KR20010009757A - protection control method and apparatus of inverter air-conditioner - Google Patents

Abstract

PURPOSE: A method and system for protecting and controlling invertor type air conditioner are provided to prevent elements of a power source of an outdoor unit of an air conditioner from being damaged by power input below normal value. CONSTITUTION: In a method and system for protecting and controlling invertor type air conditioner, the system comprises a rectification unit(3) for rectifying the full-wave of input electric power; a power source frequency detection unit(5) for receiving spheric waves generated in the rectification unit(3) and detecting the frequency of the power source; a relay(9) for controlling electric power supplied to an outdoor unit according to the frequency of the power source; and a microcomputer(7) for perceiving the frequency of the power source and switching on/off the relay(9). Accordingly, since the microcomputer(7) in an indoor unit detects the power source and controls electric power supplied to the outdoor unit, a circuit of an air conditioner is protected from damage by abrupt variation of power source, such as interruption of electric power, or low voltage power input.

Description

Protection control method and apparatus of inverter air conditioner

The present invention relates to an inverter air conditioner, and more particularly, to an inverter air conditioner protection control method and apparatus according to power fluctuations for preventing damage to an outdoor unit power element of an air conditioner according to a power input below a standard value. .

The air conditioner has been put to practical use for more than 30 years, and was used as the ROOM COOLER in the early days of commercialization, and its function was only for cooling. Later, around 1970, HEAT PUMP type air conditioners were developed, and now the name AIRCONDITION has been settled, and air conditioning, heating, humidity control, and air cleaning are used to control indoor air conditions. It plays a role of maintaining the most suitable state according to the use and purpose.

In particular, the inverter air conditioner, which appeared in 1982, has a low power consumption, and thus has become the most popular air conditioner.

Then, a conventional inverter air conditioner (hereinafter referred to as an air conditioner) will be described with reference to the accompanying drawings.

As shown in FIG. 1, an inverter air conditioner generally includes an indoor unit 100 and an outdoor unit 110. The indoor unit 100 includes an evaporator 105, and the outdoor unit 110 includes a compressor 117 and a condenser 115. The indoor unit 100 and the outdoor unit 110 may include microcomputers 103 and 113 for controlling respective components, and the microcomputers 103 and 113 may store data necessary for control between the indoor unit 100 and the outdoor unit 110. Send and receive

When power is applied to the air conditioner configured as described above, the indoor unit 100 and the outdoor unit 110 are driven to operate the air conditioner normally.

At this time, the compressor 117 is driven by the DC power is converted into AC by the power element unit. The power element unit (not shown) that provides power for driving the compressor 117, that is, the inverter unit is called an IPM (Intelligent Power Module).

The IPM is composed of a plurality of Insulated Gate Bipolar Transistors (IGBTs). Since the IGBTs have high power characteristics, they are generally used as voltage driving power devices.

In the conventional inverter air conditioner configured as described above, the indoor unit did not have a function of shutting off the outdoor unit power by recognizing the power state. Therefore, when the signal according to the compressor drive is input from the indoor unit side, the microcomputer of the outdoor unit recognizes that power is input to the air conditioner and outputs a signal for driving the compressor.

Therefore, when a power failure or too small a voltage is input, the voltage input to the power element is small, so that the driving period of the power element is increased to charge a voltage sufficient to drive the compressor, and the power element is larger than the rated value. It will have a long pulse period. That is, when the power device IGBT is driven beyond the prescribed value, that is, when the driving pulse period is too long, the device is destroyed.

That is, the conventional inverter air conditioner has no method of stopping the operation of the outdoor unit in a situation where a voltage below the standard value is applied or the power failure, and thus a voltage for driving the compressor has to be generated in the power element part, and thus the operation pulse period is increased and the device is destroyed. There was a problem.

In particular, since the IGBT constituting the power element is expensive, it is expensive to replace the element when broken. In other words, the conventional inverter air conditioner is not appropriate in terms of economics, because the maintenance cost according to the replacement of the power element is expensive.

Accordingly, an object of the present invention is to provide a protection control method and apparatus for an inverter air conditioner that can prevent the outdoor unit power element portion of the air conditioner from being damaged when a sudden power failure or low voltage is applied.

