Drive control device for single-phase motor and braking control method for single-phase motor

Abstract

To realize complete self-sustaining non-powered braking with a simple circuit configuration.SOLUTION: A drive control device 1 for a single-phase motor includes a motor drive unit 10 that energizes a coil L of a motor 3, a braking control unit 30 that outputs a braking control signal, a motor control unit 20 that outputs a drive control signal to the motor drive unit 10 to switch the energization direction of the coil L that is energized by the motor drive unit 10 in predetermined order, an inter-coil terminal short-circuit unit 40 connected between terminals A and B of the coil L and short-circuits the terminals A and B of the coil L in response to a short-circuit signal, and a short-circuit signal output unit 50 connected to both ends (terminals A and B) of the coil L and the inter-coil terminal short-circuit unit 40, and outputting the short-circuit signal to the inter-coil terminal short-circuit unit 40 when the braking control signal is input.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a drive control device for a single-phase motor and a braking control method for a single-phase motor. [Background technology]

[0002] 2. Description of the Related Art A drive control device that controls the drive of a single-phase motor is known (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-103883 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a single-phase brushless motor is operated as a fan motor, for example, a technique is generally used in which the motor coils are short-circuited by electrically shorting the drive bridge circuit after a rotation stop command is received or after the power supply is stopped and before the rotation is stopped. In this way, the motor coils are short-circuited and the electromotive force generated in the motor coils is short-circuited, so that the rotation of the motor can be quickly stopped by regenerative braking. At that time, in order to short-circuit each motor coil, a power supply is required to operate the short-circuiting system. Therefore, for example, in a braking operation when the power is shut down, the braking time depends on the amount of charge remaining in the power line. Also, when a windmill phenomenon (forced rotation of the blades due to outside wind) occurs when there is no power supply, the rotation suppression function is insufficient. Even after such a power supply is stopped, it is desirable to secure a braking state and stop the motor as soon as possible.

[0005] The present invention has been made in consideration of the above, and has an object to provide a drive control device for a single-phase motor and a braking control method for a single-phase motor that can achieve completely independent, battery-free braking with a simple circuit configuration. [Means for solving the problem]

[0006] In one aspect, a drive control device for a single-phase motor includes a motor drive unit that passes current through a coil of a single-phase motor, a motor control unit that switches the direction of current flow through the coil, which is passed by the motor drive unit, in a predetermined sequence by outputting a drive control signal to the motor drive unit, a braking control unit that outputs a braking control signal, a coil terminal short-circuit unit that is connected between the terminals of the coil and shorts the terminals of the coil in response to a short-circuit signal, and a short-circuit signal output unit that is connected to at least one terminal of the coil and the coil terminal short-circuit unit and outputs the short-circuit signal to the coil terminal short-circuit unit when the braking control signal is input. The coil terminal short-circuiting section includes a first short-circuiting element connected to one terminal of the coil and the short-circuit signal output section, and a second short-circuiting element connected to the other terminal of the coil and the short-circuit signal output section. The coil terminal short-circuiting section includes a first system of short-circuiting paths and a second system of short-circuiting paths each connected between the terminals of the coil. The first short-circuiting element is disposed in the short-circuiting path of the first system, and the second short-circuiting element is disposed in the short-circuiting path of the second system.

[0007] According to one embodiment, a completely independent, battery-less braking can be achieved with a simple circuit configuration. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of a circuit configuration of a drive control device according to a first embodiment. [Diagram 2] 1 is a cross-sectional view showing an example of a motor in an embodiment. [Figure 3A] FIG. 2 is a diagram illustrating an example of an operation mode of the drive control device in the first embodiment. [Figure 3B] FIG. 2 is a diagram illustrating an example of an operation mode of the drive control device in the first embodiment. [Figure 4] 1 is a flowchart (1) illustrating an example of an operation procedure of the drive control device in the first embodiment. [Diagram 5] 4 is a flowchart (2) illustrating an example of an operation procedure of the drive control device in the first embodiment. [Figure 6]4 is a flowchart (3) illustrating an example of an operation procedure of the drive control device in the first embodiment. [Figure 7] 5A to 5C are diagrams illustrating an example of the operation of a coil terminal short-circuit unit in the first embodiment. [Figure 8] FIG. 4 is an image diagram showing an example of the effect of a braking operation by the drive control device in the first embodiment. [Figure 9] FIG. 4 is an image diagram showing an example of the effect of a braking operation by the drive control device in the first embodiment. [Figure 10] FIG. 4 is a diagram showing a modified example of a braking control unit in the first embodiment. [Figure 11] FIG. 11 is a diagram showing an example of a modified example of a system including a drive control device and a motor in the first embodiment. [Figure 12] FIG. 11 is a block diagram showing an example of a circuit configuration of a drive control device according to a second embodiment. [Figure 13] FIG. 11 is a diagram illustrating an example of an operation mode of the drive control device in the second embodiment. [Figure 14] 10 is a flowchart (1) illustrating an example of an operation procedure of the drive control device in the second embodiment. [Figure 15] 10 is a flowchart (2) illustrating an example of an operation procedure of the drive control device in the second embodiment. [Figure 16] 10 is a flowchart (3) illustrating an example of an operation procedure of the drive control device in the second embodiment. [Figure 17] 13A to 13C are diagrams illustrating modified examples of the coil terminal short-circuit portion in the second embodiment. [Figure 18] FIG. 13 is a diagram showing a modified example of a system including a drive control device and a motor in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a drive control device for a single-phase motor disclosed in the present application will be described in detail with reference to the drawings.

[0010] (First embodiment) Fig. 1 is a block diagram showing an example of a circuit configuration of a drive control device in the first embodiment. As shown in Fig. 1, the drive control device 1 in the first embodiment has a motor drive unit 10, a motor control unit 20, a braking control unit 30, a coil terminal short-circuit unit 40, and a short-circuit signal output unit 50. Note that the components of the drive control device 1 shown in Fig. 1 are only a part of the whole, and the drive control device 1 may have other components in addition to those shown in Fig. 1.

[0011] The drive control device 1 may be an integrated circuit device (IC) in its entirety, or a portion of the drive control device 1 may be packaged as a single integrated circuit device, or all or a portion of the drive control device 1 may be packaged together with other devices to form a single integrated circuit device.

[0012] The motor driving unit 10 energizes the coil L of the motor 3. The motor control unit 20 controls the drive control signals Vah, Val, Vbh, and Vbl output to the motor driving unit 10 to switch the direction of current flow to the coil L by the motor driving unit 10 in a predetermined order.

[0013] In addition, the braking control unit 30 outputs a braking control signal. The short-circuit signal output unit 50 is connected to terminals A and B of the coil L and the coil terminal short-circuiting unit 40, and outputs a short-circuit signal to the coil terminal short-circuiting unit 40 when the braking control signal is input. The coil terminal short-circuiting unit 40 is connected between both ends (terminals A and B) of the coil L, and shorts the terminals of the coil L when the short-circuit signal is input.

