KR20200050660A - Leading power factor compensation apparatus and Air conditioner comprising the same - Google Patents

Abstract

According to an embodiment of the present invention, provided are a leading power factor compensation device and an air conditioner. The leading power factor compensation device comprises: a current sensing unit disposed between an input power source and an outdoor unit of an air-conditioner to detect current; a ground current circuit unit including a switching element, a rectification unit rectifying alternating current (AC) power inputted by being connected to the input power source, and a reactor connected between the switching element and the rectification unit; and a control unit controlling switching operation of the switching element based on the current detected from the current sensing unit. Therefore, a leading power factor can be effectively compensated.

Description

Leading power factor compensation apparatus and air conditioner comprising the same

The present invention relates to a power factor compensation device and an air conditioner including the same, and more particularly, to a true power factor compensation device and an air conditioner including the same, which effectively compensate the true power factor.

The air conditioner is installed to provide a more comfortable indoor environment to human beings by discharging cold and warm air into the room to create a comfortable indoor environment, adjusting the indoor temperature, and purifying the indoor air. In general, an air conditioner includes an indoor unit installed in a room configured as a heat exchanger, and an outdoor unit configured as a compressor and a heat exchanger to supply refrigerant to the indoor unit.

The air conditioner is separated and controlled by an indoor unit composed of a heat exchanger and an outdoor unit composed of a compressor and a heat exchanger, and is operated by controlling the power supplied to the compressor or the heat exchanger. In addition, the air conditioner may be connected to at least one indoor unit in the outdoor unit, and the refrigerant is supplied to the indoor unit according to a requested operation state, and thus is operated in a cooling or heating mode.

The air conditioner is operated by cooling or heating according to the flow of the refrigerant. In the cooling operation, when the high-temperature and high-pressure liquid refrigerant is supplied to the indoor unit from the compressor of the outdoor unit through the heat exchanger of the outdoor unit, the refrigerant expands and vaporizes in the heat exchanger of the indoor unit. As the temperature of the air decreases and the indoor unit fan rotates, cold air is discharged into the room, and when the high temperature and high pressure gas refrigerant is supplied to the indoor unit from the compressor of the outdoor unit during the heating operation, the high temperature and high pressure gas refrigerant is liquefied in the indoor unit heat exchanger The air warmed by the emitted energy is discharged into the room according to the operation of the indoor fan.

Air conditioners are often used after converting AC power to supply to loads such as motors. To this end, the air conditioner may include a converter, an inverter, and the like. The converter and the inverter include a switching element, and harmonic noise may be generated due to the switching operation of the switching element.

One of the methods for improving the harmonics of an air conditioner is using an active power filter (APF).

7 and 8 are diagrams referred to in the description of a true power factor problem according to the use of a conventional active power filter.

Referring to FIGS. 7 and 8, the AC power 201 may be supplied to a load 80 such as a motor according to on / off of the power switch 71 and the operation switch 72. In this specification, a control circuit configuration such as a switching element for power supply and load operation is simplified and illustrated by a power switch 71 and an operation switch 72.

Meanwhile, an active power filter 60 may be added between the AC power source 201 and the load 80 to improve harmonics.

Typically, the active power filter 60 has a capacitor component therein. Due to the internal capacitor component of the active power filter 60, a true current is generated and the true power factor of the air conditioner is lowered.

The true power factor causes unnecessary power consumption and an increase in electricity rates because the air conditioner is power that is not actually used. Therefore, there is a need for a method capable of minimizing unwanted currents.

As shown in FIG. 8, a reactor generating a ground current having the same magnitude as the true current generated by the capacitor component may be added to minimize the true current. However, since the reactor must also be changed according to the capacity of the capacitor component, there is a problem in that the reactor must be configured differently for each air conditioner model. In addition, it is difficult to cope with various models and manufacturing costs may increase.

An object of the present invention is to provide a true power factor compensation device and an air conditioner including the same, which can effectively improve the true power factor by minimizing the true current.

An object of the present invention is to provide a true power factor correction device and an air conditioner including the same, which can improve the true power factor with a common circuit regardless of the model.

An object of the present invention is to provide a true power factor compensation device and an air conditioner including the same, which can reduce reactive power and save electricity bills.

A true power factor compensation device and an air conditioner according to an embodiment of the present invention for achieving the above object are disposed between the input power and the outdoor unit to sense the current; A ground current circuit unit including a switching element, a rectifier connected to the input power to rectify an input AC power, and a reactor connected between the switching element and the rectifier; And a control unit controlling a switching operation of the switching element based on the current sensed by the current sensing unit, thereby effectively compensating the true power factor.

