JP2007104858A - Control unit for air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect a three-phase four-wire type AC power supply on a phase failure with a cost-effective structure. <P>SOLUTION: This control unit is made up of a control circuit means 2 connected to a neutral point power source line 9n and an R-phase power source line 9r, a current detecting means 3 connected to an S-phase power source line 9s and the neutral point power source line 9n, and an exciting coil portion of a second three-phase power source opening/closing means 11 connected to the T-phase power source line 9t and the neutral point power source line 9n via the opening/closing portion of a first three-phase four-wire type AC power supply opening/closing means 10. Even if any one of the phases fails at least in a three-phase four-wire type power source line, the opening/closing portion of the second three-phase power supply opening/closing means 11 is made to perform opening operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a phase loss detection technique for an air conditioner using a three-phase four-wire AC power source.

  Conventionally, this type of air conditioner has been devised to input the line voltage of each of the three-phase power supply, generate a pulse synchronized with the interphase voltage of the power supply, and detect the interruption of the pulse ( For example, see Patent Document 1).

FIG. 3 shows a conventional phase loss detection technique described in Patent Document 1. In FIG. As shown in FIG. 3, a line voltage is connected to a pulse generation circuit 25 from a three-phase three-wire three-phase power source 21 via a connection terminal 22. The pulse generation circuit 25 is connected to a signal processing circuit 26 and includes an open / close Ry 23 and a display means 29. With this configuration, since the pulse generation circuit 25 inputs the line voltage of the three-phase power source 21, it is possible to generate a pulse synchronized with the phase voltage. Thereby, the interruption of the pulse of a specific phase is detected, and the signal processing circuit 26 cuts off the energization of the open / close Ry 23 and displays an abnormality on the display means 29.
Japanese Patent Laid-Open No. 09-308083

  However, although the conventional configuration is effective for detecting and controlling the line voltage (AC200V) in a three-phase three-wire AC power source in Japan, a three-phase four-wire AC power source such as Europe and China. In this case, the line voltage becomes AC 380V to 415V, so that the components used in the pulse generation circuit 25 are required to have high voltage components, and there is a problem that leads to cost increase in addition to the increase in size of the components.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide an inverter air conditioner control device that realizes phase loss detection in a three-phase four-wire AC power supply with a simple configuration.

  In order to solve the above-mentioned conventional problems, in an air conditioner driven by an inverter operated by a three-phase four-wire AC power source, a three-phase wire (hereinafter referred to as a three-phase four-wire AC power source) is provided inside the air conditioner. And R-phase power supply line, S-phase power supply line, and T-phase power supply line) and a neutral point power supply line. Excitation coil of the second three-phase power supply switching means via the voltage detecting means for the wire and the neutral point power supply line, and the open / close part of the first three-phase power supply switching means for the T-phase power supply line and the neutral point power supply line The R-phase power supply line, S-phase power supply line, and T-phase power supply line are connected to the opening / closing part, smoothing means, inverter driving means, compressor of the second three-phase power supply opening / closing means, and the voltage The detection means is connected to the voltage determination means, and the control circuit means and the inverter drive means are connected by communication means, and at least Phase with a four-wire power lines, any phase and open phase, in which the control for opening operation of the opening and closing portion of the second three-phase power supply switching means.

    As a result, the neutral point power supply line of the three-phase four-wire AC power supply is used to detect the voltage, so that the phase loss can be detected with a simple configuration.

The control device of the air conditioner of the present invention uses a neutral point power line unique to a three-phase four-wire AC power supply, and because of the voltage detection method of each phase of the neutral point power line and R, T, S, Compared with the detection method between three-phase lines, the voltage is lower (1 / √3 of the line voltage), so small components can be used and the configuration is simple. become.

  The present invention relates to an air conditioner that is driven by an inverter that is operated by a three-phase four-wire AC power source, and a three-phase wire of a three-phase four-wire AC power source (hereinafter each referred to as an R-phase power source wire).・ S-phase power supply line / T-phase power supply line) and neutral point power supply line, R phase power supply line and neutral point power supply line are control circuit means, S phase power supply line and neutral point power supply line The voltage detection means is connected to the line, and the T-phase power supply line and the neutral point power supply line are connected to the excitation coil part of the second three-phase power supply switching means via the opening / closing part of the first three-phase power supply switching means, The R-phase power supply line, S-phase power supply line, and T-phase power supply line are connected to the opening / closing part, smoothing means, inverter driving means, and compressor of the three-phase power supply switching means 2, and the voltage detection means is connected to the voltage determination means The control circuit means and the inverter drive means are connected by communication means, and at least three-phase four-wire power line There also open-phase, it is possible to inexpensively open phase detecting the opening and closing portion of the second three-phase power switching means with a simple structure in order to opening operation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a block diagram of a control device according to Embodiment 1 of the present invention, and FIG. 2 is a flowchart showing its control operation.

