JP2012002443A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner configured to use a current consumption measuring circuit including a current transformer and a shunt resistor generally provided in the air conditioner to calculate current consumption as accurately as possible at a relatively low cost.SOLUTION: The air conditioner includes a current value estimation means for determining an estimated current consumption value corresponding to the operation state of the air conditioner, and a current consumption selection means for selecting a measured current value or the estimated current value. The current value estimation means stores current consumption values to be consumed in main electric parts of the air conditioner in advance, and selects and extracts the current consumption values of the electric parts according to the operation state of the air conditioner, and calculates the total thereof to obtain the estimated current value. As a result of comparing the measured current value with a predetermined first threshold, the current consumption selection means selects the estimated current value when the measured current value is smaller than the first threshold, or the measured current value when the measured current value is larger than the first threshold, respectively.

Description

  The present invention relates to an air conditioner, and more particularly to a measuring means and a calculating means for obtaining an accurate current consumption.

Conventionally, a configuration shown in FIG. 6 is disclosed as a configuration for obtaining current consumption in an air conditioner.
This air conditioner includes a storage and holding device 9 that stores the set maximum power consumption value of the air conditioner, a calculation means 10 that calculates the power consumption value of the compressor 1 from the condensation temperature and the evaporation temperature, and the compressor A storage and holding device 11 that stores power consumption values of electrical components other than 1, and a power consumption value of the air conditioner from the power consumption values obtained from the calculation means 10 and the stored power consumption values of electrical components other than the compressor 1 And a control means for controlling the output of the compressor 1 by comparing the maximum power consumption value with the power consumption value of the calculation means 12.

  This air conditioner is obtained by calculating the power consumption value of the compressor 1 from the condensing temperature and the evaporation temperature, and based on the calculated power consumption value based on the current consumed by the electrical components other than the compressor. The calculated fixed power consumption value is added to obtain the power consumption of the entire air conditioner (see, for example, Patent Document 1).

  In addition, an air conditioner having a configuration for calculating power consumption not only by calculation but also by using an input current of an outdoor unit measured using a current detection element such as a current transformer is disclosed (for example, see Patent Document 2). .) In this air conditioner, an electricity charge is calculated from the calculated power consumption, and this electricity charge is displayed to the operator.

  In addition, in a low-cost air conditioner, there is a method using a shunt resistor that measures the current of the compressor without using a relatively expensive current transformer. The current value measured by such a current transformer or shunt resistance is used for detecting a current limiting function for operating the air conditioner with a current consumption below a certain value or an overcurrent of the compressor. For this reason, it is generally designed to measure an area of 10 amperes or more.

  As described above, in order to obtain the power consumption, a method of adding mainly the current of the compressor and the current of the compressor that changes drastically depending on the operation state and the fixed current value consumed by other electrical components, as described above. There is a method of directly measuring the current consumption of the outdoor unit with a current transformer.

  However, in the method of fixing the power consumption in the electric parts other than the compressor, the four-way valve that is switched by the cooling operation or the heating operation, the fan motor consumption current that depends on the rotation speed of the fan motor for the outdoor unit, the outdoor unit It is not compatible with changes in current consumption due to detailed operating conditions, such as blowing operation in which only the fan motor of the indoor unit is rotated after stopping.

  Further, in the method using a current transformer and a shunt resistor provided in the outdoor unit, the current consumption of the indoor unit is not taken into consideration, and therefore, detection is performed with less than the actual current consumption. Furthermore, since these methods are designed on the premise of measuring a relatively large current as described above, there is a problem that an error is large when measuring a relatively small current.

  If the value of current consumption is used only for internal processing, this error is not a significant problem, but in recent years, power consumption is calculated based on current consumption and displayed as an electricity bill in order to improve the user's energy conservation awareness. Air conditioners with a function to make them available are on sale. In this case, if an operation with a relatively small current consumption, for example, an operation when the air blowing operation or the air conditioning load is small, or a preheating operation of the compressor continues for a long time, the accumulated error of the power consumption becomes large, and it is accurate for the user. In some cases, it was impossible to notify the electricity bill.

