Air conditioner

Information

  • Patent Grant
  • 6497109
  • Patent Number
    6,497,109
  • Date Filed
    Tuesday, December 19, 2000
    24 years ago
  • Date Issued
    Tuesday, December 24, 2002
    22 years ago
Abstract
An air conditioner capable of improving its assembling efficiency and reducing material costs. The air conditioner reduces the effects of the fluctuation in commercial line voltage (12) on the supply voltage to a compressor (11), while reducing the vibrations of its outdoor unit (2). The outdoor unit (2) is provided with a voltage correction circuit (14) that maintains the output voltage to the compressor (11) constant (optimal) regardless of the changes in voltage on commercial power supply line (12).
Description




TECHNICAL FIELD




The present invention relates to a separate-type air conditioner that comprises a separate indoor unit and outdoor unit connected electrically.




BACKGROUND ART




As shown in

FIG. 13

, an electric circuit of a conventional air conditioner capable of cooling and heating comprising an indoor unit


1


, an outdoor unit


2


, and an indoor-outdoor connector cable


3


connecting them electrically. The indoor unit


1


comprises a main switch


4


, an indoor electronic controller


5


, an indoor fan motor


6


such as a transistor motor, and a louver motor


7


for driving upper and lower indoor blades. The outdoor unit


2


comprises an outdoor electronic controller


8


, a four-way valve


9


for switching a refrigerant flow path according to refrigerating and heating cycles, an outdoor fan motor


10


such as an induction motor, and a compressor


11


for compressing the refrigerant.




The operation of this conventional air conditioner will be described below.




The indoor unit


1


is connected to the commercial power supply


12


. When the main switch


4


on the indoor unit


1


is turned on, power is supplied to the indoor electronic controller


5


, which starts control operation and activates the indoor fan motor


6


and the louver motor


7


to start circulating indoor air through an indoor heat exchanger (not shown). Now if the user gives an operation start command, the indoor electronic controller


5


connects the outdoor unit


2


with the commercial power supply


12


by means of the main relay (not shown) to supply power to it. Receiving power from the commercial power supply


12


, the outdoor electronic controller


8


starts control operation: it applies control voltage to the compressor


11


to start its rotation and connects the outdoor fan motor


10


with the commercial power supply


12


to start sending outdoor air to an outdoor heat exchanger (not shown). When the commercial power supply


12


is not connected, the four-way valve


9


for switching the refrigerant flow path is positioned to pass the refrigerant to the cooling-cycle path under instructions from the outdoor electronic controller


8


. In this state, the air conditioner starts cooling operation.




Next, when the user specifies heating, the commercial power supply


12


is connected to the four-way valve


9


under instructions from the outdoor electronic controller


8


. This operation switches the refrigerant flow path to the heating-cycle side to make heating to be started. The out door fan motor


10


sends outdoor air to the outdoor heat exchanger, which extracts heat from the outdoor air into the refrigerant, which consequently vaporizes, is compressed by the compressor


11


, and is sent to the indoor heat exchanger.




In either case, the outdoor electronic controller


8


amplifies or attenuates the commercial power supply


12


in accordance with the operating frequency of the compressor


11


and applies the resulting voltage to the compressor


11


.




However, with the configuration of the conventional air conditioner, in which the output voltage to the compressor solely depends on the voltage of the commercial power supply, voltage variations in the commercial power supply will fluctuate the output voltage to the compressor, which may result in a failure to start the compressor. To eliminate this disadvantage, the output signal to the compressor should be set at a little larger value, which, however, may increase the vibration of the output unit at a start-up and during an operation. To deal with this situation, currently a vibration damping part such as Coal Tape, etc. is used in large quantities for the piping of the outdoor unit or a loop-like shape is given to the piping for vibration damping. However, this increases material costs and requires a large number of manhours during assembly, resulting in poor workability. Moreover, shifts in the operating point of the compressor will degrade the efficiency of the compressor, resulting in increased power consumption. Also, if the compressor is not pressure balanced during restarting, optimum voltage will not be applied. Therefore, a compressor with a dc motor may fail to restart due to insufficient starting torque.




An object of the present invention is to provide an air conditioner and its operation control method that will reduce the effect of voltage fluctuations in commercial power supply and ensure accurate compressor operation. Another object of the present invention is to provide an air conditioner and its operation control method that will improve the starting force of the compressor considering its starting load while reducing the effect of voltage fluctuations in the commercial power supply on the compressor.




