Power supply unit, air conditioner, and control method for air conditioner

Abstract

To provide a power supply device capable of detecting miswiring without causing a failure of an apparatus even in the presence of any miswiring.SOLUTION: The power supply device includes a first input conversion unit, a first switching power supply circuit, a second input conversion unit, a second switching power supply circuit, and protection means. The first input conversion unit has a neutral line connected to one of three phase power supply lines and converts AC power to DC power. The first switching power supply circuit supplies power needed to drive and control an inverter on the basis of DC power to be input. The second input conversion unit has a neutral line connected to the other one of the three phase power supply lines and converts AC power to DC power. The second switching power supply circuit supplies power needed to drive and control apparatuses other than the inverter on the basis of DC power to be input.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power supply device, an air conditioner, and a control method for an air conditioner.

Background Art

[0002] An inverter circuit used to drive a compressor of an air conditioner is connected to, for example, a three-phase four-wire AC power supply. This three-phase four-wire AC power supply has a plurality of phases, and a problem may occur in which any one of the plurality of phases is open-circuited or the like, resulting in a phase loss. Patent Document 1 describes a determination system in which a current sensor detects a current flowing through a load based on a threshold value in the case of no phase loss, and compares this detection signal with the threshold value to determine the presence or absence of a phase loss.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above Patent Document 1, although a phase loss can be determined, only a phase loss based on a threshold value can be determined, and a miswiring cannot be detected. [[ID=三十八]]

[0005] The present invention has been made by paying attention to a conventional unsolved problem, and an object thereof is to provide a power supply device, an air conditioner, and a control method for an air conditioner that can detect miswiring without causing the device to malfunction even if there is any miswiring.

Means for Solving the Problems

[0006] To achieve the above objective, according to one aspect of the present invention, a first wire from a three-phase four-wire AC power supply is connected to the first input terminal, the second wire to the second input terminal, the third wire to the third input terminal, and a fourth wire, which is the neutral wire, is connected to the fourth input terminal, and one of the three-phase power supply wires is connected to the fourth wire, and a first input conversion unit that converts AC power to DC power, a first switching power supply circuit that supplies the power necessary to drive and control the inverter based on the input DC power, an inverter unit having the inverter and the first switching power supply circuit, and the three-phase power supply The power supply device is provided, comprising: a second input conversion unit to which one other wire, separate from the one input to the first input conversion unit, is connected, and the fourth wire is also connected, and which converts AC power to DC power; a second switching power supply circuit that supplies power necessary for driving and controlling equipment other than the inverter based on the input DC power; and protection means that detects a misconnection in which the fourth wire is connected to any one of the first input terminal, the second input terminal, or the third input terminal, and when the misconnection is detected, performs a protection process to stop the operation of the inverter. Furthermore, according to another aspect of the present invention, an air conditioner using the above-mentioned power supply device is provided.

[0007] Furthermore, according to another aspect of the present invention, a control method for an air conditioner comprising: a first board having an input conversion unit that converts AC power to DC power and a switching power supply circuit that supplies power necessary for driving and controlling an inverter based on the input DC power; and a second board having a control unit, wherein the control unit has the fourth wiring connected to the first input terminal and the second input terminal, respectively. A control method for an air conditioner is provided, which includes detecting a misconnection in which the connection state is connected to any one of the third input terminals; when a misconnection is detected between the first wiring, the second wiring, and the third wiring, and between the first input terminal, the second input terminal, and the third input terminal, the control unit does not perform a protection process to stop the operation of the inverter; and when one or more of the first, second, third, and fourth input terminals are not connected to any of the first, second, third, and fourth wirings, the control unit performs the protection process. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to obtain a power supply unit, an air conditioner, and a control method for an air conditioner that can detect miswiring without causing equipment failure, even in the event of any miswiring. [Brief explanation of the drawing]