  In order to accurately measure the current consumption, a current consumption meter may be installed on a common power line between the indoor unit and the outdoor unit. However, such a measuring device is generally expensive for an air conditioner. Yes, it could not be adopted from the viewpoint of cost.

JP-A-5-133590 (page 3-4, FIG. 1) JP 2000-147029 A (page 3-4, FIG. 1)

  The present invention solves the above-described problems, and generally uses a current transformer or a shunt resistance measuring circuit provided in an air conditioner to calculate an accurate current consumption at low cost. It aims at providing the air conditioner provided with.

In order to solve the above-mentioned problems, the present invention is an air conditioner having a compressor and a plurality of electrical components,
Current detecting means for measuring a current consumed by the compressor or measuring a current value by measuring an input current; and
A consumption current value table that prestores consumption current values consumed by the compressor and the plurality of electrical components according to the operating state of the air conditioner;
Extracting the current consumption values of the plurality of electrical components corresponding to the operating state of the air conditioner from the current consumption value table, and adding the extracted current consumption values to obtain an estimated current value;
Consumption current selecting means for selecting either the estimated current value or the measured current value corresponding to a comparison result between the measured current value and a predetermined first threshold;
The current consumption of the entire air conditioner is obtained based on the consumption current selected by the consumption current selection means.

  As a result of comparing the measured current value with the first threshold value, the consumption current selecting means determines the estimated current value when the measured current value is smaller than the first threshold value, and the measured current value is the first threshold value. If the value is larger than the measured current value, the measured current value is selected.

The consumption current selection means, when the measured current value is a value within a predetermined switching region between a second threshold value smaller than the first threshold value and a third threshold value larger than the first threshold value,
A divergence degree indicating a divergence between the estimated current value and the measured current value is calculated, and when the divergence degree is smaller than a predetermined value, the measured current value is determined in advance. If the value is larger than the predetermined value, the estimated current value is selected.

  The consumption current selection means selects the estimated current value when the measured current value is smaller than the second threshold, and selects the measured current value when the measured current value is larger than the third threshold. It is characterized by doing.

By using the above means, according to the air conditioner of the present invention,
The invention according to claim 1 corresponds to the magnitude of the measurement result in the current detection means by using the measured current value actually measured or the estimated current value estimated by combining the current values for each part obtained in advance by the test. Therefore, it is possible to reduce the error of the measured value in the current consumption of the entire air conditioner.

  The invention according to claim 2 uses a measured current value with high accuracy when the current consumption is relatively large, and uses an estimated current value with high accuracy when the current consumption is relatively small. Accurate current consumption can be obtained regardless of the magnitude of the current.

  The invention according to claim 3 is estimated when a measured current value and an estimated current value deviate by a certain amount or more in a switching region in which any of the measured current value and the estimated current value is not accurate. Since the current value is selected, the error of the measured value in the current consumption of the entire air conditioner can be reduced even when the error of the measured current value is large.

  In the invention according to claim 4, since the current consumption when the current is larger than the switching region is obtained by selecting a measured current value, and the current consumption when the current is smaller than the switching region is obtained by selecting an estimated current value in a highly accurate manner. Accurate current consumption can be obtained regardless of the current consumption.

It is a principal part block diagram which shows the Example of the air conditioner by this invention. It is a graph explaining the characteristic of the electric current detection circuit used for the air conditioner by this invention. It is explanatory drawing explaining the calculation method of the consumption current by this invention. It is explanatory drawing which prescribed | regulated the estimated consumption current by this invention previously. It is a flowchart explaining operation | movement of the air conditioner by this invention. It is a principal part block diagram which shows the conventional air conditioner.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail as examples based on the attached drawings.

  FIG. 1 is a control block showing an air conditioner. This air conditioner includes an indoor unit 1 and an outdoor unit 10, which are connected by a power line. In addition, illustration of the structure which is not directly related to this application, such as a heat exchanger and a refrigerant circuit, is abbreviate | omitted.

  The indoor unit 1 includes a remote control receiving unit 2 that receives an infrared signal of a remote controller (not shown), an indoor unit power supply unit 3, a power supply relay 4 that turns on / off power supply to the outdoor unit 10, and an indoor unit fan motor 7 And an indoor unit communication unit 5 that transmits and receives data to and from the outdoor unit 10 through a power line, a display unit 6 that displays an electricity bill, an indoor unit fan motor 7, a power supply relay 4, a remote control receiving unit 2, and an indoor unit. An indoor unit control unit 8 that controls the unit communication unit 5 and the display unit 6 is provided.

