KR20180091460A - Power supply apparatus and air conditioner including the same - Google Patents

Abstract

The present invention relates to a power supply device which prevents damage to a switched-mode power supply (SMPS) caused by an overvoltage; and an air conditioner including the same. The power supply includes an SMPS rectifying unit and an SMPS unit, and further includes an SMPS capacitor connected between the SMPS rectifying unit and the SMPS unit to charge or discharge a voltage, and a device protecting unit sensing a voltage across both ends of the SMPS capacitor, and determining whether an overvoltage flows into the SMPS capacitor based on the sensed voltage to cut off power applied to the SMPS rectifying unit. Here, the device protecting unit includes: a voltage sensing unit sensing a voltage across both ends of the SMPS capacitor; an overvoltage determining unit determining whether an overvoltage flows into the SMPS capacitor based on the voltage sensed by the voltage sensing unit; and a switching unit shutting off power applied to the SMPS rectifying unit in response to a determination signal of the overvoltage determining unit.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device, and more particularly, to a power supply device for preventing a burn-out of a Switched Mode Power Supply (SMPS) due to an overvoltage and an air conditioner including the power supply device.

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.

It is generally known that such a power conversion apparatus mainly constitutes a rectification section, a power factor control section, and an inverter type power conversion section.

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 unit and the inverter, and a DC stage capacitor may be provided between the converter and the inverter.

Further, the power supply device is connected to the power input terminal of the power conversion device, and converts the input AC power to the DC power, so that power can be supplied to the system.

Generally, a power conversion device of a single-phase product may include a relay switch at a power input terminal to block an overvoltage from being applied to a DC stage capacitor. The power supply device of the single-phase product may be directly connected to a power input terminal without a relay switch .

Therefore, when the three-phase 380V power supply is reversed to the single-phase product, the power conversion apparatus can turn off the relay switch to prevent circuit damage due to overvoltage.

However, since the power supply does not have a relay switch such as a power conversion device, when a three-phase 380V power supply is reversed to a single-phase product, an overvoltage may be directly applied and the SMPS (Switched Mode Power Supply) circuit may be damaged.

Therefore, there is a demand for a power supply device having a protection function capable of preventing burnout of the SMPS circuit due to overvoltage in the future.

The present invention is directed to solving the above-mentioned problems and other problems. Another object of the present invention is to detect the voltage across both ends of the SMPS capacitor and judge whether the overvoltage of the SMPS capacitor flows based on the sensed voltage so as to cut off the power applied to the SMPS rectifying part, And to provide a power supply device capable of driving the microcomputer even in a three-phase AC power source, and an air conditioner including the power supply device.

A power supply device according to an embodiment of the present invention includes an SMPS capacitor including an SMPS rectifying part and an SMPS (Switched Mode Power Supply) part and connected between the SMPS rectifying part and the SMPS part to charge or discharge a voltage, And a device protection unit for detecting the overvoltage of the SMPS capacitor based on the sensed voltage and cutting off the power applied to the SMPS rectification unit.

Here, the device protection unit includes a voltage sensing unit that senses a voltage across both ends of the SMPS capacitor, an overvoltage determination unit that determines whether an overvoltage of the SMPS capacitor flows based on the voltage sensed by the voltage sensing unit, And a switching unit for shutting off the power applied to the SMPS rectifying unit.

In this case, the voltage sensing unit may include a distribution resistor connected in parallel with the SMPS capacitor and having a first resistor and a second resistor connected in series.

The overvoltage determination unit may compare the voltage value sensed by the voltage sensing unit with a predetermined reference voltage value and output a determination signal for determining whether the power applied to the SMPS rectification unit is turned off.

Here, if the voltage value sensed by the voltage sensing unit is greater than a preset reference voltage value, the overvoltage determining unit outputs a determination signal low to turn off the switching unit, Is smaller than or equal to the preset reference voltage value, the determination signal may be output as high to turn on the switching unit.

If the determination signal of the overvoltage determination unit is low, the switching unit may turn off the power supply to the SMPS rectification unit by performing an off operation, and may lower the voltage applied to both ends of the SMPS capacitor.

Also, when the determination signal of the overvoltage determination unit is high, the switching unit may be turned on to apply power to the SMPS rectification unit and increase the voltage across both ends of the SMPS capacitor.

