JPH04295A - Air-conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application 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. 5 is a schematic configuration diagram of a conventional air conditioner. Fifth
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. Reference numeral 9 is a room temperature setting device for setting 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. 11 is a frequency command section, which is a control circuit 1 for the indoor unit.
A frequency control signal with an output of 0 is input. A waveform storage device 12 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. Reference numeral 14 denotes a waveform generator which takes in the waveform pattern during cooling from the waveform storage device 12 if the output of the cooling/heating detection device 13 is "0", and if the output of the cooling/heating detection device 13 is "1" For example, the waveform pattern during heating is taken in from the waveform storage device 12, a waveform is generated, and a waveform signal is output.

15 is a base drive circuit, and the waveform generator 1
A waveform signal of an output set based on the voltage-frequency characteristics in each waveform pattern during cooling and heating in step 4 is input. 16
is an inverter device, which includes a rectifier 17 and a capacitor 18.
, and a switching element 19. In particular, this switching element 19 takes in the waveform signal amplified by the base drive circuit 15 and controls the compressor 1. Further, 20 is an indoor unit, and 21 is an outdoor unit.

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

During operation of the air conditioner, the waveform generator 14 receives 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 the waveform to the base drive circuit 15 . The input waveform is
The signal is transmitted through the base drive circuit 15 to the switching element 19 in the inverter device 16, where it 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 inverter outputs 3
Phase AC voltage (R phase, S phase, T phase) and compressor (R' phase, S phase
'phase, T' phase) and '! 1i, the motor rotates in the opposite direction, causing the refrigeration cycle as an air conditioner to enter a reverse cycle state, which places an abnormal load on the compressor, resulting in the problem of damage to the compressor and inverter.

In view of the above-mentioned problems, the present invention provides that if the connection of the three-phase AC voltage (R phase, S phase, T phase) between the inverter device and the compressor is reversed, the three-phase AC voltage (R phase, S phase, The purpose of this is to avoid abnormal operating conditions and prevent damage to the compressor and inverter by switching the connection of the T-phase to normal rotation at the front of the compressor.

Means for Solving the Problems In order to solve the above problems, the air conditioner of the present invention includes an inverter device that rectifies commercial AC voltage and generates arbitrary frequency and voltage with a switching element, and a switching element in the inverter device. a voltage detection device that detects the voltage applied to the voltage and outputs a signal if the voltage is below a specified value;
It is comprised of an output switching device that switches the phase of the output voltage output from the inverter device, and a characteristic determining device that operates the output switching device if there is a signal from the voltage detection device.

According to the above-described configuration, the voltage applied to the switching elements in the inverter device is regulated when the connection of the three-phase AC voltage (R phase, S phase, T phase) between the inverter device and the compressor is reversed. By taking advantage of the fact that the voltage is below the specified value and switching the connection of the three-phase AC voltage (R phase, S phase, T phase) to the compressor at the front of the compressor so that the connection is in the forward rotation state. This is to avoid abnormal operating conditions and prevent 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. 5 will be omitted.

A voltage detection device 22 is connected in parallel between the rectifier 17 and the capacitor 18 in the inverter device 16, and the detailed circuit is shown in FIG. 2 and will be described later. 28 is a characteristic determining device which receives an output signal from the voltage detecting device 22, and if this signal is "H", determines the normal rotation state; if this signal is "L", determines the reverse state, and is connected to the voltage detecting device 22. 24 is an output switching device connected to switch the connection of the waveform output section of the inverter device 16 using the output signal E of the characteristic determining device 23.The detailed circuit is shown in FIG. 3 and will be described later. is a detailed circuit of the voltage detection device, 22-1 and 22-2 are resistors 1 and 2, respectively, which divide the voltage across the capacitor 18. 22-8 is a Zener diode;
Specifies the divided voltage. 22-4 is a photocoupler, which insulates high voltage and low voltage. 22-5 is a transistor whose base is connected to the output of the photocoupler 22-4 and whose collector is connected to the power supply.

22-6 and 22-7 are resistor 3 and resistor 4, respectively, and are connected to the emitter of transistor 22-5, respectively, and the other ends of each are connected to the power supply at 22-7 of resistor 4, and at 22-6 of resistor 3. It is connected to GND, and the resistance value of resistor 4, 22-7, is greater than that of resistor 3, 22-6. A connection point of this resistor is connected to the characteristic determining device 23. FIG. 3 shows a detailed circuit of the output switching device 24, showing the R phase, S phase, and T phase of the inverter device 16 and the R' phase and S'' phase of the compressor 1.

The connection of the T' phase is shown, with the S phase being connected to the S' phase, the R phase being connected to terminals 1 and 2, and the T phase being connected to terminals e and d. Further, in the compressor 1, the R' phase is connected to the terminal a, and the T' phase is connected to the terminal a.
The phases are each connected to terminal C. Each of these terminals is
According to the output signal E of the characteristic determining device 23, the output signal E
When is nLn, terminal A1, terminal D, terminal C
is connected. Also, when the output signal E is "H", the terminal e.

Terminal a, terminal f, and terminal cf are connected. FIG. 4 shows a voltage detection device 22, a characteristic determination device 23, and an output switching device 2.
4 is a flowchart showing the operation of step 4.

