TW201433078A - Brushless direct current motor control device - Google Patents

Abstract

The present invention relates to a brushless direct current motor control device mainly comprising a control module and a controlled module. The control module comprises a phase truncation circuit which continuously truncates the conduction angle of the alternating current power. The controlled module comprises: a rectifier circuit, a phase detection circuit, and a control unit. The rectifier circuit rectifies the truncated alternating current power. The phase detection circuit detects the truncated conduction angle, wherein the control unit controls the rotation speed or the operation of the motor according to the conduction angle detected by the phase detection circuit. Accordingly, the present invention uses the magnitude of the conduction angle as the control command instead of having the problem of low power factor. Moreover, the present invention does not require complicated circuit devices or additional wiring, and the existed power lines will suffice, thereby providing installation convenience, reducing costs and allowing easy maintenance.

Description

DC inverter motor control device

The invention relates to a control device, in particular to a control device suitable for a DC variable frequency motor.

The speed control technology of the variable frequency motor is an important development direction of modern power electronics technology. The variable frequency motor can be mainly divided into two major categories: DC and AC. Generally speaking, the electronic control system of the DC variable frequency motor is more complicated than the AC variable frequency motor. However, due to the better energy-saving effect of using DC inverter motors, more and more household appliances have been converted to DC inverter motors, such as air conditioners and fans. In addition, in terms of comfort, quietness, longevity, and control accuracy, DC inverter motors are also superior to AC inverter motors, making the market acceptance of DC inverter motors more and more high.

Generally speaking, the DC variable frequency motor needs to have a frequency converter for driving. The structure of the frequency converter is to firstly rectify and filter the 60 Hz AC power supply, and then provide the DC power to each circuit. The control unit of the DC inverter motor will perform the switching control of the power component according to the external command, thereby controlling the current flowing to the motor coil to achieve the purpose of speed regulation.

The traditional single-phase induction motor can change its speed by connecting different values of capacitance in series, but it uses the principle that AC power changes the slip through the capacitor to adjust the speed, so the capacitor can be installed on the wall control end (distal end). And by switching the different capacitors by the wall terminal, it is easy to achieve the change of the unidirectional induction motor speed. However, when the induction motor is changed to the inverter motor, the effect of the series capacitor disappears after rectification and filtering, so the capacitor wall control method used in the conventional single-phase induction motor cannot be used. Control of DC variable frequency motor.

At present, the most common control method for DC inverter motors is to use independent signal lines for control. However, it is necessary to change the wiring method, which will increase the trouble of wiring design and increase the cost. Therefore, how to design a DC inverter motor control device with simple circuit layout and no need to separately configure the signal line, but at the same time has good control effect, will become a direction for industry to think hard.

In view of this, the present invention provides a DC variable frequency motor control device, which mainly includes a control module and a controlled module. The control module includes a phase cutoff circuit electrically connected to an AC power source, and the phase cutoff circuit continuously cuts off the conduction angle of the AC power source. The controlled module of the load end comprises a rectifying circuit, a phase detecting circuit and a control unit; the rectifying circuit is electrically connected to the phase intercepting circuit to rectify the AC power source after being cut off by the phase intercepting circuit; the phase detecting The circuit is electrically connected to the rectifier circuit, and the phase detection circuit is configured to continuously detect the conduction angle of the AC power source after the phase cutoff circuit is cut off; the control unit is electrically connected to the phase detection circuit and a variable frequency motor drive circuit. The control unit is configured to change the rotation speed or the action of the motor according to the control of the motor drive circuit according to the conduction angle of the AC power source after the phase detection circuit detects the interception of the AC power supply.

Preferably, when a three-pole thyristor fluid is used as the cut-off circuit, the controlled module of the present invention may further comprise a bleeder circuit electrically connected to the rectifier circuit. The bleeder circuit is used to provide sufficient latching current and holding current for the three-pole thyristor to avoid The three-pole brake fluid is not triggered by mistake. However, the aforementioned bleeder circuit can also be an active bleeder circuit.