DISCLOSURE OF THE INVENTION




To attain the above objects, a separate-type air conditioner according to the present invention contains a correction circuit of output voltage to a compressor in an outdoor unit. This voltage correction circuit keeps the output voltage to the outdoor unit constant (optimum) despite voltage fluctuations in a commercial power supply, making it possible to largely reduce the use of vibration damping material such as Coal Tape and simplify the shape of pipings while maintaining vibration of the outdoor unit at low levels, and thus providing the advantages of reduced material costs and improved working efficiency during assembly operations.




More particularly, the separate-type air conditioner according to the present invention connects the indoor and outdoor units electrically to each other by means of an indoor-outdoor connector cable and contains a correction circuit of the output voltage to the compressor in the outdoor unit to keep the output voltage to the outdoor unit constant by correcting fluctuations in the voltage of the commercial power supply. Since the correction circuit of the output voltage to the compressor keeps the output voltage to the outdoor unit constant, the vibration of the outdoor unit is maintained at low levels, resulting in reduced material costs and improved working efficiency during assembly operations.




The voltage correction circuit of the separate-type air conditioner according to the present invention comprises voltage detection means for detecting input voltage, reception means for receiving an input voltage signal outputted by the voltage detection means, a timer and an arithmetic circuit for averaging the input voltage signal received by the reception means within a specified time period, and determination means and the arithmetic circuit for voltage correction control in order for correcting and determining the output voltage to the compressor. Since the timer, arithmetic circuit, and determination means can keep the output voltage to the compressor constant, the vibration of the outdoor unit is maintained at low levels, resulting in reduced material costs and improved working efficiency during assembly operations.




The voltage correction circuit of the separate-type air conditioner according to the present invention comprises voltage detection means for detecting input voltage, reception means for receiving an input voltage signal outputted by the voltage detection means, and determination means for voltage correction control in order for correcting and determining the output voltage to the compressor based on the input voltage signal and by means of a data table. The use of the data table instead of the arithmetic circuit for obtaining optimum output voltage to the compressor from the input voltage signal has the effect of reducing capacity requirements of a micro computer and further reducing material costs.




The voltage correction circuit of the separate-type air conditioner according to the present invention comprises voltage detection means for detecting input voltage as well as determination means and an arithmetic circuit for voltage correction control in order fore correcting and determining the output voltage to the compressor by making corrections for loads, based on an outside air temperature detection signal outputted from outside air temperature detection means installed in the outdoor unit and a room air temperature detection signal outputted from room air temperature detection means installed in the indoor unit. The measurement of outside air temperature and room air temperature clarifies the working loads on the separate-type air conditioner, and thus makes it possible to optimize the output voltage to the compressor, taking the effect of loads into consideration.




An operation control method of the separate-type air conditioner according to the present invention comprises the steps of controlling a duty of the commercial power supply, converting the duty into a power supply signal according to a voltage value of the commercial power supply, and applying a resulting power supply signal to a power supply circuit of the compressor. This allows the output voltage to the compressor to be optimized irrespective of voltage fluctuations in a commercial power supply, ensuring an accurate start-up and an efficient operation of the compressor.




More particularly, the start control method of the air conditioner according to the present invention operates the compressor for a refrigerating cycle by controlling the duty of the commercial power supply, converting the duty into a power supply signal according to a voltage value of the commercial power supply, and applying a resulting power supply signal to a power supply circuit of the compressor. This provides the capability to optimize the output voltage to the compressor irrespective of the voltage fluctuations in the commercial power supply, ensuring an accurate start-up of the compressor as well as the capability to maintain the vibration of the outdoor unit at low levels, resulting in reduced material costs and improved working efficiency during assembly operations. Besides, the compressor can always be operated efficiently.




The separate-type air conditioner according to the present invention is operated by the steps of controlling a duty of a commercial power supply, converting the duty into a power supply signal according to a voltage value of the commercial power supply, and applying a resulting power supply signal to a power supply circuit of a compressor, wherein a voltage correction controller is provided in order for correcting and determining an optimum output voltage to the compressor by allocating a duty data for determination of the output voltage to the compressor to one of high-voltage, rated-voltage and low-voltage region tables or to one of high-voltage and low-voltage region tables according to input voltage. This provides the capability to optimize the output voltage to the compressor despite the voltage fluctuations in the commercial power supply, ensuring an accurate start-up of the compressor as well as the capability to maintain the vibration of the outdoor unit at low levels, resulting in reduced material costs and improved working efficiency during assembly operations. Besides, the compressor can always be operated efficiently.




The air conditioner according to the present invention comprises detection means for detecting load conditions to allow the voltage correction controller to modify the duty data based on the load conditions to correct and determine the optimum output voltage to the compressor. Thus, it can detect the load conditions of the air conditioner, and consequently optimize the output voltage to the compressor taking into consideration the effect of the load conditions on the output voltage to the compressor.




