JP2007255800A - Control device for air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of an air conditioner for protecting an electrolytic capacitor from excess voltage. <P>SOLUTION: This control device 4 of the air conditioner 1 performs first voltage monitoring control counting the determination of abnormality when the abnormality of terminal based voltage of the electrolytic capacitor 83 is determined during the lapse of a prescribed time from the start of a compressor 11, and a second voltage monitoring control not counting the determination of abnormality when the abnormality of terminal based voltage of the electrolytic capacitor 83 is determined after the lapse of the prescribed time, by microcomputers 5, 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for an air conditioner using a variable capacity compressor that performs rotational speed control by an inverter.

Conventionally, in an air conditioner using a variable capacity compressor that performs rotation speed control by an inverter, a circuit called a converter is arranged between the AC power supply and the inverter. This converter is composed of a current limiting circuit composed of a current limiting resistor, a rectifier circuit composed of a diode, and a smoothing circuit composed of a reactance and an electrolytic capacitor, and has a function of converting alternating current output into direct current. The electrolytic capacitor placed in the converter is an important part for supplying a stable DC voltage to the inverter. If the electrolytic capacitor fails due to overvoltage, etc., secondary current may be detected as a current limiting resistor or inverter. There is a high possibility of destroying the power transistor. In order to prevent such a failure, a control device that detects a voltage between terminals of an electrolytic capacitor and performs a failure diagnosis is widely employed (see, for example, Patent Document 1 and Patent Document 2).
JP-A-3-22821 Japanese Patent Laid-Open No. 11-215880

However, although the conventional control apparatus can diagnose the abnormality of the voltage between the terminals of the electrolytic capacitor, no means for protecting from the overvoltage that causes the electrolytic capacitor to fail is taken. For example, no consideration is given to overvoltage protection control that suppresses repeated application of overvoltage to an electrolytic capacitor.
The subject of this invention is providing the control apparatus of the air conditioning apparatus which protects an electrolytic capacitor from overvoltage.

The control device for an air conditioner according to the first invention includes a converter, voltage detection means, and a microcomputer. The converter converts the output of the AC power source into DC. The voltage detecting means detects a voltage between terminals of the electrolytic capacitor connected in the converter. The microcomputer monitors the voltage across the terminals of the electrolytic capacitor detected by the voltage detection means during operation of the compressor. Further, the microcomputer determines that the voltage is abnormal when the voltage between the terminals of the electrolytic capacitor does not satisfy a preset reference value. Further, the microcomputer performs first voltage monitoring control and second voltage monitoring control. The first voltage monitoring control is a control in which the abnormality determination is counted when it is determined that the voltage between the terminals of the electrolytic capacitor is abnormal before the predetermined time elapses after the start of the compressor. . The second voltage monitoring control is a control in which the abnormality determination is not counted when the terminal voltage of the electrolytic capacitor is determined to be abnormal after a predetermined period has elapsed.
In the control device of this air conditioner, for the abnormal voltage that is reproducible and can be detected during the start-up period of the compressor, it is necessary if the abnormality determination and the abnormality determination are performed by the first voltage monitoring control. In response to this, the compressor can be stopped. For this reason, the electrolytic capacitor is prevented from being damaged by the abnormal voltage.

  A control device for an air conditioner according to a second aspect of the present invention is the control device for an air conditioner according to the first aspect, wherein the voltage across the terminals of the electrolytic capacitor is determined to be abnormal in the first voltage monitoring control. The abnormality determination is counted, and retry control for performing the first voltage monitoring control once again is executed. Further, in the second voltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor is abnormal, the abnormality determination is not counted and retry control for performing the second voltage monitoring control is executed again.

Here, the number of restarts of the compressor is limited in the event of a failure (for example, a compressor ground fault) in which overvoltage is applied between the terminals of the electrolytic capacitor. Overvoltage is not applied for a long time. For this reason, the electrolytic capacitor is protected from overvoltage.
On the other hand, when an accidental abnormal voltage with no reproducibility occurs, there is almost no damage to the electrolytic capacitor, so there is no problem even if the compressor is repeatedly stopped and restarted by the second voltage monitoring control.

An air conditioner control device according to a third aspect of the present invention is the air conditioner control device according to the second aspect of the present invention, wherein in the first voltage monitoring control, the number of times of abnormality determination has reached a preset numerical value. In the case, it is determined that there is a failure that causes an abnormality in the voltage across the terminals of the electrolytic capacitor.
Here, misjudgment is avoided and the reliability of determining an abnormality is increased.

