JP2011122799A - Control device of air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect a condition of a controlled object independently from a condition of a microcomputer, and to properly take measures against a failure even when the failure is detected in the controlled object. <P>SOLUTION: This control device of the air conditioner, controls a compressor motor by the microcomputer, and is equipped with: a motor driving circuit 3 for driving the compressor motor by outputting a prescribed signal on the basis of a command from the microcomputer; a failure detecting circuit 4 receiving an inducing or driving voltage signal of the compressor motor, and further receiving a command voltage signal transmitted from the microcomputer to the compressor motor for detecting the failure of the compressor motor on the basis of the inducing or driving voltage signal and the command voltage signal; a charging/discharging circuit 5 performing any of charging and discharging in accordance with whether the failure detecting circuit 4 detects the failure of the compressor motor or not; and a switching circuit for switching the availability of output of the motor driving circuit on the basis of a voltage level of the charging/discharging circuit 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an air conditioner control apparatus, and more particularly to an air conditioner control apparatus that controls a control target such as a compressor motor by a microcomputer.

  The air conditioner control device stores a motor drive circuit for driving the compressor motor and predetermined software for controlling the motor drive circuit in advance, and controls the motor drive circuit according to this software to control the compressor motor. A computer equipped with a microcomputer for driving and controlling has become common. In such a control device, the microcomputer detects signals such as induction or drive voltage, current, or rotor position of the compressor motor, and performs calculations according to software stored in advance, so that the state of the compressor motor (normal or Abnormal). When the microcomputer determines that the compressor motor is abnormal, the microcomputer outputs a stop signal for stopping the compressor motor to the motor drive circuit, and the voltage / current to the compressor motor is output. By stopping the supply, the compressor motor is stopped to protect the compressor motor. As a control device for such an air conditioner, for example, Patent Document 1 (Japanese Patent Laid-Open No. Sho 62-131344) describes a self-diagnosis device for a device that controls a stepping motor by a microcomputer.

Japanese Patent Laid-Open No. 62-131344

  However, in the above-described conventional air conditioner control device, for example, when the microcomputer is unable to control the compressor motor, such as when the microcomputer runs out of control, the microcomputer performs calculation according to predetermined software. Cannot be performed, and a signal for stopping the compressor motor cannot be output. For this reason, if an abnormality such as a lock occurs in the compressor motor when the microcomputer is abnormal, the microcomputer cannot judge the state of the compressor motor or stop the compressor motor. There was a problem that the compressor motor could not be protected.

  The present invention has been made to solve the above-described problem. Even when the microcomputer cannot control a control object such as a compressor motor, the microcomputer has no relation to the state of the microcomputer. An object of the present invention is to provide a control device for an air conditioner capable of accurately detecting the state of a controlled object and accurately taking measures against the abnormality even when the detected abnormality is detected in the controlled object.

In order to solve the above problems, the present invention employs the following means.
The present invention is a control device for an air conditioner that controls a compressor motor by a microcomputer, and a motor drive circuit that drives the compressor motor by outputting a predetermined signal based on a command from the microcomputer And receiving an induction or drive voltage signal of the compressor motor, and receiving a command voltage signal transmitted from the microcomputer to the compressor motor, and based on the induction or drive voltage signal and the command voltage signal, An abnormality detection circuit that detects an abnormality of the compressor motor, a charge / discharge circuit that performs either discharging or charging depending on whether the abnormality detection circuit detects an abnormality of the compressor motor, and the charge / discharge A switching circuit for switching the output of the motor drive circuit based on the voltage level of the circuit. To provide a device.

  According to the present invention, the charge / discharge state of the charge / discharge circuit is switched between the state of the compressor motor, i.e., when it is operating normally and when an abnormality is detected, and the switching circuit detects the voltage of the charge / discharge circuit. Since the output of the motor drive circuit is switched based on the level, if an abnormality occurs in the compressor motor, output to the compressor motor is prohibited regardless of the state of the microcomputer, and the compressor motor is stopped. Can be made. Therefore, for example, even if a problem such as runaway occurs in the microcomputer and the compressor motor cannot be controlled, the compressor motor can be accurately detected regardless of the state of the microcomputer. By detecting and stopping the compressor motor, the compressor motor can be protected.