  In FIG. 1, 1 is a control device, 2 is control circuit means, 3 is voltage detection means, and 4 is voltage determination means, which are connected to the control circuit means 2 and the voltage detection means 3. Reference numeral 10 denotes a first three-phase power supply switching means, and 11 denotes a second three-phase power supply switching means. In the present application, the first three-phase power supply switching means 10 is represented by an open / close relay. It is provided inside the control circuit means 2. Further, the contact portion of the first three-phase power switching means 10 is connected to the exciting coil section of the second three-phase power switching means 11 and the T-phase power line 9t. The contact portion of the second three-phase power supply switching means 11 is for three contacts, and the contact is connected to the R-phase power supply line 9r, S-phase power supply line 9s, T-phase power supply line 9t on the power supply side, and on the load side Are connected in the order of smoothing means 7, inverter driving means 6, and compressor 8. A communication means 5 is connected to the control circuit means 2 and the inverter driving means 6. Reference numeral 9n denotes a neutral point power line. The control circuit means 2 is connected to the R phase power supply line 9r and the neutral point power supply line 9n, and the voltage detection means 3 is connected to the S phase power supply line 9s and the neutral point power supply line 9n. The exciting coil portion of the second three-phase power supply switching means 11 is connected in series to the T-phase power supply line 9t and the neutral point power supply line 9n.

  The operation and action of the control device configured as described above will be described below with reference to the flowchart of FIG.

  First, when the three-phase four-wire AC power supply is normally connected to the control device 1 of the air conditioner, the control circuit means 2 and the voltage detection means 3 are energized (S1) (S2). Thereafter, when the voltage determination means 4 determines normal (S3), the excitation coil portion of the first three-phase power supply switching means 10 is energized, and the contact portion of the first three-phase power supply switching means 10 is closed. (S4). Upon receiving the signal, the excitation coil portion of the second three-phase power supply switching means 11 is excited, and the contact portion of the second three-phase power supply switching means 11 is closed (S5).

Next, when the three-phase four-wire AC power supply is not normally connected to the control device 1 of the air conditioner and one of the phases is lost, the control circuit means 2 is used when the R-phase is lost. Is not energized (S6), and the excitation coil portion of the first three-phase power switching means 10 cannot be excited. Therefore, the contact portion of the first three-phase power supply switching means 10 is opened (S9). Therefore, the contact portion of the second three-phase power switching means 11 is opened (S10) without being excited by the exciting coil section of the second three-phase power switching means 11. When the S phase is missing, the voltage of the voltage detecting means 3 is not detected (S7), and the voltage judging means 4 judges that the voltage is abnormal (S8). In this case, the excitation coil portion of the first three-phase power supply switching means 10 is not excited. Therefore, the contact portion of the first three-phase power supply switching means 10 is opened (S9). Therefore, the contact portion of the second three-phase power switching means 11 is opened (S10) without being excited by the exciting coil section of the second three-phase power switching means 11. When the T and N phases are missing, the excitation power to the excitation coil portion of the second three-phase power supply switching means 11 is cut off, so that the excitation coil portion cannot be excited. Therefore, the contact portion of the second three-phase power supply switching means 11 is opened (S10).

  As described above, in this embodiment, a neutral point power line unique to a three-phase four-wire AC power source is used, and a voltage detection method for the neutral point power line and each three-phase line is used. Compared with the detection method between lines, the voltage is low (1 / √3 of the line voltage), so small components can be used and the configuration is simple, so phase loss can be detected at low cost. .

  As described above, the control device for an air conditioner according to the present invention is configured and controlled using the neutral point power line of the three-phase four-wire AC power supply. It can be detected. Therefore, it can be applied particularly to overseas specifications (Europe and China) and high-capacity refrigeration equipment.

Configuration block diagram of a control device for an air conditioner in Embodiment 1 of the present invention The flowchart which shows operation | movement of the control apparatus of the air conditioner in Embodiment 1 of this invention. Configuration block diagram of a conventional control device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Control circuit means 3 Voltage detection means 4 Voltage judgment means 5 Communication means 6 Inverter drive means 7 Smoothing means 8 Compressor 9r R phase power supply line 9s S phase power supply line 9t T phase power supply line 9n Neutral point power supply line 10 First three-phase power source switching means 11 Second three-phase power source switching means

Claims (1)

In an air conditioner driven by an inverter operated by a three-phase four-wire AC power source, the air conditioner has three-phase four-wire AC power source three-phase wires (hereinafter referred to as R-phase power source and S-phase power source, respectively). Line and T-phase power line) and neutral point power line, the R phase power line and neutral point power line have control circuit means, and the S phase power line and neutral point power line have The voltage detection means, the T-phase power supply line and the neutral point power supply line are connected to the exciting coil section of the second three-phase power supply switching means via the opening / closing section of the first three-phase power supply switching means, and the R-phase power supply The line / S phase power line / T phase power line is connected to the switching unit / smoothing unit / inverter driving unit / compressor of the second three-phase power switching unit, and the voltage detecting unit is connected to the voltage judging unit. The control circuit means and the inverter drive means are connected by communication means, and at least a three-phase four-wire power line, which phase is open Also, the control unit of the air conditioner is characterized in that to opening operation of the opening and closing portion of the second three-phase power supply switching means.

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