According to at least one of the embodiments of the present invention, it is possible to effectively improve the true power factor by minimizing the true current.

In addition, according to at least one of the embodiments of the present invention, a true power factor can be improved by a common circuit regardless of a model.

In addition, according to at least one of the embodiments of the present invention, reactive power may be reduced to save electricity bills.

Meanwhile, various other effects will be disclosed directly or implicitly in a detailed description according to an embodiment of the present invention to be described later.

1 is a view illustrating the configuration of an air conditioner according to an embodiment of the present invention.
2 is a schematic view of the outdoor unit and the indoor unit of FIG. 1.
3 is a conceptual diagram of an air conditioner including a true power factor compensation device according to an embodiment of the present invention.
4 is a flowchart illustrating an operation method of a true power factor compensation device according to an embodiment of the present invention.
5 is a diagram illustrating a circuit configuration of a true power factor compensation device according to an embodiment of the present invention.
6 is a diagram showing a circuit configuration of a true power factor correction device according to an embodiment of the present invention.
7 and 8 are diagrams referred to in the description of a true power factor problem according to the use of a conventional active power filter.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the present invention is not limited to these embodiments and can be modified in various forms.

In the drawings, in order to clearly and briefly describe the present invention, illustration of parts irrelevant to the description is omitted, and the same reference numerals are used for the same or extremely similar parts throughout the specification.

On the other hand, the suffixes "module" and "part" for the components used in the following description are given only by considering the ease of writing the present specification, and do not impart a particularly important meaning or role in itself. Therefore, the "module" and the "unit" may be used interchangeably.

Further, in this specification, terms such as first and second may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

1 is a view illustrating the configuration of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 1, the air conditioner 50 according to an embodiment of the present invention may include a plurality of units. For example, the air conditioner 50 according to an embodiment of the present invention includes indoor units 31 to 35, outdoor units 21 and 22 connected to the indoor units 31 to 35, and indoor units 31 To 35) may include a remote control (41 to 45) connected to each. In addition, the air conditioner 50 according to an embodiment of the present invention may further include a central controller 10 for controlling the plurality of indoor units 31 to 35 and the outdoor units 21 and 22.

The central controller 10 is connected to the plurality of indoor units 31 to 36 and the plurality of outdoor units 21 and 22 to monitor and control its operation. At this time, the central controller 10 may be connected to a plurality of indoor units to perform operation setting, lock setting, schedule control, group control, and the like for the indoor unit.

The air conditioner may be any of a stand type air conditioner, a wall-mounted air conditioner, and a ceiling type air conditioner, but for convenience of description, the ceiling type air conditioner will be described as an example. In addition, the air conditioner may further include at least one of a ventilation device, an air cleaning device, a humidifying device, and a heater, and may operate in conjunction with the operation of the indoor unit and the outdoor unit.

The outdoor units (21, 22) are a compressor (not shown) that receives and compresses refrigerant, an outdoor heat exchanger (not shown) that exchanges heat between the refrigerant and outdoor air, and an accumulator that extracts gas refrigerant from the supplied refrigerant and supplies it to the compressor. (Not shown) and a four-way valve (not shown) for selecting the flow path of the refrigerant according to the heating operation. In addition, it may further include a plurality of sensors, valves and oil recovery.

The outdoor units 21 and 22 operate a compressor and an outdoor heat exchanger provided to compress or heat exchange the refrigerant according to the setting to supply the refrigerant to the indoor units 31 to 35.

The outdoor units 21 and 22 are driven by the request of the central controller 10 or the indoor units 31 to 35, and as the cooling / heating capacity varies depending on the indoor units being driven, the number of outdoor units and the compressor installed in the outdoor unit The number of operations is variable.

At this time, the outdoor units 21 and 22 are described on the basis of supplying refrigerant to each of the outdoor units and the connected indoor units, but the plurality of outdoor units are interconnected according to the connection structure of the outdoor unit and the indoor unit, and the refrigerant to the plurality of indoor units You can also supply

The indoor units 31 to 35 are connected to any one of the plurality of outdoor units 21 and 22 to receive coolant and discharge cold and hot air into the room. The indoor units 31 to 35 include an indoor heat exchanger (not shown), an indoor fan (not shown), an expansion valve (not shown) for expanding the supplied refrigerant, and a plurality of sensors (not shown).

At this time, the outdoor units (21, 22) and the indoor units (31 to 35) are connected by a communication line to transmit and receive mutual data, and the outdoor unit and the indoor unit are connected by a separate communication line to the central controller (10) to control the central controller (10). It works.