A control device for an air conditioner according to a fourth aspect of the present invention is the control device for an air conditioner according to the third aspect of the present invention, wherein in the first voltage monitoring control, there is a failure that causes an abnormality in the voltage across the terminals of the electrolytic capacitor. If it is determined, retry control is not executed.
Here, the restart of the compressor is not repeated more than necessary, and it is avoided that the abnormal voltage is repeatedly applied between the terminals of the electrolytic capacitor. For this reason, the electrolytic capacitor is prevented from being damaged.

An air conditioner control device according to a fifth aspect of the present invention is the air conditioner control device according to the third aspect of the present invention, further comprising a remote control device. In the first voltage monitoring control, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor, an abnormality display is performed, and the retry control is not executed until it is operated by the remote control device.
Here, the compressor is not started until the cause of the abnormality of the voltage across the terminals of the electrolytic capacitor is eliminated. For this reason, safety increases.

A control device for an air conditioner according to a sixth aspect of the present invention includes a converter, voltage detection means, and a microcomputer. The converter converts the output of the AC power source into DC. The voltage detecting means detects a voltage between terminals of the electrolytic capacitor connected in the converter. The microcomputer monitors the voltage across the terminals of the electrolytic capacitor detected by the voltage detection means during operation of the compressor. Further, the microcomputer determines that an abnormality occurs when the voltage across the terminals of the electrolytic capacitor does not satisfy a preset reference value. Further, the microcomputer performs overvoltage monitoring control and undervoltage monitoring control. The overvoltage monitoring control is a control in which, when the compressor is operating, when the voltage between the terminals of the electrolytic capacitor exceeds the upper limit of a preset reference value, it is determined that there is an abnormality and the abnormality determination is counted. Undervoltage monitoring control is control in which an abnormality determination is not counted when the voltage across the terminals of the electrolytic capacitor falls below the lower limit of a preset reference value during operation of the compressor.
In this air conditioner control device, if overvoltage with high reproducibility and high possibility of damaging the electrolytic capacitor is determined by overvoltage monitoring control, abnormality determination and abnormality determination are performed as necessary. The start of the compressor can be stopped. For this reason, the electrolytic capacitor is prevented from being damaged due to overvoltage.

A control device for an air conditioner according to a seventh aspect of the present invention is the control device for an air conditioner according to the sixth aspect of the present invention, wherein the overvoltage monitoring control determines that the voltage across the terminals of the electrolytic capacitor is abnormal. Abnormality determination is counted, and retry control for performing overvoltage monitoring control once again is executed. Further, in the undervoltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor is abnormal, the abnormality determination is not counted, and retry control for performing the undervoltage monitoring control is executed again.
Here, the number of restarts of the compressor is limited in the event of a failure (for example, a compressor ground fault) in which overvoltage is applied between the terminals of the electrolytic capacitor. Overvoltage is not applied for a long time. For this reason, the electrolytic capacitor is protected from overvoltage.
On the other hand, when an accidental undervoltage with no reproducibility occurs, there is almost no damage to the electrolytic capacitor, so there is no problem even if the compressor is repeatedly stopped and restarted by the undervoltage monitoring control.

An air conditioner control device according to an eighth aspect of the present invention is the air conditioner control device according to the seventh aspect of the present invention, wherein in the overvoltage monitoring control, the number of times of abnormality determination reaches a preset numerical value. It is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor.
Here, misjudgment is avoided and the reliability of determining an abnormality is increased.

An air conditioner control device according to a ninth aspect of the present invention is the air conditioner control device according to the eighth aspect of the present invention, wherein it is determined in the overvoltage monitoring control that there is a failure that causes an abnormality in the voltage across the terminals of the electrolytic capacitor. If this happens, retry control will not be performed.
Here, the restart of the compressor is not repeated more than necessary, and it is avoided that an overvoltage is repeatedly applied between the terminals of the electrolytic capacitor. For this reason, the electrolytic capacitor is prevented from being damaged.

An air conditioner control device according to a tenth aspect of the present invention is the air conditioner control device according to the eighth aspect of the present invention, further comprising a remote control device. When it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor, an abnormality is displayed and the retry control is not executed until it is operated by the remote control device.
Here, the compressor is not started until the cause of the abnormality of the voltage across the terminals of the electrolytic capacitor is eliminated. For this reason, safety increases.