The air conditioner according to the present invention comprises voltage/current detection means for detecting the output voltage and output current to the compressor to allow the voltage correction controller to modify the duty data based on the output voltage and output current detected by the voltage/current detection means to correct and determine the optimum output voltage to the compressor. Thus, it can clarify the load conditions of the air conditioner, and consequently optimize the output voltage to the compressor taking into consideration the effect of the loads on the output voltage to the compressor.




A start control method of an air conditioner according to the present invention starts the compressor by the steps of applying a power supply signal set according to the voltage value of a commercial power supply at a start-up time and corrected based on a suspension period of the compressor to the power supply circuit of the compressor. This makes it possible to reduce the effect of the loads on the output voltage to the compressor as well as to improve the starting force of the compressor taking into consideration the compressor loads at the start-up time.




More particularly, the start control method of the air conditioner according to the present invention starts the compressor for a refrigerating cycle by applying the power supply signal set according to the voltage value of the commercial power supply at the start-up time and corrected based on the suspension period of the compressor to the power supply circuit of the compressor. This makes it possible to reduce the effect of the loads on the output voltage to the compressor as well as to improve the starting force of the compressor taking into consideration the compressor loads at the start-up.




An air conditioner according to the present invention, which starts the compressor by applying a power supply signal set according to a voltage value of a commercial power supply at a start-up time to a power supply circuit of the compressor, comprises a voltage correction controller for correcting the power supply signal and determining an optimum output voltage to the compressor based on a suspension period of the compressor. This makes it possible to reduce the effect of loads on the output voltage to the compressor as well as to improve the starting force of the compressor taking into consideration the compressor loads at the start-up time.




The air conditioner according to the present invention comprises shell temperature detection means for detecting a shell temperature of the compressor to allow the voltage correction controller to correct and determine the optimum output voltage to the compressor based on a detection signal from the shell temperature detection means. By detecting the shell temperature of the compressor and determining the optimum output voltage to the compressor taking into consideration magnetic characteristics of a dc motor, it is possible to further improve the starting force of the compressor.




The air conditioner according to the present invention has the voltage correction controller configured to correct and determine the optimum output voltage to the compressor based on a room air temperature detection signal outputted from the room air temperature detection means and an outside air temperature detection signal outputted from the outside air temperature detection means. By detecting the room air temperature and outside air temperature and correcting the optimum output voltage to the compressor taking into consideration the characteristics of a refrigerant at the start-up time after a long-term shutdown, it is possible to optimize the output voltage to the compressor.




A start control method of the air conditioner according to the present invention starts a compressor for a refrigerating cycle by the steps of controlling a duty of a commercial power supply, converting the duty into a power supply signal according to a voltage value of the commercial power supply, and applying a resulting power supply signal to a power supply circuit of the compressor with the duty corrected according to a suspension period of the compressor. This makes it possible to reduce the effect of voltage fluctuations in the commercial power supply on the output voltage to the compressor as well as to improve the starting force of the compressor taking into consideration the compressor loads at the start-up time.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an electrical circuit diagram of a first embodiment of the separate-type air conditioner according to the present invention;





FIG. 2

is an electrical circuit diagram showing the internal configuration of part of

FIG. 1

;





FIG. 3

is a block diagram showing an electric circuit of a second embodiment of the separate-type air conditioner according to the present invention;





FIG. 4

is a block diagram showing the configuration of a voltage correction circuit of the second embodiment;





FIG. 5

is a block diagram showing an electric circuit of a third embodiment of the separate-type air conditioner according to the present invention;





FIG. 6

is a block diagram showing the configuration of the voltage correction circuit of the third embodiment;





FIG. 7

is a block diagram showing the electric circuit of a fourth embodiment of the separate-type air conditioner according to the present invention;





FIG. 8

is a block diagram showing the configuration of the voltage correction circuit of the fourth embodiment;





FIG. 9

is a block diagram showing the electric circuit of a fifth embodiment of the separate-type air conditioner according to the present invention;





FIG. 10

is a block diagram showing the configuration of the voltage correction circuit of the fifth embodiment;





FIG. 11

is a block diagram showing the electric circuit of a sixth embodiment of the separate-type air conditioner according to the present invention;





FIG. 12

is a block diagram showing the configuration of the voltage correction circuit of the sixth embodiment; and





FIG. 13

is a block diagram showing the electric circuit of a conventional air conditioner.