[0009] [Figure 1] This is a configuration diagram showing an example of an air conditioner according to the first embodiment of the present invention. [Figure 2] Figure 1 is a block diagram showing the configuration of the microprocessor. [Figure 3] This is a diagram showing the configuration of a power supply unit previously considered as a comparative example. [Figure 4]This is a signal waveform diagram of the detection signal detected by the phase detection circuit in a second embodiment of the present invention. [Figure 5] This figure shows a first table of phase detection patterns stored in the memory unit in the second embodiment. [Figure 6] This figure shows a second table of phase detection patterns stored in the memory unit in the second embodiment. [Figure 7] This is a flowchart showing the control processing procedure when the microprocessor is powered on in the second embodiment. [Figure 8] This flowchart shows the control processing procedure at the start of operation of the microprocessor in the second embodiment. [Modes for carrying out the invention]

[0010] Next, embodiments of the present invention will be described with reference to the drawings. In the following drawings, identical or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Furthermore, the embodiments described below illustrate devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention does not limit the structure, arrangement, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims described in the patent claims.

[0011] <First Embodiment> Figure 1 is a configuration diagram showing an example of an air conditioner 1 according to the first embodiment of the present invention. Components of the air conditioner that are not directly related to the present invention, such as heat exchangers and valves, are not shown or described. The air conditioner 1 comprises a power supply unit 10 and, for example, an outdoor unit compressor 20. The power supply unit 10 converts the output of three-phase commercial AC power supplied from an external three-phase four-wire AC power supply (not shown) into drive power and supplies it to the compressor 20.

[0012] The power supply unit 10 comprises a filter board 11, an inverter board (first board) 12 to which the compressor 20 is connected, and a main board (second board) 13. The filter board 11 is provided with four input terminals 111, 112, 113, and 114. Input terminal (first input terminal) 111 is connected to wiring (first wiring) L1 of the three phase power lines from a three-phase four-wire AC power supply. Input terminal (second input terminal) 112 is connected to wiring (second wiring) L2 of the three phase power lines from a three-phase four-wire AC power supply. Input terminal (third input terminal) 113 is connected to wiring (third wiring) L3 of the three phase power lines from a three-phase four-wire AC power supply. Input terminal (fourth input terminal) 114 is connected to wiring (fourth wiring) N, which is the neutral wire from a three-phase four-wire AC power supply. Furthermore, a filter section 115 is provided on the filter board 11. The filter section 115 suppresses noise transmitted through the wiring L1, L2, L3, and N.

[0013] The inverter board 12 is provided with a converter (not shown), an IPM (inverter) 121, a converter circuit (first input conversion unit) 122, a switching power supply circuit (first switching power supply circuit) 123, and a microprocessor (first control unit) 124. The IPM 121 is connected to wiring L11 which is connected to the input terminal 111 via a filter unit 115, wiring L22 which is connected to the input terminal 112, and wiring L33 which is connected to the input terminal 113. The IPM 121 supplies AC power supplied from the filter unit 115 via wirings L11, L22, and L33 to a motor that rotates the compressor 20.

[0014] The converter circuit 122 is connected to wiring L11, which is connected to the input terminal 111 via the filter unit 115, and wiring NN, which is connected to the input terminal 114. The converter circuit 122 converts the AC power supplied from the filter unit 115 into DC power. The switching power supply circuit 123 supplies the IPM 121 and the microprocessor 124 with the power necessary to drive and control the IPM 121 based on the DC power supplied from the converter circuit 122. The IPM 121 and the switching power supply circuit 123 constitute the inverter unit.

[0015] The microprocessor 124 operates on the power supplied by the switching power supply circuit 123, communicates with the main board 13, and comprehensively controls the processing of devices related to the drive of the compressor 20 including the processing of the IPM 121. Here, comprehensively controlling means that in addition to the processing of the IPM 121, the microprocessor 124 collectively manages and controls the communication processing with the main board 13 and the processing of the drive circuit of the compressor 20 mounted on the inverter board 12. The main board 13 is provided with a converter circuit (second input conversion unit) 133, a switching power supply circuit (second switching power supply circuit) 134, and a microprocessor (second control unit) 135.