1 is a configuration diagram of a typical inverter air conditioner,

2 is a block diagram illustrating an indoor unit of an inverter air conditioner according to the present invention;

3 is a flowchart illustrating a method for controlling and controlling an inverter air conditioner according to the present invention;

4 is a detailed circuit diagram of FIG.

* Description of the symbols for the main parts of the drawings *

1,100: indoor unit 3: rectifier

5: power frequency detector 7,55,103,113: microcomputer

105: evaporator 115: condenser

117: compressor 9: relay unit

RY-PWR: Relay 11110: Outdoor unit

50: bridge diode R1 to R8: resistance

C1, C2: Capacitor U1, U2: Transistor

The protection control device of the inverter air conditioner according to the present invention for achieving the above object is a rectifying unit for full-wave rectifying the input power, and a power frequency sensing unit for detecting the power frequency by inputting a square wave generated by the rectifier; And a relay unit for controlling the power supply of the outdoor unit according to the power source frequency, and a microcomputer recognizing the power source frequency to turn on / off the relay unit.

Here, the rectifying portion is composed of a bridge diode, and the power frequency detector outputs a signal to the microcomputer by a waveform rectified through the bridge diode, that is, a square wave, wherein the square wave is 1 if the square wave is less than or equal to a random value. If it is over the value, 0 signal is input.

The relay unit may include a relay for controlling the driving of the outdoor unit and a relay driver for controlling the operation of the relay according to a signal of a microcomputer. In the present invention, the relay is configured using a transistor.

In order to achieve the above object, a protection control method of an inverter air conditioner according to the present invention includes a first step of recognizing a power source frequency of an input power source and a power source frequency equal to a normal frequency in the first step. A second step of supplying a power supply, a power supply frequency lower than the normal frequency is recognized in the first step, a third step of shutting off the outdoor unit power supply, and a power supply frequency detected at regular intervals after the third step. If it is recognized, it is characterized by consisting of a fourth step of driving the outdoor unit after a predetermined time, for example a three-minute delay.

At this time, the microcomputer determines the frequency of the power supply, 110 pulses at 60Hz, 92 pulses at 50Hz, and when the pulse number is lower than the microcomputer, a low voltage is applied to an instantaneous power interruption state or an air conditioner. I judge it.

As described above, when power is applied to the air conditioner, power is first input to the indoor unit, and the indoor unit which inputs the power is configured to sense the power frequency to control the supply power of the outdoor unit. That is, when a power frequency of 60 Hz is input by counting a power frequency per second, for example, when the number of pulses counted by the microcomputer is 110 or higher, it is determined that power is not input or low voltage is applied. Is blocked. Therefore, it is possible to prevent the power device unit of the outdoor unit from being damaged due to a sudden power supply change such as a power failure or a low voltage input.

A protection control method and apparatus for an air conditioner according to the present invention having the above characteristics will be described in detail with reference to the accompanying drawings.

2 is a block diagram of an air conditioner according to an embodiment of the present invention, in particular, the configuration of the indoor unit 1 for controlling the power supply of the outdoor unit 11 according to the input power.

2, the air conditioner according to the present invention includes a rectifier 3 for rectifying input power, a power frequency detector 5 for detecting a power frequency, and a microcomputer that recognizes the power frequency and controls a relay ( 7), a relay unit 9 which is turned on / off by the microcomputer to control power supply of the outdoor unit, and an outdoor unit 11 to which power is supplied by the operation of the relay unit.

Next, the operation of the present invention configured as described above will be described.

When power is applied to the air conditioner, the power is first input to the indoor unit 1 of the air conditioner. The input power is rectified by the rectifier 3 of the indoor unit 1 and converted into a DC voltage. The input power rectified by the rectifier 3 is input to the power frequency detector 5 and sensed.

In this way, the microcomputer 7 turns on / off the relay unit 9 according to the output of the power frequency detector 5. If the power frequency and the recognized frequency are the same, the microcomputer 7 turns on the relay unit 9 and is recognized. If the frequency is less than the number of pulses of the power source frequency, the relay unit 9 is turned off by determining that power is not applied, that is, a momentary power failure or a low voltage is being input.

