JP3866120B2 - Air conditioner drive circuit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drive circuit for an air conditioner that converts electric power from an AC power source into direct current at a converter unit, reconverts it into arbitrary alternating current at an inverter unit, and drives a compressor. The present invention relates to a drive circuit for an electric device that includes a current detection element that detects a current with respect to the current and also includes a control unit that controls an inverter unit using the current detected by the current detection element. In this specification, an air conditioner will be described as an example.
[0002]
[Prior art]
FIG. 5 is a block diagram showing a driving circuit of a conventional air conditioner. In the figure, 1 is an AC power source, 2 is a converter circuit that converts AC input obtained from the AC power source 1 into DC, 3 is an inverter circuit that converts DC input obtained from the converter circuit 2 into arbitrary AC, The compressor driven by the inverter circuit 3, 5 is a control circuit that controls the whole or part of the drive circuit of the air conditioner, 6 detects the DC voltage value output from the converter circuit 2, and the detected value to the control circuit 5 DC voltage detector 7 for input, 7 is a temperature detector for detecting the temperature of each mechanism of the air conditioner, 8b is for detecting the voltage generated in the resistor 8a by the current flowing from the inverter circuit 3 to the converter circuit 2, An overcurrent detection unit 9 for sending a stop command for the inverter circuit 3 to the control circuit 5 when a threshold value is exceeded, an AC drive circuit that is controlled by the control circuit 5 and driven by AC A direct current drive circuit 11 controlled by the control circuit 5 and driven by direct current, a current transformer 11 for detecting all input alternating current from the alternating current power source 1 to the drive circuit and inputting the detected value to the control circuit 5 (hereinafter referred to as CT) ).
[0003]
In the conventional air conditioner, the compressor is driven by the drive circuit shown in FIG. The alternating current obtained from the alternating current power source 1 is converted into direct current by the converter circuit 2 and is converted again to arbitrary three-phase alternating current by the inverter circuit 3 to drive the compressor 4. The control circuit 5 controls the rotation of the compressor 4 by controlling the operation of the inverter circuit 3. Specifically, in the control circuit 5, the voltage input from the inverter circuit 3 to the compressor 4 is determined by the value of the DC voltage detection unit 6, and based on the temperature information of each part of the air conditioner obtained from the temperature detection unit 7, the compressor 4 is controlled.
[0004]
In addition, an AC drive circuit 9 and a DC drive circuit 10 are provided on the drive circuit, and these relays and valves are switched, and the fan motor is driven by a command from the control circuit 5. In CT11, the current values of all the circuits described above are detected immediately after the AC power supply 1, and the detected values are input to the control circuit 5.
[0005]
FIG. 6 is a block diagram of an AC power source to which an air conditioner drive circuit is connected. In general, when driving an air conditioner, as shown in FIG. 6, the AC power source 1 connected to the air conditioner has a current capacity, and when used above that capacity, a protection device 12 such as a breaker is used. Works and cuts off the power.
[0006]
FIG. 7 is a diagram showing the control of the alternating current value in the drive circuit of the conventional air conditioner. When the air conditioner is operated under an overload condition or when it is operated at the maximum capacity of the air conditioner, the total current of the drive circuit at CT11 is set so as not to exceed the current capacity of the protective device 12. When the control circuit 5 reads the value and predicts that the current value exceeds the capacity as shown in FIG. 7, the input power of the compressor 4 occupying most of the total current is suppressed. The inverter circuit 3 is commanded.
[0007]
In order to maintain the capacity, the control circuit 5 is provided with a lower limit value of the total current, and when it is predicted to be less than that value, the inverter circuit 3 is controlled in the direction of increasing the input power of the compressor 4, The maximum capacity of the air conditioner can be continuously output within the current capacity range of the AC power supply.
[0008]
In the drive circuit of FIG. 5, the operation under the overload condition of the air conditioner requires more input power to the compressor 4, but the inverter circuit 3 has a maximum rating so as not to destroy the internal elements. When the DC brushless motor is used inside the compressor 4 as well, the compressor 4 needs to be protected in order to avoid a decrease in magnetic force due to overcurrent. Therefore, in order to protect these, a resistor 8a is provided between the inverter circuit 3 and the converter circuit 2, and a voltage generated in the resistor 8a when a current flows from the inverter circuit 3 to the converter circuit 2 is detected by the overcurrent detection unit 8b. A protection mechanism is provided that detects and detects a value equal to or greater than a certain threshold value, and causes the control circuit 5 to stop the inverter circuit 3.