[0016] Wiring L11 connected to the input terminal 111 via the output terminal of the filter unit 115, wiring L33 connected to the input terminal 113, and wiring NN connected to the input terminal 114 are respectively connected to the phase detection circuit 131. The phase detection circuit 131 detects a misconnection in which the wiring N is in a connection state with any one of the input terminals 111, 112, and 113. Further, the phase detection circuit 131 detects a misconnection between each of the wirings L1, L2, and L3 and between the input terminals 111, 112, and 113. Based on the detection result by the phase detection circuit 131, the misconnection protection unit 132 performs a protection process of, for example, communicating with the microprocessor 124 provided on the inverter board 12 and stopping the drive of the IPM 121 when a misconnection is detected.

[0017] Wiring L33 connected to input terminal 113 and wiring NN connected to input terminal 114 are respectively connected to converter circuit 133 via filter section 115. Converter circuit 133 converts the AC power supplied from filter section 115 into DC power. Switching power supply circuit 134 supplies the power necessary for driving and controlling phase detection circuit 131, misconnection protection section 132, and microprocessor 135 based on the DC power supplied from converter circuit 133. Also, on main board 13, for example, an expansion valve coil, a solenoid valve coil, a base heater, a belt heater, a four-way valve coil, etc., which are control devices inside an outdoor unit (not shown), are connected. These control devices operate with the power supplied from switching power supply circuit 134.

[0018] Microprocessor 135 operates with the power supplied by switching power supply circuit 134, communicates with inverter board 12, and comprehensively controls the processing of misconnection protection section 132, including, for example, the processing of control devices inside the outdoor unit. Here, comprehensively controlling means that in addition to the processing of misconnection protection section 132, microprocessor 135 collectively manages and controls the communication processing with inverter board 12 and the processing of control devices connected to main board 13.

[0019] As shown in FIG. 2, microprocessor 135 includes a CPU 301, a storage section 302, a sensor input section 303, a device interface 304, and a communication interface​​​The memory unit 302 consists of ROM and RAM and stores control programs, detection values ​​corresponding to detection signals from various sensors, the control status of the compressor 20, etc. The device interface 304 is an interface for communication with, for example, the misconnection protection unit 132. The communication interface 305 is an interface for communication with the microprocessor 124 of the inverter board 12. The sensor input unit 303 takes the detection result from the phase detection circuit 131 and outputs it to the CPU 301. The CPU 301 operates according to the control program and various data stored in the memory unit 302, and controls the misconnection protection unit 132 and communicates with the microprocessor 124 of the inverter board 12 based on the acquired detection results and control signals.

[0021] <Comparative Examples of Embodiments> Figure 3 is a configuration diagram showing the power supply unit 10-1 of the air conditioner 1-1 previously considered as a comparative example. In Figure 3, the same reference numerals are used for parts identical to those in Figure 1, and detailed explanations are omitted. In Figure 3, the converter circuit 122 of the inverter board 12 is connected to wiring L33, which is connected to the input terminal 113 via the filter section 115, and wiring NN, which is connected to the input terminal 114. Similarly, the converter circuit 133 of the main board 13 is connected to wiring L33, which is connected to the input terminal 113 via the filter section 115, and wiring NN, which is connected to the input terminal 114.

[0022] In the previous system, if a misconnection occurred between wiring L1, L2, and L3 and input terminals 111, 112, and 113, the operation of the air conditioner 1-1 would be stopped. However, if wiring N, which is the neutral wire from the 3-phase 4-wire AC power supply, is misconnected to input terminal 111, for example, the phase detection circuit 131 on the main board 13 would not be able to detect the misconnection, causing overvoltage to occur in the switching power supply circuits 123 and 134, potentially leading to failure of the equipment mounted on the inverter board 12, including the IPM 121, or the compressor 20. To solve this problem, it would be necessary to significantly modify the phase detection circuit 131 or change the software. Therefore, there is a problem in that air conditioner 1-1 cannot be operated until the misconnection is corrected.

[0023] <Solution according to the first embodiment> Therefore, in the first embodiment, the converter circuit 122 of the inverter board 12 is connected to the input terminal 111 via the filter section 115, and the wiring NN connected to the input terminal 114 is connected to the converter circuit 122 of the inverter board 12, and the wiring L33 connected to the input terminal 113 via the filter section 115 and the wiring NN connected to the input terminal 114 are connected to the converter circuit 133 of the main board 13.

