KR102126030B1 - Electronic circuit of controller dedicated to inverter compressor - Google Patents

Abstract

The present invention is to minimize the internal and external noise to minimize the failure of the equipment, and the state of the motor can be easily performed even without additionally mounting the sensors and detection circuits separately installed on the controller dedicated to the inverter compressor. It is related to the electronic circuit of the controller dedicated to the inverter compressor that can be checked.It uses a power supply unit separated from the externally applied power supply, a voltage detection unit electrically separated from the motor's three-phase AC power supply, a phase loss, a reverse phase detection unit, a current measurement unit, and a line driver. It is equipped with a circuit for operation detection, contact output, and status output to minimize equipment failures due to internal and external noise, and reduces manufacturing costs by reducing converters and sensors that are separately installed. It was completed as a technical task with the emphasis on providing an electronic circuit of a controller dedicated to an inverter compressor that expands a communication port to improve user convenience.

Description

Electronic circuit of controller dedicated to inverter compressor

The present invention relates to an electronic circuit of a controller dedicated to an inverter compressor, and minimizes internal and external noise to minimize equipment failure, and additionally mounts a sensor and a detection circuit separately mounted on the controller dedicated to the inverter compressor. It relates to an electronic circuit of a controller dedicated to an inverter compressor that makes it possible to easily check the state of a motor even without performing work.

First, as shown in FIG. 2, a conventional general inverter compressor controller converts external three-phase AC power into DC power through a power circuit to receive electricity, and through the sensor, oil temperature, air discharge pressure, and air discharge temperature. , It determines the internal pressure of the equipment, determines the operating state of the compressor or detects an error through an external input, and the main motor receives the three-phase AC power through the inverter to determine the rotation speed.

On the other hand, the controller configured as described above uses the same ground as the sensor and the external input and output of the power supply circuit of the control circuit, and thus has a problem of being vulnerable to internal generated noise or noise introduced from outside the system.

In addition, a conventional inverter compressor reads the value using a converter that converts the output of a separately equipped sensor into a number or string when checking the equipment status such as oil temperature, air discharge pressure, and equipment internal pressure.

The inverter compressor repeats a load operation that sucks and compresses external air according to the air discharge pressure, and a no-load operation that operates while blocking the inflow of external air. At this time, the inverter controls the rotational speed of the motor to minimize power consumption. have.

The compressor without an inverter controls the opening and closing of the air intake valve according to the air discharge pressure, and repeats the load operation and no load operation.

However, a compressor with an inverter automatically adjusts the rotational speed of the motor according to the air discharge pressure.

In the case of load operation, the load of the motor is increased by opening the air intake valve and drawing outside air into the compressor. At this time, the inverter increases the rotational speed of the motor to increase the torque of the motor.

In the case of no-load operation, the air intake valve is blocked to block the external air to prevent the air discharge pressure from increasing.

Therefore, since the load inside the compressor decreases, the inverter decreases the rotational speed of the motor to reduce torque, and if the air discharge pressure keeps a value greater than the pressure required to operate the load, the inverter automatically reduces power consumption. To stop the motor.

The inverter compressor must control the rotation speed of the motor according to the air discharge pressure, equipment internal pressure, internal oil temperature, etc., which means that the sensor value must be continuously checked.

In addition, recently, for user convenience, there are cases where communication with external devices is performed wirelessly or wirelessly. In this case, the noise inside and outside the system not only causes malfunction of the equipment, but also impacts the inverter itself, so that the compressor can operate. There is a problem that often disappears, and there is a problem that economic efficiency decreases due to the additional cost and process caused by the need to install separate sensors and detection circuits, thereby minimizing internal and external noise, and separate sensors And it is necessary to develop an inverter compressor controller to check the state of the motor even if the operation of additionally mounting the detection circuit is not performed.