[0009]
As described above, since the drive circuit of the conventional air conditioner needs to be operated within the current capacity range of the connected AC power supply 1 as described above, an AC current value such as CT11 is detected in the drive circuit. It is necessary to provide a circuit for this purpose. Moreover, in order to protect the inverter circuit 3 or the compressor 4 from the electric current at the time of an overload, it is necessary to provide a current detection unit such as a resistor 8a. Therefore, the conventional air conditioner drive circuit requires two current detection circuits, a circuit for detecting an alternating current and a circuit for detecting the current of the inverter circuit.
[0010]
However, the total current of the drive circuit of the air conditioner is almost the current of the inverter circuit 3 (compressor 4), and the total current and the current of the inverter circuit 3 have a substantially proportional relationship. Therefore, it is possible to consolidate the functions of one of the two current detections and delete the other circuit.
[0011]
An inverter device that integrates the functions of the two current detections into either one is disclosed in Japanese Utility Model Laid-Open No. 6-31341. This is a current detection circuit provided between the inverter and converter that detects the current value during overload and, when judged to be above a certain value, reduces the compressor input power and protects the inverter from overload current. At the same time.
[0012]
In the inverter device disclosed in Japanese Utility Model Laid-Open No. 6-31341, the total current detection of the AC power supply is performed when the total current becomes the capacity of the protection device from the proportional relationship between the total current and the inverter current as described above. Check the current value of the inverter, set a threshold value using a comparator, etc., and count how many times the inverter current exceeds the threshold value. If the count exceeds a certain number, A command to lower the input power of the compressor is issued to realize that the air conditioner operates within the current capacity of the AC power source.
[0013]
[Problems to be solved by the invention]
However, in the inverter device disclosed in Japanese Utility Model Laid-Open No. 6-31341, it is necessary to adjust the threshold value of the comparator for each combination of the compressor and the circuit that drives the compressor. FIG. 8 is a diagram showing a difference in current flow due to a difference in compressor. As shown in FIG. 8, when the same value is set as the threshold value of the comparator in different types of compressors (for example, the number of windings), even if the current value of the AC power supply is the same, the current flow of the compressor (same (Ease of flow when voltage is applied) changes, and there are those that exceed the threshold and those that do not, and a design / evaluation load is generated for each product specification of the air conditioner.
[0014]
Furthermore, in the inverter device disclosed in Japanese Utility Model Laid-Open No. 6-31341, when the inverter current exceeds the threshold value of the comparator a certain number of times, a command to lower the input power of the compressor is issued to the inverter. As shown in FIG. 9, since it is performed only the number of times exceeding the threshold value, when the rotational speed is lowered, the level of decrease in the current value of the inverter (current value of the AC power supply) cannot be grasped. Therefore, even when it is desired to keep the capacity of the air conditioner constant, the current value of the AC power supply is likely to be uneven, and it is difficult to maintain the capacity.
[0015]
The present invention has been made to solve the above-described problems. The control circuit calculates the current value detected by the current detection element provided between the converter circuit and the inverter circuit, and the AC power supply current. An object of the present invention is to provide an inexpensive drive circuit for an electric device and a drive circuit for an air conditioner that eliminates the CT required on the AC power supply side by detecting the value, maintains the function / performance, and is inexpensive.
[0016]
[Means for Solving the Problems]
In the air conditioner drive circuit according to the present invention, an AC power source is converted into a DC power source by a converter circuit, and further converted into an arbitrary AC power source by an inverter circuit to drive a compressor. A current detection element provided between the converter circuit and the inverter circuit for detecting a current flowing from the inverter circuit to the converter circuit, a current detection element provided between the converter circuit and the inverter circuit, and detected by the current detection element in almost real time. DC current value is calculated based on the calculated current, and the AC current value is predicted from the relationship between the AC power and the DC power converted from the AC power by the DC current value. And a control circuit for performing operation control.
[0017]
Further, the air conditioner drive circuit according to the present invention is characterized in that a resistor is used for the current detection element.
[0018]
In addition, the air conditioner drive circuit according to the present invention peaks the voltage value generated by the current detection element at an arbitrary cycle, calculates an average value of the peak-held values at an arbitrary number, and The DC current value is calculated in consideration of the voltage duty.
