JPH03270691A - Air-conditioner - Google Patents

Abstract

PURPOSE:To avoid abnormal operating state of system by detecting a pressure based on the relation between the refrigeration cycle and the pressure and bringing the reverse connection of an inverter main circuit and a compressor into forward connection. CONSTITUTION:Suction pressure of an operating compressor 1 is detected through a pressure detector 20 and provided as an output signal D to a characteristic judging unit 21. In case of reverse time-pressure characteristic, the pressure decreases with time from a level P and thereby the characteristic judging unit 21 pulls the output signal E to 'H'. In an output switching unit 22, terminals (e) and (a) and terminals (f) and (c) are connected respectively, and a waveform signal is provided to the compressor 1 in order to operate the compressor 1 under forward state. The operation is carried out only at the time of charging power and the terminal connection of the output switching unit 22 is maintained so long as the phases R', S', T' of the compressor 1 are connected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air conditioner equipped with an inverter device for controlling the rotation speed of a compressor.

BACKGROUND OF THE INVENTION In recent years, many air conditioners have been used that control capacity by increasing or decreasing the rotational speed of a compressor using an inverter device that varies the frequency of a power source.

As a conventional technique, for example, Japanese Patent Application Laid-Open No. 60-23244
There is Publication No. 6.

An example of the air conditioner described above will be described below with reference to the drawings.

FIG. 6 is a schematic diagram of a conventional air conditioner. 6th
In the figure, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a pressure reducing device, and 5 is an outdoor heat exchanger, which are connected in a ring to form a refrigeration circuit. 6 is an indoor blower, and 7 is an outdoor blower. 8 is a room temperature sensor that detects the room temperature. 9 is a room temperature setting device, which sets the room temperature. Reference numeral 10 denotes a control circuit for the indoor unit, into which output signals from the room temperature sensor 8 and the room temperature setting device 9 are input. Reference numeral 11 denotes a frequency command section, into which a frequency control signal output from the control circuit 10 of the indoor unit is input. 1
2 is a waveform storage device which stores waveform patterns of two types of voltage-frequency characteristics during cooling and heating. Reference numeral 13 denotes a cooling/heating detection device, which outputs a signal "0" during cooling and a signal "1" during heating. 14 is a waveform generator;
If the output of the cooling/heating detection device 13 is “O”, a waveform pattern during cooling is fetched from the waveform storage device 12;
If the output of the cooling/heating detection device 13 is “1”, the waveform pattern during heating is taken from the waveform storage device 12;
Generate waveforms and output waveform signals. Reference numeral 14 denotes a base drive circuit, into which an output waveform signal is input which is set based on the voltage-frequency characteristics of each waveform pattern of the waveform generator 14 during cooling and heating. Reference numeral 16 denotes an inverter main circuit, which takes in the waveform signal amplified by the base drive circuit 15 and controls the compressor 1 .

Further, 17 is an indoor unit, and 18 is an outdoor unit. Reference numeral 19 denotes an inverter device, which is composed of the base drive circuit 15 and the inverter main circuit 16.

The operation of the air conditioner configured as described above will be described below.

During the operation of the air conditioner, the waveform generator 14 takes in the waveform pattern of the voltage-frequency characteristic during cooling from the waveform storage device 12 during the cooling operation, generates a waveform, and inputs it to the base drive circuit 15. The input waveform is
The signal is transmitted to the inverter main circuit 16 through the base drive circuit u10, is amplified, and controls the compressor 1 at a desired rotation speed.

Problems to be Solved by the Invention However, in the conventional configuration, the 8-phase AC voltage (R phase, S phase, T phase) outputted by the inverter main circuit and the compressor (R' phase,
Depending on the connection to the S' phase, T' phase), the motor may rotate in the opposite direction, causing the refrigeration cycle of the air conditioner to go into a reverse cycle state, placing an abnormal load on the compressor, and causing damage to the compressor and inverter. It had a point.

In view of the above problems, the present invention detects pressure from the direct relationship between the refrigeration cycle and pressure, and reverses the connection of the three-phase AC voltage (R phase, S phase, T phase) between the inverter main circuit and the compressor. If so, avoid abnormal operation of the system by switching the connections of the 8-phase AC voltage (R phase, S phase, T phase) inside the inverter so that they are in the normal rotation state, and the compression The purpose is to prevent damage to the machine and inverter.

Means for Solving the Problems In order to solve the above problems, an air conditioner of the present invention includes a compressor whose rotation speed is controlled by an inverter device, an inverter main circuit that outputs a waveform to rotate the compressor,
A pressure detection device that detects the suction pressure of the compressor, a characteristic determination device that stores different time-pressure characteristic patterns and determines the rotation direction of the compressor, and a characteristic determination device that determines the phase of the output voltage output from the inverter main circuit. I have been warned by the output switching device.

Operation The present invention uses the above-described configuration to detect pressure from the direct relationship between the refrigeration cycle and pressure, and reverse the connection of the three-phase AC voltage (R phase, S phase, T phase) between the inverter main circuit and the compressor. If so, avoid abnormal system operation by switching the connection of the three-phase AC voltage (R phase, S phase, T phase) to the compressor inside the inverter so that it is in the normal rotation state. This prevents damage to the compressor and inverter.

EXAMPLE Hereinafter, an air conditioner according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of an air conditioner according to an embodiment of the present invention. In FIG. 1, the detailed explanation of the same components as the conventional one shown in FIG. 6 will be omitted.