The switching unit of the device protection unit is connected in parallel with the switching unit of the power conversion device. The switching unit of the power conversion device is turned off when the three-phase AC power source is in reverse phase to cut off the input voltage. , The input voltage can be cut off only when the three-phase AC power supply is above the reference voltage.

In addition, the device protection unit can cut off the three-phase AC power applied to the SMPS rectifying unit only when the power applied to the SMPS rectifying unit is a reverse phase of the three-phase AC power supply, and only when the three-phase AC power is higher than the reference voltage.

Also, the air conditioner according to an embodiment of the present invention includes an SMPS capacitor including an SMPS rectifier and an SMPS (Switched Mode Power Supply) unit and connected between the SMPS rectifier and the SMPS to charge or discharge a voltage, And a power supply unit having a device protection unit for detecting a voltage applied to both ends and for determining whether an overvoltage of the SMPS capacitor flows based on the sensed voltage and for shutting down the power applied to the SMPS rectification unit.

Effects of the power supply apparatus and the air conditioner including the power supply apparatus according to the present invention will be described as follows.

According to at least one of the embodiments of the present invention, the voltage applied to both ends of the SMPS capacitor is sensed, and it is determined whether the overvoltage of the SMPS capacitor flows based on the sensed voltage to shut off the power applied to the SMPS rectifier. It is possible to prevent the SMPS power supply circuit from being burned out in the reverse phase, and to drive the microcomputer in the reverse phase of the three-phase AC power.

Further scope of applicability of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and specific examples, such as the preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.

1 is a block diagram of a power supply apparatus according to the present invention.
2 is a circuit diagram for explaining a power supply device according to the present invention.
3 is a block diagram illustrating a device protection unit of a power supply device according to the present invention.
4 is a circuit diagram for explaining a device protection unit of a power supply device according to the present invention.
5 is a circuit diagram showing a power supply apparatus to which a device protection unit according to the present invention is applied.
6 is a flowchart illustrating an overvoltage interruption process of the power supply apparatus according to the present invention.
7 is a graph showing a voltage rise of the SMPS circuit according to a three phase AC power source reverse phase.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

FIG. 1 is a block diagram of a power supply apparatus according to the present invention, and FIG. 2 is a circuit diagram for explaining a power supply apparatus according to the present invention.

1 and 2, the power supply apparatus 1000 may include a power conversion apparatus and a power supply apparatus.

The power conversion apparatus includes a rectification unit 1100 for rectifying the AC power source 100, a converter unit 1200 for boosting / reducing the DC voltage rectified by the rectification unit 1100 or controlling the power factor, a converter An inverter unit 1400 for outputting the three-phase AC current, an inverter control unit 1500 for controlling the inverter unit 1400, and a DC stage capacitor (hereinafter, referred to as " DC stage capacitor ") between the converter unit 1200 and the inverter unit 1400 C).

This inverter unit 1400 outputs a three-phase alternating current, and this output current is supplied to the motor 2000. Here, the motor 2000 may be a compressor motor that drives the air conditioner. Hereinafter, the motor 2000 is a compressor motor that drives the air conditioner, and the power inverter 1000 is a motor driving device that drives such a compressor motor.

However, the motor 2900 is not limited to a compressor motor, and can be used in various applications using frequency-varying alternating voltage, for example, AC motors such as refrigerators, washing machines, electric trains, automobiles, and vacuum cleaners.

The power conversion apparatus 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 to drive the compressor motor.

The power conversion apparatus receives AC power from the system, converts the power, and supplies the converted power to the motor 2000.

The converter unit 1200 converts the input AC power supply 100 into a DC power supply. The converter unit 1200 may use a DC-DC converter that operates as a power factor control (PFC) unit. In addition, such a DC-DC converter can use a boost converter. In some cases, the converter section 1200 may be a concept including the rectifying section 1100. Hereinafter, the converter unit 1200 will be described by way of example using a step-up converter.

The rectifying unit 1100 receives and rectifies the single-phase AC power source 100, and outputs the rectified power to the converter unit 1200 side. For this purpose, the rectifying unit 1100 can use a full-wave rectifying circuit using a bridge diode.

In this way, the converter unit 1200 can perform the power factor improving operation in the process of stepping up and smoothing the voltage rectified by the rectifying unit 1100.