[0019]
In addition, the air conditioner drive circuit according to the present invention calculates the AC current value Iac based on the DC current value Idc obtained by calculation based on the current detected by the current detection element almost in real time, and the DC voltage. Predicting from Iac = Idc × (Vdc / (Vac × cos θ × η)), where Vdc, AC voltage is Vac, power factor is cos θ, and circuit efficiency is η.
[0020]
The drive circuit for an air conditioner according to the present invention includes a DC voltage detection unit connected to the output side of the converter circuit, and the control circuit recognizes the DC voltage Vdc from the output of the DC voltage detection unit. To do.
[0021]
In addition, the air conditioner drive circuit according to the present invention is characterized in that the AC voltage Vac is selected from rated values such as 100V and 200V.
[0022]
The drive circuit for an air conditioner according to the present invention is characterized in that the power factor cos θ and the circuit efficiency η are determined by the characteristics of the converter circuit.
[0023]
The air conditioner drive circuit according to the present invention controls the operation of the air conditioner by adding the current value of a circuit other than the inverter circuit to the alternating current value.
[0024]
The drive circuit for an air conditioner according to the present invention includes an AC drive circuit and a DC drive circuit, and adds the current values of the AC drive circuit and the DC drive circuit to the AC current value in a timely manner.
[0025]
The drive circuit for an air conditioner according to the present invention is characterized in that the value to be corrected is changed depending on whether the AC drive circuit and the DC drive circuit are operating or stopped.
[0026]
Further, the air conditioner drive circuit according to the present invention includes a DC voltage detection unit connected to the output side of the converter circuit, detects voltage fluctuation after rectification of AC voltage, the peak of the voltage value and the fluctuation frequency Further, the AC voltage value and frequency are detected.
[0027]
In the air conditioner drive circuit according to the present invention, the converter circuit is provided with a circuit for half-wave rectifying an AC voltage having a diode and a resistor, and the AC voltage value is calculated from the peak of the voltage value generated in the resistor and the fluctuation frequency. It is characterized by detecting a frequency.
[0028]
In addition, the air conditioner drive circuit according to the present invention determines an upper limit value and a lower limit value of the alternating current value, and suppresses input power to the compressor when the alternating current value is predicted to exceed the upper limit value. When the inverter circuit is commanded and the AC current value is predicted to fall below the lower limit value, the inverter circuit is commanded to increase the input power to the compressor.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. Here, an air conditioner will be described as an example of an electric device. However, the present invention is not limited to an air conditioner, and an inverter load driven by an inverter occupies most of the total current of the electric device. Included.
[0030]
1 to 4 are diagrams showing Embodiment 1, FIG. 1 is a block diagram of an air conditioner drive circuit, and FIG. 2 is a diagram showing processing performed in a control circuit in the air conditioner drive circuit. 3 is a diagram showing an image of processing performed in the control circuit in the air conditioner drive circuit, and FIG. 4 is a diagram showing an AC power supply voltage detection circuit in the air conditioner drive circuit.
[0031]
In FIG. 1, 1 is an AC power source, 2 is a converter circuit that converts an AC input obtained from the AC power source 1 into DC, and 3 is an inverter circuit that converts a DC input obtained from the converter circuit 2 into an arbitrary AC. Is a compressor driven by the inverter circuit 3, 5 is a control circuit for controlling the whole or part of the air conditioner drive circuit, 6 is a DC voltage value output from the converter circuit 2, and is detected by the control circuit 5 DC voltage detection unit for inputting a value, 7 is a temperature detection unit for detecting the temperature of each mechanism of the air conditioner, 8b is for detecting a voltage generated in the resistor 8a due to a current flowing from the inverter circuit 3 to the converter circuit 2 An overcurrent detector 9 for sending a stop command for the inverter circuit 3 to the control circuit 5 when a certain threshold value is exceeded, 9 is an AC drive circuit that is controlled by the control circuit 5 and driven by AC It is controlled by the control circuit 5, a direct current drive circuit for driving at DC.
[0032]
The drive circuit of the air conditioner of FIG. 1 eliminates CT11 between the AC power supply 1 and the converter circuit 2 compared to the conventional drive circuit, and a voltage generated by the current flowing through the resistor 8a also present in the conventional drive circuit. Is detected by the control circuit 5 before the overcurrent detection unit 8b (a value detected here is hereinafter referred to as an inverter current value).
