JP4151188B2 - Multi-type air conditioner control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a multi-type air conditioner.
[0002]
[Prior art]
FIG. 7 shows a system diagram relating to a control device of a conventional multi-type air conditioner. As shown in FIG. 7, in the system diagram circuit configuration, power branched from the AC power supply 104 on the outdoor unit side is supplied to the control units of the indoor units 106 and 107 to drive the indoor units. The bus of the AC power supply is supplied to the outdoor control unit, rectified to a DC voltage by the diode bridge 109, smoothed by the smoothing capacitor 110, and supplied to the IPM 111 to drive the compressor 112. In the conventional power supply circuit, the circuit that protects the diode bridge 109, the smoothing capacitor 110, the IPM 111, and the compressor 112, which are power elements when the power supply voltage becomes abnormally high, is not incorporated in the electronic control unit. .
[0003]
[Problems to be solved by the invention]
In the conventional power supply circuit system, there is no protection circuit against overvoltage in areas where the power supply situation is unstable, so if the power supply voltage becomes abnormally high, a high voltage is applied to each inverter switching element and can be destroyed There is sex.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has a configuration in which a power supply line supplied from the outdoor side to a plurality of indoor sides is provided after the first relay circuit, a voltage detection circuit is provided, and a power supply voltage is predetermined. The microcomputer detects that the value is higher than the value, stops all the switching elements constituting the inverter directly, and then turns off the first relay circuit provided in the AC primary circuit to stop the power supply. Thus, the protection of the plurality of indoor units can be performed simultaneously with the protection of the inverter unit.
[0006]
In the present invention, a second relay circuit is connected in parallel with a series circuit of a first relay and a resistor on the outdoor AC primary side. As a result, it is possible to protect the inverter unit of the outdoor unit and the control unit of the indoor unit when the contact capacity required for the relay is reduced and the power supply voltage becomes higher than a predetermined value.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a power supply circuit of a control device according to the present invention will be described with reference to the accompanying drawings.
[0008]
(Embodiment 1)
As shown in FIG. 1, in Embodiment 1 of the present invention, the AC power supply 4 enters the outdoor control unit 8 and further supplies power to the indoor units 6 and 7. The AC power supply is rectified by the diode bridge 9, the rectified DC voltage is smoothed by the capacitor 10, and the rectified and smoothed voltage is supplied to the IPM 11 to drive the compressor 12.
[0009]
FIG. 2 is a control circuit diagram of the outdoor control unit of the multi-type model according to the first embodiment. The DC voltage rectified and smoothed by the diode bridge 17 and the smoothing capacitor 18 is converted into a low-voltage DC voltage by the DC / DC converter 19 and input to the microcomputer 33 and the IPM 11. Furthermore, the microcomputer 33 sends a signal to the indoor units 6 and 7 via the communication unit for control.
[0010]
Further, an abnormal voltage is detected (detected whether or not the voltage is larger than a predetermined value) by a power supply voltage detection circuit. The operation of the power supply voltage detection circuit is such that Lo is output from the operational amplifier 30 when the voltage between the resistors 21 becomes larger than the reference voltage divided by the resistors 23 and 24, that is, when the power supply voltage becomes abnormally high. When 31 is turned on and the 5V system is pulled, the input to the microcomputer 33 operates so as to change from Hi to Lo.
[0011]
The abnormal voltage is detected by the method as described above. Thereby, as shown in the control flow of the outdoor control unit of the first embodiment shown in FIG. 3, when the power supply voltage becomes abnormally high, the Lo signal is input to the microcomputer 33 by the overvoltage detection circuit 32 as described above. When the power supply voltage is detected to be abnormally high, an OFF signal is sent from the microcomputer 33 to the IPM 11, and all the switching elements constituting the inverter are first stopped.
[0012]
Thereafter, the relay 14 is turned off, power supply is stopped, and power components such as the diode bridge 9 and the smoothing capacitor 10 are protected.
[0013]
(Embodiment 2)