The converter unit 1200 includes an inductor L1 connected to the rectifying unit 1100, 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 converter unit 1200 is a step-up converter that can obtain an output voltage higher than the input voltage. When the switching device Q1 is turned on, the diode D1 is cut off and energy is stored in the inductor L1. The stored charge is discharged and an output voltage is generated at the output terminal.

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 applied to the base (or gate) terminal of the switching element Q1, so that the switching operation of the switching element Q1 can be driven 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 1300 can control the turn-on timing of the switching element Q1 in the converter unit 1200. [ Thus, the converter control signal Sc for the turn-on timing of the switching element Q1 can be output.

The converter control unit 1300 can 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.

The output voltage through the rectifying unit 1100 can be charged to the DC stage capacitor C or drive the inverter unit 1400. [

The input voltage detecting section A can detect the input voltage Vs from the input AC power supply 100. [ For example, it may be located at the front end of the rectifying part 1100.

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 1300 in order to generate the converter control signal Sc as a discrete signal in the form of a pulse.

Next, the input current detection section D can detect the input current Is from the input AC power supply 100. [ Specifically, it may be located at the front end of the rectifying section 1100.

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 1300 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 voltage Vdc of the detected DC stage capacitor C 1600 may be applied to the inverter control unit 1500 as a discrete signal in the form of a pulse and may be applied to the DC stage capacitor C 1600 The inverter control signal Si can be generated based on the DC voltage Vdc.

On the other hand, unlike the drawing, the detected DC voltage is applied to the converter control section 1300, and may be used to generate the converter control signal Sc.

The inverter unit 1400 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 Phase three-phase alternating-current power source, and output to the three-phase motor 2000.

Specifically, the inverter unit 1400 includes a pair of upper switching elements Qa, Qb, and Qc and lower switching elements Qa ', Qb', and Qc 'that are serially connected to each other, and a total of three pairs of upper and lower The switching elements can be connected to each other in parallel.

The switching elements Qa, Qb, Qc, Qa ', Qb', and Qc 'of the inverter section may use power transistors and may be, for example, an insulated gate bipolar transistor transistor (IGBT) can be used.

The inverter control unit 1500 can output the inverter control signal Si to the inverter unit 1400 in order to control the switching operation of the inverter unit 1400. [ The inverter control signal Si is generated based on the output current io flowing to the motor 2000 and the DC step voltage Vdc across the DC step 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 section 1400 and the motor 2000. [ That is, the current flowing in the motor 2000 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 unit 1400 and the motor unit 2000. For current detection, a current transformer (CT), a shunt resistor, or the like may be used.

The SMPS rectifier 1600, the SMPS capacitor 1700, the SMPS (Switched-Mode Power Supply) unit 1800, and the SMPS rectifier 1600 are connected to the power supply, And a device protection unit 1900 having a switching unit 1910.

Here, the SMPS capacitor 1700 is connected between the SMPS rectification part 1600 and the SMPS part 1800 to charge or discharge the voltage.

Then, the device protection unit 1900 can prevent overvoltage applied to the power supply device, thereby preventing the SMPS circuit from being burned.

Particularly, when the power supply unit is applied to a single-phase product, the device protection unit 1900 detects an input voltage when the three-phase AC power source is in a reverse phase and blocks the input voltage when the sensed input voltage is equal to or higher than the reference voltage, Can protect the SMPS circuit of

That is, when the three-phase AC power source is reversed by the power supply device, the device protection unit 1900 of the power supply device does not directly block the input voltage but only blocks the input voltage when the input voltage is an over- Thus, even when the three-phase AC power source is reversed, the power supply device can be continuously driven to supply the power so that the microcomputer (MICOM) and the like can be continuously driven without being turned off.

The device protection unit 1900 senses a voltage applied to both ends of the SMPS capacitor 1700 and determines whether the overvoltage of the SMPS capacitor 1700 flows based on the sensed voltage and applies the overvoltage to the SMPS rectifier 1600 Power can be shut off.

Here, the device protection unit 1900 includes a voltage sensing unit for sensing a voltage applied to both ends of the SMPS capacitor 1700, an overvoltage determination unit for determining whether the overvoltage of the SMPS capacitor 1700 flows based on the voltage sensed by the voltage sensing unit, And a switching unit 1910 that cuts off the power applied to the SMPS rectifier unit 1600 according to a determination signal of the overvoltage determination unit.

