Patent Publication Number: US-2009228147-A1

Title: Apparatus and Method for Controlling Air Conditioner

Description:
TECHNICAL FIELD 
     The present invention relates to an apparatus and method for controlling an air conditioner, and more particularly, to a microcomputer of an apparatus for controlling an air conditioner. 
     BACKGROUND ART 
     Generally, a prior art air conditioner is provided with two microcomputers so as to separately control a valve, a fan, a compressor, a power supply unit, etc. 
     Hereinafter, a prior art apparatus for controlling an air conditioner will be explained with reference to  FIG. 1 . 
       FIG. 1  shows an apparatus for controlling an air conditioner in accordance with the prior art. 
     As shown in  FIG. 1 , the prior art apparatus for controlling an air conditioner comprises a converter  200  consisting of a rectifying unit  210 , an active filter  220 , and a smoothening capacitor C, for converting a commercial alternating current (AC) power into a direct current (DC); inverters  300  and  330  for converting the DC converted by the converter  200  into an AC, and supplying the converted AC to a compressor-driving motor  100  and a fan-driving motor  110 ; inverter controllers  310  and  340  for driving the compressor-driving motor  100  and the fan-driving motor  100  by controlling the inverters  300  and  330 ; a first microcomputer  360  for controlling position detectors  320  and  350  that detect a position of each pole of the compressor-driving motor  100  and the fan-driving motor  110 ; and a second microcomputer  280  for controlling an active filter controller  240  that controls the active filter  220 , electrical equipment controlling switches  250  (such as relays and valves), a temperature sensor  260 , an indoor unit  270 , and the first microcomputer  360 . 
     The rectifying unit  210  rectifies an AC voltage inputted from a commercial power. The active filter  220  composed of a reactor L and a switching device Q converts a phase of the inputted AC into a sine waveform of an inputted voltage. The smoothening capacitor C smoothens the output voltage from the active filter  220  into a DC voltage. The smoothened DC voltage is supplied to the inverter  300  for supplying a voltage to the compressor-driving motor  100 , and the inverter  330  for supplying a voltage to the fan-driving motor  110 . 
     The active filter controller  240  controls a gate driving unit  23  for driving the switching device Q of the active filter  220 , thereby controlling the active filter  220 . 
     The first microcomputer  360  controls the compressor-driving motor  100 , and the fan-driving motor  110 . The second microcomputer  280  indirectly controls the compressor-driving motor  100  and the fan-driving motor  110  by controlling the first microcomputer  360 . Also, the second microcomputer  280  controls the active filter  220  for supplying power to the compressor-driving motor  100  and the fan-driving motor  110 , the electrical equipment controlling switches  250 , the temperature sensor  260 , the indoor unit  270 , etc. 
     The prior art apparatus for controlling an air conditioner has been disclosed in the U.S. Pat. No. 6,397,611 B1. 
     However, the prior art apparatus for controlling an air conditioner has the following problems. 
     First, since each high-speed microcomputer that can process data with a high speed has to be implemented as the first microcomputer  360  and the second microcomputer  280 , a fabrication cost for the apparatus is increased. 
     Second, since a data communication amount between the first microcomputer  360  and the second microcomputer  280  is increased, a reliability of the apparatus for controlling an air conditioner is degraded and a complicated circuit is implemented. 
     DISCLOSURE OF THE INVENTION 
     Therefore, an object of the present invention is to provide an apparatus and method for controlling an air conditioner capable of reducing a fabrication cost by using one high-speed microcomputer and one port-extension microcomputer, capable of enhancing a reliability thereof by reducing a data communication amount between the microcomputers, and capable of implementing a simple circuit construction. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an apparatus for controlling an air conditioner comprising: a converter for converting an alternating current (AC) voltage into a direct current (DC) voltage, and boosting the DC voltage; a smoothening unit for smoothening the DC voltage from the converter; an inverter for converting the smoothened DC voltage into an AC voltage; and a motor, the apparatus comprising: a supplementary microcomputer for controlling a valve and a relay by receiving a control signal, the valve for controlling a refrigerant flow inside a pipe of the air conditioner, and the relay for controlling a current flow; and a main microcomputer for entirely controlling the air conditioner with including a real-time controlling unit of the air conditioner and the supplementary microcomputer. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is also provided a method for controlling an air conditioner comprising: a converter for converting an alternating current (AC) voltage into a direct current (DC) voltage, and boosting the DC voltage; a smoothening unit for smoothening the DC voltage from the converter; an inverter for converting the smoothened DC voltage into an AC voltage; and a motor, the method comprising: detecting a current driving state of the air conditioner; performing a supplementary control process for controlling a refrigerant flow inside a pipe of the air conditioner, and a current flow according to the detected driving state by receiving a control signal; and performing a main control process for entirely controlling the air conditioner with including a real-time controlling unit of the air conditioner and the supplementary microcomputer. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
       In the drawings: 
         FIG. 1  is an apparatus for controlling an air conditioner in accordance with the prior art; 
         FIG. 2  is an apparatus for controlling an air conditioner according to the present invention; and 
         FIG. 3  is a flowchart showing a method for controlling an air conditioner according to the present invention. 
     
