JP2007155256A - Controller for air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect a three-phase four-line AC power source at the time of phase interruption with an inexpensive constitution. <P>SOLUTION: A neutral point power line 9n and an R-phase power line 9r of the three-phase four-line AC power source are equipped with a control circuit means 2, and an S-phase power line 9s is equipped with a low resistance element 3 and a temperature detecting means 4a in series. A T-phase power line 9t and the neutral point power line 9n are connected to an excitation coil part of a second three-phase power source opening/closing means 11 via an opening/closing part of the first three-phase power source opening/closing means 10. The opening/closing part of the second three-phase power source opening/closing means 11 is operated to open by at least a power line of a three-phase four-line type even when any phase is interrupted. <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 conventional problems, an air conditioner control device according to the present invention is an air conditioner driven by an inverter that is operated by a three-phase four-wire AC power source, and the air conditioner has a three-phase inside. A four-phase AC power supply three-phase line (hereinafter referred to as R-phase power supply line, S-phase power supply line, and T-phase power supply line) and a neutral point power supply line. Control circuit means for the power supply line, low resistance element in series with the S-phase power supply line, and the second three through the opening / closing part of the first three-phase power supply switching means for the T-phase power supply line and the neutral point power supply line Connected to the excitation coil section of the phase power supply switching means, and the R phase power supply line, S phase power supply line, and T phase power supply line are connected to the opening / closing section of the second three-phase power supply switching means, smoothing means, inverter drive means, compression The resistance element is provided with a temperature detection means, and the temperature detection means is connected to the temperature judgment means, and the control circuit And the inverter drive means are connected by communication means, and at least a three-phase four-wire power line is used to open and close the opening / closing part of the second three-phase power source switching means regardless of which phase is lost It is what.

  This makes it possible to detect a missing phase by using a neutral point power line of a three-phase four-wire AC power supply and detecting its voltage and detecting the temperature of the low-resistance element of the three-phase power line. become.

The control device for an air conditioner of the present invention uses a neutral point power line unique to a three-phase four-wire AC power source, and in addition to the neutral point power line and the R / T two-phase voltage detection method, the S phase Because the temperature detection method of the equipped low resistance element is lower than the detection method between three-phase lines (1 / √3 of the line voltage), it is possible to adopt small parts with low withstand voltage. In addition, since the overcurrent of the invar portion can also be detected as the temperature, the phase loss detection and overcurrent control can be performed with a simple (inexpensive) configuration.

  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 line and T-phase power line) and neutral point power line, R phase power line and neutral point power line are control circuit means, and S phase power line is low in series. The resistance element, 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 through the switching section of the first three-phase power supply switching means, and the R-phase power supply line The S-phase power supply line and the T-phase power supply line are connected to the opening / closing part of the second three-phase power supply switching means / smoothing means / inverter driving means / compressor, and the resistance element includes temperature detection means, The temperature detecting means is connected to the temperature determining means, and the control circuit means and the inverter driving means are connected by communication means. Both the power supply line of a three-phase four-wire, which phase is also phase loss, allowing low cost 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 a control circuit means, 3 is a low resistance element, 4a is a temperature detection means, and is provided in the low resistance element 3, and is connected to a temperature detection means 4b in the control circuit means 2. Is also connected. 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 line 9r and the neutral point power line 9n, and the low resistance element 3 is connected in series to the S phase power line 9s. 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 is energized (S1). Thereafter, the exciting coil portion of the first three-phase power supply switching means 10 is excited, and the contact portion of the first three-phase power supply switching means 10 is closed (S2). In response to 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 (S3). When the operation continues, a current flows through the low resistance element 3 to generate heat, and the temperature detecting means 4a detects a temperature rise (S4). Thereafter, when the temperature determination means 4b detects t ° C. or more (S5), the contact portion of the first three-phase power supply switching means 10 continues to be closed (S2).

  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 it is impossible to be excited by the exciting coil portion of the first three-phase power supply switching means 10. 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 open, the low resistance element 3 is not energized, so that the temperature detecting means 4a does not rise in temperature (S7), and the temperature judging means 4b cannot detect t ° C. or higher, so it is judged 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 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 and the two-phase voltage detection system, the S phase is provided. Due to the temperature detection method of the resistance element, the voltage is lower (1 / √3 of the line voltage) than the detection method between the three-phase lines, so it is possible to use small parts with low breakdown voltage and Since the overcurrent of the part can also be detected as the temperature, open phase detection and overcurrent control are possible with a simple (inexpensive) configuration.

  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 Low resistance element 4a Temperature detection means 4b Temperature 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). And a neutral point power line, control circuit means for the R phase power line and the neutral point power line, a low resistance element in series with the S phase power line, T The phase power line and the neutral point power line are connected to the exciting coil section of the second three-phase power switching means via the switching section of the first three-phase power switching means, and the R-phase power line and S-phase power supply The line / T-phase power line is connected to an opening / closing part / smoothing means / inverter driving means / compressor of a second three-phase power supply switching means, and the resistance element is provided with a temperature detection means, and the temperature detection means Is connected to the temperature judging means, and the control circuit means and the inverter driving means are connected by communication means, and at least Phase with a four-wire power lines, any phase with open-phase, the control device 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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