[0014] In addition, in the drive control method for a single-phase motor according to the first embodiment, a current is applied to the coil L of the motor 3 by the motor drive unit 10. When the power supply from the power source 2 that supplies power to the motor 3 is cut off and the current application operation of the motor drive unit 10 is lost, the braking control unit 30 detects the electromotive force generated in the coil L and outputs a braking control signal to the short-circuit signal output unit 50. Thereafter, the short-circuit signal output unit 50 generates a short-circuit signal and outputs it to the coil terminal short-circuit unit 40. The coil terminal short-circuit unit 40, which is connected to the coil L, shorts both ends (terminals A and B) of the coil L in response to the short-circuit signal.

[0015] This allows the drive control device 1 to brake the rotation of the motor 3 with a simple configuration. In addition, the short circuit signal output unit 50 of the drive control device 1 can output a short circuit signal using the electromotive force generated in the coil L, so the drive control device 1 can achieve completely independent, non-power-supply braking.

[0016] The drive control device 1 according to the first embodiment will be described in detail below.

[0017] In the first embodiment, the motor 3 is, for example, a single-phase brushless motor, for example, a fan motor that rotates a fan (not shown). FIG. 2 is a cross-sectional view showing an example of a motor in the embodiment. As shown in FIG. 2, the motor 3 includes a coil L, a rotor 70, and a stator 80. The rotor 70 rotates in conjunction with, for example, a fan (not shown). In addition, a magnet 71 is fixed to the rotor 70. The stator 80 includes four teeth 81. As shown in FIG. 2, the motor 3 is, for example, a 4-pole, 4-slot outer rotor motor.

[0018] The coil L is wound around each of the four teeth 81 of the stator 80. Although the coil L is wound around a plurality of teeth 81 in the motor 3, it is a single coil in terms of the circuit. The drive control device 1 rotates the motor 3 by repeatedly reversing the polarity of the current flowing through the coil L of the armature of the motor 3. Furthermore, when it is determined that the rotation of the motor 3 should be stopped or when the power supply from the power source 2 is cut off, the drive control device 1 brakes the rotation of the motor 3.

[0019] The motor driving unit 10 is an inverter circuit that outputs a driving signal to the motor 3 based on the driving control signals Vah, Val, Vbh, and Vbl output from the motor control unit 20, and energizes the coil L. The motor driving unit 10 is configured, for example, by arranging pairs of two series circuits of switching elements (a pair of switching elements Qah and Qal, and a pair of switching elements Qbh and Qbl) provided at both ends of the power source 2, respectively, with respect to terminals A and B at both ends of the coil L of the motor 3. In this embodiment, the switching elements Qah, Qal, Qbh, and Qbl are MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) as a specific example. However, the switching elements Qah, Qal, Qbh, and Qbl are not limited to MOSFETs. In each pair of two switching elements, the connection point between the switching elements becomes an output terminal, and a terminal connected to the coil L of the motor 3 is connected to the output terminal. Specifically, the connection point between the switching elements Qah and Qal is an output terminal connected to one terminal A of the coil L. Moreover, the connection point between the switch elements Qbh and Qbl is an output end connected to the other terminal B of the coil L.

[0020] The motor control unit 20 is configured with, for example, a microcomputer, and controls each unit of the drive control device 1. The motor control unit 20 has a motor drive control unit 21 and a motor braking command unit 22.

[0021] The motor drive control unit 21 generates drive control signals for driving the motor drive unit 10 and outputs them to the motor drive unit 10. The generated drive control signals Vah, Val, Vbh, and Vbl correspond to the switch elements Qah, Qal, Qbh, and Qbl of the motor drive unit 10, respectively. Specifically, the drive control signal Vah is output to the switch element Qah, and the drive control signal Val is output to the switch element Qal. Furthermore, the drive control signal Vbh is output to the switch element Qbh, and the drive control signal Vbl is output to the switch element Qbl. By outputting these drive control signals, the switch elements Qah, Qal, Qbh, and Qbl corresponding to the respective drive control signals perform on / off operations, and a drive signal is output to the motor 3, causing a voltage V L When the rotation of the motor 3 is to be stopped, all of the switch elements Qah, Qal, Qbh, and Qbl are turned off.

[0022] The motor braking command unit 22 generates a braking command signal for the braking control unit 30 to brake the rotation of the motor 3, and outputs it to the braking control unit 30. For example, the motor braking command unit 22 generates a braking command signal that is a Low signal when braking the rotation of the motor 3, and generates a non-braking command signal that is a High signal when not braking the rotation of the motor 3. The braking command signal may be a High signal, and the non-braking command signal may be a Low signal. In addition, when the motor drive control unit 21 stops outputting the drive control signals Vah, Val, Vbh, and Vbl while power is being supplied from the power source 2 to the drive control device 1, the motor braking command unit 22 generates a braking command signal after a preset time has elapsed since the output of the drive control signals was stopped, and outputs it to the braking control unit 30.

[0023] The braking control unit 30 outputs a braking control signal to the short-circuit signal output unit 50 when the motor braking command unit 22 outputs a braking command signal for braking the rotation of the motor 3, or when the power supply from the power source 2 is cut off. The braking control signal is a signal that is output when both ends (terminals A, B) of the coil L are short-circuited. As described below, when the braking control unit 30 outputs a braking control signal to the short-circuit signal output unit 50, the short-circuit signal is output from the short-circuit signal output unit 50 to the coil terminal short-circuit unit 40, and the coil terminal short-circuit unit 40 shorts both ends (terminals A, B) of the coil.

[0024] The motor braking command unit 22 outputs a braking command signal when the motor drive control unit 21 stops driving the motor 3. Even if the motor drive control unit 21 stops driving the motor 3, the motor 3 continues to rotate due to inertia. Therefore, the motor braking command unit 22 outputs a braking command signal to quickly stop the rotation due to inertia (coastal rotation).

[0025] When the motor braking command unit 22 outputs a braking command signal, the braking control unit 30 detects the electromotive force generated in the coil L due to the inertial rotation of the motor 3, and outputs a braking control signal using this electromotive force.

[0026] Furthermore, if the power supply from the power source 2 is interrupted while the motor 3 is rotating, the motor drive unit 10 no longer outputs a drive signal, but the motor 3 continues to rotate by inertia. Therefore, in order to quickly stop the rotation by inertia, the braking control unit 30 detects the electromotive force generated in the coil L and uses this electromotive force to output a braking control signal.

[0027] Alternatively, when the rotation of the motor 3 is stopped and the power supply from the power source 2 is cut off, an electromotive force is generated in the coil L by the rotation of the motor 3 due to an external force, such as the rotation of a fan due to outside wind. In this embodiment, the polarity of the electromotive force generated in the coil L is reversed as the distance between the coil L and the magnet 71 shown in FIG. 2 changes with the rotation of the fan. In order to suppress the rotation of the motor 3 due to an external force, the braking control unit 30 detects the cutoff of the power supply and the electromotive force generated in the coil L by the external force, and uses the electromotive force to output a braking control signal to brake the rotation of the motor 3.