The remote controllers 41 to 45 are respectively connected to the indoor unit, input a user's control command into the indoor unit, and receive and display status information of the indoor unit. At this time, the remote control communicates by wire or wireless depending on the connection type with the indoor unit, and in some cases, a single remote control unit is connected to a plurality of indoor units, so that the settings of the plurality of indoor units may be changed through a single remote control input.

Meanwhile, according to an embodiment, the remote controllers 41 to 45 may include various sensors such as a temperature sensor.

2 is a schematic view of the outdoor unit and the indoor unit of FIG. 1.

Referring to FIG. 2, the air conditioner 50 is largely divided into an indoor unit 31 and an outdoor unit 21.

The indoor unit 31 is disposed indoors to perform an air-conditioning / heating function, and an indoor fan 109a and an indoor fan arranged on one side of the indoor heat exchanger 108 to promote heat dissipation of the refrigerant. And an indoor blower 109 made of an electric motor 109b for rotating the fan 109a.

At least one indoor heat exchanger 108 may be installed. The compressor 102 may be at least one of an inverter compressor and a constant speed compressor.

In addition, the air conditioner 50 may be configured with a cooler that cools the room, or may be configured with a heat pump that cools or heats the room.

The outdoor unit 21 includes a compressor 102 serving to compress the refrigerant, an electric motor 102b for driving the compressor, an outdoor heat exchanger 104 serving to dissipate the compressed refrigerant, and outdoor An outdoor blower 105, which is disposed on one side of the heat exchanger 104 to promote heat dissipation of the refrigerant, and an outdoor fan 105 composed of an electric fan 105b that rotates the outdoor fan 105a, and expansion to expand condensed refrigerant. Mechanism 106, a cooling / heating switching valve 110 for changing the flow path of the compressed refrigerant, and an accumulator 103 for storing the vaporized refrigerant for a while to remove moisture and foreign substances, and then supplying the refrigerant at a constant pressure to the compressor. And the like.

Meanwhile, although the indoor unit 31 and the outdoor unit 21 are each shown in FIG. 2, a driving device for an air conditioner according to an exemplary embodiment of the present invention is not limited thereto, and the multi-type having a plurality of indoor units and outdoor units Of course, it can be applied to an air conditioner, an air conditioner having a single indoor unit, and a plurality of outdoor units.

3 is a conceptual diagram of an air conditioner including a true power factor compensation device according to an embodiment of the present invention, and FIG. 4 is a flow chart showing a method of operating the true power factor compensation device according to an embodiment of the present invention.

Referring to FIG. 3, the true power factor compensator according to an embodiment of the present invention is disposed between the input power supply 201 and the outdoor unit 31 to sense a current, and a current sensing unit 140 for improving current power factor It may include a ground current circuit unit 120 for generating and supplying the ground current, and a control unit 130 for controlling the ground current circuit unit 120 based on the current sensed by the current sensing unit 140. Here, the input power source 201 may be an AC power source.

3 and 4, the true power factor compensation device according to an embodiment of the present invention can detect a true current (S410).

The controller 130 may determine the true current based on the current sensed by the current sensing unit 140. In an embodiment in which the current sensing unit 140 is configured to detect a true current, the control unit 130 may detect a true current with the current sensed by the current sensing unit 140. Alternatively, in an embodiment further including a voltage sensing unit (not shown), the current sensing unit 140 and the data sensed by the voltage sensing unit (not shown) may be compared to detect whether a true current is generated and its size.

Meanwhile, the current sensing unit 140 may use various known current sensing means such as a current sensor, a current trnasformer (CT) sensor, and a shunt resistor.

Meanwhile, when a true current occurs, the ground current circuit unit 120 may operate to generate a ground current (S420).

The ground current circuit unit 120 includes a switching element (see 530 of FIGS. 5 and 6), a rectifying unit connected to the input power 201 to rectify an input AC power (see 510 of FIGS. 5 and 6), and the switching A reactor connected between the device 530 and the rectifier 510 (see 520 of FIGS. 5 and 6) may be included.

According to an embodiment, the ground current circuit unit 120 may further include a resistor (see 610 in FIG. 6) and a diode (see 620 in FIG. 6) connected in parallel to the reactor 520.

The controller 130 may control the switching operation of the switching element 530 based on the current sensed by the current sensing unit 140.