DESCRIPTION OF THE EMBODIMENTS




Embodiments of the present invention will be described below with reference to the accompanying drawings.




(Embodiment 1)





FIG. 1

is an electrical circuit diagram of a first embodiment 1 of the separate-type air conditioner according to the present invention, wherein an indoor unit


1


and an outdoor unit


2


are electrically connected to each other by means of an indoor-outdoor connector cable


3


. The indoor unit


1


comprises an indoor electronic controller


5


, a main switch


4


for connecting and disconnecting a commercial power supply


12


to the indoor electronic controller


5


, an indoor fan motor


6


such as a transistor motor and louver motor


7


for driving upper and lower indoor blades, both of which are controlled by the indoor electronic controller


5


, and an inlet temperature sensor serving as detection means


13


of room air temperature. The outdoor unit


2


comprises an outdoor electronic controller


8


, a four-way valve


9


for switching the refrigerant flow path according to the refrigerating and heating cycles, an outdoor fan motor


10


such as an induction motor and a compressor


11


, both of which are controlled by the outdoor electronic controller


8


, a voltage correction circuit


14


mounted between the outdoor electronic controller


8


and the compressor


11


, and an outside air temperature sensor serving as detection means


15


of outside air temperature.





FIG. 2

is an electrical circuit diagram showing the internal configuration of part of the voltage correction circuit


14


. In the figure,


16


denotes voltage detection means for detecting the voltage of the commercial power supply


12


sent to the outdoor electronic controller


8


by the indoor electronic controller


5


,


17


denotes reception means for receiving, as an input voltage signal, the voltage detected by the voltage detection means


16


,


18


denotes a timer,


19


denotes determination means, and


20


denotes an arithmetic circuit.




In the separate-type air conditioner of the above configuration, the voltage corrected and determined by the voltage correction circuit


14


mounted in the outdoor electronic controller


8


is applied to the compressor


11


both during cooling and heating.




The interrelationships among the individual components of the separate-type air conditioner of the above configuration will be described below. The voltage of the commercial power supply


12


sent to the outdoor electronic controller


8


by the indoor electronic controller


5


is detected by the voltage detection means


16


of the voltage correction circuit


14


inserted between the outdoor electronic controller


8


and the compressor


11


, and received as an input voltage signal by the reception means


17


. At this time, the timer


18


comes into action. Then the determination means


19


and the arithmetic circuit


20


average the input voltages within a specified time period and detect the output voltage of the commercial power supply


12


, that is, voltage fluctuations in the commercial power supply


12


sent to the outdoor electronic controller


8


.




The arithmetic circuit


20


carries out arithmetic operations and determines the amplification factor (attenuation factor) of the output voltage so that the output voltage (optimum voltage) corresponding to the operating frequencies at rated voltage will be applied constantly to the compressor


11


. And the resulting output voltage is applied to the compressor


11


.




Here, the arithmetic circuit


20


may be a data table that represents the relationship between input voltages and the results of arithmetic operations.




The voltage of the commercial power supply


12


sent to the outdoor electronic controller


8


is detected by the voltage detection means


16


of the voltage correction circuit


14


at specified intervals by means of the timer


18


.




Furthermore, the detection signal of the room air temperature detected by the inlet temperature sensor


13


serving as a detection means of room air temperature in the indoor unit


1


and the detection signal of the outside air temperature detected by the outside air temperature sensor


15


serving as a detection means of outside air temperature in the outdoor unit


2


are received by the reception means


17


of the outdoor unit


2


. Using this data, the determination means


19


and arithmetic circuit


20


determine the loads on the separate-type air conditioner and add them to the operation results of the arithmetic circuit


20


as corrections for the working loads for use as a data table in determining the output voltage, for further optimization of the output voltage.




(Embodiment 2)




A second embodiment 2 of the separate-type air conditioner shown in

FIG. 3

comprises an indoor unit


1


, an outdoor unit


2


, and an indoor-outdoor connector cable


3


that connects them electrically, as is the case with the conventional air conditioner shown in FIG.


13


. The only difference is that a voltage correction circuit


23


has been added as a voltage correction controller.




The voltage correction circuit


23


controls the duty of the commercial power supply


12


, converts it into a power supply signal according to the voltage value of the commercial power supply


12


, and applies the resulting power supply signal to the power supply circuit of the compressor


11


. Specifically, as shown in

FIG. 4

, it comprises voltage detection means


24


and an arithmetic circuit


25


for correcting and determining the optimum output voltage to the compressor


11


by allocating the duty data for determination of the output voltage to the compressor


11


to a high-voltage region, rated-voltage region, or low-voltage region duty table according to the input voltage.




