

First, it is possible to prevent a malfunction that turns on the switching element (IGBT) due to noise or other components at off timing.

Thus, the risk that the IGBT can be turned on by another error signal, noise, or the like can be prevented.

Therefore, it is possible to prevent the IGBT from being burned out, and to prevent the occurrence of burnout in other parts connected to the same circuit pattern as the IGBT due to the overcurrent.

1 is a block diagram showing an example of a power conversion apparatus.
2 is a circuit diagram showing an example of a power conversion apparatus.
3 is a circuit diagram showing a power conversion apparatus according to the first embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, such elements, components, regions, layers and / And should not be limited by these terms.

Fig. 1 is a block diagram showing an example of a power conversion apparatus, and Fig. 2 is a circuit diagram showing an example of a power conversion apparatus.

1 and 2, the power inverter 100 includes a rectifier 110 for rectifying an AC power source 10, a converter 120 for controlling the power factor of the DC voltage rectified by the rectifier 110, A converter control unit 130 for controlling the converter 120, an inverter 140 for outputting a three-phase AC current, an inverter control unit 150 for controlling the inverter 140 and a converter 120 and an inverter 140, And a DC-side capacitor C between the first and second capacitors.

This inverter 140 outputs a three-phase alternating current, and this output current is supplied to the motor 200. Here, the motor 200 may be a compressor motor for driving the air conditioner. Hereinafter, the motor 200 is a compressor motor that drives the air conditioner, and the power inverter 100 is a motor driving device that drives such a compressor motor.

However, the motor 200 is not limited to a compressor motor and can be used in various applications using frequency-varying alternating voltages, for example, AC motors such as refrigerators, washing machines, electric trains, automobiles, and vacuum cleaners.

The motor driving apparatus 100 may further include a DC voltage detection unit B, an input voltage detection unit A, an input current detection unit D, and an output current detection unit E.

The motor drive apparatus 100 receives the AC power from the system, converts the power, and supplies the converted power to the motor 200.

The converter 120 converts the input AC power supply 10 into a DC power supply. The converter 120 may use a DC-DC converter operating as a power factor control (PFC) unit. In addition, such a DC-DC converter can use a boost converter. Optionally, the converter 120 may be a concept that includes the rectifier 110. Hereinafter, the converter 120 will be described by way of example using a step-up converter.

The rectifying unit 110 receives and rectifies the single-phase AC power supply 10 and outputs the rectified power to the converter 120 side. For this purpose, the rectifying part 110 can use a full-wave rectifying circuit using a bridge diode.

In this way, the converter 120 can perform the power factor improving operation in the process of stepping up and smoothing the voltage rectified by the rectifier 110.

The converter 120 includes an inductor L1 connected to the rectifying section 110, a switching device Q1 connected to the inductor L1, a capacitor C connected in parallel with the switching device Q1, And a diode D1 connected between the switching element Q1 and the capacitor C. [

The boost converter 120 is a converter that can obtain an output voltage higher than the input voltage. When the switching device Q1 is turned on, energy is stored in the inductor L1 while the diode D1 is shut off, And the output voltage is generated at the output terminal while the charge is discharged.

Further, when the switching element Q1 is interrupted, the energy stored in the inductor L1 at the time of the switching element Q1 is added and is transferred to the output terminal.

Here, the switching device Q1 may perform a switching operation by a separate pulse width modulation (PWM) signal. That is, the PWM signal transmitted from the converter control unit 130 is connected to the base (or gate) terminal of the switching element Q1, and the switching operation can be performed by the PWM signal.

The switching element Q1 may use a power transistor, for example, an insulated gate bipolar mode transistor (IGBT).

The IGBT is a switching device having a structure of a metal oxide semi-conductor field effect transistor (MOSFET) and a bipolar transistor. The IGBT is a device capable of small driving power, high speed switching, high voltage conversion and high current density.

In this manner, the converter control unit 130 can control the turn-on timing of the switching element Q1 in the converter 120. [ Thus, the converter control signal Sc for the turn-on timing of the switching element Q1 can be output.

The converter control unit 130 may receive the input voltage Vs and the input current Is from the input voltage detection unit A and the input current detection unit B, respectively.

Optionally, such converter 120 and converter control 130 may be omitted. That is, the output voltage passing through the rectifying unit 110 can be charged to the DC stage capacitor C or the inverter 140 can be driven.

The input voltage detecting section A can detect the input voltage Vs from the input AC power supply 10. [ For example, at the front end of the rectifying part 110. [

The input voltage detecting section A may include a resistance element, an OP AMP, or the like for voltage detection. The detected input voltage Vs can be applied to the converter control unit 130 to generate a converter control signal Sc as a discrete signal in the form of a pulse.

Next, the input current detection unit D can detect the input current Is from the input AC power supply 10. [ Specifically, it may be located at the front end of the rectifying section 110. [

The input current detection unit D may include a current sensor, a current transformer (CT), a shunt resistor, or the like, for current detection. The detected input voltage Is may be applied to the converter control unit 130 to generate the converter control signal Sc as a discrete signal in the form of a pulse.