The voltage sensing portion of the device protection portion 1900 may include a distribution resistor connected in parallel with the SMPS capacitor 1700 and having a first resistor and a second resistor connected in series.

The overvoltage determination unit of the device protection unit 1900 compares the voltage value sensed by the voltage sensing unit with a predetermined reference voltage value and outputs a determination signal for determining whether the power applied to the SMPS rectification unit 1600 is cut off .

For example, the overvoltage determination unit may output a determination signal low to turn off the switching unit 1910 if the voltage sensed by the voltage sensing unit is greater than a preset reference voltage value, The switching unit 1910 can be turned on by outputting the determination signal high. [0064] As shown in FIG.

If the determination signal is low, the overvoltage determination unit may continuously turn off the switching unit 1910 during a period in which the low signal is applied.

The reason is that the overvoltage is not input until the voltage applied to the SMPS capacitor 1700 is lowered to a predetermined voltage value.

Further, the switching unit 1910 of the device protection unit 1900 may be a relay switch, but is not limited thereto.

Here, if the determination signal of the overvoltage determination unit is low, the switching unit 1910 may turn off the power applied to the SMPS rectifier unit 1600 by performing an off operation, and may lower the voltage applied across the SMPS capacitor 1700 .

If the determination signal of the overvoltage determination unit is high, the switching unit 1910 may turn on the power to apply power to the SMPS rectification unit 1600 and increase the voltage across the SMPS capacitor 1700. [

In some cases, the switching unit 1910 of the device protection unit 1900 may be connected in parallel with the switching unit of the power conversion device. The switching unit of the power conversion device is turned off when the three- , The switching unit 1910 of the device protection unit 1900 can be turned off and shut off the input voltage only when the three-phase AC power source is higher than the reference voltage when the three-phase AC power source is reversed.

The reason why the switching unit 1910 of the device protection unit 1900 is not immediately turned off in the three-phase AC power source is that the switching unit 1910 of the device protection unit 1900 operates even when the three- So that the operation of the microcomputer or the like can be maintained.

The switching unit 1910 of the device protection unit 1900 can perform an OFF operation only when a high voltage equal to or higher than a threshold value that can damage the SMPS circuit is input to protect the SMPS circuit.

In this way, the device protection unit 1900 can cut off the three-phase AC power applied to the SMPS rectification unit 1600 only when the power applied to the SMPS rectification unit 1600 is a reverse phase of the three-phase AC power supply, have.

As described above, according to the present invention, the voltage applied to both ends of the SMPS capacitor is sensed, and it is determined whether or not the overvoltage of the SMPS capacitor flows based on the sensed voltage, thereby shutting off the power applied to the SMPS rectifier. It is possible to drive the microcomputer in the reverse phase of the three-phase AC power source.

FIG. 3 is a block diagram for explaining a device protection unit of the power supply device according to the present invention, and FIG. 4 is a circuit diagram for explaining a device protection unit of the power supply device according to the present invention.

3 and 4, the device protection unit 1900 of the power supply may include a voltage sensing unit 1920, an overvoltage determination unit 1930, and a switching unit 1910.

Here, the voltage sensing unit 1920 can sense a voltage applied across both ends of the SMPS capacitor 1700.

In one example, the voltage sensing portion 1920 may include a distribution resistor connected in parallel with the SMPS capacitor 1700 and having a first resistor 1922 and a second resistor 1924 connected in series.

The overvoltage determining unit 1930 can determine whether the overvoltage of the SMPS capacitor 1700 is flowing based on the voltage sensed by the voltage sensing unit 1920.

Here, the overvoltage determination unit 1930 may compare the voltage value detected from the voltage detection unit 1920 with a preset reference voltage value, and output a determination signal for determining whether the power applied to the SMPS rectification unit is turned off.

The overvoltage determining unit 1930 outputs a determination signal low to turn off the switching unit 1910 if the voltage value detected by the voltage sensing unit 1920 is greater than a predetermined reference voltage value If the voltage value sensed by the voltage sensing unit 1920 is less than or equal to a preset reference voltage value, the determination unit 1920 outputs a determination signal high to turn on the switching unit 1910 have.