  On the other hand, the outdoor unit 10 drives an outdoor unit power supply unit 13, a current detection unit 14 that is a current detection unit that measures current consumption of the outdoor unit power supply unit 13, that is, an input current of the outdoor unit 10, and a compressor motor 17. Compressor driving unit 16 that performs, outdoor unit communication unit 15 that transmits and receives data to and from the indoor unit through a power line, four-way valve 19 that switches the circulation direction of the refrigerant, outdoor unit fan motor 20, and current detection unit 14 And a compressor drive unit 16, an outdoor unit communication unit 15, a four-way valve 19, and an outdoor unit control unit 18 that controls the outdoor unit fan motor 20.

  Further, the current detection unit 14 detects a current supplied to the outdoor unit power supply unit 13 and converts it into a voltage, a diode 14b that rectifies the converted voltage, and a capacitor that smoothes the rectified voltage 14c and the like. The smoothed voltage (corresponding to the consumption current of the outdoor unit 10) is output to the outdoor unit control unit 18 and converted into a current value by an A / D converter (not shown) inside the outdoor unit control unit 18. A filter circuit for reducing the ripple voltage is not shown.

  In addition, the compressor driving unit 16 inputs a DC voltage supplied from the outdoor unit power supply unit 13, and controls the inverter motor 16 to three-phase drive the compressor motor 17 under the control of the outdoor unit control unit 18, and to the inverter unit 16a. And a shunt resistor 16b for converting the input current (current consumption) into a voltage. The voltage corresponding to the converted current consumption is output to the outdoor unit control unit 18 and converted into a current value by an A / D converter (not shown) inside the outdoor unit control unit 18. These current values are used in the current limiting function and the overcurrent detection function as described in the background art, and are also used in the calculation of current consumption according to the present application.

  When power is supplied to the power supply plug, the indoor unit power supply unit 3 supplies power to each unit of the indoor unit 1, and a control signal, for example, a power-on signal is transmitted from the remote control via the remote control receiving unit 2 to the indoor unit control unit 8. The indoor unit control unit 8 turns on the power supply relay 4 and then gives an operation instruction to the outdoor unit control unit 18 via the indoor unit communication unit 5. The outdoor unit control unit 18 controls the compressor driving unit 16 in accordance with a given instruction and performs a specified operation. At this time, the current supplied to the outdoor unit power supply unit 13 is monitored by the outdoor unit control unit 18 via the current detection unit 14, and the compressor is operated within the range of the limited current defined in advance. It is like that.

  FIG. 2 is a graph for explaining the characteristics of the current detection unit 14 used in this embodiment. The horizontal axis represents time, the vertical axis represents current (voltage corresponding to current), and 0 to 20 A (ampere). Is supposed to measure. Then, this voltage is converted into a current value by the A / D converter as described above. The low-cost microcomputer provided in the outdoor unit control unit 18 generally has a resolution of 8 bits, that is, 20A is detected in 256 stages, and is a measurement unit of about 0.1A.

  Further, as described above, the current detection unit 14 includes the smoothing capacitor 14c, and the voltage corresponding to the current value includes a ripple voltage. This ripple voltage has a relatively small ratio when the consumption current is large, and a relatively large ratio when the consumption current is small, that is, an error becomes large. Therefore, when the current consumption is small, the error becomes large even with a measurement unit of about 0.1 A, and accurate measurement cannot be performed. In addition, since the current detection unit 14 measures only the consumption current of the outdoor unit 10, when the consumption current is small, the consumption current of the indoor unit 1 having a relatively large consumption current is ignored. Will not be able to measure properly.