In the control device for an air conditioner according to the first aspect of the present invention, an abnormal voltage that has a high possibility of damaging the electrolytic capacitor and can be detected during the start-up period of the compressor is determined to be abnormal by the first voltage monitoring control, Stop compressor startup if necessary. For this reason, the electrolytic capacitor is prevented from being damaged by the abnormal voltage.
In the control device for an air conditioner according to the second aspect of the present invention, when a failure occurs such that an overvoltage is applied between the terminals of the electrolytic capacitor, the overvoltage is not applied between the terminals of the electrolytic capacitor for a long time. For this reason, the electrolytic capacitor is protected from overvoltage.

In the control device for an air conditioner according to the third aspect of the present invention, in the first voltage monitoring control, when the number of abnormality determinations reaches a preset value, there is a failure that causes an abnormality in the voltage across the terminals of the electrolytic capacitor. Determined. For this reason, misjudgment is avoided and the reliability of determining an abnormality is increased.
In the control device for an air conditioner according to the fourth aspect of the present invention, the restart of the compressor is not repeated more than necessary, and repeated application of an abnormal voltage between the terminals of the electrolytic capacitor is avoided. For this reason, the electrolytic capacitor is prevented from being damaged.

In the control device for an air conditioner according to the fifth aspect of the present invention, the compressor is not started until the cause of the abnormality in the voltage between the terminals of the electrolytic capacitor is eliminated. For this reason, safety increases.
In the control device for an air conditioner according to the sixth aspect of the present invention, the compressor can be protected from an overvoltage that has reproducibility and is likely to damage the electrolytic capacitor. For this reason, the electrolytic capacitor is prevented from being damaged due to overvoltage.

In the control device for an air conditioner according to the seventh aspect of the present invention, when a failure occurs such that an overvoltage is applied between the terminals of the electrolytic capacitor, the overvoltage is not applied between the terminals of the electrolytic capacitor for a long time. For this reason, damage to the electrolytic capacitor due to overvoltage is prevented.
In the control device for an air conditioning apparatus according to the eighth aspect of the present invention, in the overvoltage monitoring control, when the number of abnormality determinations reaches a preset numerical value, it is determined that there is a failure that causes an abnormality in the voltage across the terminals of the electrolytic capacitor. The Here, misjudgment is avoided and the reliability of determining an abnormality is increased.

In the control device for an air conditioner according to the ninth aspect of the present invention, the restart of the compressor is not repeated more than necessary, and repeated application of overvoltage between the terminals of the electrolytic capacitor is avoided. For this reason, the electrolytic capacitor is prevented from being damaged.
In the control device for an air conditioner according to the tenth aspect of the invention, the compressor is not started until the cause of the abnormality in the voltage between the terminals of the electrolytic capacitor is eliminated. For this reason, safety increases.

[First Embodiment]
<Configuration of air conditioner>
The block diagram of an air conditioning apparatus is shown in FIG. The air conditioner 1 is a multi-type air conditioner for buildings, and a refrigerant circuit so that a plurality of indoor units 3 are connected in parallel to one or a plurality of outdoor units 2 so that a refrigerant can circulate. 10 is formed. The control device 4 controls various components such as the compressor 11 so that the air conditioner 1 is efficiently operated. The remote operation device 4 a transmits and receives signals to and from the control device 4 by manual operation, and starts and stops the compressor 11.
The compressor 11 is often used in combination with a variable capacity inverter compressor that performs rotational speed control by an inverter and a constant capacity constant capacity compressor that is controlled on and off.

<Control device for air conditioner>
FIG. 2 is a block diagram of the control device for the air-conditioning apparatus according to the first embodiment of the present invention, and FIG. 3 is an electric circuit diagram of the control device for the air-conditioning apparatus. In FIG. 2, the control device 4 includes a control microcomputer 5 and an inverter control microcomputer (hereinafter referred to as INV control microcomputer) 6. The control microcomputer 5 operates a first relay 52 (see FIG. 3) and a second relay 84 (see FIG. 3), which will be described later, to protect the electrolytic capacitor 83 (see FIG. 3) of the converter 8. The INV control microcomputer 6 controls the inverter 9 via the drive circuit 41.

In FIG. 3, in the control device 4, the R phase, S phase, and T phase of the AC power source 7 are connected to the converter 8 in order to convert the output of the AC power source into DC. The R phase and the T phase are connected to the converter 8 via the first relay 52. Further, a current limiting circuit 8c including a second relay 84 and a current limiting resistor 85 is connected in parallel with the first relay 52 of the R phase and the T phase.
The converter 8 includes a rectifier circuit 8 a including six diodes 81 and a smoothing circuit 8 b including reactance 82 and an electrolytic capacitor 83. The inverter 9 converts the direct current output from the converter 8 into alternating current having an arbitrary frequency and supplies the alternating current to the motor of the compressor 11. The inverter 9 is driven by a drive circuit 41, and the drive circuit 41 is controlled by the INV control microcomputer 6. Further, the INV control microcomputer 6 detects the inter-terminal voltage Vpn of the electrolytic capacitor 83 via the voltage detection means 42.