Now the operation of this separate-type air conditioner will be described below.




As shown in

FIG. 3

, with the main switch


4


of the indoor unit


1


on and with power being delivered to the indoor electronic controller


5


from the commercial power supply


12


, when the user specifies operation start, the power from the commercial power supply


12


is delivered through the indoor electronic controller


5


to the outdoor electronic controller


8


and to the voltage correction circuit


23


.




As shown in

FIG. 4

, the voltage detection means


24


detects the input voltage supplied to the outdoor electronic controller


8


from the commercial power supply


12


i.e., detects voltage fluctuations in the commercial power supply


12


. The voltage detection means


24


outputs the detected input voltage as an input voltage signal to the arithmetic circuit


25


.




The arithmetic circuit


25


allocates the duty data to the appropriate one of the duty tables based on the input voltage signal so that the output voltage to the compressor


11


will be the optimum output voltage corresponding to the operating frequencies at a voltage within rated range. The output voltage is corrected accordingly and the resulting optimum voltage is applied to the compressor


11


.




More particularly, based on the input voltage delivered from the commercial power supply


12


, the duty data for determining the pulse duty factor of the output voltage to the compressor


11


is allocated to one of the three duty tables: the high-voltage region duty table that decreases the average value of the output voltages by reducing the duty, rated-voltage region duty table that uses standard duty, or low-voltage region duty table that increases the average value of the output voltages by increasing the duty; to determine the optimum output voltage by correcting the average value of the output voltages to the compressor


11


.




If the duty data is allocated to the high-voltage region duty table, the optimum output voltage is determined by decreasing the average value of the output voltages through duty reduction. If the duty data is allocated to the low-voltage region duty table, the optimum output voltage is determined by increasing the average value of the output voltages through duty increase. If the duty data is allocated to the rated-voltage region duty table, there is no need to correct the average value of the output voltages because the given duty is standard duty, and thus the given output voltage is adopted as the optimum output voltage.




With the present separate-type air conditioner, not only during a start-up as described above, but also during heating and cooling, the optimum output voltage corrected and determined by the voltage correction circuit


23


in a manner similar to that described above is constantly applied to the compressor


11


.




Although the second embodiment


2


described above has the voltage detection means


24


and arithmetic circuit


25


configured to correct and determine the optimum output voltage to the compressor


11


by allocating the duty data to one of the three duty tables: the high-voltage region duty table, rated-voltage region duty table, or low-voltage region duty table, it is also possible to omit the rated-voltage region duty table for the purpose of simplicity and allocate the duty data to either the high-voltage region duty table or low-voltage region duty table.




(Embodiment 3)




A third embodiment 3 of the separate-type air conditioner according to the present invention is similar to the second embodiment 2 described above except that room air temperature detection means


26


and outside air temperature detection means


27


are provided as load condition detection means as shown in FIG.


5


and that the voltage correction controller


23


has been configured to correct and determine the optimum output voltage to the compressor


11


by changing the duty data based on the working loads (load conditions) as shown in FIG.


6


.




The voltage correction controller


23


is configured by a voltage detection means


24


and arithmetic circuit


25




a.


The arithmetic circuit


25




a


has a shift amount data table that contains the amounts to shift the duty data according to the working loads.




Now, the operation of this separate-type air conditioner will be described below.




As shown in

FIG. 6

, a room air temperature detection signal S


1


detected by the inlet temperature sensor serving as the room air temperature detection means


26


and an outside air temperature detection signal S


2


detected by the outside air temperature sensor serving as the outside air temperature detection means


27


are entered in the arithmetic circuit


25




a.






The arithmetic circuit


25




a


calculates the working loads from the room air temperature detection signal S


1


and outside air temperature detection signal S


2


, looks up the amount of shift in the duty data that corresponds to the calculated working loads in the shift amount data table, adds the amount of shift to the duty data as corrections for the working loads to further optimize the output voltage, and determines the optimum output voltage to the compressor


11


.




In addition to the capabilities of the second embodiment


2


, this configuration provides the capability to detect the load conditions of the air conditioner, which makes it possible to further optimize the output voltage to the compressor


11


by taking into consideration the effect of the load conditions on the compressor, and thus enables efficient operation appropriate to the load conditions.




Although the third embodiment 3 configures the voltage correction controller


23


to modify the duty data based on the load conditions of the air conditioner detected by the load condition detection means and correct and determine the optimum output voltage to the compressor


11


, the load conditions of the air conditioner could also be detected by a voltage/current detection means for detecting the output voltage and output current to the compressor. Then the voltage correction controller


23


could modify the duty data based on the output voltage and output current detected by the voltage/current detection means and optimize the output voltage to the compressor


11


taking into consideration the effect of the load conditions on the output voltage to the compressor


11


.