In the present invention described above, the abnormality detection circuit is a motor lock detection circuit that detects a lock state of the compressor motor based on the induction or drive voltage signal and the command voltage signal, and the charge / discharge circuit includes It is preferable to perform either charging or discharging depending on whether or not the motor lock detection circuit detects the locked state of the compressor motor.
According to the present invention, particularly when the compressor motor is locked, charging / discharging of the charging / discharging circuit is switched depending on whether or not the locked state of the compressor motor is detected. Whether or not the motor drive circuit can be output can be switched based on the voltage level, and the compressor motor can be stopped by accurately detecting the lock state of the compressor motor regardless of the state of the microcomputer. Thereby, the compressor motor in the locked state can be stopped without depending on the microcomputer, the occurrence of overcurrent in the compressor motor can be prevented, and the compressor motor can be protected.

In the present invention described above, the motor lock detection circuit outputs different types of pulses depending on whether or not the compressor motor is locked, and the charge / discharge circuit outputs from the motor lock detection circuit. It is preferable to perform either charging or discharging according to the type of pulse to be applied.
According to the present invention, the charge / discharge circuit switches between charge and discharge according to the type of pulse output from the motor lock detection circuit. As a result, the switching circuit can switch the output of the motor drive circuit based on the voltage level of the charge / discharge circuit, accurately detect the lock state of the compressor motor regardless of the state of the microcomputer, and compress it. The machine motor can be stopped.

  Thus, according to the present invention, even when the microcomputer is in a state where it cannot control the control object such as the compressor motor, the state of the control object is accurately detected, and the control object is abnormal. Even when an error is detected, an appropriate measure can be taken for the abnormality.

It is the block diagram which showed schematic structure of the control apparatus of the air conditioner which concerns on one Embodiment of this invention. It is a block diagram which shows schematic structure of the motor lock detection circuit of the control apparatus of the air conditioner which concerns on one Embodiment of this invention. It is a block diagram which shows schematic structure of the charging / discharging circuit of the control apparatus of the air conditioner which concerns on one Embodiment of this invention.

An embodiment of a control device for an air conditioner according to the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a control device for an air conditioner according to the present embodiment. As shown in FIG. 1, the control device for the air conditioner includes a microcomputer 2 that drives and controls the compressor motor 1 of the air conditioner, a motor drive circuit 3 that drives the compressor motor 1, and a lock for the compressor motor 1. A motor lock detection circuit 4 that detects a state and a charge / discharge circuit 5 that performs charge / discharge based on the detection result of the motor lock detection circuit 4 are provided. In the present embodiment, an example in which a so-called three-phase motor is applied as the compressor motor 1 and a three-phase output motor is applied as the motor drive circuit 3 will be described.

  The microcomputer 2 outputs a predetermined command signal such as a command voltage signal to the motor drive circuit 3 in order to drive and control the compressor motor 1. The motor drive circuit 3 drives and controls the compressor motor 1 by outputting a predetermined drive voltage / current to the compressor motor 1 in accordance with the command signal output from the microcomputer 2. The motor drive circuit 3 is provided with a so-called enable port (switching circuit). When the enable port is enabled, the drive voltage / current corresponding to the command signal of the microcomputer 2 is compressed from the motor drive circuit 3. When the Enable port is disabled, the driving voltage / current is not output from the motor driving circuit 3 to the compressor motor 1. The Enable port can be switched between Enable and Disable based on the voltage level of the charge / discharge circuit 5 described later. Therefore, the propriety of the drive voltage / current output from the motor drive circuit 3 to the compressor motor 1 is switched based on the voltage level of the charge / discharge circuit 5.

  The motor lock detection circuit 4 (abnormality detection circuit) receives the induction or drive voltage signal output from the compressor motor 1 and receives the command voltage signal output from the microcomputer 2 to the compressor motor 1 to induce or By comparing the drive voltage signal and the command voltage signal, it is possible to detect an abnormality of the compressor motor 1, that is, in the present embodiment, whether or not the compressor motor 1 is in a locked state. Therefore, the motor lock detection circuit 4 includes a motor voltage detection circuit 6, a microcomputer command voltage detection circuit 7, a comparison circuit 8, and a lock detection signal output circuit 9, as shown in FIG.

  Motor voltage detection circuit 6 The motor voltage detection circuit 6 receives the induction or drive voltage signal from the compressor motor 1, converts it into a predetermined induction or drive voltage signal, and outputs it to the comparison circuit 8. Since the compressor motor 1 is a three-phase motor, the motor voltage detection circuit 6 receives three motor induction or drive voltage signals from the compressor motor 1 and synthesizes or converts these three induction or drive voltage signals. Thus, an induced or drive voltage signal is generated, and the generated induced or drive voltage signal is output to the comparison circuit 8.