<Temperature limiting suppression control for temperature rise>
When the power is turned on, the second relay 84 is turned on prior to the first relay 52, and the electrolytic capacitor 83 is gradually charged by the current limiting resistor 85. If the first relay 52 is turned on while the electrolytic capacitor 83 is empty or insufficiently charged, an inrush voltage is applied to the electrolytic capacitor 83 and the electrolytic capacitor 83 may be damaged. For this reason, the first relay 52 is turned on after the electrolytic capacitor 83 is appropriately charged. The charging time varies depending on the model of the air conditioner 1, but is charged for 4 seconds in this embodiment.

  In FIG. 3, when the PN is short-circuited, that is, the terminals of the electrolytic capacitor 83 are short-circuited, a power supply voltage of 200 V is applied to both ends of the current-limiting resistor 85 during charging, and the current-limiting resistor 85 generates abnormal heat. The surrounding parts may be damaged. In the control device 4, a temperature rise suppression logic is set in advance in order to determine a short circuit between PNs (between the terminals of the electrolytic capacitor 84) at an early stage and prevent abnormal heat generation of the current limiting resistor 85.

<Undervoltage detection control>
When it is determined that there is no abnormality between the PNs, the control device 4 continues to charge the electrolytic capacitor 83. When the electrolytic capacitor 83 is normally charged, the control device 4 can turn on the first relay 52 and start the motor of the compressor 11. However, if charging to the electrolytic capacitor 83 is not normally performed, an inrush voltage is applied to the electrolytic capacitor 83 when the first relay 52 is turned on, and if it is repeated, the electrolytic capacitor 83 may be destroyed. . Therefore, before turning on the first relay 52, the control device 4 needs to detect the voltage Vpn between the terminals of the electrolytic capacitor 83 and determine whether the voltage value is insufficient. In the control device 4, an undervoltage detection logic of the electrolytic capacitor 83 is set in advance.

<Ground fault overvoltage protection control>
When it is determined that the voltage between the terminals of the electrolytic capacitor 83 is normal in the current rise resistance temperature rise suppression control and the undervoltage detection control, the control device 4 turns on the first relay 52 and turns on the compressor 11. Start the motor. The compressor 11 enters a steady operation after an activation period of 90 seconds or less after receiving the activation command. The terminal voltage Vpn of the electrolytic capacitor 83 is constantly monitored, and when an abnormal voltage is confirmed, an operation stop command is transmitted from the microcomputer 5 to the INV control microcomputer 6, and the compressor 11 is stopped. However, the stop command is automatically canceled after waiting for a predetermined time. Therefore, when an overvoltage is detected as a surge voltage due to lightning or the like, the compressor 11 is temporarily stopped, but since it is not a failure, the compressor 11 is restarted.

  However, when the motor winding in the compressor 11 is grounded, the voltage between the terminals of the electrolytic capacitor 83 is boosted by the induced electromotive force from the reactance 82, and Vpn becomes abnormally high. This phenomenon is called ground fault overvoltage. The ground fault overvoltage is caused by the ground fault of the compressor 11, and causes fatal damage to the electrolytic capacitor 83. Therefore, in order to protect the electrolytic capacitor 83, the ground fault overvoltage protection control logic is set. This ground fault overvoltage protection control logic discriminates whether the overvoltage applied to the voltage across the terminals of the electrolytic capacitor 83 is a surge voltage or a ground fault overvoltage. In this control, the compressor 11 is not operated.

<Ground fault overvoltage protection control logic>
FIG. 4 is a flowchart of the ground fault overvoltage protection control. The control microcomputer 5 turns on the first relay 52 (S101), and transmits a start command flag to the INV control microcomputer 6 (S102). Thereafter, the first voltage monitoring control and the second voltage monitoring control are executed.
(First voltage monitoring control logic)
The INV control microcomputer 6 receives the start command flag (S121), operates the timer, and measures the elapsed time t1 (S122). Next, the terminal voltage Vpn of the electrolytic capacitor 83 is detected, and it is determined whether or not Vpn exceeds 160V (S123). If Yes in S123, it is not an insufficient voltage, so the process proceeds to determine whether Vpn exceeds 390V (S124). If Yes in S124, it is determined that the voltage is overvoltage, and the process proceeds to the next, and it is determined whether or not t1 is within 90 seconds (S125). If Yes in S125, this means that an overvoltage has been detected during the start-up period of the compressor 11, so it is determined that there is a high possibility of a ground fault overvoltage, and an abnormality flag and a standby request flag are transmitted to the control microcomputer 5 (S126). )