[0024] Here, for example, if wiring N, which is the neutral wire from a 3-phase 4-wire AC power supply, is incorrectly connected to input terminal 111, and wiring L1 is incorrectly connected to input terminal 114, the switching power supply circuit 123 on the inverter board 12 will operate, but the switching power supply circuit 134 on the main board 13 will not operate. As a result, the microprocessor 135 will not operate, causing a communication error with the microprocessor 124 on the inverter board 12, and it can be determined that there is a wiring error.

[0025] <Effects and Effects of the First Embodiment> As described above, according to the first embodiment, the switching power supply circuit 123 of the inverter board 12 and the switching power supply circuit 134 of the main board 13 can be separated by connecting the switching power supply circuit 123 of the inverter board 12 via the converter circuit 122, connecting the wiring L11 connected via the filter unit 115 to the input terminal 111 to which the wiring L1 of the three phases of the three phases of the AC power supply is connected, and the wiring NN connected via the filter unit 115 to the input terminal 114 to which the neutral wire wiring N is connected, and connecting the wiring L33 connected via the filter unit 115 to the input terminal 113 to which the wiring L3 of the three phases of the AC power supply is connected, and connecting the wiring NN connected via the filter unit 115 to the input terminal 114 to which the wiring N is connected, via the converter circuit 133 of the main board 13.

[0026] Therefore, unlike when the same wiring L33,NN is connected to the switching power supply circuit 123 of the inverter board 12 and the switching power supply circuit 134 of the main board 13, the equipment will not malfunction even if wiring N is incorrectly connected to any of the input terminals 111, 112, or 113.

[0027] Furthermore, according to the first embodiment, the switching power supply circuit 123 of the inverter board 12 and the switching power supply circuit 134 of the main board 13 can be separated. Therefore, if the wiring N is incorrectly connected to any of the input terminals 111, 112, or 113, at least one of the microprocessors 124 and 135 will not operate, resulting in a communication error. This allows it to be determined that the wiring N has been incorrectly connected to any of the input terminals 111, 112, or 113.

[0028] <Second Embodiment> A second embodiment of the present invention is a modification of the first embodiment, which allows the air conditioner 1 to continue operating in the event of a wiring misconnection that does not affect its operation. It also allows for handling of phase loss as described later. In the second embodiment, a phase detection circuit (protection means) 131 and a misconnection protection unit (protection means) 132 are connected to the main board 13.

[0029] Figure 4 is a signal waveform diagram of the detection signal detected by the phase detection circuit 131 in a second embodiment of the present invention. The level shifting means of the phase detection circuit 131 sends a Hi or Lo signal to the microprocessor 135. Thus, Figure 5 is a diagram showing the first table 400 of the phase detection patterns stored in the storage unit 302 in a second embodiment. In Figure 4, when the N phase is lost, the detection signal (L1-N), which corresponds to the potential difference between wiring L1 and wiring N, becomes high level (Hi) at phases of 90 degrees and 150 degrees, and low level (Lo) at phases of 210 degrees, 270 degrees, and 330 degrees.

[0030] Therefore, in this second embodiment, the memory unit 302 is provided with a first table 400 that stores the phase detection pattern 410 for when the N phase is missing (N phase loss). The first table 400 stores information representing the correspondence between the pattern name, the phase difference, and the detection signal. It stores information representing the correspondence between the pattern name, the phase difference between wiring L1 and wiring L3, and the detection signal corresponding to the potential difference between wiring L1 and wiring N. The microprocessor 135 applies the detection signal sent from the phase detection circuit 131 to the first table 400 to determine the phase difference and wiring pattern of wiring L1 and wiring L3. As for the pattern name, in addition to "N phase loss" of the phase detection pattern 410, information indicating "3-phase 4-wire positive phase" and "3-phase 4-wire negative phase" is stored. Note that "N phase loss" is a state in which only wiring N is not connected to any input terminal. In the case of a "3-phase 4-wire positive phase" system, the phase difference is 120 degrees, and the detection signal is high level (Hi) at a phase of 90 degrees, low level (Lo) at 150 degrees, 210 degrees, and 270 degrees, and high level (Hi) at 330 degrees. In the case of a "3-phase 4-wire negative phase" system, the phase difference is 240 degrees, and the detection signal is high level (Hi) at a phase of 90 degrees, 150 degrees, and 210 degrees, and low level (Lo) at 270 degrees and 330 degrees. The "3-phase 4-wire negative phase" system indicates a state where the phase difference is 240 degrees.