  Further, in the method using the shunt resistor 16b, it is not necessary to consider the ripple voltage unlike the method using the current transformer 14a. However, if the value of the shunt resistor 16b is increased in order to improve the measurement accuracy, In order to reduce the power loss, it is necessary to reduce the resistance value of the shunt resistor 16b, which increases the measurement error. As described in the background art, since the current detection circuit is designed on the assumption of measurement of 10 A or more, the detection accuracy itself is the same even when the current is large and when the current is low, but the current consumption is small. The ratio of measurement error to the measured current value increases. The same applies to the system using the current transformer 14a. In other words, both the method using the current transformer 14a and the method using the shunt resistor 16b have a problem that the error is large when the current consumption is small.

  Therefore, in the present application, when the measurement accuracy of the current detection unit 14 is high, that is, when the consumption current is large, the current consumption is calculated using the current value measured in the current detection unit 14 and the measurement accuracy of the current detection unit 14 is When the current consumption is low, that is, when the current consumption is small, the current consumption is calculated using a predicted value obtained individually by the operation of the air conditioner in advance, instead of the actually measured current value in the current detection unit 14. Yes.

  FIG. 4 is a table showing predetermined current values, which are experimentally obtained values. The table of predicted current consumption for each element in FIG. 4 is stored as a current consumption value table in a storage unit (not shown) in the indoor unit control unit 8, and data on current values consumed by the indoor unit 1 and the outdoor unit 10. Is defined in a table for each block or component. For example, the case where only the indoor unit is operating and the indoor fan is stopped is referred to as “indoor unit basic state”. At this time, the indoor unit 1 consumes 0.5 A.

  In the case of “indoor fan rotation”, it is defined that 0.2 A is consumed. Similarly, in the “outdoor unit basic state” in the outdoor unit 10, that is, when power is supplied to the outdoor unit 10, the compressor motor 17, the four-way valve 19, and the outdoor unit fan motor 20 are stopped. .5A. “Minimum compressor operation”, that is, 1.0A when rotating at the minimum speed, 0.3A for “pre-heat treatment”, 0.2A for “four-way valve” operation, The rotation is defined as 0.1 A to 0.3 A as the number of rotations increases.

  The table of predicted current consumption for each operation state in FIG. 4 is a calculation of the current consumption of blocks and parts driven for each operation state of the air conditioner based on the table of predicted current consumption for each element in FIG. It is. Means for estimating the current consumption by calculation is current value estimation means. In the current value estimation means, when the indoor unit control unit 8 or the outdoor unit control unit 18 controls each block or component by itself and executes this control, the current value estimation unit simultaneously calculates the expected current value of each block or component. In addition, current consumption in each state of the air conditioner is sequentially estimated.

  For example, in the case of “air conditioner shutdown state”, it is number 1 in the table of predicted current consumption for each element in FIG. In the case of “only blowing operation”, the value of No. 1 in the table of expected current consumption for each element in FIG. 4 is 0, which is the expected current value of “Indoor fan rotation” of No. 2 in the table of expected current consumption for each element. .2A is added to give a total of 0.7A. Thus, a predicted value (predicted current value) can be obtained corresponding to each operation state of the air conditioner. Note that the table of predicted current consumption for each operating state in FIG. 4 is an example, and other cases are also defined in advance. Alternatively, it may be calculated every time it is controlled.

  FIG. 3 is an explanatory diagram for explaining the timing for switching between the current value measured by the current detector 14 and the estimated current value. The horizontal axis represents time, and the vertical axis represents current consumption (rectified voltage of the current transformer 14a), showing an example in which the current consumption of the air conditioner gradually increases.

  In FIG. 3, the solid line curve is the measured current value measured by the current detector 14, the dotted thin line is the actual current value, and the stepped solid line is the estimated current consumption value described in FIG. 4, that is, The estimated current value. A current switching point indicated by an arrow is a timing point at which the measured current value and the estimated current value are switched. The function of switching between the measured current value and the estimated current value is performed by the consumption current selection means provided in the outdoor unit control unit 14.

  In the current consumption selection means, basically, if the measured current value is the first threshold, for example, 3.0A or more, the measured current value is adopted, and if the measured current value is less than the first threshold, for example, 3.0A, the estimated current value is adopted. Just do it. Thereby, when the consumption current is small, the predicted value is used instead of the actual measurement value, so that the error of the detected consumption current value can be reduced.