The present invention has been devised to solve the above-described problems of the prior art, and includes a power supply unit separated from an externally applied power supply, a voltage detection unit electrically separated from a motor's three-phase AC power supply, a phase loss, a reverse phase detection unit, a current measurement unit, and a line driver. It is equipped with a circuit for operation detection, contact output, and status output, which can be used to minimize equipment failures due to internal and external noise, and reduce manufacturing costs by reducing converters and sensors that are separately installed. It was completed as a technical task with the emphasis on providing an electronic circuit of a controller dedicated to an inverter compressor that expands its communication port to improve user convenience.

According to the present invention for achieving the above object, the electronic circuit of the controller dedicated to the inverter compressor, comprising: a power supply unit with ground separated according to different voltage levels supplying power to the controller dedicated to the inverter compressor; A communication unit configured to communicate with an inverter and an external device, but includes an RS-232 communication chip communicating with an inverter and an RS-485 or RS-422 communication chip communicating with an external device; A voltage detector for measuring the voltage of the three-phase AC power supplied to the motor; A phase and reverse phase detection unit that detects a rotating magnetic field direction and connection of a three-phase AC power source; A sensor detector that converts the output of the sensor so that it can be measured by the controller; Current measuring unit for measuring the line current of the three-phase AC power; An operation detection unit for determining whether a switch and an external input are ON or OFF; A contact output unit that connects the photo triac and the triac and transmits a control signal generated by the control unit to an external contact to control external AC power; It is to solve the problem by providing an electronic circuit of a controller dedicated to the inverter compressor, characterized in that consisting of.

According to the electronic circuit of the controller dedicated to the inverter compressor according to the present invention, it is possible to minimize noise generated by electrically separating the external input/output terminals and the internal ground, thereby minimizing equipment failure, and sensors required for compressor control. And by inserting the detection circuit into one board, it is possible to reduce the cost incurred in the process of using a separate product, thereby improving economic efficiency, and the communication unit including RS-485 or RS-422 communication chip for external communication. It is a useful invention that can increase the scalability of the equipment by providing.

1 is a block diagram showing a preferred embodiment of the present invention
2 is a view showing an electronic circuit block of a conventional general controller
Figure 3 is a circuit diagram showing the power supply unit of the electronic circuit configuration of the controller dedicated inverter compressor of the present invention
Figure 4 is a circuit diagram showing a communication unit of the electronic circuit configuration of the controller dedicated inverter compressor of the present invention
Figure 5 is a circuit diagram showing the voltage detection unit of the electronic circuit configuration of the controller dedicated inverter compressor of the present invention
Figure 6 is a circuit diagram showing a phase loss, reverse phase detection of the electronic circuit configuration of the controller dedicated to the present invention inverter compressor
7 is a circuit diagram showing the sensor detection unit of the electronic circuit configuration of the controller dedicated to the present invention inverter compressor
8 is a circuit diagram showing a current measuring unit of the electronic circuit configuration of the controller dedicated to the present invention inverter compressor
Figure 9 is a circuit diagram showing the operation detection unit of the electronic circuit configuration of the controller dedicated inverter compressor of the present invention
10 is a circuit diagram showing a contact output unit of the electronic circuit configuration of the controller dedicated to the present invention inverter compressor

The present invention is to minimize the internal and external noise to minimize the failure of the equipment, and the state of the motor can be easily performed even without additionally mounting the sensors and detection circuits separately installed on the controller dedicated to the inverter compressor. An electronic circuit of a controller dedicated to an inverter compressor is provided.

Hereinafter, a preferred configuration and operation of the present invention for achieving the above object in connection with the accompanying drawings will be described with reference to FIGS. 1 to 10 as follows.