[0033]
FIG. 2 shows a process performed in the control circuit 5 after detecting the inverter current value, and FIG. 3 shows an image of the process. FIG. 3 shows that the process progresses from top to bottom.
[0034]
As shown in FIG. 3, the current waveform immediately after detecting the inverter current value has a section in which current flows by the inverter carrier and a section in which it does not, as shown in FIG. Therefore, in the control circuit 5, the current value at the time of carrier ON (current flows) is detected every n times (for example, every time) of the inverter carrier cycle in (b), and the data is buffered in the control circuit 5 ( Hereinafter, m (for example, 4) are held in the buffer a). The data in the buffer a is constantly updated, and the latest detected data at that time is held.
[0035]
The data held in the buffer a is compared with the data in the buffer a at the timing (c) (for example, when the energized phase of the inverter circuit is switched), and kth (for example, second) from the maximum value in the data. A larger value is selected, and the data is extracted to another buffer (hereinafter referred to as buffer b) in the control circuit 5.
[0036]
As described above, the processes from (a) to (c) are repeated, and when x data is extracted in the buffer b, the average value of x data is calculated in the control circuit 5 in (d). Further, an inverter duty correction calculation is performed on the average value.
[0037]
By performing the above processing, the inverter current value detected by the resistor 8a is converted into a DC current value. Since the drive circuit of the air conditioner is a circuit that converts alternating current into direct current, the alternating voltage is Vac, the alternating current is Iac, the power factor is cos θ, the direct current voltage is Vdc, the direct current is Idc, and the circuit efficiency is η.
Iac = Idc × (Vdc / (Vac × cos θ × η)) (1)
The relationship holds. Here, from FIG. 1, the value of Vdc can be recognized by the control circuit 5 by the DC voltage detection unit 6, and rated values such as 100 V and 200 V are selected for Vac, and the converter circuit 2 for cos θ and η. The AC current Iac can be predicted by calculating in the control circuit 5 using these values.
[0038]
Further, in order to increase the accuracy of the expression (1), by adding a circuit for more accurately detecting the value of the AC voltage Vac as shown in FIG. 4, it is possible to perform calculation in consideration of fluctuations in the AC voltage.
[0039]
In each detection method of FIG. 4, (a) uses a conventional DC voltage detection unit to detect voltage fluctuation after rectification of AC voltage, and determines the AC voltage value and frequency from the peak of the voltage value and the fluctuation frequency. It is to detect.
(B) A diode and a resistor are added on the converter circuit to provide a circuit for half-wave rectification of AC voltage. From the voltage value generated in the resistor, (a) Similarly, the AC voltage value and frequency are determined from the peak and frequency of the voltage value. Is detected.
[0040]
Moreover, the drive circuit of the air conditioner of the present invention generates an alternating current from the theory of equation (1) based on the current value detected by the resistor 8a that is a current detecting element provided between the converter circuit and the inverter circuit. As shown in FIG. 1, the path through which the current flows from the AC power source 1 includes the AC drive circuit 9 and the DC drive circuit 10 in addition to the inverter circuit 3, as shown in FIG. The circuit current cannot be detected. However, since the currents of the AC drive circuit 9 and the DC drive circuit 10 are relatively small compared to the current of the inverter circuit 3, the current values of the AC drive circuit 9 and the DC drive circuit 10 are detected by current in order to correct the detection accuracy. The control circuit corrects the current value detected by the element to be added in a timely manner. This timely means that the control circuit 5 can grasp the operations of the AC drive circuit 9 and the DC drive circuit 10, and therefore changes the correction value depending on whether these circuits are operating or stopped. .
[0041]
As described above, the air conditioner drive circuit of the present invention can detect the AC power supply current based on the current value detected by the current detection element provided between the converter circuit and the inverter circuit. Even if the current transformer for detecting all input AC current from the AC power supply 1 to the drive circuit is omitted, the conventional AC current value shown in FIG. 7 can be controlled.
[0042]
【The invention's effect】
An air conditioner drive circuit according to the present invention is provided between a converter circuit and the inverter circuit, and is based on a current detected almost in real time by a current detection element that detects a current flowing from the inverter circuit to the converter circuit. The DC current value is calculated by calculation, the AC current value is predicted from the relationship between the AC power and the DC power converted from the AC power, and the operation control of the air conditioner is performed based on the AC current value. Thus, it is possible to detect the AC current value without providing a means for detecting the AC current value on the AC power supply side, and it is possible to realize an inexpensive air conditioner drive circuit while maintaining the function and performance.