  If No in S123, that is, if Vpn does not exceed 160V, it is determined that the voltage is insufficient and the process proceeds to S125, and it is determined whether or not t1 is within 90 seconds (S125). If Yes in S125, it means that an undervoltage has been detected during the start-up period of the compressor 11, so it is determined that there is a high possibility of failure of the electrolytic capacitor 83, and an abnormality flag and a standby request flag are transmitted to the control microcomputer 5. (S126).

Therefore, regardless of whether undervoltage or overvoltage is detected, if t1 is within 90 seconds in S125, the process proceeds to S126, and an abnormality flag and a standby request flag are transmitted to the control microcomputer 5.
The control microcomputer 5 receives the abnormality flag and the standby request flag transmitted from the INV control microcomputer 6 (S103), turns off the first relay 52 (S104), and counts the number N1 of abnormality flag reception (S105). ). Then, it is determined whether or not N1 is less than 4 (S106). If Yes, the timer is operated to measure t2 (S107). Then, it is determined whether or not t2 has reached 180 seconds (S108). If Yes, the second relay 84 is turned on. The reason for waiting for 180 seconds in S108 is to discharge the electric charge in the electrolytic capacitor 83. If the determination in S106 is No, the overvoltage or the undervoltage has been reproduced four times, and it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor 83, and an abnormality display is performed. Once the abnormality is displayed, the compressor is not restarted unless manually returned by the remote control device 4a. Here, S121 to S126 and S103 to S106 are referred to as first voltage monitoring control, and S107 and S108 are referred to as retry control.

As described above, in the present embodiment, when an overvoltage is detected within 90 seconds after the compressor 11 starts to start, it is determined that the possibility that the compressor 11 is grounded is extremely high. Retry control is executed. If there are four abnormality determinations, it is determined that there is a ground fault overvoltage, and the restart of the compressor is stopped.
(Second voltage monitoring control logic)
On the other hand, if No in S125, that is, if t1 is longer than 90 seconds, there is a high possibility of an undervoltage due to power shortage of the main power source or an overvoltage due to a surge voltage, etc. An abnormality flag and a standby flag are transmitted to the microcomputer 5 (S127).

Therefore, regardless of whether undervoltage or overvoltage is detected, if t1 exceeds 90 seconds in S125, the process proceeds to S127, and an abnormality flag and a standby request flag are transmitted to the control microcomputer 5.
FIG. 5 is a flowchart of part A in FIG. The control microcomputer 5 receives the abnormality flag and the standby request flag transmitted from the INV control microcomputer 6 (S111), turns off the first relay 52 (S112), operates the timer, and measures t3 (S113). . Then, it is determined whether or not t3 has reached 180 seconds (S114). If Yes, the second relay 84 is turned on. Here, S121 to S125, S127, S111, and S112 are referred to as second voltage monitoring control, and S113 and S114 are referred to as retry control.

As described above, in this embodiment, when an overvoltage or an undervoltage is detected after 90 seconds have elapsed since the compressor 11 started to start, a surge voltage or the like is not a ground fault of the compressor 11. Therefore, it is determined that there is no damage to the electrolytic capacitor 83, and a retry is performed without counting the abnormality determination. This is called infinite retry and protects the electrolytic capacitor 83 from accidental abnormalities with no reproducibility.
Note that the microcomputers 5 and 6 of the control device 4 first turn on the second relay 84 when the first voltage monitoring control and the second voltage monitoring control are retried, and the temperature of the current limiting resistor 85 increases. After the suppression control and the undervoltage detection control, the first relay 52 is started again.

<Features>
(1)
In this air conditioner control device, the microcomputers 5 and 6 monitor the voltage across the terminals of the electrolytic capacitor 83 detected by the voltage detection means 42 when the compressor 11 is in operation. Further, the microcomputers 5 and 6 determine that the voltage is abnormal when the voltage between the terminals of the electrolytic capacitor 83 does not satisfy a preset reference value. Further, the microcomputers 5 and 6 perform the first voltage monitoring control and the second voltage monitoring control. In the first voltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor 83 is abnormal before the predetermined time (90 seconds) elapses after the compressor 11 starts to start, the abnormality determination is counted. Is controlled. The second voltage monitoring control is a control in which the abnormality determination is not counted when the terminal voltage of the electrolytic capacitor 83 is determined to be abnormal after a predetermined period (90 seconds) has elapsed. For this reason, for the abnormal voltage that is reproducible and can be detected during the start-up period of the compressor, the abnormality determination and the abnormality determination count are performed by the first voltage monitoring control, and if necessary, the compressor Therefore, the electrolytic capacitor is prevented from being damaged by an abnormal voltage.