Although the second and third embodiments 2 and 3 use the voltage detection means


24


to detect the output voltage from the outdoor electronic controller


8


, the voltage detection means


24


could also detect the output voltage to the compressor


11


without problems.




(Embodiment 4)




A fourth embodiment 4 of the separate-type air conditioner shown in

FIG. 7

comprises an indoor unit


1


, an outdoor unit


2


, and an indoor-outdoor connector cable that connects them electrically, as is the case with the conventional air conditioner shown in FIG.


13


. The difference is that a voltage correction circuit


33


serving as a voltage correction controller and a compressor suspension-time counter


34


for measuring the suspension periods of the compressor


11


have been added.




The voltage correction circuit


33


applies the power supply signal set according to the voltage value of the commercial power supply


12


at a start-up and corrected based on the suspension period of the compressor


11


to the power supply circuit of the compressor


11


. Specifically, it comprises a voltage detection circuit


35


, reception means


36


, and an arithmetic circuit


37


. The compressor suspension-time counter


34


is installed in the indoor electronic controller


5


.




Now a start-up operation of the separate-type air conditioner will be described below.




It is assumed that the suspension period of the compressor


11


was sufficiently long and that the compressor


11


is started in a pressure-balanced state.




As shown in

FIG. 7

, with the main switch


4


of the indoor unit


1


on and with power being delivered to the indoor electronic controller


5


from the commercial power supply


12


, when the user specifies operation start, the power from the commercial power supply


12


is delivered through the indoor electronic controller


5


to the outdoor electronic controller


8


and to the voltage correction circuit


33


.




As shown in

FIG. 8

, the voltage detection circuit


35


detects the input voltage supplied to the outdoor electronic controller


8


from the commercial power supply


12


at a start-up i.e., detects voltage fluctuations in the commercial power supply


12


. Then the voltage detection circuit


35


outputs the detected input voltage as a power supply voltage signal S


3


to the reception means


36


.




The reception means


36


receives the power supply voltage signal S


3


and the suspension-period signal S


4


that was read from the compressor suspension-time counter


34


under instructions from the arithmetic circuit


37


and that represents the suspension period of the compressor


11


, and outputs them to the arithmetic circuit


37


.




The arithmetic circuit


37


modifies the duty of the input voltage delivered from the commercial power supply


12


according to the power supply voltage signal S


3


so that the output voltage to the compressor


11


will be the optimum output voltage corresponding to the operating frequencies at a voltage within rated range, and starts the compressor


11


by applying the optimum output voltage V


1


to the power supply circuit of the compressor


11


. In this example, the arithmetic circuit


37


detects, based on the suspension-period signal S


4


, that the suspension period of the compressor


11


was sufficiently long and assumes that the compressor


11


is in a pressure-balanced state, and thus determines that there is no need to correct the optimum output voltage V


1


for the suspension period of the compressor


11


.




Since the compressor


11


is pressure balanced, it starts normally at the optimum output voltage V


1


without corrections and starts to compress the refrigerant.




If the user specifies operation stop during the operation of the compressor


11


, the indoor electronic controller


5


stops the compressor


11


by disconnecting the outdoor electronic controller


8


from the commercial power supply


12


by means of the main relay (not shown).




When the compressor


11


stops, the compressor suspension-time counter


34


starts counting the suspension period of the compressor


11


.




Now the restart operation of this separate-type air conditioner will be described below.




If the user specifies operation start to restart the compressor


11


within a short period of time (for example, about 1 minute) after the compressor


11


stops, the indoor electronic controller


5


activates the main relay (not shown) and power is delivered from the commercial power supply


12


through the indoor electronic controller


5


to the outdoor electronic controller


8


and to the voltage correction circuit


33


.




As is the case with the start-up operation described above, the voltage detection circuit


35


detects the input voltage supplied to the outdoor electronic controller


8


from the commercial power supply


12


and outputs a power supply voltage signal S


3


to the reception means


36


.




The reception means


36


receives the power supply voltage signal S


3


and the suspension-period signal S


4


that was read from the compressor suspension-time counter


34


and that represents the suspension period of the compressor


11


, and outputs them to the arithmetic circuit


37


.