[0031] The second table 500 shown in Figure 6 visualizes the combinations of incorrect wiring connections and the wiring patterns detected by the first table 400. The second table 500 stores information representing the correspondence between the combinations of incorrect wiring connections, the detection results of the phase detection circuit in those cases, the connection status, and the phase difference between wiring L1 and wiring L3. The combinations stored include information indicating "normal" and "incorrect connection". In the case of "normal", wiring L1 is connected to input terminal 111, wiring L2 is connected to input terminal 112, wiring L3 is connected to input terminal 113, and wiring N is connected to input terminal 114. Also, in the case of "normal", the connection status is "positive phase connection", and the phase difference is 120 degrees.

[0032] "Incorrect connections" can be classified into several categories depending on the combination. In the following incorrect connection combination (1), the connection state is "positive phase connection" and the phase difference is 120 degrees. This corresponds to "3-phase 4-wire positive phase" as shown in Table 400. (i) Wiring L2 is connected to input terminal 111, wiring L3 is connected to input terminal 112, wiring L1 is connected to input terminal 113, and wiring N is connected to input terminal 114. (ii) Wiring L3 is connected to input terminal 111, wiring L1 is connected to input terminal 112, wiring L2 is connected to input terminal 113, and wiring N is connected to input terminal 114.

[0033] On the other hand, in the case of "incorrect connection," the following combination of incorrect connection (2) results in a "reverse phase connection" with a phase difference of 240 degrees. This corresponds to the "three-phase four-wire reverse phase" shown in Table 400. (i) Wiring L1 is connected to input terminal 111, wiring L3 is connected to input terminal 112, wiring L2 is connected to input terminal 113, and wiring N is connected to input terminal 114. (ii) Wiring L2 is connected to input terminal 111, wiring L1 is connected to input terminal 112, wiring L3 is connected to input terminal 113, and wiring N is connected to input terminal 114. (iii) Wiring L3 is connected to input terminal 111, wiring L2 is connected to input terminal 112, wiring L1 is connected to input terminal 113, and wiring N is connected to input terminal 114.

[0034] Furthermore, in the case of "misconnection," the following combination of misconnection (3) is a "N-phase misconnection," and the phase difference is one of 30 degrees, 60 degrees, 300 degrees, or 330 degrees. (i) Wire L1 is connected to input terminal 111, wire L2 is connected to input terminal 112, wire N is connected to input terminal 113, and wire L3 is connected to input terminal 114. In addition, wire L3 may be connected to input terminal 112, and wire N may be connected. In addition, wire L2 may be connected to input terminal 113, and wire L3 may be connected. Furthermore, wire L2 may be connected to input terminal 114, and wire N may be connected.

[0035] (ii) Wiring L2 is connected to input terminal 111, wiring L1 is connected to input terminal 112, wiring N is connected to input terminal 113, and wiring L3 is connected to input terminal 114. In addition, wiring L3 may be connected to input terminal 112, and wiring N may be connected. In addition, wiring L1 may be connected to input terminal 113, and wiring L3 may be connected. Furthermore, wiring L1 may be connected to input terminal 114, and wiring N may be connected.

[0036] (iii) Wiring L3 is connected to input terminal 111, wiring L1 is connected to input terminal 112, wiring N is connected to input terminal 113, and wiring L2 is connected to input terminal 114. In addition, wiring L2 may be connected to input terminal 112, and wiring N may be connected. In addition, wiring L1 may be connected to input terminal 113, and wiring L2 may be connected. Furthermore, wiring L1 may be connected to input terminal 114, and wiring N may be connected.