  In this embodiment, the current consumption selection means predefines a switching area in which the current value is more accurate or unknown between the measured current value and the estimated current value, and the measured current value and the estimated current value within this switching area. And are switched. The range of the switching area is defined by a second threshold value that is smaller than the first threshold value and a third threshold value that is larger than the first threshold value.

  This is because the accuracy of the measured current value measured by the current detection unit 14 becomes lower as the current consumption is smaller. Therefore, when the measured current value and the estimated current value are switched based on the current value having a lower accuracy, the error increases. Because there is a possibility of becoming. In this embodiment, between the switching areas, the measured current value measured by the current detector 14 is compared with the estimated current value, and if the current difference deviates from the estimated value by a predetermined ratio, for example, 20% or more. The estimated current is used. Note that if the current value at the lower limit of the switching region, that is, the measured current value is lower than the second threshold value, the estimated current value is forcibly selected.

  Specifically, in FIG. 3, the current consumption value is defined as a switching region between the third threshold value: 4.0A and the second threshold value: 2.0A. In this switching region, when the estimated current value is 1.9 A and the measured current value is 2.6 A, the difference between the estimated current value and the measured current value is 0.7 A, and the current with respect to the estimated current value is The difference ratio, that is, the degree of divergence is 37%. Since this value exceeds 20% of the predetermined threshold value, the measured current value is switched to the estimated current value. This switching timing is a current value switching point.

  Since the degree of divergence only needs to indicate the degree of divergence between the measured current value and the estimated current value, the ratio between the measured current value and the estimated current value, the ratio of the current difference to the measured current value, or the like may be used. The switching area is determined in advance from an experimentally obtained error distribution or the like. Note that although processing is troublesome in order to remove the ripple component of the ripple voltage, the ripple voltage may be periodically taken in, stored, and averaged. However, as described with reference to FIG. 2, the measured current value has a larger error rate as the value is smaller. Therefore, even when using an averaged current value, it is necessary to monitor the degree of deviation and select a current value. is there.

  As shown in FIG. 1, the outdoor unit control unit 18 selects and obtains a measured current value or an estimated current value in the outdoor unit 10, and transmits this current value to the indoor unit control unit 8 via the outdoor unit communication unit 15. . Since the indoor unit 1 does not have a circuit for actually measuring the current, the indoor unit control unit 8 calculates the predicted current consumption value shown in FIG. 4 and adds the current consumption value of the outdoor unit 10 to this value. Obtain the current consumption of the entire harmonic machine. Then, the power consumption is obtained by multiplying the current consumption value by the voltage, and the power consumption is calculated by accumulating the power consumption, and the electricity charge is calculated by multiplying the power consumption by a predetermined unit power charge. 6 is displayed.

  As described above, the measured current value actually measured or the estimated current value estimated by combining the current values for each part obtained in advance by the test is selected according to the magnitude of the measurement result in the current detection means. Therefore, the measurement value error in the current consumption of the entire air conditioner can be reduced.

  In addition, when the current consumption is relatively large, the measured current value with high accuracy is used, and when the current consumption is relatively small, the estimated current value with high accuracy is used. Accurate current consumption can be obtained.

In addition, when the measured current value and the estimated current value deviate more than a certain value in the switching region where it is unknown which current value is accurate between the measured current value and the estimated current value, the estimated current value is selected. Therefore, even when the measurement current value error is large, the measurement value error in the current consumption of the entire air conditioner can be reduced.
In addition, since the current consumption when it is larger than the switching area is determined by a highly accurate method by selecting the measured current value and the current consumption when it is smaller than the switching area, respectively, it depends on the magnitude of the current consumption. Therefore, accurate current consumption can be obtained.

  Next, the process for obtaining and displaying the electricity charge of the air conditioner will be described with reference to the flowchart of the indoor unit process and the outdoor unit process shown in FIG. ST shown in FIG. 5 represents a step, the number following this represents a step number, Y represents Yes, and N represents No. The processing flow of the indoor unit shows the operation steps of the indoor unit control unit 8, and the processing flow of the outdoor unit shows the operation steps of the outdoor unit control unit 18.

  FIG. 5 (1) Processing of the indoor unit will be described. When the indoor unit control unit 8 starts operating, it first checks whether a remote control signal has been received (ST1). When the remote control signal is received (ST1-Y), the operation instructed by the remote control signal, for example, air conditioning, temperature setting, air volume setting, and the like are performed. In response to this processing, an operation instruction is transmitted to the outdoor unit 10. (ST2).