In addition, the control unit 130 may generate an effect equivalent to the use of various reactance components with one reactor 520 by varying the switching frequency of the switching element 530. For example, the control unit 130 may increase the switching frequency of the switching element 530 to cause the reactor 520 to operate more to generate an effect of using a reactor having a relatively larger capacity. Conversely, the control unit 130 may reduce the switching frequency of the switching element 530 so that the reactor 520 operates less, thereby generating an effect of using a reactor having a relatively smaller capacity.

In addition, since it is possible to generate an effect equivalent to the use of various reactance components by adjusting the switching frequency, the capacity of the reactor 520 itself has an effect of using a small one.

When a true current occurs, the controller 130 may switch the switching element 530 to generate a ground current.

According to an embodiment, when the current sensed by the current sensing unit 140 is greater than or equal to a predetermined reference value, the controller 130 may switch the switching element 530 to generate a ground current.

Under the control of the control unit 130, the ground current circuit unit 120 may generate a ground current to minimize reactive power.

According to the present invention, it is possible to minimize the reactive power by detecting the true current and generating an opposite ground current.

For example, the controller 130 may supply the ground current by operating the ground current circuit unit 120 until the reactive power becomes 0 (S430).

If the reactive power becomes 0 (S430), the controller 130 may stop the operation of the ground current circuit 120 (S440).

The air conditioner according to the present invention may further include an active power filter 60 for improving harmonics of the product.

In this case, due to the DC capacitor inside the active power filter 60, after the power is applied, a true current flows in a standby state, and there is a problem that an electric charge increases.

Accordingly, the current sensed by the current sensing unit 140 disposed between the input power supply 201 and the outdoor unit 31 and between the input power supply 201 and the active power filter 60 may be a true current.

According to the present invention, when the true current is sensed, the ground power for canceling the true current is implemented as a minimum reactor, so that the true power factor can be increased at low cost. In addition, there is an effect that can reduce the user's electricity bill by reducing the unnecessary true current. In addition, reliability of electrical equipment can be improved by reducing the use of power.

The power factor compensation device according to an embodiment of the present invention may be detachably attached to the outdoor unit 31. More preferably, the ground current circuit unit 120 of the power factor compensation device according to an embodiment of the present invention may be arranged to be connected to the same node as the active power filter 60.

5 is a diagram illustrating a circuit configuration of a true power factor compensation device according to an embodiment of the present invention.

Referring to FIG. 5, a true power factor compensator according to an embodiment of the present invention may include a current sensing unit 140 capable of measuring current when power is applied and a ground current circuit unit 120 for flowing ground current. have.

Referring to FIG. 5, a true power factor compensator and an air conditioner according to an embodiment of the present invention are disposed between an input power source 201 and an outdoor unit to sense a current, a current sensing unit 140 and a switching element 530 , A ground current circuit unit 120 including a rectifier 510 connected to the input power 201 to rectify an input AC power, and a reactor 520 connected between the switching element 530 and the rectifier 510. ), And a control unit 130 controlling a switching operation of the switching element 530 based on the current sensed by the current sensing unit 140.

The input power 201 may be supplied to the load 80 on the outdoor unit 31 side according to operations such as the power switch 71 and the operation switch 72.

When the initial power switch 71 is turned on, current may flow. For example, current may flow through the capacitor of the active filter 60. In this case, a true current may be generated due to the capacitor of the active filter 60. The current sensing unit 140 may detect a true current generated when power is applied.

The rectifying unit 510 may rectify and output an input AC power for the switching element 530, which is a one-way element. For example, the rectifier 510 may include a bridge circuit in which four diodes are connected.

When a true current occurs, under the control of the controller 130, the ground current circuit unit 120 may operate to generate a ground current.

In addition, the ground current circuit unit 120 may operate when the current sensed by the current sensing unit 140 is greater than or equal to a reference value. To this end, if the current sensed by the current sensing unit 140 is greater than or equal to a reference value, the controller 130 may start a switching operation of the switching element 530.

When the current sensed by the current sensing unit 140 senses a predetermined size or more, the ground current circuit unit 120 may operate. That is, the switching element 530 may pass a current while performing the switching operation.

The control unit 130 may change the switching frequency of the switching element 530 by checking the current flowing through the current sensing unit 140. For example, the controller 130 may change the switching frequency so that the sum of the ground current and the true current becomes “0”.

The control unit 130 may vary the switching frequency of the switching element 530 according to the amount of current sensed by the current sensing unit 140.

For example, the control unit 130 may increase the switching frequency of the switching element 530 as the amount of current sensed by the current sensing unit 140 increases. Accordingly, the reactor 520 is further operated to implement a reactance having a relatively larger capacity.