That is, the microcomputer 7 controls the power supplied to the outdoor unit by turning the relay unit 9 on and off. When the relay unit 9 is driven, the outdoor unit 11 power is turned on and the relay unit 9 is driven. If not, the outdoor unit 11 power is turned off.

Next, Figure 3 is a flow chart showing the operation of the air conditioner according to the power input in the present invention, it will be described with respect to the protection control method of the air conditioner according to the present invention.

When power is supplied to the air conditioner (step 202), first, the microcomputer 7 of the indoor unit 1 recognizes the power source frequency (step 204) to determine whether the air conditioner is operated. For example, when a power supply frequency of 60 Hz is input, the microcomputer 7 counts the square wave number of the frequency, and when the number of pulses is greater than 110 (step 206), the air conditioner operates normally (step 214).

However, if the number of square waves recognized by the microcomputer 7 is 110 or less (step 208), the microcomputer 7 sends a signal to the relay 9 to cut off the power applied to the outdoor unit 11 (the first step). Step 210).

Thereafter, the microcomputer 7 continues to monitor pulses at 1 second intervals. After the power supply of the outdoor unit 11 is cut off and the number of pulses recognized by the microcomputer 7 is greater than 110 after a three minute delay (step 212), the outdoor unit 11 is supplied with power due to the driving of the power relay 9. In operation 214, the air conditioner is normally operated. That is, the microcomputer 7 outputs a signal to drive the relay 9 so that power is supplied to the outdoor unit 11 so that the air conditioner is normally operated (step 214).

On the other hand, even after 3 minutes (step 212), if the number of pulses of the power frequency recognized by the microcomputer is 110 or less, the power relay 9 continues to be turned off and the power supplied to the outdoor unit is cut off (step 210). Then, step 212 is repeated.

Next, the operation of the circuit according to the present invention will be described with reference to FIG. 4.

Referring to FIG. 4, the present invention provides a bridge diode 50 for full-wave rectification of supplied AC power, a resistor R1 connected between the output of the bridge diode 50 and the ground, and an output of the bridge diode 50. And a resistor (R2, R3) connected in series to the base terminal of the TR (U1), and one side is connected between the two resistors (R2, R3), the other side is composed of a capacitor (C1) connected to the ground. The resistor R4 is connected between the base terminal of the TR U1 and the emitter terminal, and the resistors R5 and R6 connected in series to the collector terminal are connected to the input terminal of the microcomputer 55. A resistor R6 and a capacitor C2 are connected to the connection portions of the two resistors R5 and R6, and the other side of the resistor R6 is connected to the + 5V input power and the other side of the capacitor C2 to ground, respectively. do.

The output terminal of the microcomputer 55 is connected to the base terminal of the TR (U2) through the resistor R8, and the resistor R9 is connected between the base terminal and the emitter terminal of the TR (U2). In addition, a relay RY-PWR is connected to the collector terminal of TR (U2), and the other side of the relay RY-PWR is connected to a + 17V input power source.

In the circuit, the resistors R2, R5 and R6 and the capacitor C2 serve to remove noise of the input power source and limit the current.

Next, the operation and function of the present invention configured as described above will be described in detail.

The operation of the circuit will be described, for example, when the power source frequency of the input power source is 60 Hz. When AC power is input to the circuit, it is first full-wave rectified by the bridge diode 50. The square wave generated in this way has 120 pulses per second because the full wave rectification by the bridge diode 50 converts all negative waveforms into positive portions. Therefore, the power supply frequency is converted to 120 Hz by the bridge diode 50.

The square wave is input to the base terminal of TR (U1). At this time, if the voltage of the square wave is more than a predetermined value, TR (U1) is driven. That is, when a voltage equal to or greater than a predetermined value is input to TR (U1), TR (U1) is driven, whereby an input voltage of + 5V flows to ground through the TR (U1). Therefore, the voltage input to the microcomputer 50 becomes 0V. That is, the low signal is input to the microcomputer 50.