Here, the overvoltage determination unit 1930 can continuously turn off the switching unit 1910 during a time period during which the low signal is applied when the determination signal is low.

The reason is that the overvoltage is not input until the voltage applied to the SMPS capacitor 1700 is lowered to a predetermined voltage value.

For example, the overvoltage determination unit 1930 can set the preset reference voltage value to about 450V, but it is not limited thereto.

That is, if the voltage value sensed by the voltage sensing unit 1920 is greater than a predetermined reference voltage value of 450V, the overvoltage determination unit 1930 outputs a determination signal low to turn off the switching unit 1910 (off).

For example, when a power supply of about 537 V is applied to an SMPS power supply, the voltage across the SMPS capacitor can rise to about 645 V, taking into account a voltage variation of about 15%.

Here, when the voltage applied to the SMPS capacitor is detected to be about 645 V, the voltage applied to the switching element of the SMPS part rises to about 715 V in consideration of the switching noise, and the element may be burned out.

The overvoltage determination unit 1930 of the device protection unit 1900 outputs a determination signal at a low level when the voltage value detected by the voltage detection unit 1920 is greater than a preset reference voltage value of 450V The switching unit 1910 can be turned off to protect the SMPS circuit.

For example, the overvoltage determination unit 1930 may include a distribution resistor 1938 and the like.

Here, in the distribution resistor 1938, the overvoltage determination unit 1930 can generate the reference voltage by connecting the third resistor 1938a and the fourth resistor 1938b in series.

The comparator 1932 is connected to the node between the third resistor 1938a and the fourth resistor 1938b of the distribution resistor 1938 and connected to the first input terminal to which the reference voltage is applied and the voltage sensing unit 1920 And a second input terminal to which the sensed voltage is applied.

A fifth resistor 1934 may then be coupled between the second input of the comparator 1932 and the voltage sensing portion 1920 and a capacitor 1936 may be coupled between the second input of the comparator 1932 and the fifth resistor 1934, and the other side may be grounded.

Next, the switching unit 1910 may cut off the power applied to the SMPS rectifying unit according to the determination signal of the overvoltage determining unit 1930. [

In one example, the switching unit 1910 may be, but is not limited to, a relay switch.

Here, when the determination signal of the overvoltage determination unit 1930 is low, the switching unit 1910 may turn off the power applied to the SMPS rectification unit by performing the off operation, and may lower the voltage applied across the SMPS capacitor 1700 have.

If the determination signal of the overvoltage determination unit 1930 is high, the switching unit 1910 may turn on the power to apply power to the SMPS rectification unit and increase the voltage applied across the SMPS capacitor 1700.

As described above, according to the present invention, the voltage applied to both ends of the SMPS capacitor is sensed, and it is determined whether or not the overvoltage of the SMPS capacitor flows based on the sensed voltage, thereby shutting off the power applied to the SMPS rectifier. It is possible to drive the microcomputer in the reverse phase of the three-phase AC power source.

5 is a circuit diagram showing a power supply apparatus to which a device protection unit according to the present invention is applied.

As shown in FIG. 5, the power supply device can operate by receiving a single-phase AC power as the power conversion device.

Here, the power supply device may include a device protection unit 1900 having an SMPS rectification unit 1600, an SMPS capacitor 1700, a SMPS (Switched Mode Power Supply) unit 1800, and a switching unit 1910 .

Here, the SMPS capacitor 1700 is connected between the SMPS rectification part 1600 and the SMPS part 1800 to charge or discharge the voltage.

Then, the device protection unit 1900 can prevent overvoltage applied to the power supply device, thereby preventing the SMPS circuit from being burned.

Particularly, when the power supply unit is applied to a single-phase product, the device protection unit 1900 detects an input voltage when the three-phase AC power source is in a reverse phase and blocks the input voltage when the sensed input voltage is equal to or higher than the reference voltage, Can protect the SMPS circuit of

That is, when the three-phase AC power source is reversed by the power supply device, the device protection unit 1900 of the power supply device does not directly block the input voltage but only blocks the input voltage when the input voltage is an over- Thus, even when the three-phase AC power source is reversed, the power supply device can be continuously driven to supply the power so that the microcomputer (MICOM) and the like can be continuously driven without being turned off.