  Next, the estimated current of the indoor unit 1 is calculated (ST3). As described with reference to FIG. 4, this is a process of estimating the current consumption corresponding to the operating state of the operating unit or component. Next, the data of the consumption current value of the outdoor unit 10 is received from the outdoor unit 10 (ST4).

  Then, the estimated current value of the indoor unit 1 and the consumption current value of the outdoor unit 10 are added to calculate the consumption current of the entire air conditioner, and the power value is calculated by multiplying this by the rated voltage. Then, the amount of power consumption is obtained by integrating this, and the amount of power consumption is multiplied by the unit amount of the electricity bill to convert it into an electricity bill (ST5). The accumulated power amount is cleared by a user operation.

Next, the calculated electricity bill is displayed on the display unit 6 (ST6), and the process jumps to ST1.
On the other hand, if the remote control signal is not received (ST1-N), the process jumps to ST3 to calculate the electricity bill.

  Next, FIG. 5 (2) processing of the outdoor unit will be described. When the outdoor unit control unit 18 starts operating, it first checks whether an operation instruction from the indoor unit 1 has been received (ST11). When an operation instruction is received from the indoor unit 1 (ST11-Y), control corresponding to the operation instruction, for example, starting operation of the compressor, switching between cooling and heating, pre-heat treatment, defrosting operation, etc. is performed (ST12).

  Next, the estimated current of the outdoor unit 10 is calculated (ST13). As described with reference to FIG. 4, this is a process of estimating the current consumption corresponding to the operating state of the operating unit or component. Next, the consumption current (measured current value) of the outdoor unit 10 is measured via the current detection unit 14 (ST14).

  Since the current consumption value measured as described in FIG. 3 is defined as the switching area between the third threshold value: 4.0A and the second threshold value: 2.0A, is the value within this switching area? In order to confirm, next, it is confirmed whether this measured current value is smaller than 2 amperes (ST15). When the measured current value is 2 amperes or more (ST15-N), it is confirmed whether the measured current value is larger than 4 amperes (ST16). When the measured current value is 4 amperes or less (ST16-N), the difference between the estimated current value of the outdoor unit 10 and the measured current value is obtained and divided by the estimated current value to obtain the degree of divergence (ST17).

  Next, it is confirmed whether the deviation degree is larger than 20% (ST18). When the degree of deviation is 20% or less (ST18-N), the measured current value is set as the current consumption value of the outdoor unit 10 (ST19). Next, the data of the consumption current value of the outdoor unit 10 is transmitted to the indoor unit 1 (ST20). Then jump to ST11.

  On the other hand, when the operation instruction from the indoor unit 1 has not been received (ST11-N), the process jumps to ST13. When the measured current value is smaller than 2 amperes (ST15-Y), the estimated current value is set as the current consumption value of the outdoor unit 10 (ST21). Then jump to ST20. If the measured current value is larger than 4 amperes (ST16-Y), the process jumps to ST19. If the divergence degree is greater than 20% (ST18-Y), the process jumps to ST21.

  The indoor unit control unit 8 and the outdoor unit control unit 18 incorporate a microcomputer (not shown), and each microcomputer executes a program corresponding to each step in each flowchart in FIG. It has been realized.

Specifically, Step 3 and Step 13 are steps executed by the current value estimating means, Step 14 is executed by the current detecting means, and Steps 15 to 19 and Step 21 are executed by the consumed current selecting means. Each step is shown.
The power consumption and the electricity charge calculated in this way are displayed on the display unit 6 of the indoor unit 1 so that the user can check them. Note that power consumption and electricity charges may be displayed on a wireless remote controller that replaces the infrared remote controller.

  Next, another embodiment according to the present invention will be described. In this embodiment, a relatively inexpensive air conditioner is assumed, and the current detection unit 14 provided in the outdoor unit 10 is omitted. As an alternative to the current detection unit 14, a compressor measured current value that is a drive current of the compressor motor 17 detected by a shunt resistor 16 b that is a current detection unit in the compressor drive unit 16 is used.