[0028] The braking control unit 30 has a power interruption detection circuit 41, an electromotive force detection circuit 42, a braking control circuit 43, and a short circuit control circuit 44. Although details will be described later, when the power interruption detection circuit 41 detects a power interruption while the motor drive unit 10 is driving the motor 3, the braking control unit 30 outputs a braking control signal. When the power interruption detection circuit 41 detects a power interruption and detects an electromotive force generated in the coil L while the motor drive unit 10 is not driving the motor 3, the braking control unit 30 outputs a braking control signal. The electromotive force detection circuit 42 detects the electromotive force generated in the coil L. The braking control circuit 43 switches between braking and non-braking of the motor 3 according to the detection result of the power interruption detection circuit 41 that the power supply is interrupted. The short circuit control circuit 44 outputs a braking control signal using the electromotive force detected by the electromotive force detection circuit 42. In the first embodiment, the electromotive force detection circuit 42 includes a first electromotive force detection circuit 42a and a second electromotive force detection circuit 42b. The short circuit control circuit 44 includes a first short circuit control circuit 44a and a second short circuit control circuit 44b.

[0029] The power interruption detection circuit 41 detects interruption of power supply from the power source 2. The power interruption detection circuit 41 has a series circuit of resistive elements R1 and R2 connected in parallel with the power source 2, and a resistive element R3 arranged between the series circuit and the braking control circuit 43. The power supply voltage of the power supply 2 is divided according to the resistance values ​​of the resistive elements R1 and R2. The power interruption detection circuit 41 outputs a power supply detection signal (High signal) according to the divided voltage value to the braking control circuit 43. When the power supply from the power source 2 is interrupted, the power supply voltage value becomes zero, so the power interruption detection circuit 41 outputs an interruption detection signal (Low signal) indicating power interruption.

[0030] The braking control circuit 43 switches between braking and non-braking of the motor 3 according to the result of detection of the interruption of the power supply from the power source 2 by the power interruption detection circuit 41, or according to the braking command signal or non-braking command signal output by the motor braking command unit 22.

[0031] The braking control circuit 43 includes a switch element SW7 and first and second diode elements D1 and D2. In this embodiment, the switch element SW7 is a transistor, as a specific example. The first output terminal (collector) of the switch element SW7 is connected to the power supply 2 via a resistor element R5, and the second output terminal (emitter) is grounded to the ground via a resistor element R6. The first output terminal (collector) of the switch element SW7 is connected to the short circuit control circuit 44. The first diode element D1 has an anode connected to the power supply interruption detection circuit 41 and a cathode connected to the control terminal (base) of the switch element SW7. The second diode element D2 has an anode connected to the control terminal (base) of the switch element SW7 and a cathode connected to the motor braking command unit 22.

[0032] The first short-circuit control circuit 44a has a switch element SW5, and the second short-circuit control circuit 44b has a switch element SW6. In this embodiment, the switch elements SW5 and SW6 are transistors, as a specific example. The switch element SW5 is provided between the first electromotive force detection circuit 42a and the short-circuit signal output unit 50, and the switch element SW6 is provided between the second electromotive force detection circuit 42b and the short-circuit signal output unit 50. The control terminal (base) of the switch element SW5 is connected to the braking control circuit 43 and is connected to the coil L via a resistor element R7, which will be described later. The control terminal (base) of the switch element SW6 is connected to the braking control circuit 43 and is connected to the coil L via a resistor element R9, which will be described later.

[0033] For example, when the power supply 2 is not cut off and the power cutoff detection circuit 41 outputs a power supply detection signal (High signal), the first diode element D1 is turned on. At this time, if the motor braking command unit 22 outputs a non-braking command signal (High signal) that does not brake the rotation of the motor 3, the second diode element D2 is turned off, and the power supply detection signal is input to the control terminal (base) of the switch element SW7 through the first diode element D1, and the switch element SW7 is turned on.

[0034] On the other hand, even if the power cutoff detection circuit 41 is outputting a power detection signal, when the motor braking command unit 22 outputs a braking command signal (Low signal) for braking the rotation of the motor 3, the second diode element D2 turns on, and the power detection signal flows to the second diode element D2 side and is not input to the control terminal (base) of the switch element SW7. Therefore, the switch element SW7 turns off.

[0035] In addition, when the power supply interruption detection circuit 41 outputs an interruption detection signal (Low signal), regardless of the output of the motor braking command unit 22, no current flows through the first diode element D1, so that no current is input to the control terminal (base) of the switch element SW7, and the switch element SW7 is turned off.

[0036] Although details will be described later, when the switch element SW7 of the braking control circuit 43 is off, the first short circuit control circuit 44a outputs a braking control signal according to the detection result of the first electromotive force detection circuit 42a, and the second short circuit control circuit 44b outputs a braking control signal according to the detection result of the second electromotive force detection circuit 42b. On the other hand, when the switch element SW7 of the braking control circuit 43 is on, the first short circuit control circuit 44a and the second short circuit control circuit 44b do not output a braking control signal regardless of the detection results of the first electromotive force detection circuit 42a and the second electromotive force detection circuit 42b. The braking control circuit 43 controls the output of the first short circuit control circuit 44a and the second short circuit control circuit 44b by switching the switch element SW7 off / on, and switches between braking and non-braking of the motor 3.

[0037] The electromotive force detection circuit 42 detects the electromotive force generated in the coil L. The first electromotive force detection circuit 42a has a resistive element R4 and a resistive element R7. The second electromotive force detection circuit 42b has a resistive element R8 and a resistive element R9.

[0038] When an electromotive force that satisfies VA>VB is generated in the coil L, a trigger current I1 that activates the braking function flows through the resistive element R4 of the first electromotive force detection circuit 42a. In this case, a voltage according to the magnitude of the trigger current I1 and the resistance value of the resistive element R4 is generated across the resistive element R4, and is applied to the first output terminal (collector) of the switch element SW5 of the first short-circuit control circuit 44a. In addition, a voltage is applied to the control terminal (base) of the switch element SW5 via the resistive element R7. These operate to detect the electromotive force generated in the coil L, and as a result, the switch element SW5 is turned on.

[0039] On the other hand, when an electromotive force such that VA < VB is generated in the coil L, a trigger current I2 flows through the resistance element R8 of the second electromotive force detection circuit 42b. In this case, a voltage corresponding to the magnitude of the trigger current I2 and the resistance value of the resistance element R8 is generated across both ends of the resistance element R8, and is applied to the first output terminal (collector) of the switch element SW6 of the second short-circuit control circuit 44b. Also, a voltage is applied to the control terminal (base) of the switch element SW6 via the resistance element R9. These constitute an operation for detecting the electromotive force generated in the coil L, and as a result, the switch element SW6 turns on.

[0040] When the braking control circuit 43 switches the motor 3 from non-braking to braking, the short-circuit control circuit 44 outputs a braking control signal using the generated electromotive force when an electromotive force is generated in the coil L.