(2)
In the control device for the air conditioner, in the first voltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor 83 is abnormal, the abnormality determination is counted, and the first voltage monitoring control is performed again to perform the first voltage monitoring control. Trial control is performed. In the second voltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor 83 is abnormal, the abnormality determination is not counted, and retry control for performing the second voltage monitoring control is executed again. . For this reason, when a ground fault of the compressor 11 occurs, an overvoltage is not applied between the terminals of the electrolytic capacitor 83 for a long time, and the electrolytic capacitor 83 is protected from the overvoltage. On the other hand, when an accidental abnormal voltage with no reproducibility occurs, there is almost no damage to the electrolytic capacitor 83. Therefore, there is no problem even if the compressor 11 is repeatedly stopped and restarted by the second voltage monitoring control. .

  Further, in the first voltage monitoring control, when the number of abnormality determinations reaches a preset numerical value, it is determined that there is a failure that causes an abnormality in the voltage across the terminals of the electrolytic capacitor 83. For this reason, misjudgment is avoided and the reliability which judges a failure becomes high. Further, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor 83, the retry control is not executed. For this reason, the restart of the compressor 11 is not repeated more than necessary, and it is avoided that an abnormal voltage is repeatedly applied between the terminals of the electrolytic capacitor, so that the electrolytic capacitor is prevented from being damaged.

(3)
This air conditioner control device further includes a remote control device 4a. In the first voltage monitoring control, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor 83, an abnormality is displayed, and the retry control is not executed until the remote control device 4a is operated. For this reason, since the compressor 11 is not started until the abnormal cause of the voltage between the terminals of the electrolytic capacitor 83 is eliminated, safety is improved.

[Second Embodiment]
<Abnormal voltage protection control>
Next, a control device for an air-conditioning apparatus according to a second embodiment of the present invention will be described. Since the second embodiment is obtained by changing a part of the control logic of the first embodiment, only the changed control logic will be described here. The microcomputers 5 and 6 of the control device 4 perform abnormal voltage protection control. The abnormal voltage protection control is composed of overvoltage monitoring control and undervoltage monitoring control. In order to protect the electrolytic capacitor 83 from damage due to overvoltage, the overvoltage monitoring control is retried after counting the abnormality determination when it is determined abnormal. The undervoltage monitoring control is retried without counting the abnormality determination when it is determined abnormal because there is almost no damage to the electrolytic capacitor 83.

(Overvoltage monitoring control logic)
FIG. 6 is a flowchart of the abnormal voltage protection control. The control microcomputer 5 turns on the first relay 52 (S201), and transmits a start command for the compressor 11 to the INV control microcomputer 6 (S202). The INV control microcomputer 6 receives the activation command (S221), detects the voltage Vpn between the terminals of the electrolytic capacitor 83, and determines whether or not Vpn exceeds 160V (S222). If Yes in S222, it is not an insufficient voltage, so the process proceeds to determine whether Vpn exceeds 390V (S223). If Yes in S223, it is determined that an overvoltage has been applied between the terminals of the electrolytic capacitor 83, and an abnormality flag and a standby request flag are transmitted to the control microcomputer 5 (S224).

  The control microcomputer 5 receives the abnormality flag and the standby request flag transmitted from the INV control microcomputer 6 (S203), turns off the first relay 52 (S204), and counts the number N2 of reception of the abnormality flag ( S205). Then, it is determined whether or not N2 is less than 4 (S206). If Yes, the timer is operated to measure t4 (S207). Then, it is determined whether t4 has reached 180 (S208). If Yes, the second relay 84 is turned on. The reason for waiting for 180 seconds in S208 is to discharge the electric charge in the electrolytic capacitor 83. If the determination in S206 is No, the overvoltage has been reproduced four times, and the abnormality is confirmed and an abnormality display is performed. Once the abnormality is displayed, the compressor is not restarted unless manually returned by the remote control device 4a. The flow from S223, S224, and S203 to S206 is referred to as overvoltage monitoring control. S207 and S208 are referred to as retry control.

