JP5671697B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner using a power supply device having a rectifier circuit and a power factor correction circuit.

  FIG. 2 is a configuration diagram of a power supply device for an outdoor unit of a conventional air conditioner. As shown in FIG. 2, there is a circuit that includes a rectifier circuit that converts an AC voltage into a DC voltage and a power factor correction circuit that improves the power factor (see, for example, Patent Document 1).

  On the other hand, the indoor unit includes a communication unit to which one end of an AC power supply is connected, and a main relay in which the other end of the AC power supply is connected to one end and the other end is connected to a terminal (L side terminal). . And while connecting the other end of AC power supply to a terminal (N side terminal) via a communication part, the communication line from a communication part is connected to the terminal.

  On the other hand, the power supply device for the outdoor unit has a coil having one end connected to a terminal (connected to the N-side terminal of the indoor unit) and one AC input terminal connected to the other end of the coil. And a smoothing capacitor connected to both ends of the DC output terminal of the diode bridge.

  In addition, the power supply device includes a power factor improvement circuit using a semiconductor switch, a voltage detection unit that detects the voltage across the smoothing capacitor, and the on / off of the semiconductor switch SW based on the DC voltage detected by the voltage detection unit. And a control unit for controlling. The outdoor unit includes a communication unit that is controlled by the control unit.

  Conventionally, an outdoor unit of an air conditioner determines that an overvoltage has been applied to the smoothing capacitor when the voltage detected by the voltage detection unit exceeds a certain value, stops the semiconductor switch, and abnormally detects the indoor unit through the communication unit. Send a signal. The indoor unit determines that the outdoor unit power factor correction circuit is abnormal, and cuts off the main relay, thereby blocking the input of the AC power supply.

JP 2003-134826 A

  However, in the conventional configuration, an abnormality is transmitted to the indoor unit even for an overvoltage that is not caused by an abnormality of the power factor correction circuit, and the main relay is shut off. Here, as a cause of occurrence of overvoltage when not caused by abnormality of the power factor correction circuit, the regenerative voltage from the compressor motor is applied to the smoothing capacitor when the compressor is stopped, and the voltage rises.

  However, the indoor unit receives an abnormal signal regardless of the cause of the overvoltage, shuts down the main relay as an abnormality of the power factor correction circuit, and abnormalities as an abnormality of the power factor improvement circuit in the failure diagnosis history displayed on the indoor unit and the remote control Leave a history.

For this reason, when a service person checks the air conditioner, it checks the fault diagnosis history of the power factor correction circuit abnormality, which has the problem that the outdoor unit power supply device is faulty and misjudged. It was.

  The present invention solves the above-described conventional problem, and even if an overvoltage that does not result from an abnormality in the power factor correction circuit occurs, the outdoor unit does not transmit an abnormality signal to the indoor unit, and the power factor improvement circuit abnormality is displayed. It aims at providing the air conditioner which does not perform.

In order to solve the above-described conventional problems, an air conditioner of the present invention includes a rectifier circuit that converts an AC voltage into a DC voltage, a power factor improving semiconductor switch that boosts a DC voltage output from the rectifier circuit by an ON operation, An outdoor unit having a power supply unit including a voltage detection unit for detecting a DC voltage output from the rectifier circuit, a control unit for controlling the power factor improving semiconductor switch based on the DC voltage detected by the voltage detection unit, and a power supply unit And an indoor unit having a main power switch for turning on and off the AC voltage supplied to the power supply, and the control means of the power supply device turns off the power factor improving semiconductor switch when the DC voltage detected by the voltage detection means exceeds the upper limit voltage. and, the voltage detection and outputs a control signal to turn off the main power switch to the indoor unit, the compressor is stopped, after the compressor stops Within longer predetermined time than the discharge time until the drop below the determined upper limit voltage abnormality of the DC voltage detected power factor improvement circuit by means DC voltage detected by the voltage detection means becomes the upper limit voltage or higher Even if the control signal is not output, the regenerative voltage from the compressor motor is applied to the smoothing capacitor when the compressor stops, and even if the voltage rises and exceeds the upper limit voltage, an abnormal signal is not sent to the indoor unit, The unit can be energized without shutting off the power.

  The present invention provides an air conditioner in which an outdoor unit does not transmit an abnormal signal to an indoor unit and does not display a power factor correction circuit abnormality even if an overvoltage that is not caused by an abnormality of the power factor improvement circuit occurs. Can do.

Block diagram of the power supply circuit of the air conditioner in Embodiment 1 of the present invention The block diagram of the power supply circuit of the air conditioner in Embodiment 1

An air conditioner according to a first aspect of the present invention includes a rectifier circuit that converts an AC voltage into a DC voltage, a power factor improving semiconductor switch that boosts the DC voltage output from the rectifier circuit by an ON operation, and a DC voltage output from the rectifier circuit. An outdoor unit having a power supply device having a voltage detection means for detecting the power supply, a control means for controlling the power factor improving semiconductor switch based on the DC voltage detected by the voltage detection means, and an AC voltage supplied to the power supply device are turned on / off And an indoor unit having a main power switch. When the DC voltage detected by the voltage detecting means exceeds the upper limit voltage, the control means of the power supply device turns off the power factor improving semiconductor switch, and the main power switch is connected to the indoor unit. outputs a control signal to turn off, the compressor is stopped, direct current detected by the voltage detecting means after the compressor stops In There a longer predetermined time than the discharge time until the drop abnormality of the power factor improving circuit below determines the upper limit voltage, the detected DC voltage not even if the upper limit voltage or to output a control signal by the voltage detecting means Thus, when the compressor is stopped, the regenerative voltage from the compressor motor is applied to the smoothing capacitor, and even if the voltage rises and exceeds the upper limit voltage, an abnormal signal is not sent to the indoor unit, and the outdoor unit is energized without shutting off the power. Since the power supply to the outdoor unit is continued, the operation information in the outdoor unit power supply device is not reset, and the restart time of the compressor can be shortened.