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 in FIG. 4, in 5TEPI, first, depending on the state of the indoor unit control circuit 10, the compressor 1
receives a desired frequency for rotating the base drive circuit 15 from the frequency command unit 11, outputs the waveform pattern in the waveform storage device 12 to the waveform generator 14,
The operation of the compressor 1 is started via the switching element 19 and the output switching device 24. In this case, the terminal state of the output switching device 24 is from terminal to terminal a.
, the zero-order 5TEP2 has a normal rotation connection in which the terminal d and the terminal C are connected. First, let us consider the case where the compressor 1 rotates at 5TEPI and is in the normal rotation. At this time capacitor 1
The voltage across the terminal 8 is normal, and this voltage is applied to the voltage detection device 22. The voltage is divided by resistor 1 22-1 and resistor 2 22-2, regulated by Zener diode 22-3, and turns on the LED of photocoupler 22-4. As a result, the transistor of the photocoupler 22-4 becomes 0NL.
7. The transistor 22-5 is also turned on. Therefore, the output signal of the voltage detection device 22 becomes "H", and the output signal E of the characteristic determining device 28 is determined to be "L", that is, the normal rotation state.
5TEP3 is skipped, the process moves to 5TEP4, and the waveform signal is output to the compressor 1. Next, consider a case where the compressor 1 rotates at 5 TEPI in reverse rotation. At this time, an excessive current flows through the compressor 1, so the voltage across the capacitor 18 decreases, and this voltage is applied to the voltage detection device 22. As before, the voltage is 22-1 of resistor 1 and 22-1 of resistor 2.
The voltage is divided by 2 and regulated by the Zener diode 22-3, but since the voltage is low, the LED of the photocoupler 22-4 becomes clear. As a result, the transistor of the photocoupler 22-4 is turned off, and the transistor 22-5 is also turned off.

Here, regarding the resistance values of 22-7 of resistor 4 and 22-6 of resistor 3, 22-7 of resistor 4 has a considerably larger value than 22-6 of resistor 3, so the output signal of voltage detection device 22 becomes L", and the output signal E of the characteristic determining device 23 becomes nH"
That is, it is determined that it is in a reverse rotation state, and at 5TEP3, the terminal state of the output switching device 24 is connected between terminal e and terminal a, and between terminal f and terminal C. At TEP4, a waveform signal is output to the compressor 1, and the compressor 1 is reversed. Change the state to normal rotation state and operate. This operation is performed only for a certain period of time after the start of compressor operation, and the connection state of the terminal of the output switching device 24 is the R' phase of the compressor 1.

It shall be maintained unless the S' phase, T and l phase are disconnected. As a result, if the connection of the three-phase AC voltage (R phase, S phase, T phase) of the inverter device 16 and the compressor 1 is in reverse convergence, the three-phase AC voltage (R phase, S phase, T phase)
By switching the connection inside the inverter so that the connection is in the forward rotation state, abnormal operating conditions can be avoided and damage to the compressor and inverter can be prevented.The detection method can also be done with a simple circuit because it detects voltage. Cost reduction can also be achieved.

Effects of the Invention As described above, the present invention provides an inverter device that rectifies a commercial AC voltage and generates a desired frequency and voltage using a switching element, a compressor whose rotation speed is controlled by the inverter device, and a compressor in which the rotation speed is controlled by the inverter device. a voltage detection device that detects the voltage applied to the switching element and outputs a signal if the voltage is below a specified value; and an output switching device that switches the phase of the output voltage output from the inverter device;
Since it is characterized in that it is equipped with a characteristic determining device that operates the output switching device if there is a signal from the voltage detecting device, the three-phase AC voltage of the inverter device and the compressor (R phase, S phase, T If the connection of phase) is reverse convergence, then 3
By switching the connection of the phase AC voltage (R phase, S phase, T phase) at the front of the compressor so that it is in the normal rotation state, abnormal operating conditions can be avoided and damage to the compressor and inverter can be avoided. The practical effects are great.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an air conditioner according to an embodiment of the present invention, Fig. 2 is an internal circuit diagram of a voltage detection device, Fig. 8 is an internal circuit diagram of an output switching device, and Fig. 4 is a voltage detection device. , a flowchart showing the operations of the characteristic determination device and the output switching device, and FIG. 5 is a schematic configuration diagram of a conventional air conditioner. 1... Compressor, 16... Inverter device, 22... Voltage detection device, 23...
Characteristic determination device, 24... Output switching device. Name of agent: Patent attorney Shigetaka Awano 1 idiot Figure 2 Figure 2 Figure 2

Claims (1)

[Claims] An inverter device that rectifies commercial AC voltage and generates arbitrary frequency and voltage using a switching element, a compressor whose rotation speed is controlled by this inverter device, and a voltage applied to the switching element in the inverter device that is detected and regulated. a voltage detection device that outputs a signal if the voltage is below a value; an output switching device that switches the phase of the output voltage output from the inverter device; and a voltage detection device that operates the output switching device if there is a signal from the voltage detection device. An air conditioner comprising: a characteristic determination device.