    
    
     MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     Hereinafter, with reference to  FIG. 2 , will be explained an apparatus and method for controlling an air conditioner capable of reducing a fabrication cost by using one high-speed microcomputer and one port-extension microcomputer, capable of enhancing a reliability thereof by reducing a data communication amount between the microcomputers, and capable of implementing a simple circuit construction. 
     The same reference numerals as those of  FIG. 1  will be given to the same parts of  FIG. 2  as those of  FIG. 1 . 
       FIG. 2  is an apparatus for controlling an air conditioner according to the present invention. 
     As shown in  FIG. 2 , an apparatus for controlling an air conditioner comprising: a converter  200  for converting an alternating current (AC) voltage into a direct current (DC) voltage, and boosting the DC voltage; a smoothening unit C for smoothening the DC voltage from the converter  200 ; inverters  300  and  330  for converting the smoothened DC voltage into an AC voltage; and motors  100  and  110 , the apparatus comprises: a supplementary microcomputer  400  for controlling a valve and a relay by receiving a control signal, the valve for controlling a refrigerant flow inside a pipe of the air conditioner, and the relay for controlling a current flow; and a main microcomputer  360  for entirely controlling the air conditioner with including a real-time controlling unit of the air conditioner and the supplementary microcomputer  400 . 
     The real-time controlling unit comprises: a converter for converting an input AC into an input AC voltage of a sine waveform, converting the AC voltage into a DC voltage, and boosting the converted DC voltage; converter controllers  230  and  240  for controlling the converter  200  according to a control signal; a compressor-driving motor  100  for driving a compressor; a first position detector  320  for detecting a position of a pole of the compressor-driving motor; a fan-driving motor  110  for driving a fan; a second position detector  350  for detecting a position of a pole of the fan-driving motor; inverters  300  and  340  for converting the smoothened DC voltage into an AC voltage; and an inverter controller for controlling the inverter according to a control signal so that the converted AC voltage can be supplied to the compressor-driving motor and the fan-driving motor. 
     The real-time controlling unit further comprises a temperature sensor  260 , and an indoor unit  270  for supplying cool air to an indoor room. 
     The converter controller comprises a gate driving unit  230  for driving a switch that opens and closes a path of an input power supplied to the smoothening unit C, and an active filter controller  240  for generating a switching signal supplied to the gate driving unit. 
     The main microcomputer  360  is implemented as a high-speed microcomputer, and the supplementary microcomputer is implemented as a port-extension microcomputer  400 . 
     The rectifying unit  210 , the active filter  220 , the smoothening capacitor C, and the active filter controller  240  have the same structure and operation as those of the prior art, and thus detailed explanation thereof will be omitted. 
     The main microcomputer and the supplementary microcomputer will be explained as follows. 
     The main microcomputer is implemented as a high-speed microcomputer, and entirely controls the air conditioner with including the real-time controlling units and the supplementary microcomputer  400  that require a fast response characteristic, the real-time controlling units including the converter  200 , the converter controllers  230  and  240 , the first and second inverters  300  and  330 , the first and second inverter controllers  310  and  340 , the temperature sensor  260 , the indoor unit  270 , the motors  100  and  110 , etc. The main microcomputer controls the air conditioner except for the electrical equipment controlling switches  250  that require no real-time control. The supplementary microcomputer  400  is implemented as a port-extension microcomputer, and controls the electrical equipment controlling switches  250  including each relay and each valve which do not require the real-time control. 
     In the present invention, an expensive high-speed microcomputer serves as the main microcomputer, thereby performing a real-time control. Also, a cheap port-extension microcomputer serves as the supplementary microcomputer, thereby performing a non real-time control. Accordingly, the expensive high-speed microcomputers need not be used in two. 
     Accordingly, a data communication amount between the microcomputers  360  and  400  is decreased, thereby enhancing a reliability of the apparatus. 
       FIG. 3  is a flowchart showing a method for controlling an air conditioner according to the present invention. 
     As shown in  FIG. 3 , the method for controlling an air conditioner comprising: a converter for converting an alternating current (AC) voltage into a direct current (DC) voltage, and boosting the DC voltage; a smoothening unit for smoothening the DC voltage from the converter; an inverter for converting the smoothened DC voltage into an AC voltage; and a motor, the method comprises: detecting a current driving state of the air conditioner (S 31 ); performing a supplementary control process for controlling a refrigerant flow inside a pipe of the air conditioner, and a current flow according to the detected driving state by receiving a control signal (S 32 , S 33 ); and performing a main control process for entirely controlling the air conditioner with including a real-time controlling unit of the air conditioner and the supplementary microcomputer (S 32 , S 34 ). 
     The main control process S 34  comprises: converting an input AC into an input AC voltage of a sine waveform, converting the AC voltage into a DC voltage, and boosting the converted DC voltage; first-position detecting for detecting a position of a pole of a compressor-driving motor; second-position detecting for detecting a position of a pole of a fan-driving motor; and converting the smoothened DC voltage into an AC voltage according to the detected first and second positions. 
     The main control process further comprises: detecting each temperature of an indoor room and a compressor valve; and controlling the indoor unit so that cool air can be supplied to the indoor room. 
     The converting an input AC voltage and boosting comprises: generating a switching signal to drive a converter; and opening and closing a path of an input power supplied to the smoothening unit according to the generated switching signal. 
     In the main control process (S 34 ), the air conditioner is entirely controlled by the high-speed microcomputer. In the supplementary control process, a refrigerant flow and a current flow inside the air conditioner are controlled by the port-extension microcomputer. 
     As aforementioned, in the present invention, one expensive high-speed microcomputer and one cheap port-extension microcomputer are used, thereby reducing a fabrication cost of the apparatus for controlling an air conditioner. Furthermore, since the high-speed microcomputer performs a real-time control requiring a fast response characteristic and the port-extension microcomputer controls the relay or the valve requiring no real-time control. Accordingly, a data communication amount between the microcomputers is decreased thus to enhance a reliability of the apparatus. 
     As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.