Furthermore, the phase shutoff circuit of the present invention may comprise: a three-pole thyristor fluid comprising a first terminal, a second terminal, and a gate; a bipolar thyristor fluid comprising a first anode terminal, and a second anode end, the first anode end is connected to the gate of the three-pole thyristor; a variable resistor electrically connected to the second terminal; and a resistor electrically connected to the variable resistor; a capacitor includes a first end and a second end, the first end is electrically connected to the resistor and the second anode end of the bipolar thyristor, and the second end is electrically connected to the tripolar thyristor The first terminal. Wherein, adjusting the variable resistance system can adjust the conduction angle of the AC power to cut off the phase cutoff circuit.

In addition, the phase cutoff circuit of the present invention may further include a switching capacitor and a switch. The switching capacitor is connected in series with the switching switch and then in parallel with the capacitor. Preferably, switching the switching-on relationship causes the phase-cutting circuit to generate a control signal with a sudden change in the conduction angle as a signal for causing the driving circuit to control the inversion of the DC-converting motor.

Preferably, the controlled module of the present invention further includes an electromagnetic interference filter circuit and a power factor adjustment circuit electrically connected to the phase cutoff circuit and the rectifier circuit.

Accordingly, the present invention is a command that utilizes the conduction angle size as a control function of speed, duty cycle, etc., compared to a conventional phase controller using a three-pole thyristor fluid. Moreover, more importantly, the present invention does not utilize the conduction angle to control the transmitted energy, so that the circuit can be operated at a large conduction angle state, and a wide range of control can be performed. There will be no problem with the low power factor of the traditional three-pole thyristor dimmer in deep dimming. Moreover, the DC variable frequency motor control device provided by the invention does not need to add an assembly line, and can effectively utilize the conduction angle of the alternating current through the original power line to perform DC variable frequency motor control.

Please refer to FIG. 1 and FIG. 2 together. FIG. 1 is a block diagram of a system according to a preferred embodiment of the present invention. FIG. 2 is a circuit diagram of a preferred embodiment of the present invention. As shown in the figure, the DC variable frequency motor control device 1 of the present invention mainly comprises a control module 3 disposed at the control end and a controlled module 4 disposed at the load end. Taking the embodiment as an example, the control end is a wall control end, and the load end is disposed at the proximal end of the DC inverter motor 2. The control module 3 is mainly composed of a phase cutoff circuit 11 , and the controlled module 4 mainly includes a rectifier circuit 12 , a bleeder circuit 13 , a phase detection circuit 14 , a control unit 15 , and an electromagnetic interference filter . The circuit 16, the DC power supply circuit 17, and a variable frequency motor drive circuit 21 are formed.

The phase cutoff circuit 11 is electrically connected to an AC power source 10, and the phase cutoff circuit 11 continuously cuts off the conduction angle of the AC power source until the speed or action of the DC inverter motor 2 is changed, and the different conduction of the AC power source is cut off again. Until the corner. In addition, the rectifier circuit 12 is electrically connected to the phase cutoff circuit 11 of the control module 3 to rectify the cut AC power. Furthermore, the bleeder circuit 13 is electrically connected to the rectifier circuit 12, and the bleeder circuit 13 is used to provide sufficient latching current and holding current for the three-pole thyristor to avoid the three-pole gate. The fluid is falsely triggered.

In addition, the DC variable frequency motor 2 is driven by a variable frequency motor drive circuit 21. The phase detecting circuit 14 is electrically connected to the rectifying circuit 12 and the control unit 15. The phase detecting circuit 14 is configured to detect the turned-on angle after the truncation. In addition, the control unit 15 is electrically connected to the phase detecting circuit 14 to control the inverter motor driving circuit 21 according to the conduction angle of the AC power source 10 detected by the phase detecting circuit 14, and to the DC inverter motor 2 Control of speed or PWM duty cycle, etc. For convenience of description, the DC inverter motor 2 of the present embodiment is exemplified by a fan motor.