First of all, referring to FIGS. 1 to 10 before describing the present invention, in the electronic circuit of the inverter compressor-only controller, the ground is separated from the power supply according to different voltage levels for supplying power to the controller for exclusive use of the inverter compressor. ; A communication unit configured to communicate with an inverter and an external device, but includes an RS-232 communication chip communicating with an inverter and an RS-485 or RS-422 communication chip communicating with an external device; A voltage detector for measuring the voltage of the three-phase AC power supplied to the motor; A phase and reverse phase detection unit that detects a rotating magnetic field direction and connection of a three-phase AC power source; A sensor detector that converts the output of the sensor so that it can be measured by the controller; Current measuring unit for measuring the line current of the three-phase AC power; An operation detection unit for determining whether a switch and an external input are ON or OFF; A contact output unit that connects the photo triac and the triac and transmits a control signal generated by the control unit to an external contact to control external AC power; It consists of.

First, looking at the electronic circuit of the controller dedicated to the inverter compressor, as shown in Figure 1, according to the operation command detected through the operation detection unit, the control unit sends a control signal to the contact output unit to control the operation of the equipment, the sensor detection unit The operation of the inverter compressor is controlled through the communication unit according to the internal state of the system identified in.

In addition, if an error occurs in the system through the voltage detection unit, the phase loss detection unit, the reverse phase detection unit, the current measurement unit, and the sensor detection unit, the equipment is stopped according to the importance of the error or a simple warning message is displayed through the status output unit as an output device.

Here, the control unit may transmit a state of the current system to an external device (monitoring equipment) through a communication unit so that the user can confirm and remotely control the inverter compressor.

If the present invention configured as described above in more detail,

As shown in FIG. 3, the power unit converts externally applied power into internal DC power, and the ground is separated according to different voltage levels that supply power to the controller dedicated to the inverter compressor.

That is, the externally applied single-phase AC power AC1 is converted into a DC power V1 with a pulse through the bridge rectifying circuits D1 to D4, which connects the capacitor C1 to smooth the DC voltage.

In addition, the light emitting diode LED1 is continuously turned on while an external power is applied by connecting the light emitting diode LED1 to check whether a voltage is applied.

In addition, the DC voltage rectified as described above is converted to a secondary DC power supply (V2) through a DC-DC converter with separate ground, and the DC power supply (V1) converted to primary is passed through another DC-DC converter to control the controller. It is converted to DC power (VCC) for driving the CPU.

Here, the ground of each power source is electrically separated, which is to minimize noise generation, which is the object of the present invention.

In addition, the DC power supply (VCC) for driving the CPU connects a separate capacitor (C2) to remove pulsation, and connects a light emitting diode (LED2) to check whether the power is applied to the CPU, thereby providing power. To be able to confirm.

In addition, it is preferable to connect the ground of each DC power supply with a chip bead so that the ground of the DC component is matched, but high-frequency noise caused by high-speed switching is eliminated.

4, the communication unit is configured to communicate with an inverter and an external device, respectively, but an RS-232 communication chip for communicating with an inverter and an RS-485 or RS-422 for communicating with an external device (monitoring equipment). Communication chip is included.

Here, to minimize noise during communication, the ground of the RS-485 or RS-422 communication interface is electrically separated, and a separate line driver chip (shown in FIG. 10) is used to remove any noise that may occur. Is provided.

That is, by providing an RS-485 or RS-422 communication chip for external communication, it is to provide a cost saving effect by not configuring a separate device or modifying a program when remotely controlling multiple compressors from the outside.

As shown in FIG. 5, the voltage detector measures the line voltage of the three-phase AC power applied to the motor.

Here, the voltage detector comprises a transformer that converts a high-voltage external AC power to a voltage that the voltage detector can measure.

The voltage detection unit primarily provides high-capacity resistors (R5, R6, R10, R11, R15, R16) to prevent damage to the control circuit to limit the primary current of the transformers (T1, T2, T3), and the transformer ( T1, T2, T3), the single-phase AC voltage is converted to DC through the bridge rectifier circuit (D6, D7, D8), and the converted DC voltage is passed through the operational amplifiers (AR1 to AR3) to the CPU ADC (ADC1 to ADC3). ).