The DC voltage detecting section B detects the pulsating voltage Vdc of the DC stage capacitor C. For such power detection, a resistance element, OP AMP, or the like can be used. The detected voltage Vdc of the DC stage capacitor C may be applied to the inverter controller 150 as a discrete signal in the form of a pulse and may be applied to the DC voltage Vdc of the DC stage capacitor C The inverter control signal Si can be generated based on the inverter control signal Si.

On the other hand, unlike the drawing, the detected DC voltage is applied to the converter control unit 130 and may be used for generating the converter control signal Sc.

The inverter 140 includes a plurality of inverter switching elements Qa, Qb, Qc, Qa ', Qb' and Qc ', and supplies the smoothed DC power source Vdc to a predetermined frequency Phase AC power supply of the three-phase motor 200, and outputs the three-phase AC power to the three-phase motor 200.

Specifically, the inverter 140 is a pair of the upper switching elements Qa, Qb, and Qc and the lower switching elements Qa ', Qb', and Qc 'that are serially connected to each other, and a total of three pairs of upper and lower switching The devices can be connected in parallel with each other.

As with the converter 120, the switching elements Qa, Qb, Qc, Qa ', Qb', Qc 'of the inverter can use power transistors, for example, an insulated gate bipolar mode transistor ; IGBT) can be used.

The inverter control unit 150 can output the inverter control signal Si to the inverter 140 in order to control the switching operation of the inverter 140. [ The inverter control signal Si is generated based on the output current io flowing to the motor 200 and the DC short voltage Vdc across the DC short capacitor C as a switching control signal of the pulse width modulation method And output. The output current io at this time can be detected from the output current detection unit E and the DC short voltage Vdc can be detected from the DC voltage detection unit B. [

The output current detection section E can detect the output current io flowing between the inverter 140 and the motor 200. [ That is, the current flowing in the motor 200 is detected. The output current detection unit E can detect all of the output currents ia, ib, ic of each phase or can detect the output currents of two phases using the three-phase balance.

The output current detection unit E may be located between the inverter 140 and the motor 200. For current detection, a current transformer (CT), a shunt resistor, or the like may be used.

3 is a circuit diagram showing a power conversion apparatus according to the first embodiment of the present invention.

FIG. 3 mainly shows a configuration corresponding to a DC-DC converter operating as a power factor control (PFC) part of the power converter.

As described with reference to FIG. 2, the converter 120 can perform the power factor improving operation in the process of stepping up and smoothing the voltage rectified by the rectifier 110.

Here, the inductor L1, the switching element Q1 (hereinafter referred to as a first switching element) and the diode D1 connected between the capacitor C and the like as shown in FIG. 2 are omitted.

In addition, the first switching device Q1 can perform a switching operation by a pulse width modulation (PWM) signal transmitted from the driving unit 131. [ That is, the PWM signal transmitted from the driving unit 131 is connected to the gate terminal of the switching element Q1, and the switching operation can be performed by the PWM signal.

The control unit 132 may control the driving unit 131 and the first switching device Q1 by transmitting a PWM driving signal to the driving unit 131. [

As a result of the operation of the first switching device Q1, the voltage rectified by the rectifying part 110 is stepped up and smoothed by the operation of the converter shown in FIG. 2, and the step-up and smoothed voltage is supplied to the DC- ). ≪ / RTI >

A device protection unit 160 may be connected to the gate terminal of the first switching device Q1 to prevent malfunction of the first switching device Q1.

The controller 132 applies the first driving signal PWM1 to the first switching device Q1 and applies the second driving signal PWM2 to the device protection unit 160 to apply the first driving signal PWM1 to the first switching device Q1, The gate terminal of the first switching device Q1 can be controlled to be connected to the ground through the device protection unit 160 during an off operation of the device.

Here, the device protection unit 160 includes a second switching device Q1 having a base end connected to the control unit 132, a collector end connected to the gate terminal of the first switching device Q1, (Q2).

The controller 132 applies the first driving signal PWM1 to the first switching device Q1 and applies the first driving signal PWM1 and the first driving signal PWM1 to the second switching device Q2, The second drive signal PWM2 having a phase difference can be applied.

Here, the first switching device Q1 may be an inverter switching device included in the power factor control unit 120 (see Figs. 1 and 2) or an inverter switching device included in the inverter 140 (see Figs. 1 and 2) .

The device protection unit 160 having the configuration as described above is capable of charging the voltage Vce of the collector-emitter end of the first switching device Q1 when the first switching device Q1 is turned off .

The first switching device Q1 has a gate-collector capacitance Cgc and a gate-emitter capacitance Cge. The gate-emitter voltage Vge is charged by the voltage charged in Cgc. The first switching element Q1 can be turned on according to the Vge voltage.

However, it is possible to prevent the first switching device Q1 from being unnecessarily turned on during the off timing of the first switching device Q1 by the role of the device protection unit 160 described above .

Thus, switching loss or malfunction due to unnecessary on operation of the first switching device Q1 can be prevented.