The device protection unit 1900 senses a voltage applied to both ends of the SMPS capacitor 1700 and determines whether the overvoltage of the SMPS capacitor 1700 flows based on the sensed voltage and applies the overvoltage to the SMPS rectifier 1600 Power can be shut off.

The device protection unit 1900 includes a voltage sensing unit 1920 that senses a voltage applied across the SMPS capacitor 1700 and a voltage sensing unit 1920 that senses a voltage across the SMPS capacitor 1700 based on the voltage sensed by the voltage sensing unit 1920. [ And a switching unit 1910 for turning off the power applied to the SMPS rectifying unit 1600 according to a determination signal of the overvoltage determining unit 1930. [

The voltage sensing unit 1920 of the device protection unit 1900 may include a distribution resistor connected in parallel with the SMPS capacitor 1700 and having a first resistor 1922 and a second resistor 1924 connected in series.

The overvoltage determination unit 1930 of the device protection unit 1900 compares the voltage value sensed by the voltage sensing unit 1920 with a predetermined reference voltage value and determines whether the power applied to the SMPS rectification unit 1600 is cut off It is possible to output a judgment signal to judge.

The overvoltage determining unit 1930 outputs a determination signal low to turn off the switching unit 1910 if the voltage value detected by the voltage sensing unit 1920 is greater than a predetermined reference voltage value If the voltage value sensed by the voltage sensing unit 1920 is less than or equal to a preset reference voltage value, the determination unit 1920 outputs a determination signal high to turn on the switching unit 1910 have.

If the determination signal is low, the overvoltage determination unit 1930 may continuously turn off the switching unit 1910 during a time period during which the low signal is applied.

The reason is that the overvoltage is not input until the voltage applied to the SMPS capacitor 1700 is lowered to a predetermined voltage value.

Further, the switching unit 1910 of the device protection unit 1900 may be a relay switch, but is not limited thereto.

If the determination signal of the overvoltage determination unit 1930 is low, the switching unit 1910 turns off the power applied to the SMPS rectification unit 1600 by performing an off operation and outputs a voltage across the SMPS capacitor 1700 Can be lowered.

When the determination signal of the overvoltage determination unit 1930 is high, the switching unit 1910 performs an on operation to apply power to the SMPS rectification unit 1600 and increase the voltage applied across the SMPS capacitor 1700 .

The switching unit 1910 of the device protection unit 1900 may be connected in parallel with the switching unit 1110 of the power conversion device. The switching unit 1910 of the power conversion device may be configured such that when the three- Off to cut off the input voltage and the switching unit 1910 of the element protection unit 1900 can be turned off to block the input voltage only when the three-phase AC power supply is equal to or higher than the reference voltage.

The reason why the switching unit 1910 of the device protection unit 1900 is not immediately turned off in the three-phase AC power source is that the switching unit 1910 of the device protection unit 1900 operates even when the three- So that the operation of the microcomputer or the like can be maintained.

The switching unit 1910 of the device protection unit 1900 can perform an OFF operation only when a high voltage equal to or higher than a threshold value that can damage the SMPS circuit is input to protect the SMPS circuit.

In this way, the device protection unit 1900 can cut off the three-phase AC power applied to the SMPS rectification unit 1600 only when the power applied to the SMPS rectification unit 1600 is a reverse phase of the three-phase AC power supply, have.

For example, when the three-phase 380V power supply is reversed to the power conversion apparatus to which the single-phase AC power is applied, the microcomputer 3100 detects the input voltage through the input voltage sensing unit 3200, , It is possible to control the switching unit 1110 of the power conversion apparatus to perform an OFF operation.

Also, the microcomputer 3100 can control the switching unit 1110 of the power conversion apparatus to perform an OFF operation even when the voltage applied to the DC stage capacitor is about 450 V or more.

When the three-phase 380V power supply is reversed to the power supply to which the single-phase AC power is applied, the device protection unit 1900 senses the voltage across both ends of the SMPS capacitor 1700, 1700 is turned off and the power applied to the SMPS rectifying unit 1600 is turned off to prevent burnout of the SMPS power supply circuit in the case of three-phase AC power supply and to operate the microcomputer on the three-phase AC power source.