  Since most of the current consumption in the outdoor unit 10 is related to driving of the compressor motor 17, it is estimated that the compressor measured current value of the compressor motor 17 is consumed by components other than the compressor motor 17 in the outdoor unit 10. The combined current value that is the current consumption of the outdoor unit 10 is obtained by adding the current values. The concept of the estimated current value is to predict the current consumption of a predetermined circuit according to the control state of each component or unit as described with reference to FIG.

  However, when the consumption current of the compressor motor 17 is small, the relative error of the current value increases depending on the value of the shunt resistor 16b as described above. For this reason, the present embodiment includes the consumption current selection means described in the first embodiment. In this consumption current selection means, when the current value measured by the shunt resistor 16b is a threshold value, for example, 4 amperes or less, the estimated current value of the consumption current value of the compressor motor 17 is used instead of the compressor measurement current value, The estimated current value and the estimated current value consumed by components other than the compressor motor 17 are added to calculate the consumed current value of the entire outdoor unit 10.

  Then, a value obtained by adding the measured current value thus switched and the estimated current value, or the estimated current value is transmitted to the indoor unit 1 as the current consumption value of the outdoor unit 10. Since the subsequent processing of the indoor unit 1 is the same as that of the first embodiment, the description thereof is omitted.

  As described above, in the air conditioner that measures the drive current of the compressor motor 17 instead of the measurement of the input current, the actually measured current value or the current value of each component obtained in advance by a test is combined. Since the estimated current value estimated in this way is selectively used corresponding to the magnitude of the measurement result in the current detection means, the error in the measured value in the current consumption of the entire air conditioner can be reduced.

  In each embodiment, the indoor unit 1 and the outdoor unit 10 can communicate with each other, and each current value data can be transmitted and received by communication. Therefore, a current value estimation unit, a consumption current selection unit, and an addition process for obtaining a total current The above is not limited to the present embodiment, and may be performed by either the indoor unit 1 or the outdoor unit 10.

DESCRIPTION OF SYMBOLS 1 Indoor unit 2 Remote control receiving part 3 Indoor unit power supply part 4 Power supply relay 5 Indoor unit communication part 6 Display part 7 Indoor unit fan motor 8 Indoor unit control part 10 Outdoor unit 13 Outdoor unit power supply part 14 Current detection part 14a Current transformer 14b Diode 14c Capacitor 15 Outdoor unit communication unit 16 Compressor drive unit 16a Inverter unit 16b Shunt resistor 17 Compressor motor 18 Outdoor unit control unit 19 Four-way valve 20 Outdoor unit fan motor

Claims (4)

An air conditioner having a compressor and a plurality of electrical components,
Current detecting means for measuring a current consumed by the compressor or measuring a current value by measuring an input current; and
A consumption current value table that prestores consumption current values consumed by the compressor and the plurality of electrical components according to the operating state of the air conditioner;
Extracting the current consumption values of the plurality of electrical components corresponding to the operating state of the air conditioner from the current consumption value table, and adding the extracted current consumption values to obtain an estimated current value;
Consumption current selecting means for selecting either the estimated current value or the measured current value corresponding to a comparison result between the measured current value and a predetermined first threshold;
An air conditioner characterized in that the current consumption of the entire air conditioner is obtained based on the consumption current selected by the consumption current selection means.   As a result of comparing the measured current value with the first threshold value, the consumption current selecting means determines the estimated current value when the measured current value is smaller than the first threshold value, and the measured current value is the first threshold value. 2. The air conditioner according to claim 1, wherein the measured current value is selected for each of the air conditioners when the value is larger. The consumption current selection means, when the measured current value is a value within a predetermined switching region between a second threshold value smaller than the first threshold value and a third threshold value larger than the first threshold value,
A divergence degree indicating a divergence between the estimated current value and the measured current value is calculated, and when the divergence degree is smaller than a predetermined value, the measured current value is determined in advance. 2. The air conditioner according to claim 1, wherein when the estimated current value is larger than a predetermined value, the estimated current value is selected.   The consumption current selection means selects the estimated current value when the measured current value is smaller than the second threshold, and selects the measured current value when the measured current value is larger than the third threshold. The air conditioner according to claim 3.

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