[0041] Suppose that the first electromotive force detection circuit 42a detects the electromotive force generated in the coil L when the switch element SW7 of the braking control circuit 43 is off, that is, the power supply from the power source 2 is cut off, or when the motor drive command unit 22 outputs a braking command signal. In this case, a trigger current I1 flows through the switch element SW5 of the first short-circuit control circuit 44a, and the switch element SW5 turns on. As a result, a braking control signal is output from the first short-circuit control circuit 44a to the short-circuit signal output unit 50. Also, suppose that the second electromotive force detection circuit 42b detects the electromotive force generated in the coil L. In this case, a trigger current I2 flows through the switch element SW6 of the second short-circuit control circuit 44b, and the switch element SW6 turns on. As a result, a braking control signal is output from the second short-circuit control circuit 44b to the short-circuit signal output unit 50. As described above, when an electromotive force is generated in the coil L, the trigger current I1 or the trigger current I2 flows in conjunction with the detection of the electromotive force by the first electromotive force detection circuit 42a or the second electromotive force detection circuit 42b. As a result, a braking control signal is output from the first short-circuit control circuit 44a or the second short-circuit control circuit 44b to the short-circuit signal output unit 50.

[0042] On the other hand, when the switch element SW7 of the braking control circuit 43 is on, i.e., when power is being supplied from the power source 2 and the motor braking command unit 22 is outputting a non-braking command signal, the switch element SW5 of the first short-circuit control circuit 44a and the switch element SW6 of the second short-circuit control circuit 44b remain off even if the first electromotive force detection circuit 42a or the second electromotive force detection circuit 42b detects the electromotive force generated in the coil L. Therefore, the braking control signal is not output from the first short-circuit control circuit 44a or the second short-circuit control circuit 44b to the short-circuit signal output unit 50.

[0043] The short-circuit signal output unit 50 is connected to both ends (terminals A, B) of the coil L and the coil terminal short-circuiting unit 40. When a braking control signal is input from the short-circuit control circuit 44, the short-circuit signal output unit 50 outputs a short-circuit signal to the coil terminal short-circuiting unit 40. The short-circuit signal output unit 50 has a switch element SW3 and a switch element SW4. The switch elements SW3 and SW4 are examples of a first signal element and a second signal element, respectively.

[0044] In this embodiment, the switch elements SW3 and SW4 are thyristors. The switch element SW3 has an anode connected to the terminal A of the coil L, a cathode connected to the coil terminal short-circuiting unit 40, and a gate connected to the first short-circuit control circuit 44a. The switch element SW4 has an anode connected to the terminal B of the coil L, a cathode connected to the coil terminal short-circuiting unit 40, and a gate connected to the second short-circuit control circuit 44b.

[0045] The braking control signal output by the first short-circuit control circuit 44a is input to the gate of the switch element SW3 of the short-circuit signal output unit 50. This turns on the switch element SW3, and a current based on the trigger current I1 is output as a short-circuit signal to the coil-terminal short-circuit unit 40. Similarly, the braking control signal output by the second short-circuit control circuit 44b is input to the gate of the switch element SW4 of the short-circuit signal output unit 50. This turns on the switch element SW4, and a current based on the trigger current I2 is output as a short-circuit signal to the coil-terminal short-circuit unit 40.

[0046] The coil terminal short-circuiting unit 40 is connected to the coil L and short-circuits both ends (terminals A and B) of the coil L in response to a short-circuit signal. The coil terminal short-circuiting unit 40 includes a switch element (an example of a first short-circuiting element) SW1 connected to the terminal A of the coil L and the switch element SW3 of the short-circuiting signal output unit 50, and a switch element (an example of a second short-circuiting element) SW2 connected to the terminal B of the coil L and the switch element SW4 of the short-circuiting signal output unit 50. In this embodiment, the switch elements SW1 and SW2 are thyristors. The coil terminal short-circuiting unit 40 also includes a first system short-circuit path and a second system short-circuit path each connected between both ends (terminals A and B) of the coil L, with the switch element SW1 being disposed on the first system short-circuit path and the switch element SW2 being disposed on the second system short-circuit path. The anodes of the switch elements SW1 and SW2 are connected to the terminals A and B of the coil L, respectively, and the cathodes are connected to the terminals B and A of the coil L, respectively. The gates of the switch elements SW1 and SW2 are connected to the short-circuit signal output unit 50 (specifically, the cathodes of the switch elements SW3 and SW4), respectively. That is, when a short-circuit signal is input to the gate of each of the switch elements SW1 and SW2 from the switch elements SW3 and SW4 of the short-circuit signal output unit 50, the switch elements SW1 and SW2 are turned on, enabling the short-circuit path of the first system or the short-circuit path of the second system, and directly short-circuiting the terminals A and B of the coil L.

[0047] For example, when a voltage equal to or higher than a certain level is generated between both ends (terminals A and B) of the coil L, the two terminals A and B of the coil L are directly short-circuited by the switch element SW1 or switch element SW2 of the coil terminal short-circuiting unit 40. Therefore, a short-circuit current i Sw1 or i Sw2 As will be explained later, the direction of the short-circuit current changes depending on the polarity of the electromotive force generated in coil L.

[0048] In this way, the two terminals A, B of the coil L are short-circuited by the coil-terminal short-circuit portion 40. Therefore, the circuit for performing self-contained non-powered braking can be configured simply.

[0049] Furthermore, by configuring the coil terminal short-circuiting portion 40 using a highly versatile thyristor, the coil terminal short-circuiting portion 40 can have a simple configuration.

[0050] Next, the operation modes of the braking operation by the drive control device 1 will be described with reference to Figs. 3A and 3B. Figs. 3A and 3B are diagrams showing an example of the operation modes of the drive control device in the first embodiment. As described above, the drive control device 1 brakes the rotation of the motor 3 when the power supply from the power source 2 is cut off or when the motor braking command unit 22 outputs a braking command signal. The braking operation of the drive control device 1 is divided into five operation modes A to E as shown in Figs. 3A and 3B.

[0051] First, when the motor control unit 20 rotates the motor 3 without braking it (operation mode A), as shown in Fig. 3A, the drive control device 1 is supplied with power from the power source 2, and a non-braking command signal (High signal) is output from the motor braking command unit 22. In this case, the first diode element D1 of the braking control circuit 43 is turned on, the second diode element D2 is turned off, and the switch element SW7 is turned on. As a result, even if an electromotive force is generated in the coil L, all of the switch elements SW1 to SW6 are turned off, neither a braking control signal nor a short-circuit signal is output, and no braking operation is performed by the drive control device 1 (no braking).

