JP3276991B2 - DC brushless motor controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a DC brushless motor used, for example, for opening and closing an automatic door.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing an electric configuration of a conventional motor control device 1. As shown in FIG. Motor control device 1
Is provided with a transformer 3 for transforming the power supply from the AC power supply 2. The output of the transformer 3 is converted into a DC voltage via an inverter circuit 4, and this DC voltage is supplied to a DC motor 5 as a drive voltage. A battery 6 is connected to the output side of the transformer 3 and is charged by the transformer 3. The battery 6 drives the DC motor 5 at the time of a power failure of the AC power supply 2 and slightly opens and closes an automatic door driven by the DC motor 5.

The transformer 3 is provided with a power transformer 7 for transforming the drive power from the AC power supply 2 and supplying the transformed power to the inverter circuit 4. The transformer 3 detects a current on the primary side and outputs a detection signal. A current transformer 8 is provided. A switching element 9 such as a power transistor is connected in series to a primary coil of the transformer 3, and an output voltage from the transformer 3 is adjusted by controlling on / off of the switching element 9.

The detection output of the current transformer 8 is connected to diodes 10 and 12 connected in series to the secondary coil of the current transformer 8 and connected in parallel with each other in the forward direction.
And a voltage via the resistor 11 connected in parallel with the diode 12 and output to the speed control circuit 13.
The speed control circuit 13 detects a deviation between a rotation speed signal from a resistor 16 connected to the inverter circuit 4 and detecting the rotation speed of the DC motor 5 as a voltage level, and an output from the current transformer 8. A control signal to the PWM circuit 14 is generated based on a separately input reference speed signal.

[0005] The speed control circuit 13 outputs a control signal for eliminating the deviation to a PWM (pulse width modulation) circuit 14. The PWM circuit 14 passes through a pulse transformer 15
A control signal is output to the switching element 9 of the transformer 3 to perform on / off control of the switching element 9. The switching operation of the switching element 9 changes the output level of the transformer 3 and controls the rotation speed of the DC motor 5.

[0006]

The control device 1 of the prior art relating to the DC motor 5 includes a current transformer 8 and a pulse transformer 15, so that the configuration of the control device 1 becomes large and the power consumption increases. There is a problem that. In addition, there is a problem that the cost increases due to an increase in the size of the configuration.

An object of the present invention is to solve the above-mentioned technical problems, to provide a control device for a DC brushless motor whose configuration is downsized and simplified and whose power consumption can be suppressed.

[0008]

According to the present invention, drive power from an AC power supply is input to an inverter circuit via a transformer.
Or, the driving power from the DC power supply is input to the inverter circuit, a control device of a DC brushless motor for controlling a rotational state of the DC brushless motor with an output from the inverter circuit, said DC brushless motor
The rotation speed detection signal corresponding to the rotation speed of
Outputs the secondary deviation signal from the corresponding secondary reference voltage
A secondary speed control circuit; the secondary deviation signal;
The primary reference voltage corresponding to the number of turns and the primary
Generates a primary deviation signal from the primary current flowing through the
Then, the primary side deviation signal causes the primary side
Switch on / off the switching element
The output level of the transformer to change the DC
Primary speed control circuit for controlling the rotation speed of the brushless motor
Path and secondary voltage detection for detecting the secondary voltage of the transformer
And the secondary-side speed control circuit comprises:
When the secondary voltage cannot be detected by the voltage detection circuit,
The DC brushless using the drive power from the DC power supply.
PWM control of motor rotation speed by secondary deviation signal
This is a control device for a DC brushless motor.

[0009]

[Operation] The present invention will be described. Drive from AC power supply
Dynamic power is input to the inverter circuit via the transformer
At the time, the primary speed control circuit, the secondary deviation signal,
A primary-side reference voltage corresponding to a reference rotation speed;
The primary deviation signal is derived from the primary current flowing through the primary line.
Generate the primary deviation signal of the transformer
Turns on / off the switching element provided on the side line.
To change the output level of the transformer,
Controls the rotation speed of the brushless motor. Also exchange
Drive power from power supply to inverter circuit via transformer
No input and the secondary voltage detection circuit
When pressure cannot be detected, the secondary speed control circuit
The DC brushless using the drive power from the DC power supply.
PWM control of motor rotation speed by secondary deviation signal
I will.