Please refer to FIG. 2 for the circuit layout of the DC inverter motor control device 1 provided in this embodiment. As shown, the phase cutoff circuit 11 includes a three-pole thyristor 111, a bipolar thyristor 112, a variable resistor 113, a resistor 114, and a capacitor 115. The three-pole thyristor 111 includes a first terminal 111a, a second terminal 111b, and a gate 111c. The bipolar thyristor 112 includes a first anode end 112a and a second anode end 112b. The first anode end 112a is connected to the gate 111c of the three-pole thyristor 111, the variable resistor 113 is electrically connected to the second terminal 111b, and the resistor 114 is electrically connected to the variable resistor 113. The capacitor 115 includes a first end 115a and a second end 115b. The first end 115a is electrically connected to the resistor 114 and the second anode end 112b, and the second end 115b is electrically connected to the first terminal 111c.

The main feature of the embodiment is that the variable resistor 113 of the phase-cutting circuit 11 can adjust the conduction angle of the alternating current that is continuously cut by the phase-cutting circuit 11 , and the turned-off conduction angle passes through the phase detecting circuit 14 . The control unit 15 controls the variable frequency drive circuit 21 to control the DC variable frequency motor 2 to operate at a corresponding speed based on the conduction angle detected by the phase detecting circuit 14. Preferably, the phase cutoff circuit 11 is cut off The AC conduction angle is between 0 and 60 degrees, which has little effect on the power factor.

For a schematic diagram of the operation of this embodiment, please refer to FIG. 2 and FIG. 3 together. FIG. 3 is a schematic diagram of the operation of a preferred embodiment of the present invention. As shown in the figure, the user can adjust the size of the variable resistor 113 by a knob 8 to adjust the rotation speed of the DC inverter motor 2 accordingly. In the present embodiment, the phase cutoff circuit 11 is designed on the wall control end so that the user can adjust the variable resistor 113 by rotating the knob 8. Since the DC inverter motor 2 of the present embodiment is exemplified by a fan motor, the ceiling fan 7 is used as a drive target of the DC inverter motor 2. By adjusting the variable resistor 113 by the knob 8, the rotation speed of the DC inverter motor 2 can be adjusted, and the wind speed of the ceiling fan 7 can be adjusted.

Therefore, in the present embodiment, the variable-speed resistor 113 is used to adjust the DC inverter motor 2, and the rotation speed and the wind speed can be finely adjusted, and the "no-stage regulation" effect is obtained. Of course, in other embodiments of the present invention, the variable resistor can also be changed to a band switch of a resistor having different resistance values for segment control, and the capacitor 115 can be changed to a band switch. The capacitance value is used for segment control.

In addition, referring to FIG. 4, FIG. 4 is a circuit diagram of another preferred embodiment of the present invention. In another embodiment of the present invention, a switching capacitor 116 is added to the phase blocking circuit 11, and a switching is performed. Switch 117. As shown, switching capacitor 116 is coupled in series with switching switch 117 and then in parallel to capacitor 115. Preferably, the switch 117 is a bounce switch. Since pressing the switch 117 causes the capacitor to be turned on, the phase angle is cut off to generate a sudden change in the conduction angle, and the change can be used as a control signal for switching the DC inverter motor 2 to be reversed, for actuating the DC inverter motor 2 The drive circuit 21 controls the DC inverter motor 2 to reverse. This operation can be referred to FIG. 4 and FIG. 5 together. FIG. 5 is a schematic view showing the operation of another preferred embodiment of the present invention. As shown in the figure, the switch 9 is connected to the changeover switch 117, and the push switch 9 synchronously switches the changeover switch 117, so that the phase cutoff circuit 11 can generate a control signal to invert the ceiling fan 7.

In addition, other common functional circuits, such as power factor adjustment circuits conventionally used in power supply circuits, are omitted in the embodiments, but may be changed or added depending on actual application requirements.

In summary, the DC variable frequency motor control device 1 provided in this embodiment does not need to add a complicated circuit device to the DC variable frequency motor 2, and does not need to change the circuit wiring separately, that is, the original line can effectively utilize the conduction of the alternating current. The angle is used to regulate the DC inverter motor 2. Therefore, the present invention is quite convenient in installation, and has the advantages of low manufacturing cost and easy maintenance.