For example, the voltage sensing unit 1920 of the device protection unit 1900 can sense a voltage across both ends of the SMPS capacitor 1700 when the three-phase 380V power supply is reversed.

The overvoltage determination unit 1930 of the device protection unit 1900 can determine whether the overvoltage of the SMPS capacitor 1700 is flowing based on the voltage sensed by the voltage sensing unit 1920.

Here, the overvoltage determination unit 1930 may compare the voltage value detected from the voltage detection unit 1920 with a preset reference voltage value, and output a determination signal for determining whether the power applied to the SMPS rectification unit is turned off.

The overvoltage determining unit 1930 outputs a determination signal low to turn off the switching unit 1910 if the voltage value detected by the voltage sensing unit 1920 is greater than a predetermined reference voltage value If the voltage value sensed by the voltage sensing unit 1920 is less than or equal to a preset reference voltage value, the determination unit 1920 outputs a determination signal high to turn on the switching unit 1910 have.

Here, the overvoltage determination unit 1930 can continuously turn off the switching unit 1910 during a time period during which the low signal is applied when the determination signal is low.

The reason is that the overvoltage is not input until the voltage applied to the SMPS capacitor 1700 is lowered to a predetermined voltage value.

For example, the overvoltage determination unit 1930 can set the preset reference voltage value to about 450V, but it is not limited thereto.

That is, if the voltage value sensed by the voltage sensing unit 1920 is greater than a predetermined reference voltage value of 450V, the overvoltage determination unit 1930 outputs a determination signal low to turn off the switching unit 1910 (off).

For example, when a power supply of about 537 V is applied to an SMPS power supply, the voltage across the SMPS capacitor can rise to about 645 V, taking into account a voltage variation of about 15%.

Here, when the voltage applied to the SMPS capacitor is detected to be about 645 V, the voltage applied to the switching element of the SMPS part rises to about 715 V in consideration of the switching noise, and the element may be burned out.

The overvoltage determination unit 1930 of the device protection unit 1900 outputs a determination signal at a low level when the voltage value detected by the voltage detection unit 1920 is greater than a preset reference voltage value of 450V The switching unit 1910 can be turned off to protect the SMPS circuit.

In this way, the switching unit 1910 of the device protection unit 1900 can be connected in parallel with the switching unit 1110 of the power conversion device.

When the three-phase AC power source is in the reverse phase, the switching unit 1910 of the device protection unit 1900 turns off the three-phase AC power source, Only when it is higher than the reference voltage, it can be turned off to block the input voltage.

Here, the three-phase AC power source may be about 380 V, and the reference voltage may be about 450 V, but is not limited thereto.

In this way, the device protection unit 1900 can cut off the three-phase AC power applied to the SMPS rectification unit 1600 only when the power applied to the SMPS rectification unit 1600 is a reverse phase of the three-phase AC power supply, have.

FIG. 6 is a flow chart for explaining the overvoltage cutoff process of the power supply device according to the present invention, and FIG. 7 is a graph showing a voltage rise of the SMPS circuit according to a three phase AC power source phase.

6, the device protection unit can sense a voltage across both ends of the SMPS capacitor when the three-phase 380 V power supply is reversed (S10)

Then, the device protection unit can determine whether the sensed voltage value is greater than a preset reference voltage value of 450 V. (S20)

If the detected voltage value is greater than a preset reference voltage value of 450 V, the device protection unit outputs a determination signal at a low level. (S30)

Then, based on the output low signal, the device protection unit can turn off the relay switch to cut off the power applied to the SMPS power supply unit. (S40)

When the voltage applied to both ends of the SMPS capacitor is lowered according to the cutoff of the applied power, the device protection unit can repeatedly perform the operation of sensing the voltage applied across the SMPS capacitor.

If it is determined that the detected voltage value is not greater than the reference voltage value 450V, the device protection unit outputs a determination signal as high (S60)

Based on the output high signal, the device protection unit can turn on the relay switch and apply power to the SMPS power supply unit (S70). [

Next, the device protection unit may repeatedly perform an operation of sensing a voltage across both ends of the SMPS capacitor when the voltage across both ends of the SMPS capacitor rises according to the applied power supply. (S80)

In some cases, the device protection section can turn off the power supply by continuously turning off the relay switch for a time period during which the low signal is applied when the determination signal is low.