  The microcomputer command voltage detection circuit 7 receives the command voltage signal output from the microcomputer 2 to the compressor motor 1, converts it into a predetermined command voltage signal, and outputs it to the comparison circuit 8. Since the compressor motor 1 is a so-called three-phase motor, the microcomputer command voltage detection circuit 7 receives six command voltage signals and generates a command voltage signal by synthesizing or converting these six command voltage signals. The generated command voltage signal is output to the comparison circuit 8.

  The comparison circuit 8 compares the induction or drive voltage signal output from the motor voltage detection circuit 6 with the command voltage signal output from the microcomputer command voltage detection circuit 7 to determine whether or not the compressor motor 1 is in a locked state. And the determination result is output to the lock rotation detection signal output circuit 9. The comparison circuit 8 determines that the compressor motor 1 is in a locked state when an induction or drive voltage signal that matches the command voltage signal from the microcomputer is obtained. The comparison circuit 8 determines that the compressor motor 1 is not in a locked state when an induction or drive voltage signal deviating from the command voltage signal from the microcomputer is obtained.

  The lock detection signal output circuit 9 outputs a high-level pulse to the charge / discharge circuit 5 when the signal output from the comparison circuit 8 is determined to be in the locked state, and is not in the locked state. When the signal indicates that it has been determined, a low level pulse is output to the charge / discharge circuit 2.

In the charge / discharge circuit 5, as shown in FIG. 3, the first resistor 17, the first transistor 15, and the second transistor 16 are connected in series between the power source and the ground level, and the second resistor 19 and a capacitor 18 are connected in parallel with the second transistor 16.
The charge / discharge circuit 5 discharges the capacitor 18 in a state where the motor lock detection circuit 4 detects the lock state of the compressor motor, that is, in a state where a high level pulse is output from the lock detection signal output circuit 9. . On the other hand, the capacitor 18 is charged when the motor lock detection circuit 4 does not detect the lock state of the compressor motor, that is, when a low level pulse is output from the lock detection signal output circuit 9.

  More specifically, the charge / discharge circuit 5 is configured such that the first transistor 15 is switched on while the second transistor 16 is switched in a state where a low level pulse is output from the lock detection signal output circuit 9. Is turned OFF, and current flows from the power source to the ground level as indicated by an arrow Low in FIG. As a result, the capacitor 18 is charged, and the enable port of the motor drive circuit 3 is set to the enable state, thereby enabling output from the motor drive circuit 3 to the compressor motor 1.

  In the state where the high-level pulse is output from the lock detection signal output circuit 9, the charging / discharging circuit 5 turns on the switch of the second transistor 16, while the switch of the first transistor 15 turns off. As shown by the arrow Hi in FIG. When a current flows to the Hi side, the capacitor 18 is discharged, and the enable port of the motor drive circuit 3 is set to a disabled state, thereby prohibiting output from the motor drive circuit 3 to the compressor motor 1.

  Since the charging resistance has a resistance value that is sufficiently small (for example, 1/1000) with respect to the discharging resistance, the time constant of the charging circuit is set sufficiently smaller than the time constant of the discharging circuit. Yes. The motor lock detection circuit periodically detects the locked state of the compressor motor 1 and charges the capacitor 18 when the compressor motor 1 is not locked each time. 18 discharges are performed. When it is detected once that it is not in the locked state, the capacitor 18 is rapidly charged, the voltage level of the charge / discharge circuit 5 is restored, and the Enable port is in the Enable state, while the locked state is If the voltage level of the charging / discharging circuit 5 is not detected continuously for a plurality of times, the voltage level of the charging / discharging circuit 5 does not sufficiently decrease, and it takes time for the Enable port to enter the Disable state.

Hereinafter, the process in the case of driving and controlling the compressor motor 1 by the air conditioner control apparatus configured as described above will be described.
When the compressor motor 1 to be controlled is operating normally, a low level pulse is continuously output from the motor lock detection circuit 1, and a current flows through the first transistor in the charge / discharge circuit 5. The charged state of the capacitor 18 continues. Therefore, the Enable port of the motor drive circuit 3 is in an enable state, and a predetermined command signal is output from the motor drive circuit 3 to the compressor motor 1 based on the command voltage signal from the microcomputer 2, and compression is performed. The machine motor 1 is operating normally.