1‧‧‧DC inverter motor control unit

10‧‧‧AC power supply

11‧‧‧ phase cutoff circuit

12‧‧‧Rectifier circuit

13‧‧‧Relief circuit

14‧‧‧ phase detection circuit

15‧‧‧Control unit

16‧‧‧Electromagnetic interference filter circuit

17‧‧‧DC power supply circuit

111‧‧‧Three-pole thyristor fluid

112‧‧‧Bipolar thyristor fluid

113‧‧‧Variable resistor

114‧‧‧resistance

115‧‧‧ Capacitance

116‧‧‧Switching capacitor

117‧‧‧Toggle switch

111a‧‧‧First terminal

111b‧‧‧second terminal

111c‧‧‧ gate

112a‧‧‧First anode end

112b‧‧‧second anode end

115a‧‧‧ first end

115b‧‧‧ second end

2‧‧‧DC inverter motor

21‧‧‧Inverter motor drive circuit

3‧‧‧Control Module

4‧‧‧Controlled modules

7‧‧‧ Ceiling fan

8‧‧‧ knob

9‧‧‧ switch

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of a system in accordance with a preferred embodiment of the present invention.

Figure 2 is a circuit diagram of a preferred embodiment of the present invention.

Figure 3 is a schematic illustration of the operation of a preferred embodiment of the present invention.

Figure 4 is a circuit diagram of another preferred embodiment of the present invention.

Figure 5 is a schematic view showing the operation of another preferred embodiment of the present invention.

1‧‧‧DC inverter motor control unit

10‧‧‧AC power supply

11‧‧‧ phase cutoff circuit

12‧‧‧Rectifier circuit

13‧‧‧Relief circuit

14‧‧‧ phase detection circuit

15‧‧‧Control unit

16‧‧‧Electromagnetic interference filter circuit

17‧‧‧DC power supply circuit

2‧‧‧DC inverter motor

21‧‧‧Drive circuit

3‧‧‧Control Module

4‧‧‧Controlled modules

Claims (6)

A DC variable frequency motor control device includes: a control module and a controlled module; the control module includes a phase cutoff circuit electrically connected to an AC power source, and the phase cutoff circuit continuously cuts off the AC a conduction angle of the power supply; the controlled module includes: a rectifier circuit electrically connected to the phase cutoff circuit of the control module, the rectifier circuit rectifying the AC power source after the phase cutoff circuit; a phase detecting circuit electrically connected to the rectifying circuit, wherein the phase detecting circuit is configured to continuously detect the conduction angle of the AC power source after being cut off by the phase intercepting circuit; and a control unit Electrically connected to the phase detecting circuit and a variable frequency motor driving circuit; wherein the control unit is based on the conduction angle of the AC power source after the phase detecting circuit detects that the phase switching circuit is cut off Correspondingly controlling the variable frequency motor drive circuit to change the speed or action of the DC inverter motor. The DC inverter motor control device of claim 1, wherein the phase shutoff circuit comprises: a three-pole thyristor fluid, comprising a first terminal, a second terminal, and a gate, the second The terminal is electrically connected to the rectifier circuit; a bipolar thyristor fluid includes a first anode end, and a first a second anode end, the first anode end is connected to the gate of the three-pole thyristor; a variable resistor electrically connected to the second terminal; and a resistor electrically connected to the variable resistor And a capacitor comprising a first end and a second end, the first end electrically connected to the resistor and the second anode end of the bipolar thyristor, the second end being electrically connected The first terminal of the three-pole thyristor fluid and the AC power source; wherein the variable resistance of the phase-cut circuit is adjusted to adjust the conduction angle of the AC power supply by the phase-cut circuit. The DC variable frequency motor control device of claim 2, wherein the controlled module further comprises a bleeder circuit electrically connected to the rectifier circuit, the bleeder circuit for providing the three poles The thyristor has sufficient latching current and holding current to avoid false triggering of the triode thyristor. The DC inverter motor control device of claim 2, wherein the phase cutoff circuit further comprises a switching capacitor and a switch, the switching capacitor is connected in series with the switch, and then connected in parallel. To the capacitor; switching the switching-on relationship causes the phase-cutting circuit to generate a control signal with a sudden change in the conduction angle, the control signal causing the driving circuit to control the DC inverter motor to reverse. For example, in the DC variable frequency motor control device described in claim 4, the switching on relationship is a bounce switch. The direct current inverter motor control device according to claim 1, wherein the phase cutoff circuit cuts off the conduction angle of the alternating current power source between 0 and 60 degrees.