Next, the power supply circuit according to the second embodiment will be described. The circuit configuration and operation of the power supply circuit of this embodiment are basically the same as those of the first embodiment. In the first embodiment, when the power supply voltage becomes abnormally high, a voltage detection circuit is provided to protect the indoor unit, and power supply to the indoor control device unit is not stopped using a relay circuit or the like. Don't be.
[0014]
Here, as shown in FIG. 4, in the second embodiment, the power supply to the indoor side is performed after the first relay circuit of the first embodiment. As a result, the outdoor inverter unit can be protected, and at the same time, the indoor unit can be protected by the outdoor first relay circuit without installing a power detection circuit and a relay on the indoor unit side.
[0015]
(Embodiment 3)
Next, the power supply circuit of Embodiment 3 will be described. The circuit configuration and operation of the power supply circuit of this embodiment are basically the same as those of the first embodiment. In the first and second embodiments, the relay 14 provided on the AC primary side is turned on / off, but since a large current flows, the relay needs to have a large contact capacity.
[0016]
Therefore, as shown in FIG. 5, in the third embodiment, a series circuit is formed by the first relay circuit 14 on the outdoor AC primary side and the resistor 16, and the second relay circuit 15 is installed in parallel therewith. The load applied to one relay circuit 14 is reduced, and the relay is reduced in size. If the power supply voltage becomes abnormally high, the inverter unit is protected by simultaneously turning off the first relay circuit 14 and the second relay 15 as shown in the control flow of the third embodiment in FIG. Do.
[0017]
【The invention's effect】
According to the control device of claim 1 of the present invention, when the power supply voltage becomes abnormally high, the microcomputer detects the abnormal voltage with a signal from the voltage detection circuit, and stops all the switching elements constituting the inverter, Thereafter, the first relay circuit provided in the AC primary circuit is turned off, power supply can be stopped, and the inverter unit can be protected.
[0018]
Further, if the power supply to the indoor unit is performed after the relay circuit as in claim 2, the abnormal voltage protection on the indoor side can be performed without the voltage detection circuit and relay circuit on the indoor unit side. . In addition, since the multi-model has a plurality of indoor units, considerable cost improvement can be achieved.
[0019]
Further, according to the control device of claim 3, by forming a series circuit with the relay circuit and a resistor, and providing a second relay circuit in parallel therewith, it is possible to reduce the contact capacity required for the relay, The cost of the relay can be reduced and the mounting on the printed circuit board can be improved, and at the same time, the inverter can be protected.
[Brief description of the drawings]
FIG. 1 is a system diagram in Embodiment 1 of a control apparatus for a multi-type air conditioner according to the present invention. FIG. 2 is a control circuit diagram in Embodiment 1 of the control apparatus for a multi-type air conditioner according to the present invention. FIG. 4 is a control flow diagram in Embodiment 2 of the control apparatus for a multi-type air conditioner according to the present invention. FIG. 4 is a system diagram in Embodiments 2 and 3 of the control apparatus for a multi-type air conditioner according to the present invention. FIG. 6 is a system flow diagram in Embodiments 2 and 3 of a control device for a multi-type air conditioner according to the present invention. FIG. 6 is a control flow diagram in Embodiment 3 of the control device for a multi-type air conditioner according to the present invention. System diagram of a multi-type air conditioner control device [Description of symbols]
4 AC power source 5 Outdoor fan motor 6, 7 Indoor unit 9 Diode bridge 10 Smoothing capacitor 11 IPM
12 Compressor 13 Outdoor Fan Motor 17 Diode Bridge 18 Smoothing Capacitor 19 DC / DC Converter 33 Microcomputer

Claims (2)

A first relay that turns on and off the power supply to an outdoor unit in a multi-type air conditioner that is composed of a single inverter-driven outdoor unit and a plurality of indoor units and that is supplied with AC primary power to the outdoor unit. A circuit, a power supply voltage detection means, and a power supply voltage judgment means, wherein power is supplied to the plurality of indoor units after the first relay circuit, and the inverter is turned on when the power supply voltage becomes higher than a predetermined value. The air conditioner control device is configured to turn off the first relay circuit after stopping all the switching elements constituting the. By connecting a resistor to the first relay circuit to the outdoor AC primary side in series, the control apparatus of the air conditioner of the parallel to the serial circuit according to claim 1, wherein connecting the second relay circuit.

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