[0010]

FIG. 1 is a block diagram showing an electric configuration of a motor control device 21 of a DC brushless motor according to one embodiment of the present invention. The motor control device 21 includes a transformer 23 for transforming power supply power from an AC power supply 22. Transformer 23
Is converted into a DC voltage via an inverter circuit 24, and this DC voltage is supplied to a DC motor 25 as a drive voltage. A battery 26 is connected to the output side of the transformer 23 and is charged by the transformer 23. This battery 26 is used to store the DC motor 25 when the AC power supply 22 fails.
To slightly open and close the automatic door driven by the DC motor 25.

The transformer 23 is provided with a primary line 27 and a secondary line 28 for transforming the driving power from the AC power supply 22 and supplying it to the inverter circuit 24.
A switching element 29 such as a power transistor is connected in series to the primary line 27, and the switching element 2
9 by the on / off control described later.
The output voltage from is adjusted.

The inverter circuit 24 is connected to a resistor 30 through which a current of drive power supplied to the DC motor 25 flows. A speed signal corresponding to the number of rotations of the DC motor 25 is output from the resistor 30 as a voltage level in the speed control circuit 31.
Is output to The speed control circuit 31 is implemented as an integrated circuit element, and is a secondary-side switching circuit with respect to the transformer 23. The speed control circuit 31 stores a reference voltage corresponding to the reference rotation speed of the DC motor 25 in the reference voltage generation circuit 3.
2 is input. The reference voltage generating circuit 32 may be a microprocessor or the like that controls the entire operation of an automatic door or the like using the DC motor 25, and may have a voltage that changes every moment.

The speed control circuit 31 compares the reference voltage from the reference voltage generation circuit 32 with the rotation speed signal from the resistor 30 and outputs a deviation signal for eliminating these deviations. The deviation signal is output to the inverter circuit 24 and to the photocoupler 33. The signal from the photocoupler 33 is output to the speed control circuit 34 on the primary side with respect to the transformer 23. The speed control circuit 34 may use the same configuration as the speed control circuit 31. A current detection line 35 from the primary line 27 of the transformer 23 is connected to the speed control circuit 34, and a current flowing through the primary line 27 of the transformer 23 is detected and input to the speed control circuit 34.

The speed control circuit 34 receives a reference voltage corresponding to the reference rotation speed of the DC motor 25 from a reference voltage generation circuit 36. This reference voltage generation circuit 36
The microprocessor may be used. The speed control circuit 34 compares the reference voltage from the reference voltage generation circuit 36 with the deviation signal from the photocoupler 33 and the current flowing from the current detection line 35 through the primary line 27 of the transformer 23 to determine the deviation. It detects and outputs a deviation signal for eliminating these deviations. The deviation signal is output to the switching element 29 as an on / off control signal, and performs on / off control of the switching element 29. The switching operation of the switching element 29 changes the output level of the transformer 23 and controls the rotation speed of the DC motor 25.

FIG. 2 is a circuit diagram showing a configuration example of the control circuit 21. The power supply from the AC power supply 22 is full-wave rectified and smoothed by a rectifying and smoothing circuit 38 via a noise filter 37. The output of the rectifying and smoothing circuit 38 is input to the transformer 23. The output of the inverter circuit 24 is
At 9, the DC three-phase motor 25 is time-sequentially distributed and supplied. The inverter circuit 24 and the speed control circuit 31 include a clock signal and a forward / reverse control signal from a control device 40 such as a microprocessor that controls the operation of the automatic door using the DC three-phase motor 25 as a whole. Are input. The inverter circuit 24 is provided in the DC three-phase motor 25,
A signal from the Hall element 41 for detecting a signal corresponding to the rotation speed is input.