  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 shows a block diagram of a power supply circuit of an air conditioner according to an embodiment of the present invention.

  In FIG. 1, the indoor unit 100 includes a power relay 11 that turns on and off an AC voltage supplied to a power supply device of the outdoor unit, and on / off is controlled by the control unit 12. A communication unit 13 that communicates with the outdoor unit is connected to the control unit 12. An AC voltage is supplied to the outdoor unit through the L1 and L2 terminals, and a communication signal is transmitted through the C1 terminal.

  The outdoor unit 200 includes a diode bridge 2 that converts an AC voltage generated between the L2 terminal and the N2 terminal into a DC voltage via the reactor 3, and an IGBT 4b and a diode that boost the DC voltage output from the rectifier circuit by an ON operation. A power factor correction circuit 4 constituted by a bridge 4a; a DC voltage detection unit 10 for detecting a DC voltage output from the diode bridge 2 and smoothed by a smoothing capacitor 5; and a DC voltage detected by the DC voltage detection unit 10 The power supply device includes a control unit 8 that controls on / off of the IGBT 4b based on the voltage.

  The control unit 8 issues an on / off instruction to the IGBT 4b, which is a power factor improving semiconductor switch, an abnormality determination processing unit 8b that performs abnormality determination based on the voltage of the DC voltage detection unit 10, and after the compressor stops It is comprised by the stop time determination process part 8c which judges the output permission of abnormality determination based on the elapsed time of. Further, the DC voltage generated in the smoothing capacitor 5 is connected to the inverter circuit 6, and the output voltage of the inverter circuit is connected to the compressor 7, and the rotational speed control of the compressor 7 is performed.

  About the air conditioner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, when the DC voltage detected by the DC voltage detection unit 10 exceeds the upper limit voltage of 350 V, the control unit 8 of the outdoor unit 200 turns off the IGBT 4b, and then the abnormality determination processing unit 8b The communication unit 9 outputs a power factor correction circuit abnormality signal to the indoor unit 100 through the communication unit 13, and the control unit 12 outputs a control signal for turning off the power relay 11.

  When the indoor unit receives the power factor correction circuit abnormality signal, the indoor unit stores the power factor correction circuit abnormality as a failure diagnosis history and displays it as a failure history on the remote controller and the display unit of the main body.

  As for an abnormal signal of the power factor correction circuit, even if the DC voltage detected by the DC voltage detector 10 is 350 V or more within a predetermined time (45 seconds in the present embodiment) after the compressor 7 is stopped. The stop time determination processing unit 8c is configured not to output.

  With this configuration, when the compressor speed is 140 Hz, the regenerative voltage from the compressor motor is applied to the smoothing capacitor when the compressor is stopped, the voltage rises up to 400 V and exceeds the upper limit voltage of 350 V. The power factor correction circuit abnormality signal is not transmitted to the unit 100, and the outdoor unit can be energized without shutting off the power.

  The time of 45 seconds is longer than the discharge time until the maximum voltage value of 400 V due to the regenerative voltage after the compressor is stopped is dropped to less than the upper limit voltage of 350 V for determining abnormality of the power factor correction circuit by the power consumption of the power supply device, and It is set as a time that can satisfy the condition that the time is shorter than the time until restarting after the compressor stops.

As a result, even if an overvoltage due to the regenerative voltage from the compressor motor that does not result from the abnormality of the power factor correction circuit occurs, the outdoor unit 200 does not transmit an abnormality signal to the indoor unit 100 and displays the power factor improvement circuit abnormality. Therefore, it is possible to avoid erroneous determination of abnormality when checking the air conditioner.

  In addition, since energization of the outdoor unit is continued, the operation information in the outdoor unit power supply device is not reset, and the restart time of the compressor can be shortened.

  As described above, the air conditioner according to the present invention can avoid erroneous determination of power factor correction circuit abnormality in a product that uses a motor that generates a high regenerative voltage when stopped. It can also be used for machine applications.

1 AC power supply 2 Diode bridge 3 Reactor 4 Power factor correction circuit 4a Diode bridge 4b IGBT
DESCRIPTION OF SYMBOLS 5 Smoothing capacitor 6 Inverter circuit 7 Compressor 8 Control part 8a Pressure | voltage rise control part 8b Abnormality determination process part 8c Determination process part at the time of stop 11 Power relay 12 Control part 13 Communication part 100 Indoor unit 200 Outdoor unit

Claims (1)

A rectifier circuit for converting an AC voltage into a DC voltage; a power factor improving semiconductor switch for boosting the DC voltage output from the rectifier circuit by an ON operation; a voltage detection means for detecting the DC voltage output from the rectifier circuit; An outdoor unit having a power supply device having a control means for controlling the power factor improving semiconductor switch based on the DC voltage detected by the voltage detection means, and a main power switch for turning on and off the AC voltage supplied to the power supply device. The power unit control means, when the DC voltage detected by the voltage detection means exceeds the upper limit voltage, the power factor improving semiconductor switch is turned off, and the main unit is connected to the main unit. the power switch outputs a control signal so as to turn off, since the compressor is stopped, the voltage detected after the compressor stops Within longer predetermined time than the discharge time until the direct current voltage detected by the step drops the abnormality of the power factor correction circuit below determines the upper limit voltage, the DC voltage detected by the voltage detecting means is an upper limit voltage or higher The air conditioner is characterized in that the control signal is not output.