[0052] Also, for example, it is assumed that the motor control unit 20 decides to stop the rotation of the motor 3, the motor drive control unit 21 stops the drive of the motor 3, and the motor braking command unit 22 brakes the motor 3 (operation mode B). In this case, the drive control device 1 is supplied with power from the power source 2, and after a preset time has elapsed since the motor drive control unit 21 stopped outputting the drive control signals Vah, Val, Vbh, and Vbl, the motor braking command unit 22 outputs a braking command signal (Low signal). In this case, both the first diode element D1 and the second diode element D2 of the braking control circuit 43 are turned on, and the switch element SW7 is turned off. At this time, when an electromotive force is generated in the coil L, the switch element SW5 of the first short-circuit control circuit 44a or the switch element SW6 of the second short-circuit control circuit 44b is turned on, and a braking control signal is generated using the electromotive force generated in the coil L. In this case, the braking control signal turns on the switch element (first signal element) SW3 or the switch element (second signal element) SW4 of the short-circuit signal output unit 50, generating a short-circuit signal. As a result, the switch element (first short-circuit element) SW1 or the switch element (second short-circuit element) SW2 of the coil terminal-to-coil short-circuit unit 40 turns on, forming a short-circuit path of the first system or a short-circuit path of the second system, and a regenerative current based on the electromotive force generated in the coil L flows through the formed regenerative path, braking the rotation of the motor 3 (with braking). Note that the switch element SW3 of the short-circuit signal output unit 50 turns on the switch element SW1 of the coil terminal-to-coil short-circuit unit 40, causing the current flowing in the first direction (short-circuit current i Sw1 A first regenerative path is formed in response to a regenerative current in a second direction (the short-circuit current i Sw2 A second regenerative path is formed in response to the regenerative current (the direction in which the regenerative current flows).

[0053] In this way, when the motor control unit 20 stops the rotational drive of the motor 3, the drive control device 1 can brake the rotation of the motor 3 by using the electromotive force generated in the coil L due to the inertial rotation of the motor 3.

[0054] Moreover, the operation modes C to E are the cases where the power supply from the power source 2 to the drive control device 1 is cut off and there is no power supply. When there is no power supply and no electromotive force is generated in the coil L (operation mode E), both the first diode element D1 and the second diode element D2 of the braking control circuit 43 are turned off, and the switch element SW7 is turned off. In this case, the switch element SW5 of the first short-circuit control circuit 44a and the switch element SW6 of the second short-circuit control circuit 44b are turned off, and both the switch elements SW3 and SW4 of the short-circuit signal output unit 50 are turned off. As a result, neither the braking control signal nor the short-circuit signal is output, and the braking operation by the drive control device 1 is not performed (no braking).

[0055] On the other hand, the operation when an electromotive force is generated in the coil L differs depending on the polarity of the voltage generated between both ends (terminals A, B) of the coil L. When the voltage VA at the terminal A is greater than the voltage VB at the terminal B (VA>VB) (operation mode C), the switch element SW5 of the first short-circuit control circuit 44a is turned on, a braking control signal is generated using the electromotive force generated in the coil L, the switch element SW3 of the short-circuit signal output unit 50 is turned on by the braking control signal, and a short-circuit signal is generated. As a result, the switch element SW1 of the coil terminal short-circuit unit 40 is turned on, and a first regenerative path (a regenerative route of coil L → terminal A → switch element SW1 → terminal B → coil L) is formed according to the regenerative current flowing to the coil L in the direction from terminal B to terminal A (first direction), and the rotation of the motor 3 is braked (with braking). In this case, the switch element SW6 of the second short-circuit control circuit 44b and the switch element SW4 of the short-circuit signal output unit 50 are turned off, and the second regenerative path passing through the switch element SW2 arranged in the short-circuit path of the second system is not formed.

[0056] Also, when the voltage VA at terminal A is smaller than the voltage VB at terminal B (VA < VB, operation mode D), the switch element SW6 of the second short-circuit control circuit 44b is turned on, and a braking control signal is generated using the electromotive force generated in the coil L. The switch element SW4 of the short-circuit signal output unit 50 is turned on by the braking control signal, and a short-circuit signal is generated. As a result, the switch element SW2 of the coil terminal short-circuit portion 40 is turned on, and a second regeneration path (a regeneration route of coil L → terminal B → switch element SW2 → terminal A → coil L) is formed according to the regeneration current flowing through the coil L in the direction from terminal A to terminal B (the second direction), and the rotation of the motor 3 is braked (with braking). In this case, the switch element SW5 of the first short-circuit control circuit 44a and the switch element SW3 of the short-circuit signal output unit 50 are turned off, and the first regeneration path passing through the switch element SW1 arranged in the first short-circuit path is not formed.

[0057] As described above, in the first embodiment, the switch elements SW3 and SW4 of the short-circuit signal output unit 50 switch between the operations during normal operation (when power is supplied) (operation modes A and B) and the operation when the power is off (operation modes C to E). Also, by switching the switch elements SW1 and SW2 of the coil terminal short-circuit portion 40 (commutation operation), a bidirectional short circuit associated with the polarity of the electromotive force is realized.

[0058] Note that in operation modes C to E, when the power supply from the power source 2 is cut off, the drive control device 1 brakes the rotation of the motor 3 whether the motor 3 is being rotationally driven or stopped by the motor control unit 20. That is, the drive control device 1 brakes the rotation of the motor 3 when the power supply from the power source 2 is cut off regardless of whether the signal output immediately before the power supply from the motor braking command unit 22 is cut off is a non-braking command signal or a braking command signal.

[0059] Therefore, for example, when the motor 3 stops rotating and the power supply is cut off, the rotation of the motor 3 caused by an external force can be braked. This makes it possible to suppress forced rotation caused by outside wind when the motor 3 is a fan motor installed in a user system, for example.

[0060] In this way, the drive control device 1 can brake the rotation of the motor 3 when the power supply from the power source 2 is cut off, and can stop the rotation of the motor 3 more quickly. Furthermore, since the drive control device 1 brakes the rotation using the electromotive force generated in the coil L, even when the power supply from the power source 2 is cut off, there is no need to provide an external power source such as a battery separate from the power source 2, and a completely independent braking operation without a power source is possible. Furthermore, since the drive control device 1 detects the power supply cutoff and outputs a braking command signal, there is no need to provide a separate external device that detects the power supply cutoff and outputs a braking command signal, and the drive control device 1 can realize an independent braking system.

[0061] Next, the operation procedure of the drive control device 1 will be described with reference to Figures 4 to 6. Figure 4 is a flowchart (1) for explaining an example of the operation procedure of the drive control device in the first embodiment. Figure 4 explains the operation of the drive control device 1 when the power supply from the power source 2 is cut off while the motor 3 is being driven to rotate by the drive control device 1.

[0062] As shown in FIG. 4, if the power interruption detection circuit 41 of the drive control device 1 does not detect an interruption in the power supply (step S101, No), the power interruption detection circuit 41 continues to detect an interruption in the power supply shown in step S101.

[0063] On the other hand, when the power interruption detection circuit 41 detects an interruption in the power supply (step S101, Yes), the first diode element D1 of the braking control circuit 43 is turned off (step S102), and the switch element SW7 is turned off (step S103).