[0043]
In addition, the air conditioner drive circuit according to the present invention can maintain a function and performance by using a resistor for the current detection element, and can realize an inexpensive air conditioner drive circuit.
[0044]
In addition, the air conditioner drive circuit according to the present invention peaks the voltage value generated by the current detection element at an arbitrary cycle, calculates an average value of the peak-held values at an arbitrary number, and By calculating the direct current value in consideration of the voltage duty, it is possible to maintain the function and performance and to realize an inexpensive air conditioner drive circuit.
[0045]
In addition, the air conditioner drive circuit according to the present invention calculates the AC current value Iac based on the DC current value Idc obtained by calculation based on the current detected by the current detection element almost in real time, and the DC voltage. Predicting from Vac, AC voltage Vac, power factor cosθ, circuit efficiency η, and Iac = Idc × (Vdc / (Vac × cos θ × η)) The drive circuit of the machine can be realized.
[0046]
Further, the air conditioner drive circuit according to the present invention includes a DC voltage detection unit connected to the output side of the converter circuit, and the DC voltage Vdc is recognized by the control circuit from the output of the DC voltage detection unit. -The performance can be maintained and an inexpensive air conditioner drive circuit can be realized.
[0047]
In the air conditioner drive circuit according to the present invention, the AC voltage Vac is selected from rated values such as 100 V and 200 V, so that the function and performance can be maintained and an inexpensive air conditioner drive circuit can be realized.
[0048]
In the air conditioner drive circuit according to the present invention, the power factor cos θ and the circuit efficiency η are determined by the characteristics of the converter circuit, so that the function and performance can be maintained and an inexpensive air conditioner drive circuit can be realized. .
[0049]
In addition, the air conditioner drive circuit according to the present invention improves the AC current detection accuracy by controlling the operation of the air conditioner by adding the current value of the circuit other than the inverter circuit to the AC current value. Can be made.
[0050]
In addition, the air conditioner drive circuit according to the present invention includes an AC drive circuit and a DC drive circuit, and the AC drive circuit and the DC drive circuit add the current value to the AC current value in a timely manner, thereby detecting the AC current detection accuracy. Can be improved.
[0051]
In addition, the air conditioner drive circuit according to the present invention can improve the detection accuracy of the alternating current by changing the correction value depending on whether the AC drive circuit or the DC drive circuit is operating or stopped. Can do.
[0052]
Further, the air conditioner drive circuit according to the present invention includes a DC voltage detection unit connected to the output side of the converter circuit, detects voltage fluctuation after rectification of AC voltage, the peak of the voltage value and the fluctuation frequency By detecting the AC voltage value and frequency more, even if the AC power supply voltage fluctuates, it can be calculated with high accuracy, so that detection accuracy compensation for disturbance factors can be realized.
[0053]
In the air conditioner drive circuit according to the present invention, the converter circuit is provided with a circuit for half-wave rectifying an AC voltage having a diode and a resistor, and the AC voltage value is calculated from the peak of the voltage value generated in the resistor and the fluctuation frequency. By detecting the frequency, even if the AC power supply voltage fluctuates, it can be calculated with high accuracy, so that detection accuracy compensation for disturbance factors can be realized.
[0054]
In addition, the air conditioner drive circuit according to the present invention determines an upper limit value and a lower limit value of the alternating current value, and suppresses input power to the compressor when the alternating current value is predicted to exceed the upper limit value. If the AC current value is predicted to fall below the lower limit, the AC current can be detected by instructing the inverter circuit to increase the input power to the compressor. Therefore, the same control as before can be performed without being caught by the detection part on the circuit. Since the detection accuracy can be compensated widely from a large current to a small current, the output capability of the air conditioner can be maintained equivalent to the conventional one.
[Brief description of the drawings]
FIG. 1 is a block diagram of a drive circuit for an air conditioner, showing Embodiment 1. FIG.
FIG. 2 is a diagram illustrating the first embodiment, and is a diagram illustrating processing performed in the control circuit in the drive circuit of the air conditioner.
FIG. 3 is a diagram illustrating the first embodiment, and is a diagram illustrating an image of processing performed in a control circuit in the drive circuit of the air conditioner.