  When the compressor motor 1 is in a locked state from a normally operated state, the rotation of the compressor motor 1 is stopped regardless of a command signal from the microcomputer 2. At this time, the motor voltage detection circuit 6 receives an induction or drive voltage signal that matches the command voltage signal of the microcomputer from the compressor motor 1, generates a predetermined induction or drive voltage signal, and outputs it to the comparison circuit 8. . The command voltage detection circuit 7 receives the command voltage signal output from the microcomputer 2, generates a predetermined command voltage signal, and outputs it to the comparison circuit 8.

  The comparison circuit 8 compares the induction or drive voltage signal received from the motor induction or drive voltage detection circuit with the command voltage signal received from the command voltage detection circuit 7. As a result of the comparison, when the induction or drive voltage signal whose induction or drive voltage signal matches the command voltage signal from the microcomputer is obtained, it is determined that the compressor motor 1 is in the locked state, and the signal to that effect is locked. The detection signal output circuit 9 outputs. The lock detection signal output circuit 9 outputs a high level pulse to the charge / discharge circuit 5 when it receives a signal indicating that the compressor motor 1 is in the locked state.

  In the charge / discharge circuit 5 that has received the high-level pulse, a current flows to the second transistor 16, whereby the charge of the capacitor 18 is discharged. When the detection of the lock state continues, when the electric charge of the capacitor 18 is discharged below a predetermined voltage level, the enable port of the motor drive circuit 3 is switched from the enable state to the disable state, and the motor drive circuit 3 switches from the compressor motor. Output to 1 is prohibited. While the Enable port is in the disable state, the command signal output from the microcomputer 2 to the motor drive circuit 3 is not output to the compressor motor 1 regardless of the state of the microcomputer 2.

  As described above, according to the present invention, when the compressor motor 1 is locked, the lock state is detected by hardware by the motor lock detection circuit provided separately from the microcomputer 2, and the charge / discharge circuit By prohibiting the output from the motor drive circuit 3 to the compressor motor 1 based on the voltage level of 5, the voltage / current supply to the compressor motor 1 can be stopped. Therefore, even if the microcomputer 2 is in a runaway state, the voltage / current flowing to the compressor motor 1 is stopped regardless of the operating state of the microcomputer 2 to prevent the overcurrent from occurring. Can be protected.

In this embodiment, the battery is discharged when the locked state is reached, and is charged when the locked state is not reached. In addition, the time constant of the charging circuit is set to be sufficiently small as compared with the time constant of the discharging circuit, but the ratio may be appropriately set as necessary.
In addition, the locked state of the compressor motor 1 is detected as an abnormal state, but instead of this, an abnormal state other than the locked state, such as an overload state, may be detected.

1 Compressor motor 2 Microcomputer 3 Motor drive circuit 4 Motor lock detection circuit (abnormality detection circuit)
5 Charge / Discharge Circuit 6 Motor Voltage Detection Circuit 7 Microcomputer Command Voltage Detection Circuit 8 Comparison Circuit 9 Lock Detection Signal Output Circuit

Claims (3)

A control device for an air conditioner that controls a compressor motor by a microcomputer,
A motor drive circuit for driving the compressor motor by outputting a predetermined signal based on a command from the microcomputer;
The compressor receives an induction or drive voltage signal of the compressor motor, receives a command voltage signal transmitted from the microcomputer to the compressor motor, and based on the induction or drive voltage signal and the command voltage signal, the compressor An abnormality detection circuit for detecting an abnormality of the motor;
A charge / discharge circuit that performs either charging or discharging depending on whether or not the abnormality detection circuit detects an abnormality of the compressor motor;
A switching circuit for switching the output of the motor drive circuit based on the voltage level of the charge / discharge circuit;
The control apparatus of the air conditioner provided with. The abnormality detection circuit is a motor lock detection circuit that detects a lock state of the compressor motor based on the induction or drive voltage signal and the command voltage signal;
2. The air conditioner control device according to claim 1, wherein the charge / discharge circuit performs either charging or discharging according to whether the motor lock detection circuit detects a locked state of the compressor motor. 3. The motor lock detection circuit outputs different types of pulses depending on whether or not the compressor motor lock state is detected,
The control device for an air conditioner according to claim 2, wherein the charge / discharge circuit performs either charging or discharging according to a type of pulse output from the motor lock detection circuit.

Images