[0064] Next, if the first electromotive force detection circuit 42a or the second electromotive force detection circuit 42b does not detect the electromotive force generated in the coil L (step S104, No), the first electromotive force detection circuit 42a and the second electromotive force detection circuit 42b continue to determine whether or not an electromotive force has been detected as shown in step S104.

[0065] On the other hand, when the first electromotive force detection circuit 42a detects the electromotive force generated in the coil L (step S104, Yes), the switch element SW5 of the first short-circuit control circuit 44a is turned on, and a braking control signal is output (step S105). As a result, the switch element (first signal element) SW3 of the short-circuit signal output unit 50 is turned on, and a short-circuit signal is output (step S106). When the short-circuit signal is input to the coil-terminal short-circuiting unit 40, the switch element (first short-circuiting element) SW1 of the coil-terminal short-circuiting unit 40 is turned on, and the short-circuit path of the first system is enabled. Therefore, the coil L is short-circuited (step S107).

[0066] In the above case, when the second electromotive force detection circuit 42b detects the electromotive force generated in the coil L, instead of the first electromotive force detection circuit 42a (Yes in step S104), the switch element SW6 of the second short-circuit control circuit 44b is turned on, and a braking control signal is output (step S105). As a result, the switch element (second signal element) SW4 of the short-circuit signal output unit 50 is turned on, and a short-circuit signal is output (step S106). As a result, when the short-circuit signal is input to the coil-terminal short-circuit unit 40, the switch element (second short-circuit element) SW2 of the coil-terminal short-circuit unit 40 is turned on, and the short-circuit path of the second system is enabled. Therefore, the coil L is short-circuited (step S107).

[0067] As a result, a short-circuit current flows through a short-circuit path that directly shorts both ends (terminals A and B) of the coil L, and the drive control device 1 starts a regenerative braking operation (step S108), and the rotation of the motor 3 is braked (step S109). As a result, the rotation speed of the motor 3 decreases (step S110), and the electromotive force generated in the coil L decreases (step S111), so that the output voltage of the switch element SW5 of the first short-circuit control circuit 44a or the switch element SW6 of the second short-circuit control circuit 44b decreases (step S112). When the output voltage of the switch element SW5 or SW6 becomes less than a certain value, the switch element SW3 or the switch element SW4 of the short-circuit signal output unit 50 is maintained in an OFF state (step S113), and the switch element SW1 or the switch element SW2 of the coil terminal short-circuit unit 40 is maintained in an OFF state (step S114).

[0068] Next, the operation of the drive control device 1 when braking the motor 3 while the drive control device 1 is supplying power from the power source 2 while the rotation drive of the motor 3 is stopped will be described with reference to Fig. 5. Note that the same operations as those in Fig. 4 are denoted by the same reference numerals and will not be described.

[0069] As shown in Fig. 5, when the power supply cutoff detection circuit 41 of the drive control device 1 does not detect the cutoff of the power supply from the power source 2 (step S101, No) and the motor braking command unit 22 does not output a braking command signal (step S201, No), the braking control circuit 43 continues the process of step S201 and waits for the input of a braking command signal. On the other hand, when a braking command signal is output (step S201, Yes), the second diode element D2 of the braking control circuit 43 is turned on (step S202) and the switch element SW7 is turned off (step S203). Thereafter, as in Fig. 4, the drive control device 1 brakes the rotation of the motor 3, so that the rotation of the motor 3 decreases.

[0070] Next, with reference to FIG. 6, the operation of the drive control device 1 when the rotational drive of the motor 3 is stopped, the motor 3 is not rotating, or the power supply from the power source 2 is cut off and the motor 3 is forced to rotate by an external force will be described. That is, the operation of the drive control device 1 when the motor 3 is forced to rotate by an external force such as external wind in a state where the rotation of the motor 3 has stopped will be described.

[0071] In this case, since the motor braking command unit 22 is outputting a braking command signal or the power supply cut-off detection circuit 41 has detected a power cut-off, as shown in FIG. 6, the switch element SW7 of the braking control circuit 43 is turned off (step S301). Thereafter, when the generated voltage detection circuit 42 detects the generated voltage generated in the coil L in step S104, the drive control device 1 brakes the rotation of the motor 3 in the same manner as the operation after step S105 in FIG. 4.

[0072] FIG. 7 is a diagram showing an example of the operation of the short-circuit portion between the coil terminals in the first embodiment. As shown in FIG. 7, in the case of operation mode C (VA>VB), the short-circuit current i Sw1 flows through the first short-circuit path including the switch element SW1 as shown in FIG. 1. Thereby, a first regeneration path is formed according to the direction of the short-circuit current (regeneration current) i Sw1 . Also, in the case of operation mode D (VA<VB), the short-circuit current i Sw2 flows through the second short-circuit path including the switch element SW2 as shown in FIG. 1. Thereby, a second regeneration path is formed according to the direction of the short-circuit current (regeneration current) i Sw2 .

[0073] Next, the effect of the braking operation by the drive control device 1 will be described with reference to Figs. 8 and 9. Figs. 8 and 9 are image diagrams showing an example of the effect of the braking operation by the drive control device in the first embodiment. Figs. 8 and 9 explain a case where the power supply from the power source 2 is cut off while the drive control device 1 is driving the motor 3 to rotate. In Fig. 8, the horizontal axis shows the elapsed time from when the power was cut off. Furthermore, a period T1 indicates the period during which the rotor 70 shown in Fig. 2 makes one rotation. That is, in the period T1, the coil L alternately approaches the N pole and the S pole of the magnet 71 twice each, and thus electromotive forces of opposite polarities are generated twice each.

[0074] As shown in Fig. 8, when the power supply from the power source 2 is cut off, the rotation due to the inertia of the motor 3 (coast rotation) generates electromotive forces of opposite polarity in the coil L. In this case, when the voltage of the electromotive force reaches the gate trigger voltage v of the switch element SW1 or switch element SW2 of the coil terminal short-circuiting unit 40, the coil terminal short-circuiting unit 40 shorts both ends (terminals A and B) of the coil L. As a result, a short-circuit current (regenerative current) i flows through the first short-circuit path or the second short-circuit path of the coil terminal short-circuiting unit 40 as shown in Fig. 8 depending on the polarity of the electromotive force. Sw1 or short circuit current (regenerative current) i Sw2 In this case, the switch elements SW1 and SW2 alternately operate in response to the switching of the polarity of the electromotive force generated in the coil L. As a result, a first regenerative path including the coil L or a second regenerative path including the coil L is formed, and a regenerative current i Sw1 or regenerative current i Sw2 Then, the rotation speed of the motor 3 decreases due to short circuit braking, and when the electromotive force generated in the coil L decreases, the electromotive force does not reach the gate trigger voltage v, so the regenerative current i Sw1 and regenerative current i Sw2 will no longer occur.