Based on the suspension-period signal S


4


from the compressor suspension-time counter


34


, the arithmetic circuit


37


corrects the optimum output voltage V


1


that was set according to the power supply voltage signal S


3


in such a way that the output voltage to the compressor


11


would be the optimum output voltage corresponding to the operating frequencies at a voltage within rated range, and restarts the compressor


11


by applying the resulting optimum output voltage V


2


to the power supply circuit of the compressor


11


.




More particularly, if the suspension period of the compressor


11


is short (for example, less than 1 minute), the compressor


11


is not pressure balanced and the optimum output voltage V


1


set according to the power supply voltage signal S


3


will not provide sufficient starting torque, thus the arithmetic circuit


37


increases the average value of the optimum output voltages V


1


(for example, increases the average value of the output voltages by increasing the duty) based on the suspension-period signal S


4


and restarts the compressor


11


by applying the resulting optimum output voltage V


2


to the power supply circuit of the compressor


11


. The amount of correction made to the average value of the optimum output voltages V


1


based on the suspension-period signal S


4


are set, for example, to decrease with increase in the suspension period.




If the suspension period of the compressor


11


is sufficiently long, the compressor


11


is pressure balanced and the optimum output voltage V


1


alone can start the compressor


11


, thus no correction is made to the average value of the optimum output voltages V


1


.




Both during cooling and heating, the optimum output voltage determined by the voltage correction circuit


33


is applied to the compressor


11


.




This configuration makes it possible to reduce the effect of the voltage fluctuations in the commercial power supply


12


on the output voltage to the compressor


11


and improve the starting force of the compressor


11


taking into consideration the loads on the compressor


11


at the start-up.




(Embodiment 5)




A fifth embodiment 5 of the separate-type air conditioner according to the present invention is similar to the fourth embodiment 4 described above except that a compressor shell temperature detection means


38


is provided for detecting the shell temperature of the compressor


11


as shown in

FIG. 9

, and that the voltage correction circuit


33


has been configured to determine the optimum output voltage to the compressor


11


by correcting the power supply signal set according to the voltage value of the commercial power supply


12


, based on the detection signal S


5


from the compressor shell temperature detection means


38


, as shown in FIG.


10


.




The voltage correction circuit


33


comprises a voltage detection circuit


35


, reception means


36




a,


and arithmetic circuit


37




a.






Now the restart operation of this separate-type air conditioner will be described below.




The power supply voltage signal S


3


from the voltage detection circuit


35


, suspension-period signal S


4


of the compressor


11


from the compressor suspension-time counter


34


, and detection signal S


5


of the shell temperature of the compressor


11


detected by the compressor shell temperature detection means


38


are entered in the arithmetic circuit


37




a


through the reception means


36




a.






The arithmetic circuit


37




a


temporarily determines an optimum output voltage V


2


, based on the suspension-period signal S


4


from the compressor suspension-time counter


34


, by correcting the optimum output voltage V


1


that was set according to the input voltage signal S


3


in such a way that the output voltage to the compressor


11


would be the optimum output voltage corresponding to the operating frequencies at a voltage within rated range, determines the optimum output voltage V


3


finally by correcting the temporary optimum output voltage V


2


based on the detection signal S


5


from the compressor shell temperature detection means


38


, and restarts the compressor


11


by applying the final optimum output voltage V


3


to the power supply circuit of the compressor


11


.




More particularly, if the shell temperature of the compressor


11


is low (for example, −15° C. or so), the viscosity of the compressor


11


motor oil is high resulting in insufficient starting torque, thus the final optimum output voltage V


3


is determined by increasing the average value of the temporary optimum output voltages V


2


(for example, increasing the average value of the output voltages by increasing duty) based on the detection signal S


5


from the compressor shell temperature detection means


38


, and the compressor


11


is restarted by the application of the final optimum output voltage V


3


to the power supply circuit of the compressor


11


. The amount of correction made to the average value of the optimum output voltages V


2


based on the detection signal S


5


are set, for example, to increase with decrease in the shell temperature.




This configuration makes it possible further improve the starting force of the compressor by detecting the shell temperature of the compressor


11


and determining the optimum output voltage to the compressor


11


taking into consideration the magnetic characteristics of the dc motor.




(Embodiment 6)




A sixth embodiment 6 of the separate-type air conditioner according to the present invention is similar to the fourth embodiment 4 except that an inlet temperature sensor


39


serving as a room air temperature detection means and outside air temperature sensor


40


serving as an outside air temperature detection means are provided as shown in

FIG. 11

, and that the voltage correction circuit


33


has been configured to correct and determine the optimum output voltage to the compressor


11


based on the room air temperature detection signal S


6


from the inlet temperature sensor


39


and outside air temperature detection signal S


7


from the outside air temperature sensor


40


as shown in FIG.