[0037] (iv) Wire N is connected to input terminal 111, wire L1 is connected to input terminal 112, wire L2 is connected to input terminal 113, and wire L3 is connected to input terminal 114. In addition, wire L2 may be connected to input terminal 112, and wire L3 may be connected. In addition, wire L1 may be connected to input terminal 113, and wire L3 may be connected. Furthermore, wire L1 may be connected to input terminal 114, and wire L2 may be connected.

[0038] (Control processing of microprocessor 135) Figure 7 is a flowchart showing the control processing procedure when the microprocessor 135 of the main board 13 of the second embodiment is powered on. First, the microprocessor 135 monitors whether the switching power supply circuit 134 is turned on (step ST6a). If the switching power supply circuit 134 is turned on (step ST6a-Yes), it communicates with the microprocessor 124 on the inverter board 12 and determines whether a communication error has been detected (step ST6b). Communication error detection is performed by detecting a misconnection that includes wiring N, similar to the first embodiment. In other words, a communication error is detected in the case of "N phase misconnection" among the combinations listed in the second table 500 in Figure 6. If a communication error is detected (step ST6b-Yes), the microprocessor 135 stops the operation of the entire air conditioner 1. If no communication error is detected (step ST6b-No), the detection signal from the phase detection circuit 131 is compared with the phase detection pattern in the first table 400 of the storage unit 302 (step ST6c) to determine whether wiring L1, L2, and L3 are misconnected (step ST6d).

[0039] The misconnections of wiring L1, L2, and L3 referred to here are the five patterns of "misconnections" in Table 500, Section 2 of Figure 6, which include both "positive-phase connection" and "negative-phase connection". In the case of the above misconnections, for example, the detection signal (L1-N) corresponding to the difference between wiring L1 and wiring N will be high level (Hi) at 90 degrees, 150 degrees, and 210 degrees, and low level (Lo) at 270 degrees and 330 degrees.

[0040] If it is determined that wiring L1, L2, and L3 are misconnected (step ST6d-Yes), the microprocessor 135 stops the operation of the misconnection protection unit 132 (step ST6e) and starts operation, i.e., drives the motor of the compressor 20 (step ST6h). On the other hand, if it is determined that wiring L1, L2, and L3 are not misconnected (step ST6d-No), the microprocessor 135 determines whether or not there is a phase loss (step ST6f). If the microprocessor 135 cannot receive a signal from the phase detection circuit 131, it determines that there is a phase loss. Also, if the N phase is missing, it detects the phase detection pattern 410 of the first table 400 and determines that there is a phase loss.

[0041] In this context, a phase loss means that none of the wires L1, L2, L3, or N are connected to any one of the input terminals 111, 112, 113, or 114. However, in this second embodiment, since no voltage detection circuit is connected to wire L2, the pattern in which only wire L2 is out of phase is determined in step ST8f, described later, after the compressor 20 is started. If it is determined that there is a phase loss (step ST6f-Yes), the microprocessor 135 continues the operation of the misconnection protection unit 132 to stop the operation of the entire air conditioner 1 (step ST6g), and terminates the process.

[0042] On the other hand, if it is determined that there is no phase loss (step ST6f-No), the microprocessor 135 proceeds to step ST6e. Also, if the switching power supply circuit 134 is off in step ST6a (step ST6a-No), the microprocessor 135 terminates processing.

[0043] Figure 8 is a flowchart showing the control processing procedure at the start of operation of the microprocessor 135 on the main board 13 according to the second embodiment. Here, the detailed processing procedure of step ST6h is shown. First, the microprocessor 135 determines whether or not the motor of the compressor 20 is running (step ST8a). Since operation was started in step ST6h above (step ST8a-Yes), the microprocessor 135 communicates with the microprocessor 124 on the inverter board 12 and determines whether or not a communication error has been detected (step ST8b). If a communication error is detected here (step ST8b-Yes), the microprocessor 135 returns to step ST8a.

[0044] On the other hand, if no communication error is detected (step ST8b-No), the microprocessor 135 compares the detection signal from the phase detection circuit 131 with the phase detection pattern in the second second table 500 of the storage unit 302 (step ST8c) to determine whether or not wiring L1, wiring L2, and wiring L3 are misconnected (step ST8d).