In addition, the voltage input to the primary coils of the transformers T1, T2, and T3 is applied by the difference of each phase of the three-phase AC voltage, and the transformer ratio of the transformer and the resistance ratio of the operational amplifier (R8/(R7+R8) ), R13/(R12+R13), R18/(R17+R18)), the voltage is applied within the range of the voltage detectable by the CPU, and the applied voltage is calculated as the actual applied voltage through calculation by the CPU .

As shown in Fig. 6, the phase-and-phase detection unit detects the rotational direction of the rotating magnetic field applied to the motor and the wiring of the power source (here, the terminal connection sequence is: R-S, S-T, T-R).

Here, the phase detection and reverse phase detection unit is configured to include a photo coupler to determine the direction of the rotating magnetic field of the AC power and whether or not the connection state of the three-phase AC power.

If the rotating magnetic field of the three-phase AC power is rotated, the phase applied to the actual motor generates a phase difference of 60 degrees in the order of R-S-T.

That is, based on 0 degree, since the value of R phase is larger than S phase, current flows from R phase to S phase input terminal, which turns on the light emitting diode of photocoupler 2 to turn terminal 4 of photocoupler 2 to terminal 3 Will flow.

At this time, since current flows to the input terminal 1 and the input terminal 2 of the port coupler 2, eventually the terminal 4 and the terminal 2 of the photo coupler 1 are conducted and the applied voltage drops to a low level.

In the case of S-phase and T-phase, since the S-phase has a lower voltage than the T-phase, no current flows, so the S-T phase voltage measurement terminal maintains a high level.

In the case of the T phase and the R phase, a current flows from the T phase to the R phase, and the voltage measurement terminal of the T-R phase falls to a low level.

In addition, the diode (D9) connected to each input terminal serves to limit the current from flowing in the reverse direction from the AC input power.

As described above, as the voltage difference according to the phase difference of each phase of the RST, the input voltage of each measurement terminal repeats the high level and the low level constantly, and by using this, the direction of rotation of the motor is detected by detecting the rotation direction of the rotating magnetic field applied to the motor. It can detect whether it is normal or reversed.

As shown in FIG. 7, the sensor detection unit converts the output of the sensor to be measured by the controller and measures the sensor value connected to the compressor.

That is, the measured value of each sensor is converted into a voltage and output, and the output voltage of the sensor input through the input terminal is high frequency components removed through the chip bead (CHIP BEAD) so that only the DC component is input to the operational amplifier (AR4). Is transmitted, and the operational amplifier amplifies the input sensor output voltage and inputs it to the ADC terminal of the CPU, and the CPU outputs the measured sensor values on the screen.

As shown in FIG. 8, the current measuring unit measures the line current of the three-phase AC power applied to the motor.

That is, the three-phase alternating current applied to the motor is measured by a current sensor chip using a Hall effect, and the measured value is output from the sensor as a voltage.

At this time, the current sensor chip has a form in which the input terminal and the output terminal are electrically separated, thereby preventing circuit damage due to overcurrent.

The output voltage of the sensor is input to the ADC terminal (ADC6) of the CPU through the primary amplification circuit (AR5). At this time, the Zener diode (D13) connected to the (-) terminal is the current when the Zener breakdown voltage is 0 amperage. The sensor output voltage must be satisfied.

In addition, the output voltage of the current sensor is input to the two ADC terminals ADC6 and ADC7 through the primary amplification circuit AR5 and the secondary amplification circuit AR6 to increase the accuracy of the measurement.

This is because the range of the current to be measured is wide, so that the output voltage of the sensor may exceed the input range of the CPU. If the output voltage range of the sensor is reduced to prevent this, the measurement resolution of the current decreases, making precise current measurement difficult.

Therefore, a 1-stage amplification circuit for measuring a low value and a 2-stage amplification circuit for measuring a high value are provided to select the measurement terminal through a program according to the measured current value and calculate the value.

In addition, the Zener diode D14 connected to the output terminal of the secondary amplification circuit is such that the Zener breakdown voltage is set to the CPU driving voltage VCC so that the voltage input to the ADC terminal ADC7 of the CPU does not exceed the CPU's input voltage range. Should be.

