JP2007244019A - Controller of air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect an air conditioner at the time of phase interruption of a three-phase four wire AC power supply through an inexpensive constitution. <P>SOLUTION: The neutral power supply line 9n and the R phase power supply line 9r of a three-phase four wire AC power supply are provided with a control circuit means 2 and a current detection means 3, the S phase power supply line 9s is provided with the current detection means 3, the S phase power supply line 9s and the neutral power supply line 9n after the current detection means are connected with the exciting coil section of a second three-phase power supply opening/closing means 11 through the opening/closing section of a first three-phase power supply opening/closing means 10, and the T phase power supply line 9t is connected with the second three-phase power supply opening/closing means 11 so that the opening/closing section of the second three-phase power supply opening/closing means 11 is opened when any one phase is interrupted in the three-phase four wire power supply line. <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. , Through the current detection means, the S-phase power supply line also penetrates the current detection means, and the S-phase power supply line and the neutral point power supply line after passing through the current detection means open and close the first three-phase power supply switching means Connected to the exciting coil section of the second three-phase power supply switching means, and the R and the S-phase power supply line / T-phase power supply line after passing through the current detection means are connected to the second three-phase power supply switching means. Connected to the opening / closing part, smoothing means, inverter driving means, compressor, and the current detection means connected to the first communication means, The circuit means and the inverter drive means are configured to be connected by the second communication means, and at least a three-phase four-wire power line, whichever phase is lost, the opening / closing part of the second three-phase power switching means Is a control for opening the.

  As a result, the neutral point power supply line of the three-phase four-wire AC power supply is used and the R-phase and S-phase currents are detected, 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 source,
In addition to the neutral point power line and the R-phase and S-phase voltage detection methods, the R-phase and S-phase current detection methods reduce the voltage (line voltage) compared to the detection method between three-phase wires. Since 1 / √3), small components can be used and the configuration is simple, and phase loss can be detected at low cost. Furthermore, since current detection is an average current of the R-phase and S-phase, stable inverter drive control can be utilized even when three-phase voltage is unbalanced, so that comfortable control can be expected.

  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. The R-phase power supply line and neutral point power supply line are connected to the control circuit means and penetrated to the current detection means. The S-phase power supply line also penetrates the current detection means, and the S-phase power supply line and the neutral point power supply line after passing through the current detection means are connected to the second through the opening / closing part of the first three-phase power supply opening / closing means. Are connected to the exciting coil section of the three-phase power supply switching means, and the R and S-phase power supply lines / T-phase power supply lines after passing through the current detection means are connected to the opening / closing section / smoothing means of the second three-phase power supply switching means. Connected to the inverter drive means / compressor, the current detection means is connected to the first communication means, the control circuit means and the inverter The moving means is constituted by connecting with the second communication means, and at least a three-phase four-wire power supply line is used to open and close the opening / closing part of the second three-phase power supply switching means regardless of which phase is lost. Therefore, it is possible to detect the phase loss at a low cost with a simple configuration.

  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 current detection means, and 4 is a first communication means connected to the control circuit means 2 and the current 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 S-phase power line 9s.

  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 second communication means 5 is connected to the control circuit means 2 and the inverter drive 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. The primary coil of the current detection means 3 is passed through the R-phase power supply line 9r, and the S-phase power supply line 9 s is also passed through and connected to the contact of the second three-phase power supply switching means 11. The exciting coil section of the second three-phase power supply switching means 11 is connected in series to the S-phase power supply line 9s and the neutral power supply line 9n after passing through the current detection means 3. .

  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 current detection means 3 are energized (S1) (S2). After that, when the first communication means 4 determines that it is normal (S3), it is excited by the exciting coil part of the first three-phase power supply switching means 10, and the contact part of the first three-phase power supply switching means 10 is The closing operation is performed (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 T phase is missing, current flows through the current detection means 3 for the R phase and the S phase. However, when the T phase is lost, the R phase current and the S phase current cancel each other out of phase, so the output of the current detection means 3 becomes zero (S7), and the first communication means 4 is abnormal. Is determined (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 S 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 the present embodiment, the neutral point power line unique to the three-phase four-wire AC power supply is used, and in addition to the neutral point power line, the R phase and the S phase voltage detection method, the R phase And S-phase current detection method, lower voltage (1 / √3 of line voltage) compared to detection method between three-phase lines, so it is possible to adopt small parts and simple configuration Therefore, it is possible to detect phase loss at low cost. Furthermore, since current detection is an average current of the R-phase and S-phase, stable inverter drive control can be utilized even when three-phase voltage is unbalanced, so that comfortable control can be expected.

  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 refrigeration equipment having overseas specifications (Europe and China) and a large-capacity inverter.

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 Current detection means 4 1st communication means 5 2nd 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 Sexual point power 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 a neutral point power line. The R-phase power line and the neutral point power line are connected to the control circuit means in addition to the current detection means, and the S-phase power line. The power supply line also penetrates the current detection means, and the S-phase power supply line and the neutral point power supply line after passing through the current detection means are connected to the second three-phase power supply via the opening / closing part of the first three-phase power supply switching means. Connected to the exciting coil section of the switching means, and the R and S phase power lines / T phase power lines after passing through the current detection means are connected to the switching section / smoothing means / inverter driving means of the second three-phase power switching means, Connected to the compressor, the current detection means is connected to the first communication means, the control circuit means and the inverter drive means are The two communication means are connected to each other, and the three-phase four-wire power supply line opens the opening / closing part of the second three-phase power supply opening / closing means regardless of which phase is lost. Air conditioner control device.

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