[0045] The misconnections of wiring L1, L2, and L3 referred to here include the five patterns of "misconnection" in Table 500, Section 2 of Figure 6, specifically "positive-phase connection" and "negative-phase connection". In the case of positive-phase connection, for example, the detection signal (L1-N) corresponding to the difference between wiring L1 and wiring N will be high level (Hi) at a phase of 90 degrees, low level (Lo) at 150 degrees, 210 degrees, and 270 degrees, and high level at 330 degrees. In the case of negative-phase connection, for example, the detection signal (L1-N) corresponding to the difference between wiring L1 and wiring N will be high level (Hi) at a phase of 90 degrees, 150 degrees, and 210 degrees, and low level (Lo) at 270 degrees and 330 degrees.

[0046] If it is determined that there is a misconnection (step ST8d-Yes), the microprocessor 135 displays the result of the misconnection on an external display unit (not shown) (step ST8e) and returns to step ST8a. Specifically, if wire L2 is connected to input terminal 111, wire L3 is connected to input terminal 112, and wire L1 is connected to input terminal 113, the display unit will show "L2,L3,L1,N: Positive phase connection: 120 degrees". Also, if wire L3 is connected to input terminal 111, wire L1 is connected to input terminal 112, and wire L2 is connected to input terminal 113, the display unit will show "L3,L1,L2,N: Positive phase connection: 120 degrees". Furthermore, if wiring L1 is connected to input terminal 111, wiring L3 is connected to input terminal 112, and wiring L2 is connected to input terminal 113, the display unit will show "L1,L3,L2,N: Reverse phase connection: 240 degrees".

[0047] On the other hand, if it is determined that there is no misconnection (step ST8d-No), the microprocessor 135 determines whether or not there is a phase loss, including wiring L2 (step ST8f). If it is determined that there is a phase loss (step ST8f-Yes), the microprocessor 135 activates the misconnection protection unit 132 to stop the operation of the entire air conditioner 1 (step ST8g), and terminates the process.

[0048] On the other hand, if it is determined that there is no phase loss (step ST8f-No), the microprocessor 135 proceeds to step ST8e. Also, if the switching power supply circuit 134 is off in step ST8a (step ST8a-No), the microprocessor 135 terminates processing.

[0049] <Effects and Effects of the Second Embodiment> As described above, according to the second embodiment, when an incorrect connection is detected between each of the wirings L1, L2, and L3 and between input terminals 111, 112, and 113, the equipment does not malfunction and is not detected as an error, allowing the air conditioner 1 to continue operating without having to correct the connections of each wiring.

[0050] Furthermore, according to the second embodiment, if none of the wirings L1, L2, L3, or N are connected to one of the input terminals 111, 112, 113, or 114, it can be determined that there is a phase loss and the operation of the air conditioner 1 can be stopped. Furthermore, according to the second embodiment, when the air conditioner 1 starts operation, the result of the misconnection is displayed on an external display unit, so that the user can look at the display unit and understand whether the misconnection between wiring L1, wiring L2, and wiring L3 and between input terminals 111, 112, and 113 is a positive-phase connection or a negative-phase connection, and which wiring is misconnected to which input terminal.

[0051] <Other Embodiments> As described above, the present invention has been described by first and second embodiments, but the descriptions and drawings that constitute part of this disclosure should not be understood as limiting the present invention. Those skilled in the art will understand the spirit of the technical content disclosed in the first and second embodiments above, and will see that various alternative embodiments, examples, and operational techniques can be included in the present invention. Furthermore, the configurations disclosed in the first and second embodiments can be combined as appropriate, within a non-contradictory scope. For example, configurations disclosed in multiple different embodiments may be combined, or configurations disclosed in multiple different modifications of the same embodiment may be combined. [Explanation of Symbols]