  As described above, when the microcomputers 5 and 6 of the control device 4 detect the voltage value of Vpn exceeding 390 V after turning on the first relay 52, the microcomputer 5 and 6 determine that it is abnormal and count the abnormality determination. The second relay 84 is turned on after waiting for 180 seconds. Then, the first relay 52 is turned on again through the temperature rise suppression control of the current limiting resistor 85 and the undervoltage detection control. When the abnormality determination is repeated four times, it is determined that there is an abnormality due to a ground fault or the like of the compressor 11, and in order to protect the electrolytic capacitor 83, an abnormality is displayed and control is performed so that the compressor is not restarted.

(Undervoltage monitoring control logic)
On the other hand, if No in S222, it is determined that the voltage is insufficient, and an abnormality flag and a standby request flag are transmitted to the control microcomputer 5 (S225). FIG. 7 is a flowchart of part B in FIG. In FIG. 7, the control microcomputer 5 receives the abnormality flag and the standby request flag transmitted from the INV control microcomputer 6 (S211), turns off the first relay 52 (S212), operates the timer, and counts t5. (S213). Then, it is determined whether or not t5 has reached 180 seconds (S214). If Yes in S214, the second relay 84 is turned on. S22 and S225 in FIG. 6 and S211 and S212 in FIG. 7 are referred to as undervoltage monitoring control. Further, S213 and S214 are referred to as retry control.

As described above, if the microcomputers 5 and 6 of the control device 4 detect a voltage value of Vpn of 160 V or less, it is determined as abnormal, and after waiting for 180 seconds without counting the abnormality determination, 2 The relay 84 is turned on. Then, the first relay 52 is turned on again through the temperature rise suppression control of the current limiting resistor 85 and the undervoltage detection control. This operation is repeated indefinitely.
<Features>
(1)
In the control device 4 of the air conditioner 1, the microcomputers 5 and 6 monitor the voltage across the terminals of the electrolytic capacitor 83 detected by the voltage detection means 42 during the operation of the compressor 11. Further, the microcomputers 5 and 6 determine that the voltage is abnormal when the voltage across the terminals of the electrolytic capacitor 83 does not satisfy a preset reference value. Further, the microcomputers 5 and 6 perform overvoltage monitoring control and undervoltage monitoring control. The overvoltage monitoring control is a control in which, when the compressor 11 is operated, when the voltage between the terminals of the electrolytic capacitor 83 exceeds the preset upper limit of the reference value, it is determined that there is an abnormality and the abnormality determination is counted. The undervoltage monitoring control is a control in which, when the compressor 11 is in operation, when the voltage between the terminals of the electrolytic capacitor 83 falls below the preset lower limit of the reference value, it is determined as abnormal and the abnormality determination is not counted. For this reason, it is possible to protect against an overvoltage that has reproducibility and is likely to damage the electrolytic capacitor 83, and thus the electrolytic capacitor 83 is prevented from being damaged by the overvoltage.

(2)
In the control device 4 of the air conditioner 1, in the overvoltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor 83 is abnormal, the abnormality determination is counted, and the retry control for performing the overvoltage monitoring control again. Is executed. Further, in the undervoltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor 83 is abnormal, the abnormality determination is not counted, and retry control for performing the undervoltage monitoring control is executed again. For this reason, when an overvoltage occurs, the overvoltage is not applied between the terminals of the electrolytic capacitor 83 for a long time, so that the electrolytic capacitor 83 is prevented from being damaged by the overvoltage. On the other hand, when an accidental undervoltage with no reproducibility occurs, there is almost no damage to the electrolytic capacitor 83. Therefore, there is no problem even if the stop and restart of the compressor are repeated by the undervoltage monitoring control.

  Further, in the overvoltage monitoring control, when the number of times of abnormality determination reaches a preset numerical value, it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor 83. The reliability of determining is increased. Further, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor 83, the retry control is not executed. For this reason, the restart of the compressor is not repeated more than necessary, and it is avoided that the overvoltage is repeatedly applied between the terminals of the electrolytic capacitor 83, and the electrolytic capacitor 83 is prevented from being damaged.

(3)
In the control device 4 of the air conditioner 1, the air conditioner 1 further includes a remote operation device 4a. If it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor 83, the microcomputers 5 and 6 display an abnormality and the retry control is not executed until the microcomputer 5 is operated by the remote control device 4a. For this reason, since the compressor 11 is not started until the abnormal cause of the voltage between the terminals of the electrolytic capacitor 83 is eliminated, safety is improved.

  As described above, according to the present invention, the electrolytic capacitor in the converter that converts alternating current into direct current can be protected from overvoltage, which is useful for a control device of an air conditioner.