Another transformer 44 is provided on the output side of the noise filter 37, and two rectifying / smoothing circuits 42 and 43 are connected to the secondary side thereof.
A drive voltage is supplied to the various drive circuit elements provided in the device 1. The speed control circuit 31 outputs the deviation signal to the photocoupler 33 via the buffer 45. The deviation signal is input to one input terminal of the AND circuit 46. The rectification / smoothing circuit 43 is connected to a secondary voltage detection circuit 47 for detecting whether or not the secondary voltage output from the rectification / smoothing circuit 43 is a predetermined voltage such as 100 V, for example. The detection output of the detection circuit 47 is
The signal is input to the other input terminal of the AND circuit 46. The secondary voltage detection circuit 47 detects a drop in the secondary voltage of the transformer 23 due to a power outage of the AC power supply 22 or the like, and detects the
A high level signal is output to the D circuit 46 to make the AND circuit 46 conductive. When the secondary voltage detection circuit 47 detects a normal secondary voltage, a low-level signal is output to the AND circuit 46, and the AND circuit 46 is shut off.

The operation of the control device 21 according to the present embodiment will be described below with reference to FIGS. When a predetermined power supply is supplied from the AC power supply 22, the AND circuit 46 is shut off as described above, and the DC three-phase motor (hereinafter abbreviated as “motor”) 25 performs switching under the control of the speed control circuit 34. Normal operations such as acceleration / deceleration can be performed by turning on / off the element 29.

On the other hand, when the AC power supply 22
When the secondary voltage of the transformer 23 drops, the operation of the secondary voltage detection circuit 47 causes the AND circuit 46 to conduct, and the inverter circuit 24 operates based on the driving power from the DC power supply 26.
The PWM control of the motor 25 is performed by the control of the speed control circuit 31.

As described above, the control device 21 of the present embodiment
Thus, control of the rotation speed of the motor 25 and protection in the event of overload can be realized. In realizing such a control operation, the control of the motor 25 can be performed irrespective of whether or not the driving power is supplied from the AC power supply 22. Moreover, in the configuration for performing the control, the necessity of providing the current transformer 8 and the pulse transformer 15 in the above-described conventional technology is eliminated, and the configuration of the control device 21 can be reduced in size and power consumption can be suppressed. In addition, cost can be suppressed because the configuration can be downsized and power consumption can be suppressed.

[0020]

As described above, according to the present invention, control for accelerating and decelerating a DC brushless motor can be realized by a small and simplified control device.

[Brief description of the drawings]

FIG. 1 is a control device 21 of a motor 25 according to an embodiment of the present invention.
It is a block diagram of.

FIG. 2 is a circuit diagram showing a configuration example of a control device 21.

FIG. 3 is a block diagram of a conventional control device 1 for a motor 5.

[Description of Signs] 21 Motor control device 22 AC power supply 23 Transformer 24 Inverter circuit 25 DC brushless motor 29 Switching element 31, 34 Speed control circuit 33 Photocoupler 35 Current detection line 46 AND circuit 47 Voltage detection circuit

Claims (1)

(57) [Claims] 1. A drive power from an AC power supply is input to an inverter circuit via a transformer , or a drive power from a DC power supply is input to the inverter circuit, and an output from the inverter circuit is used for DC brushless. In a DC brushless motor control device for controlling a rotation state of a motor, a rotation speed detection corresponding to a rotation speed of the DC brushless motor is performed.
Output signal and the secondary side reference voltage corresponding to the reference speed.
A secondary side speed control circuit for outputting a secondary side deviation signal; the secondary side deviation signal;
Quasi-voltage and primary current flowing through the primary line of the transformer
Generates a primary deviation signal from
Therefore, the switch provided on the primary line of the transformer
The switching element is turned on / off and the output level of the transformer is
Change the rotation speed of the DC brushless motor.
And a secondary voltage detection circuit for detecting a secondary voltage of the transformer
If has the secondary speed control circuit, Do can be detected secondary voltage by the secondary voltage detector circuit
At the same time, using the driving power from the DC power supply to
The rotation speed of the brushless motor is determined by the secondary deviation signal.
A DC brushless motor control device characterized by performing PWM control .