[0052] 1,1-1 Air conditioner 10,10-1 Power supply 11 Filter substrate 12. Inverter board (first board) 121 IPM 13. Main board (second board) 20 Compressors 111 Input terminal (1st input terminal) 112 Input terminal (2nd input terminal) 113 Input terminal (3rd input terminal) 114 Input terminal (4th input terminal) 115 Filter section 122 Converter circuit (first input conversion section) 123 Switching power supply circuit (First switching power supply circuit) 124 Microprocessor (First Control Unit) 131 Phase detection circuit (protection means) 132 Misconnection protection unit (protection means) 133 Converter circuit (second input conversion section) 134 Switching power supply circuit (Second switching power supply circuit) 135 Microprocessor (Second Control Unit) 301 CPU 302 Storage section 303 Sensor Input Section 304 Device Interface 305 Communication Interface 306 Control Bus 400 First Table 410 Phase Detection Patterns 500 Second Table

Claims

1. Of the three phase power lines from a three-phase four-wire AC power supply, the first wire is connected to the first input terminal, the second wire to the second input terminal, the third wire to the third input terminal, and the fourth wire, which is the neutral wire, is connected to the fourth input terminal. One of the three phase power lines is connected to the fourth wiring, and a first input conversion unit converts AC power to DC power, A first switching power supply circuit that supplies the power necessary for driving and controlling the inverter based on the input DC power, The inverter unit having the inverter and the first switching power supply circuit, The first circuit board on which the inverter unit is provided, One of the three-phase power lines, different from the one input to the first input conversion unit, is connected to the fourth wiring, and a second input conversion unit that converts AC power to DC power is connected. A second switching power supply circuit that supplies the power necessary to drive and control equipment other than the inverter based on the input DC power, The second switching power supply circuit is provided, and the second board communicates with the first board, A protection means detects a misconnection, which occurs when at least one of the first or second boards becomes inoperable due to a misconnection in which the fourth wiring is connected to any one of the first, second, or third input terminals, and when the misconnection is detected, it performs a protection process to stop the operation of the inverter. A power supply unit equipped with the following features.

2. The protective means is provided on the second substrate The power supply device according to claim 1.

3. The first circuit board is powered by the first switching power supply circuit and includes a first control unit that comprehensively controls the processing of the inverter section. The second circuit board is powered by the second switching power supply circuit, is able to communicate with the first control unit, and includes a second control unit that comprehensively controls the processing of the protection means. The power supply device according to claim 2.

4. The second control unit does not perform the protection process by the protection means when it detects an incorrect connection between the first wiring, the second wiring, and the third wiring, and between the first input terminal, the second input terminal, and the third input terminal. The power supply device according to claim 3.

5. The second control unit causes the protection means to perform a protection process if one or more of the first, second, third, and fourth input terminals are not connected to any of the first, second, third, or fourth wirings. The power supply device according to claim 3.

6. An air conditioner using the power supply device described in any one of claims 1 to 5.

7. A control method for an air conditioner comprising: a first board having an input conversion unit that converts AC power to DC power and a first switching power supply circuit that supplies power necessary for driving and controlling an inverter based on the input DC power; and a second board having a control unit that supplies power necessary for driving and controlling equipment other than the inverter based on the input DC power; wherein first, second, and third wires from a three-phase four-wire AC power supply are connected to the first, second, and third input terminals, and a fourth wire, which is a neutral wire, is connected to the fourth input terminal, and one of the three-phase power lines from the three-phase four-wire AC power supply is connected to the fourth wire; an input conversion unit that converts AC power to DC power and a first switching power supply circuit that supplies power necessary for driving and controlling an inverter based on the input DC power; and a second board having a control unit that supplies power necessary for driving and controlling equipment other than the inverter based on the input DC power. The control unit, The system detects a misconnection by detecting a communication error that occurs when at least one of the first or second boards becomes inoperable due to a misconnection in which the fourth wiring is connected to any one of the first, second, or third input terminals, and the system communicates between the first and second boards. When a misconnection is detected between the first, second, and third wiring, and between the first, second, and third input terminals, the control unit does not perform a protection process to stop the inverter's operation. If, among the aforementioned misconnections, one or more of the first, second, third, and fourth input terminals are not connected to any of the first, second, third, or fourth wirings, the control unit will perform the protection process. A method for controlling an air conditioner, including the control of an air conditioner.

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