As illustrated in FIG. 9, the operation detection unit determines whether a switch and an external input used when a user operates the inverter compressor are ON or OFF.

That is, the initial state of the button S1 or the multi-input switch (external input) is a high level, and at this time, a high level is detected at the input terminal of the CPU.

In addition, when the switch S1 is pressed or the external contact input (external input) is changed to a low level, the CPU's input terminal (input detection) falls to a low level, and the CPU detects this value and the user detects the operating mode of the compressor. You will know that you have entered.

At this time, the capacitors C32 and C33 connected to the switch S1 or the external contact input (external input) are provided to remove noise due to the instantaneous voltage fluctuation.

In addition, as suggested by the internal circuit of the line driver, the input value is transmitted to the buffer inside the line driver, but only when all output control signals are 0, the value of the buffer is transferred to the output. Can.

As shown in FIG. 10, the contact output unit connects the photo triac and triac to transmit a control signal generated by the control unit to an external contact to control external AC power.

The control signal of the CPU becomes the gate driving signal of the photo triac through the line driver (FIG. 9).

That is, the photo triac acts as a driving element of the triac that controls the actual external contact, which does not supply enough power to drive the triac and the ground of the CPU and the ground of the external contact do not match. This is because the external contact works with AC power, so the same ground as the CPU cannot be used.

The current applied from the driving voltage for the CPU (VCC) turns on the light emitting diode inside the photo triac, and accordingly, a current flows through the photo triac, and the current flowing through the photo triac is the gate signal of the external contact control triac To enable current to flow through the triac.

In addition, a resistor R53 and a capacitor C31 connected in parallel with the external contact control triac are provided as snubber circuits to reduce malfunction and noise of the circuit when driving the triac.

On the other hand, the ground separation technique described in this specification is a technique used in the production of electronic circuit boards, and a driving circuit using a line driver, a triac, or a photocoupler is a method commonly used in actual motor driving circuits, or a control circuit of an inverter type screw compressor. There is no case in which a circuit is designed by applying all of the above, and only a part is applied at the same time.

According to the electronic circuit of the controller dedicated to the inverter compressor according to the present invention, it is possible to minimize noise generated by electrically separating the external input/output terminals and the internal ground, thereby minimizing equipment failure, and sensors required for compressor control. And by inserting the detection circuit into one board, it is possible to reduce the cost incurred in the process of using a separate product, thereby improving economic efficiency, and the communication unit including RS-485 or RS-422 communication chip for external communication. It is a useful invention that can increase the scalability of the equipment by providing.

Claims (3)

In the electronic circuit of the controller dedicated to the inverter compressor,
A power supply unit with ground separated according to different voltage levels supplying power to a controller dedicated to the inverter compressor;
A communication unit configured to communicate with an inverter and an external device, but includes an RS-232 communication chip communicating with an inverter and an RS-485 or RS-422 communication chip communicating with an external device;
A voltage detector for measuring the voltage of the three-phase AC power supplied to the motor;
A phase and reverse phase detection unit that detects a rotating magnetic field direction and connection of a three-phase AC power source;
A sensor detector that converts the output of the sensor so that it can be measured by the controller;
Current measuring unit for measuring the line current of the three-phase AC power;
An operation detection unit for determining whether a switch and an external input are ON or OFF;
A contact output unit that connects the photo triac and the triac and transmits a control signal generated by the control unit to an external contact to control external AC power; Electronic circuit of a controller dedicated to an inverter compressor, characterized in that consisting of.
According to claim 1,
In the electronic circuit of the controller dedicated to the inverter compressor,
Inverter compressor dedicated controller electronic circuit comprising a transformer that converts a high voltage external AC power to a voltage that the voltage detector can measure.
According to claim 1,
In the electronic circuit of the controller dedicated to the inverter compressor,
Inverter compressor dedicated controller electronic circuit comprising a photocoupler to determine the direction of rotation of magnetic field of AC power and whether it is connected by grasping the connection state of three-phase AC power.

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