12


.




The voltage correction circuit


33


comprises a voltage detection circuit


35


, reception means


36




b,


and arithmetic circuit


37




b.






Now, a restart operation of this separate-type air conditioner will be described below.




As shown in

FIG. 12

, the power supply voltage signal S


3


from the voltage detection circuit


35


, suspension-period signal S


4


of the compressor


11


from the compressor suspension-time counter


34


, room air temperature detection signal S


6


from the inlet temperature sensor


39


, and outside air temperature detection signal S


7


from the outside air temperature sensor


40


are entered in the arithmetic circuit


37




b


through the reception means


36




b.






The arithmetic circuit


37




b


temporarily determines an optimum output voltage V


2


based on the suspension-period signal S


4


from the compressor suspension-time counter


34


by correcting the optimum output voltage V


1


that was set according to the power supply voltage signal S


3


in such a way that the output voltage to the compressor


11


would be the optimum output voltage corresponding to the operating frequencies at a voltage within rated range, determines the optimum output voltage V


4


finally by correcting the temporary optimum output voltage V


2


based on the room air temperature detection signal S


6


and outside air temperature detection signal S


7


, and restarts the compressor


11


by applying the final optimum output voltage V


4


to the power supply circuit of the compressor


11


.




More particularly, if it is considered that a large difference between the room air temperature and outside air temperature will result in insufficient starting torque, based on the room air temperature detection signal S


6


and outside air temperature detection signal S


7


, the average value of the output voltages is increased, for example, by increasing the duty.




This configuration makes it possible to calculate the loads on the compressor


11


from the difference between the room air temperature and outside air temperature just before the start-up, based on the room air temperature detection signal S


6


and outside air temperature detection signal S


7


, and thus to optimize the output voltage to the compressor


11


by correcting the optimum output voltage to the compressor, taking into consideration the characteristics of the refrigerant at the start-up after a long-term shutdown.




Although the fourth and fifth embodiments 4 and 5 described above correct the input voltage from the commercial power supply


12


by controlling its duty, other methods such as increasing/decreasing the peak values of the input voltage from the commercial power supply


12


will have the same effect.



Claims
  • 1. An operation control method of an air conditioner wherein a compressor (11) for a refrigerating cycle is activated by the steps of:controlling duty of a commercial power supply (12); converting the duty into a power supply signal according to a voltage value of the commercial power supply (12) initially applied to the compressor (11); and applying a resulting power supply signal to a power supply circuit of said compressor (11).
  • 2. An air conditioner which is activated by controlling duty of a commercial power supply (12) initially applied to a compressor (11), converting the duty into a power supply signal according to a voltage value of the commercial power supply (12), and applying a resulting power supply signal to a power supply circuit of the compressor (11), whereina voltage correction controller is provided in order for correcting and determining an optimum output voltage to said compressor (11) by allocating a duty data for determination of the output voltage to said compressor (11) to one of high-voltage, rated-voltage and low-voltage region tables or to one of high-voltage and low-voltage region tables according to input voltages.
  • 3. The air conditioner according to claim 2, further comprising detection means (26,27) for detecting load conditions, wherein the voltage correction controller is configured to correct and determine the optimum output voltage to the compressor (11) by modifying the duty data based on said load conditions.
  • 4. The air conditioner according to claim 2, further comprising voltage/current detection means for detecting the output voltage and the output current to the compressor (11), wherein the voltage correction controller is configured to correct and determine the optimum output voltage to said compressor (11) by modifying the duty data based on the output voltage and output current detected by said voltage/current detection means.
Priority Claims (3)
Number Date Country Kind
10-189820 Jun 1998 JP
10-365808 Dec 1998 JP
10-368335 Dec 1998 JP
PCT Information
Filing Document Filing Date Country Kind
PCT/JP99/02907 WO 00
Publishing Document Publishing Date Country Kind
WO99/66205 12/23/1999 WO A
US Referenced Citations (1)
Number Name Date Kind
5018058 Ionescu et al. May 1991 A
Foreign Referenced Citations (14)
Number Date Country
0 652 634 May 1995 EP
0 695 024 Jan 1996 EP
0 820 136 Jan 1998 EP
62040091 Feb 1987 JP
62-238938 Oct 1987 JP
1016297 Jan 1989 JP
64-16297 Jan 1989 JP
01313681 Dec 1989 JP
2-78759 Jun 1990 JP
05184180 Jul 1993 JP
7-163182 Jun 1995 JP
10131859 Oct 1996 JP
9-264260 Oct 1997 JP
11014124 Jan 1999 JP