On the other hand, when the voltage of the square wave is less than a predetermined value, TR is turned off, so the + 5V input voltage is input to the microcomputer 55 through the resistor R6. That is, the high signal is input to the microcomputer 55.

By the above operation, the microcomputer 55 checks the frequency of the input power. That is, since the low signal and the high signal are repeatedly input to the microcomputer 55 according to the pulse waveform of the power frequency, the microcomputer 55 counts the low / high signal input for one second to supply power. It will detect the frequency.

In this way, when the microcomputer 55 senses 120Hz, that is, counts 110 or more, the microcomputer 55 outputs a high signal to the output terminal. The high signal generally has a value equal to or greater than a random value and is input to the base terminal of TR (U2), which drives TR (U2). Accordingly, current flows to drive the relay RY-PWR.

In this manner, the relay RY-PWR is driven to supply power to the outdoor unit, thereby operating the air conditioner normally.

On the other hand, if the microcomputer 55 does not detect a power supply frequency of 120 Hz, that is, if the number of pulses counted by the microcomputer 55 is 110 or less, the microcomputer 55 outputs a low signal to the output terminal. The low signal is input to the base terminal of TR (U2) with a voltage less than a predetermined value, and TR (U2) is turned off at this time.

When TR (U2) is turned off, no current flows, so relay RY-PWR is turned off. That is, since the relay RY-PWR is not driven, the outdoor unit power supply is cut off.

In this operation, if the power source frequency of the power source input to the air conditioner is 50 Hz, the frequency is first converted into a square wave of 100 Hz by the bridge diode 50. Therefore, the microcomputer 55 recognizes a power frequency of 100 Hz and controls the driving of the relay RY-PWR. When the microcomputer 55 counts 92 or more pulses, the relay RY-PWR is driven to operate the outdoor unit. Power is supplied. If the microcomputer 55 counts the number of pulses of 92 or less, the outdoor unit power supply is cut off because the relay RY-PWR is turned off by judging it as a momentary power failure or a low voltage input state.

In general, a power failure often occurs due to the large amount of electricity used in the summer, and sudden changes in the input power supply such as a power failure cause damage to the circuit. In particular, since air conditioners are mainly used in summer, a situation in which a circuit is broken due to a power failure often occurs.

Accordingly, the present invention is configured as described above, that is, when power is applied to the air conditioner, the power is not applied directly to the outdoor unit, but is first detected by the microcomputer on the indoor unit side and then the power is supplied to the outdoor unit side. When suddenly interrupted or a low voltage is input, it is possible to prevent the outdoor unit circuit of the air conditioner, especially the power element part.

The present invention configured as described above is configured to control the power supplied to the outdoor unit by sensing the power by the microcomputer of the indoor unit is input to the indoor unit first input power is not directly supplied to the outdoor unit, such as sudden power fluctuations such as power failure An effect of preventing the power device portion of the outdoor unit from being damaged by the low voltage input can be obtained.

Claims (4)

A rectifier for full-wave rectifying the input power; A power frequency detector detecting a power frequency by inputting a square wave generated by the rectifier; A relay unit controlling a power supply of the outdoor unit according to the power frequency; And a microcomputer for recognizing the power supply frequency to turn on / off the relay unit. The method of claim 1 wherein: The power supply frequency sensing unit may include switching means turned on / off by a square wave output through a bridge diode; And a power frequency output means for outputting a signal to the microcomputer according to the operation of the switch means. A first step of recognizing a power frequency of an input power source; A second step of driving the outdoor unit when a power source frequency equal to a normal frequency is recognized in the first step; A third step of shutting off the power of the outdoor unit when a power source frequency lower than the normal frequency is recognized in the first step; A fourth step of sensing a power frequency at a predetermined interval after the third step and driving the outdoor unit when a normal frequency is recognized, and repeating the third step again when a frequency lower than the normal frequency is recognized; When the outdoor unit is driven through the second and fourth stages, the protection control method of the inverter air conditioner, characterized in that repeating again from the first stage. The method of claim 3 wherein: The first step may include generating a pulse according to an input signal; Sampling the pulse at regular intervals; And determining the number of pulses generated by the sampling step.