The reason is that the overvoltage is not input until the voltage across the SMPS capacitor drops to a constant voltage value.

For example, when a power supply of about 537 V is applied to an SMPS power supply, the voltage across the SMPS capacitor can rise to about 645 V, taking into account a voltage variation of about 15%.

Here, when the voltage applied to the SMPS capacitor is detected to be about 645 V, the voltage applied to the switching element of the SMPS part rises to about 715 V in consideration of the switching noise, and the element may be burned out.

As shown in FIG. 7, it can be seen that the voltage applied to the switching element of the SMPS section rises to about 623 V as in the case of the area A, considering the switching noise.

As described above, the voltage applied to the switching element of the SMPS part increases greatly depending on the switching noise, so that the switching element may be burned out.

Therefore, according to the present invention, a device protection unit is disposed in an SMPS power supply device applied to a single-phase product to protect the SMPS power supply device even when the three-phase AC power supply is reversed, .

That is, the present invention detects a voltage applied to both ends of an SMPS capacitor, determines whether an overvoltage of the SMPS capacitor flows based on the detected voltage, and cuts off the power applied to the SMPS rectifier, It is possible to prevent the burn-out and drive the microcomputer even in the three-phase AC power source reverse phase.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

1000: Power supply device 1100:
1200: converter section 1300: converter control section
1400: Inverter section 1500: Inverter control section
1600: SMPS rectifier part 1700: SMPS capacitor
1800: SMPS section 1900: Device protection section
1910: Switching part 1920: Voltage sensing part
1930: Overvoltage determination unit 2000: Motor

Claims (10)

1. A power supply apparatus including an SMPS rectification unit and a SMPS (Switched Mode Power Supply) unit,
An SMPS capacitor connected between the SMPS rectification part and the SMPS part to charge or discharge a voltage; And,
And a device protection unit that detects a voltage applied to both ends of the SMPS capacitor and determines whether the overvoltage of the SMPS capacitor flows based on the sensed voltage and cuts off the power applied to the SMPS rectification unit, . The device according to claim 1,
A voltage sensing unit sensing a voltage across both ends of the SMPS capacitor;
An overvoltage determination unit for determining whether an overvoltage of the SMPS capacitor flows based on a voltage sensed by the voltage sensing unit; And,
And a switching unit for shutting off power supplied to the SMPS rectifier unit according to a determination signal of the overvoltage determination unit. The apparatus of claim 2, wherein the voltage sensing unit comprises:
And a distribution resistor connected in parallel with the SMPS capacitor and having a first resistor and a second resistor connected in series. 3. The overvoltage detecting apparatus according to claim 2,
Wherein the comparison unit compares a voltage value sensed by the voltage sensing unit with a predetermined reference voltage value and outputs a determination signal for determining whether the power applied to the SMPS rectifier unit is turned off. 5. The overvoltage detector according to claim 4,
And outputting the determination signal at a low level to turn off the switching unit if the voltage value detected from the voltage sensing unit is greater than the preset reference voltage value, And outputs the determination signal as high to turn on the switching unit if the reference voltage value is smaller than or equal to the preset reference voltage value. 6. The overvoltage detecting apparatus according to claim 5,
And turns off the switching unit for a time period during which a low signal is applied when the determination signal is low. 3. The overvoltage detecting apparatus according to claim 2,
A distribution resistor connected in series between the third resistor and the fourth resistor to generate a reference voltage;
A comparator coupled to a node between a third resistor and a fourth resistor of the distribution resistor and having a first input to which the reference voltage is applied and a second input coupled to the voltage sensing unit and to which the sensed voltage is applied;
A fifth resistor coupled between the second input of the comparator and the voltage sensing unit; And,
And a capacitor having one side connected to a node between the second input terminal of the comparator and the fifth resistor and the other side grounded. The apparatus of claim 2,
And turns off the power applied to the SMPS rectifier by lowering the voltage applied to both ends of the SMPS capacitor when the determination signal of the overvoltage determination unit is low. The apparatus of claim 2,
Wherein when the determination signal of the overvoltage determination unit is high, the power supply unit applies power to the SMPS rectification unit by performing an on-operation to increase the voltage across both ends of the SMPS capacitor. An air conditioner comprising the power supply device according to any one of claims 1 to 9.

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