FIG. 4 is a diagram illustrating the first embodiment and is a diagram illustrating an AC power supply voltage detection circuit in the drive circuit of the air conditioner.
FIG. 5 is a block diagram showing a driving circuit of a conventional air conditioner.
FIG. 6 is a block diagram of an AC power source to which an air conditioner drive circuit is connected.
FIG. 7 is a diagram illustrating control of an alternating current value in a conventional air conditioner drive circuit.
FIG. 8 is a diagram illustrating a difference in current flow due to a difference in compressor.
FIG. 9 is a diagram illustrating control of an alternating current value when protection is used to count the number of times a threshold value is exceeded in a conventional air conditioner drive circuit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 AC power supply, 2 Converter circuit, 3 Inverter circuit, 4 Compressor, 5 Control circuit, 6 DC voltage detection part, 7 Temperature detection part, 8a Resistance, 8b Overcurrent detection part, 9 AC drive circuit, 10 DC drive circuit, 12 Protection device.

Claims (13)

In the drive circuit of an air conditioner that converts an AC power source into a DC power source by a converter circuit and further converts it to an arbitrary AC power source by an inverter circuit to drive a compressor.
A current detection element that is provided between the converter circuit and the inverter circuit and detects a current flowing from the inverter circuit to the converter circuit ;
A direct current value is obtained by calculation based on the current detected by the current detection element in almost real time, and the alternating current value is calculated from the relationship between the alternating current power and the direct current power converted from the alternating current power by the direct current value. A control circuit that predicts and controls the operation of the air conditioner according to the alternating current value;
A drive circuit for an air conditioner, comprising:   The air conditioner drive circuit according to claim 1, wherein a resistor is used for the current detection element.   The voltage value generated by the current detection element is peak-held at an arbitrary cycle, the peak-held value is averaged by an arbitrary number, and the DC current value is calculated in consideration of the voltage duty of the inverter circuit. The air conditioner drive circuit according to claim 1, wherein:   The AC current value Iac is calculated based on the DC current value Idc obtained by calculation based on the current detected almost in real time by the current detection element, the DC voltage is Vdc, the AC voltage is Vac, the power factor is cos θ, and the circuit. 2. The air conditioner drive circuit according to claim 1, wherein the efficiency is predicted from Iac = Idc × (Vdc / (Vac × cos θ × η)), where η is the efficiency.   5. The air conditioner according to claim 4, further comprising a DC voltage detection unit connected to an output side of the converter circuit, wherein the control circuit recognizes the DC voltage Vdc from an output of the DC voltage detection unit. Drive circuit.   The drive circuit for an air conditioner according to claim 4, wherein the AC voltage Vac is selected from rated values such as 100V and 200V.   5. The air conditioner drive circuit according to claim 4, wherein the power factor cos θ and the circuit efficiency η are determined by characteristics of the converter circuit. 6.   2. The air conditioner drive circuit according to claim 1, wherein the operation value of the air conditioner is controlled by adding a current value for a circuit other than the inverter circuit to the AC current value. 3.   9. The air conditioner drive circuit according to claim 8, further comprising an AC drive circuit and a DC drive circuit, wherein the current values of the AC drive circuit and the DC drive circuit are added to the AC current value in a timely manner.   10. The air conditioner drive circuit according to claim 9, wherein a value to be corrected is changed depending on whether the AC drive circuit and the DC drive circuit are operating or stopped.   A DC voltage detection unit connected to the output side of the converter circuit, detects voltage fluctuation after rectification of AC voltage, and detects an AC voltage value and frequency from the peak of the voltage value and the fluctuation frequency. The air conditioner drive circuit according to claim 1. 2. The converter circuit is provided with a circuit for half-wave rectifying an AC voltage having a diode and a resistor, and an AC voltage value and a frequency are detected from a peak of a voltage value generated in the resistor and a fluctuation frequency. The drive circuit of the air conditioner of Claim 1 .   An upper limit value and a lower limit value of the alternating current value are determined, and when the alternating current value is predicted to exceed the upper limit value, a command is given to the inverter circuit to suppress input power to the compressor, and the alternating current value is 2. The air conditioner drive circuit according to claim 1, wherein when the current value is predicted to fall below a lower limit value, the inverter circuit is commanded to increase the input power to the compressor. 3. .

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