The block diagram of an air conditioning apparatus. The block diagram of the control apparatus of the air conditioning apparatus which concerns on 1st Embodiment of this invention. The electric circuit diagram of the control apparatus of the air conditioning apparatus. The flowchart of the ground fault overvoltage protection control used in 1st Embodiment of this invention. The flowchart of the A section in FIG. The flowchart of the abnormal voltage protection control used in 2nd Embodiment of this invention. The flowchart of the B section in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 4 Control apparatus 4a Remote operation apparatus 5 Control microcomputer 6 INV control microcomputer 7 AC power supply 8 Converter 42 Voltage detection apparatus 83 Electrolytic capacitor

Claims (10)

A converter (8) disposed between the AC power source (7) and the compressor (11) and converting the output of the AC power source (7) to DC;
Voltage detection means (42) for detecting a voltage between terminals of the electrolytic capacitor (83) disposed in the converter (8);
During operation of the compressor (11), the voltage between the terminals of the electrolytic capacitor (83) detected by the voltage detection means (42) is monitored, and the voltage between the terminals does not satisfy a preset reference value. In the case, the microcomputer (5, 6) that judges as abnormal,
With
A first voltage monitor in which an abnormality determination is counted when the terminal voltage of the electrolytic capacitor (83) is determined to be abnormal before the predetermined time elapses after the compressor (11) starts to start. Control and second voltage monitoring control in which the abnormality determination is not counted when the voltage between the terminals of the electrolytic capacitor (83) is determined to be abnormal after the predetermined time has elapsed.
Control device (4) of air conditioner (1). In the first voltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor (83) is abnormal, the abnormality determination is counted, and retry control for performing the first voltage monitoring control again is performed. Executed,
In the second voltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor (83) is abnormal, the retry determination for performing the second voltage monitoring control again without counting the abnormality determination. Is executed,
The control device (4) of the air conditioner (1) according to claim 1. In the first voltage monitoring control, when the number of times of abnormality determination reaches a preset numerical value, it is determined that there is a failure that causes abnormality in the voltage between terminals of the electrolytic capacitor (83).
Control device (4) of an air harmony device (1) according to claim 2. In the first voltage monitoring control, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor (83), the retry control is not executed.
Control device (4) of the air conditioner (1) according to claim 3 The air conditioner (1) further includes a remote control device (4a),
In the first voltage monitoring control, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor (83), an abnormality is displayed and the operation is performed by the remote control device (4a). The retry control is not executed,
The control device (4) of the air conditioner (1) according to claim 3. A converter (8) disposed between the AC power source (7) and the compressor (11) and converting the output of the AC power source (7) to DC;
Voltage detection means (42) for detecting a voltage between terminals of the electrolytic capacitor (83) disposed in the converter (8);
During operation of the compressor (11), the voltage between the terminals of the electrolytic capacitor (83) detected by the voltage detection means (42) is monitored, and the voltage between the terminals does not satisfy a preset reference value. In the case, the microcomputer (5, 6) that judges as abnormal,
With
Overvoltage monitoring control in which, when the compressor (11) is operated, when the voltage between the terminals of the electrolytic capacitor (83) exceeds an upper limit of a preset reference value, it is determined that there is an abnormality and the abnormality determination is counted. When the compressor (11) is in operation, if the voltage between the terminals of the electrolytic capacitor (83) falls below the preset lower limit of the reference value, it is determined that there is an abnormality and the undervoltage monitoring control is not counted. And do,
Control device (4) of air conditioner (1). In the overvoltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor (83) is abnormal, the abnormality determination is counted, and retry control for performing the overvoltage monitoring control is executed again.
In the undervoltage monitoring control, when it is determined that the voltage between the terminals of the electrolytic capacitor (83) is abnormal, the abnormality determination is not counted, and retry control for performing the undervoltage monitoring control is executed again. To be
Control device (4) of an air harmony device (1) according to claim 6. In the overvoltage monitoring control, when the number of times of abnormality determination reaches a preset numerical value, it is determined that there is a failure that causes an abnormality in the voltage between terminals of the electrolytic capacitor (83).
Control device (4) of an air harmony device (1) according to claim 7. In the overvoltage monitoring control, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor (83), the retry control is not executed.
Control device (4) of the air conditioner (1) according to claim 8 The air conditioner (1) further includes a remote control device (4a),
In the overvoltage monitoring control, when it is determined that there is a failure that causes an abnormality in the voltage between the terminals of the electrolytic capacitor (83), an abnormality display is performed and the operation is repeated until the remote control device (4a) is operated. Trial control is not performed,
Control device (4) of an air harmony device (1) according to claim 8.

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