Conversely, the control unit 130 may decrease the switching frequency of the switching element 530 as the amount of current sensed by the current sensing unit 140 is smaller. Accordingly, the reactor 520 is less operated to implement a relatively small capacity reactance.

According to an embodiment, the controller 130 may vary the length of the on section in which the switching element 530 is turned on according to the amount of current sensed by the current sensing unit 140.

According to an embodiment, a true power factor compensation device and an air conditioner according to an embodiment of the present invention are disposed between the input power source 201 and the outdoor unit 31 to sense a voltage (not shown) It may further include. The controller 130 may control the true power factor compensation device more precisely based on data sensed by the current sensing unit 140 and the voltage sensing unit.

A true power factor compensating device that attenuates a true current by passing a ground current may be disposed connected to the circuit of the outdoor unit 31. For example, the air conditioner according to an embodiment of the present invention may include a true power factor compensation device on the power input end side of the outdoor unit 31. In addition, the air conditioner may further include an active power filter 60 connected to the same node as the ground current circuit 120 of the true power factor compensation device. Accordingly, the harmonic power factor can be solved while improving harmonics.

True power factor compensation device according to an embodiment of the present invention. By using the small-scale reactor 520 using the switching element 530 to generate the ground current, it is possible to attenuate the true current at low cost.

According to an embodiment of the present invention, by using an active circuit rather than a fixed passive element, it can be applied to multiple models with one common circuit without separately configuring each model.

FIG. 6 is a diagram showing a circuit configuration of a true power factor compensation device according to an embodiment of the present invention. In the embodiment described with reference to FIG. 5, only the resistor 610 and the diode 620 are added. Therefore, the embodiments of FIGS. 5 and 6 can operate on the same principle except for the above differences. Hereinafter, the differences will be mainly described.

Referring to FIG. 6, the ground current circuit unit 120 may further include a resistor 610 and a diode 620 connected in parallel to the reactor 520.

In this case, the diode 620 may have an anode connected to the resistor 610 and a cathode connected to the reactor 520.

When the switching element 530 is turned on, the ground current is generated by the reactor 520. When the switching element 530 is turned off, the reactor 520 forms a closed loop with the resistor 610 and the diode 620. Therefore, energy of the reactor 520 may be consumed in the resistor 610. Accordingly, the effect due to the energy charged in the reactor 520 can be minimized to operate more precisely.

The true power factor compensation apparatus and the air conditioner including the same according to the present invention are not limited to the configuration and method of the above-described embodiments, and the above-described embodiments are provided in various embodiments so that various modifications can be made. All or part may be configured by selectively combining.

On the other hand, the true power factor compensation apparatus according to an embodiment of the present invention and a method of operating an air conditioner including the same can be implemented as a code readable by a processor on a record carrier readable medium. The processor-readable recording medium includes all kinds of recording devices in which data that can be read by the processor are stored. Examples of the recording medium that can be read by the processor include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc., and include those implemented in the form of carrier waves such as transmission through the Internet. . In addition, the processor-readable recording medium may be distributed over a networked computer system so that the processor-readable code is stored and executed in a distributed manner.

In addition, although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications can be implemented by those skilled in the art, and these modifications should not be individually understood from the technical idea or prospect of the present invention.

31: outdoor unit
120: ground current circuit
130: control unit
140: current sensing unit

Claims (10)

A current sensing unit disposed between the input power and the outdoor unit to sense current;
A ground current circuit unit including a switching element, a rectifier connected to the input power to rectify an input AC power, and a reactor connected between the switching element and the rectifier; And,
And a control unit controlling a switching operation of the switching element based on the current sensed by the current sensing unit. According to claim 1,
The ground current circuit unit,
A true power factor compensating device further comprising a resistor and a diode connected in parallel to the reactor. According to claim 2,
The diode is an anode (anode) is connected to the resistor, a cathode (cathode) is connected to the reactor, power factor correction device. According to claim 1,
The ground current circuit unit operates when the current sensed by the current sensing unit is greater than or equal to a reference value. According to claim 1,
When the current sensed by the current sensing unit is greater than or equal to a reference value, the control unit starts a switching operation of the switching element. According to claim 1,
The control unit is a true power factor correction device characterized in that for changing the switching frequency of the switching element according to the amount of current sensed by the current sensing unit. According to claim 1,
The rectifying part comprises a bridge circuit to which four diodes are connected. According to claim 1,
And a voltage sensing unit disposed between the AC power supply and the outdoor unit to sense a voltage. An air conditioner comprising the true power factor compensation device of claim 1. The method of claim 9,
And an active power filter connected to the same node as the ground current circuit.

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