[0075] Here, as indicated by the dashed line G2 in FIG. 8, if the drive control device 1 does not brake the motor 3 after the power supply from the power source 2 is cut off, the motor 3 continues to rotate by inertia.

[0076] On the other hand, as shown by solid line G1 in Fig. 8, when braking is performed by the drive control device 1, braking of the motor 3 causes a significant drop in the rotation speed of the motor 3. Thereafter, the drop in the rotation speed of the motor 3 reduces the electromotive force generated in the motor 3, so that braking operation by the drive control device 1 is no longer performed and the motor 3 continues to rotate by inertia, but because the rotation speed is low, the rotation stops due to mechanical friction.

[0077] In this way, by the drive control device 1 performing the braking operation even when the power supply is cut off, the time until the motor 3 stops can be shortened compared to the case where braking is not performed.

[0078] The coil terminal short-circuit section 40 has two short-circuit paths (a first system short-circuit path in which the switch element SW1 is arranged and a second system short-circuit path in which the switch element SW2 is arranged) respectively connected between both ends (terminals A, B) of the coil L. Therefore, regardless of the polarity of the electromotive force generated in the coil L, two regenerative paths (a first regenerative path and a second regenerative path) in which the regenerative current flows in different directions are formed, and regenerative braking can be performed, thereby increasing the braking force.

[0079] Next, a specific example of the braking effect when the motor 3 stops rotating and an external force is applied to the motor 3 due to external wind hitting the fan will be described with reference to FIG.

[0080] The horizontal axis of Fig. 9 represents the volume of outside wind, and the vertical axis represents the rotation speed of the motor 3. As shown by the dotted line in Fig. 9, when no braking operation is performed by the drive control device 1, as the volume of outside wind increases, the rotation speed of the motor 3 also increases.

[0081] On the other hand, as shown by the solid line in Fig. 9, when braking is performed by the drive control device 1, an increase in the rotation speed of the motor 3 can be significantly suppressed even if the volume of outside wind increases. In this way, by the drive control device 1 performing braking while the rotation of the motor 3 is stopped, the rotation of the motor 3, i.e., the rotation of the fan, can be suppressed even when the outside wind is strong.

[0082] As described above, in this embodiment, the braking function works automatically based on the electromotive force generated in the motor coil, so even when the power supply is stopped, the rotation of the motor 3 is automatically detected and the braking function is activated. This makes it possible to realize a completely independent, battery-free braking system with a simple circuit configuration.

[0083] In addition, in this embodiment, no mechanical relay or switch is required to realize the above-mentioned braking function, and the reliability of the drive control device 1 can be improved and the product life can be extended. In this embodiment, the switch elements SW1 and SW2 of the coil terminal short-circuiting unit 40 do not require switching control of the regeneration timing even if the polarity of the electromotive force changes. Furthermore, in this embodiment, both ends (terminals A and B) of the coil L are directly short-circuited without passing through other circuits such as the motor drive unit 10, so the structure of the drive control device 1 can be simplified.

[0084] In the drive control device 1 of the above embodiment, the braking control unit 30 detects the interruption of the power supply from the power source 2, but this is not limited thereto. For example, the motor control unit 20 may monitor the voltage of the power source 2 to detect the interruption of the power supply. In this case, as shown in FIG. 10, the braking control unit 30A of the drive control device 1A has a braking short-circuit control circuit 45 and an electromotive force detection circuit 46 instead of the power interruption detection circuit 41, the electromotive force detection circuit 42, the braking control circuit 43, and the short-circuit control circuit 44. As described below, the braking short-circuit control circuit 45 receives a braking command signal output from the motor braking command unit 22, and when the electromotive force detection circuit 46 detects the electromotive force generated in the coil L, it outputs a braking control signal using the detected electromotive force.

[0085] FIG. 10 is a diagram showing a modified example of the braking control unit in the first embodiment. In FIG. 10, the components of the drive control device 1A that are not necessary for the description are omitted. For example, the braking short-circuit control circuit 45 includes a second braking short-circuit control circuit 45b (not shown) in addition to the first braking short-circuit control circuit 45a shown in FIG. 10. The electromotive force detection circuit 46 includes a second electromotive force detection circuit 46b (not shown) in addition to the first electromotive force detection circuit 46a shown in FIG. 10. The short-circuit signal output unit 50 includes a switch element SW4 (not shown) in addition to the switch element SW3 shown in FIG. 10. In each of the following modified examples and each embodiment, the same parts as those shown in the drawings described above are given the same reference numerals, and duplicated descriptions are omitted.

[0086] As shown in Fig. 10, the first braking short-circuit control circuit 45a has a switch element SW5A. The second braking short-circuit control circuit 45b (not shown) has a switch element SW6A. The switch elements SW5A and SW6A are, for example, transistors, and are arranged between the electromotive force detection circuit 46 (the first electromotive force detection circuit 46a and the second electromotive force detection circuit 46b) and ground. A non-braking command signal or a braking command signal is input from the motor braking command unit 22 to the control terminals (bases) of the switch elements SW5A and SW6A.

[0087] The motor braking command unit 22 outputs a non-braking command signal (High signal) when driving and rotating the motor 3. As a result, the switch element SW5A of the first braking short-circuit control circuit 45a is turned on, and even if the first electromotive force detection circuit 46a detects the electromotive force generated in the coil L, the trigger current I1 flows to the ground via the switch element SW5A, and therefore the first braking short-circuit control circuit 45a does not output a braking control signal.

[0088] On the other hand, the motor braking command unit 22 outputs a braking command signal (Low signal) when stopping the rotation of the motor 3, for example, when detecting a cutoff of the power supply from the power source 2 based on the monitoring result of the voltage of the power source 2. As a result, the switch element SW5A of the first braking short-circuit control circuit 45a is turned off. In this state, when the first electromotive force detection circuit 46a detects the electromotive force generated in the coil L, the trigger current I1 does not flow through the switch element SW5A, and the first braking short-circuit control circuit 45a outputs a braking control signal to the short-circuit signal output unit 50.

[0089] In this way, by the motor control unit 20 detecting the interruption of the power supply from the power source 2, the circuit configuration of the braking control unit 30A can be simplified.

[0090] In the drive control device 1 of the above embodiment, the coil L to which power is supplied is used for regenerative braking, but the present invention is not limited to this. Fig. 11 is a diagram showing an example of a modified example of a system including a drive control device and a motor in the first embodiment. In Fig. 11, illustration of components of the drive control device 1B that are not necessary for explanation is omitted.

[0091] In the modified example shown in Fig. 11, a drive control device 1B is connected to a motor 3B that further includes a coil M in addition to the coil L to which power is supplied. The drive control device 1B uses the coil M for detecting electromotive force.