A pressure detection device 20 is connected between the inverter main circuit 16 and the compressor 1 to detect suction pressure. Reference numeral 21 denotes a characteristic determination device which calculates the time-opening-pressure characteristic from the output signal from the pressure detection device 20 and determines whether it is a characteristic of a forward rotation state or a characteristic of a reverse rotation state, and is connected to the pressure detection device. has been done. Reference numeral 22 denotes an output switching device which is connected to switch the connection of the waveform output section of the inverter main circuit based on the output signal E of the characteristic determining device 21.

FIG. 2 shows the pressure detection device 20, the characteristic determination device 21,
3 is a flowchart showing the operation of the output switching device 22, FIG. 3 is a time-pressure characteristic diagram during normal rotation stored inside the characteristic determining device 21, and FIG. 4 is a diagram showing the inside of the characteristic determining device 21. FIG. 5 shows a time-pressure characteristic diagram at the time of reverse rotation, which is stored in the internal circuit of the output switching device 22. The connection of the R' phase, 51 phases, 7 + phases is shown, and the S phase is connected to the S' phase, the R phase is connected to the terminal f, and the T phase is connected to the terminal e and terminal d. Further, in the compressor 1, the R' phase is connected to the terminal a, and the T'' phase is connected to the terminal C.The output signal E of each terminal is connected to "L" depending on the output signal level of the characteristic determining device 20. ”, the terminals A1, d, and C are connected. Also, when the output signal E is H, the terminals e, a, and f
.

Terminal C is connected.

The operation of the air conditioner configured as described above will be explained using FIG. 1, FIG. 2, FIG. 3, and FIG. 4. From the flowchart of FIG. 2, at 5 TEPI, a desired frequency for rotating the compressor 1 is received from the frequency command unit 11 according to the state of the indoor unit control circuit 10, and the waveform pattern of the waveform storage device 12 is used to generate the waveform. Device 1
4, and the operation of the compressor 1 is started via the base drive circuit 15, the inverter main circuit 16, and the output switching device 22. In this case, the terminal connection of the output switching device 22 is the same as that of the characteristic determining device 21.
The output signal E of is in the "L" state, that is, the terminals A, Terminal a, Terminal d, and Terminal C are connected. 5TEP2, the suction pressure of the compressor 1 during operation is detected by the pressure detection device 20.
is detected and outputted to the characteristic determining device 21 as an output signal. At 5TEP3, it is determined from the signal input to the characteristic determining device 21 whether the time-pressure characteristic is the normal rotation characteristic shown in FIG. 3 or the reverse rotation characteristic shown in FIG.

In the case of time-pressure characteristics during forward rotation, as shown in Fig. 3, the pressure tends to increase with time from the pressure value P, so the output signal E is set to "L" and the terminal state of the output switching device 22 shown in Fig. 5 is changed. Connect terminal S, m terminal a1, terminal d, terminal C, 5
A waveform signal is output to the compressor 1 as TEP5. In addition, in the case of time-pressure characteristics during reverse rotation, as shown in Figure 3, the pressure tends to decrease with time from the pressure value P, so the output signal E
is set to "H" and set as 5TEP4 to change the terminal states of the output switching device 22 in FIG. 5 to terminal e, terminal a, terminal f,
#Child ct! : connected, outputs a waveform signal as TEP5 to the compressor 1, changes the reverse rotation state of the compressor 1 to the normal rotation state, and operates the compressor 1. This operation is performed only when the power is turned on, and the terminal of the output switching device 22 is connected to the R' phase of the compressor 1.

It shall be maintained unless the S' phase and T'' phase are disconnected.

As a result, if the connection of the three-phase AC voltage (R phase, S phase, T phase) of the inverter main circuit 16 and the compressor 1 is reversed, the three-phase AC voltage (R phase, S phase, T phase) This system avoids an abnormal single-rotation state of the system by switching the connections of the two phases inside the inverter so that they are in the normal rotation state, thereby preventing damage to the compressor and inverter.

Effects of the Invention As described above, the present invention comprises a compressor whose rotation speed is controlled by an inverter device, an inverter main circuit that outputs a waveform to rotate the compressor, and a pressure detection device that detects the suction pressure of the compressor. , by providing a characteristic determination device that stores patterns of different time-pressure characteristics and determines the rotational direction of the compressor, and an output switching device that switches the phase of the output voltage output from the inverter main circuit. The pressure is detected from the direct quantity system of cycle and pressure, and the three-phase AC voltage (R phase,
If the connection of the 3-phase AC voltage (R phase, S phase, T phase) is in the reverse state, the connection of the 3-phase AC voltage (R phase, S phase, T phase) can be switched inside the inverter so that the connection is in the normal state. This prevents damage to the compressor and inverter, and has great practical effects.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an air conditioner according to an embodiment of the present invention, Fig. 2 is a flowchart showing the operations of the pressure detection device, the characteristic determining device, and the output switching device, and Fig. 3 is a diagram showing the internal structure of the characteristic determining device. The stored time-current characteristic diagram during forward rotation, Figure 4 is the time-pressure characteristic diagram during reverse rotation stored in the characteristic determining device, and Figure 5 is the internal circuit diagram of the output switching device. , FIG. 6 is a schematic elliptical diagram of a conventional air conditioner. 1... Compressor, 16... Inverter main circuit, 20... Pressure detection device, 21...
- Characteristic determination device, 22... Output switching device.

Claims (1)

[Claims] A compressor whose rotation speed is controlled by an inverter device, an inverter main circuit that outputs a waveform to rotate the compressor, a pressure detection device that detects the suction pressure of the compressor, and different time-pressure characteristic patterns. An air conditioner comprising: a characteristic determination device that stores the information and determines the rotational direction of the compressor; and an output switching device that switches the phase of the output voltage output from the inverter main circuit.