Hereinafter, the operation of the present invention will be described in detail with reference to FIGS. 1 to 3. FIG.

As described above, the first switching device Q1 has a gate-collector capacitance Cgc and a gate-emitter capacitance Cge. This capacitance represents the parasitic capacitance value of the first switching device Q1. In addition, the first switching device Q1 may be implemented as an IGBT.

Normally, an IGBT has the following operation principle.

That is, when a voltage higher than the threshold voltage of the device is applied to the gate electrode, the polarity of the surface of the p-type semiconductor at the bottom of the electrode is reversed and an n-type channel is formed. The electron current injected into the drift region through the channel induces the injection of the hole current from the p + substrate in the same manner as the base current of the bipolar transistor, so that a high level injection of the carrier (High Level Injection Conductivity modulation, which increases the conductivity by several tens to hundreds of times, occurs. The IGBT is used as a switching element by using this conductivity modulation.

Referring to the circuit of FIG. 3, when the IGBT used as the first switching device Q1 is turned on / off, a current is conducted to Cgc according to the change of the voltage Vce between the collector and the emitter, Is charged.

Then, the voltage charged by Cgc charges the Vge voltage which can turn on the IGBT. The IGBT can be turned on according to the Vge voltage.

At this time, the IGBT may malfunction due to noise or other components at off timing. That is, the Vge voltage can also be formed in the off-timing of the IGBT, and there is a risk that the IGBT can be turned on due to other error signals, noise, or the like.

As a result, IGBT burnout may occur, driving efficiency and product efficiency may be deteriorated, and an overcurrent may occur, so that other parts connected to the same circuit pattern as the IGBT may be burned.

Therefore, a transistor is applied as the second switching device Q2 to the device protection unit 160 so that the second switching device Q2 is supplied with the first switching device Q1 (IGBT) The second driving signal PWM2 having a phase difference of 180 degrees from the signal PWM1 can be applied.

That is, when the IGBT is on, the transistor which is the second switching element Q2 is off, and when the IGBT is off, the transistor is on.

Therefore, even if Vge is charged according to the change of the Vce voltage, the transistor is turned on when the IGBT is off timing, so that the turn-on phenomenon of the unnecessary IGBT does not occur.

That is, when the IGBT used as the first switching device Q1 is off timing, the transistor used as the second switching device Q2 is turned on so that the gate of the IGBT is connected to the ground .

Therefore, Vge is not charged when the IGBT is off timing, and thus it is possible to prevent the IGBT from being turned on due to noise or other errors when the IGBT is off timing.

Thus, the risk that the IGBT can be turned on by another error signal, noise, or the like can be prevented.

Therefore, it is possible to prevent the IGBT from being burned out, and to prevent the occurrence of burnout in other parts connected to the same circuit pattern as the IGBT due to the overcurrent.

1 and 2 can be applied as they are.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: power converter 110: rectifying part
120: converter 130: converter control unit
131: driving unit 132:
140: inverter 150: inverter controller
160:

Claims (10)

A rectifying part for rectifying AC power;
A first switching device connected to the rectifying part and connected to the ground through a sense resistor;
A driving unit for driving the first switching device;
A device protection unit connected to a gate terminal of the first switching device to prevent a malfunction of the first switching device; And
And a gate driving circuit for applying a first driving signal to the first switching device and applying a second driving signal to the device protecting unit to turn off the gate terminal of the first switching device when the first switching device is off, And a control unit connected to the ground through the first power supply unit and the second power supply unit. The device according to claim 1,
And a second switching element having a base end connected to the control unit, a collector end connected to the gate end of the first switching device, and an emitter end connected to the ground. The method of claim 2, wherein the controller applies a first driving signal to the first switching element and applies a second driving signal having a phase difference of 180 degrees to the first driving signal to the second switching element Characterized in that the power conversion device. The power conversion device of claim 1, wherein the first switching device is an inverter switching device included in the power factor control unit or an inverter switching device included in the inverter. The device according to claim 1, wherein the device protection unit prevents charging of a voltage (Vce) at a collector-emitter end of the first switching device when the first switching device is off, Device. A rectifying part for rectifying AC power;
A power conversion unit connected to the rectification unit and including a first switching device connected to the ground through a sense resistor;
A driving unit for driving the first switching device;
A control unit for applying a first driving signal to the driving unit; And
And a device protection unit connected between the control unit and the first switching device to prevent charging of the voltage Vce at the collector-emitter end of the first switching device when the first switching device is off The power conversion device comprising: The device of claim 6, wherein the control unit applies a second driving signal to the device protection unit, and when the first switching device is off, the gate terminal of the first switching device is grounded via the device protection unit And the power converter. 7. The device according to claim 6,
And a second switching element having a base end connected to the control part, a collector end connected to the gate end of the switching element, and an emitter end connected to the ground. The method of claim 8, wherein the control unit applies a first driving signal to the first switching element and applies a second driving signal having a phase difference of 180 degrees to the first driving signal to the second switching element Characterized in that the power conversion device. An air conditioner comprising the power conversion device according to any one of claims 1 to 9.

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