[0092] In the modification shown in FIG. 11, the coil M is not connected to the coil L. The coil M is connected to the short-circuit signal output unit 50 and the braking control unit 30 (not shown) and is used for detecting the electromotive force generated in the coil M. That is, the braking control unit 30 detects the electromotive force generated in the coil M. In this case, the anode of the switch element SW1B of the coil terminal short-circuit unit 40B is connected to the terminal MA of the coil M, and the anode of the switch element SW2B is connected to the terminal MB of the coil M. The braking control unit 30 outputs a braking control signal to the short-circuit signal output unit 50 based on the result of detecting the electromotive force generated in the coil M. This allows the detection of the electromotive force generated in the coil M to be performed independently of the control of the coil L for rotational drive, thereby enabling stable operation.

[0093] Second embodiment In the first embodiment, a configuration in which both ends (terminals A, B) of the coil L are directly short-circuited has been described, but the embodiment is not limited to this. FIG. 12 is a block diagram showing an example of a circuit configuration of a drive control device in a second embodiment. As shown in FIG. 12, a drive control device 1C in the second embodiment includes a braking control unit 30C, a coil terminal short-circuiting unit 40C, and a short-circuit signal output unit 50C, instead of the braking control unit 30, the coil terminal short-circuiting unit 40, and the short-circuit signal output unit 50. In addition, the braking control unit 30C has a power supply interruption detection circuit 41, an electromotive force detection circuit 42C, a braking control circuit 43C, and a short-circuit control circuit 44C.

[0094] The short-circuit signal output unit 50C is connected to the terminal A of the coil L and the coil terminal short-circuiting unit 40C. When a braking control signal is input from the short-circuit control circuit 44C, the short-circuit signal output unit 50C outputs a short-circuit signal to the coil terminal short-circuiting unit 40C. The short-circuit signal output unit 50C has a switch element SW3C. In this embodiment, the switch element SW3C is a thyristor, and the anode is connected to the terminal A of the coil L, the cathode is connected to the coil terminal short-circuiting unit 40C, and the gate is connected to the short-circuit control circuit 44C. The switch element SW3C is an example of a third signal element. The short-circuit signal output unit 50C may be connected to the terminal B of the coil L instead of the terminal A of the coil L.

[0095] The coil terminal short circuit unit 40C is connected between both ends (terminals A, B) of the coil L, and short-circuits the both ends (terminals A, B) of the coil L in response to a short circuit signal. The coil terminal short circuit unit 40C includes a third system short circuit path connected between both ends (terminals A, B) of the coil L, and switch elements (one example of a third short circuit element) SW1C, SW2C arranged on the third system short circuit path, and the gates of the switch elements SW1C, SW2C are connected to the cathode of the switch element SW3C of the short circuit signal output unit 50C. The switch element SW3C forms a regenerative path for both directions of the regenerative current flowing through the coil L by turning on the switch elements SW1C, SW2C. In this embodiment, the switch elements SW1C, SW2C are thyristors. The anodes of the switch elements SW1C, SW2C are connected to the terminals A and B of the coil L, respectively, and the cathodes are grounded to ground.

[0096] A short-circuit signal is input to the gates of the switch elements SW1C and SW2C from the switch element SW3C of the short-circuit signal output unit 50C. When the short-circuit signal is input, the switch elements SW1C and SW2C are turned on, and both ends (terminals A and B) of the coil L are short-circuited. Depending on the polarity of the electromotive force generated in the coil L, a short-circuit current i Sw1c and the short-circuit current i flowing through the switch element SW2C Sw2c flows to ground. The short circuit current i Sw1c When the short-circuit current i flows through the switch element SW1C, a regenerative path is formed through the coil L → terminal A → switch element SW1C → ground → parasitic diode of the switch element Qbl → terminal B → coil L. Sw2cWhen the regenerative current Ia flows through the switch element SW2C, a regenerative path is formed through the route coil L → terminal B → switch element SW2C → ground → parasitic diode of switch element Qal → terminal A → coil L. That is, when both ends (terminals A and B) of coil L are short-circuited by the short-circuit signal output unit 50C, two regenerative paths are formed depending on the polarity of the electromotive force generated in coil L. In this way, the parasitic diodes of the switch elements Qal and Qbl of the motor drive unit 10 can be used as part of the regenerative paths of the regenerative currents Ia and Ib based on the electromotive force generated in the coil L.

[0097] Next, the operation modes of the braking operation by the drive control device 1C will be described with reference to Fig. 13. Fig. 13 is a diagram showing an example of the operation modes of the drive control device in the second embodiment. The operation related to braking of the drive control device 1C is divided into three operation modes A to C as shown in Fig. 13.

[0098] First, when the motor control unit 20 rotates the motor 3 without braking it (operation mode A), as in the first embodiment, the drive control device 1C is supplied with power from the power source 2, and a non-braking command signal (High signal) is output from the motor braking command unit 22. In this case, the first diode element D1 of the braking control circuit 43C is turned on, the second diode element D2 is turned off, and the switch element SW7C is turned on. As a result, even if an electromotive force is generated in the coil L, the switch element SW5C of the short circuit control circuit 44C and the switch element SW3C of the short circuit signal output unit 50C are both turned off, and neither the braking control signal nor the short circuit signal is output. As a result, the switch elements SW1C and SW2C of the coil terminal short circuit unit 40C remain off, and the braking operation by the drive control device 1C is not performed (no braking).

[0099] Also, for example, it is assumed that the motor control unit 20 determines to stop the rotation of the motor 3, the motor drive control unit 21 stops the drive of the motor 3, and the motor braking command unit 22 brakes the motor 3 (operation mode B). In this case, the drive control device 1C is supplied with power from the power source 2, and a braking command signal (Low signal) is output from the motor braking command unit 22. In this case, the first diode element D1 and the second diode element D2 of the braking control circuit 43C are both turned on, and the switch element SW7C is turned off. At this time, when an electromotive force is generated in the coil L, the trigger current I1 flows through the resistance element R4 of the electromotive force detection circuit 42C. In this case, a voltage according to the magnitude of the trigger current I1 and the resistance value of the resistance element R4 is generated across both ends of the resistance element R4, and is applied to the first output terminal (collector) of the switch element SW5C of the short circuit control circuit 44C. In addition, a voltage is applied to the control terminal (base) of the switch element SW5C via the resistance element R7. These operations detect the electromotive force generated in the coil L, and as a result, the switch element SW5C of the short circuit control circuit 44C is turned on.

[0100] In this case, a braking control signal is generated using the electromotive force generated in the coil L, and the switching element SW3C of the short-circuit signal output unit 50C is turned on by the braking control signal. This generates a short-circuit signal, which is output to the switching elements SW1C and SW2C of the coil-terminal short-circuit unit 40C, turning on the switching elements SW1C and SW2C. As a result, the short-circuit current i Sw1c The regenerative path in which the short-circuit current i flows from terminal A of coil L to ground via switch element SW1C, Sw2c A regenerative path corresponding to a bidirectional regenerative current is formed, which includes a regenerative path flowing from terminal B of coil L via switch element SW2C.

[0101] In the second embodiment, once the switch elements SW1C and SW2C of the coil terminal short-circuit unit 40C are turned on by the switch element SW3C of the short-circuit signal output unit 50C, they repeatedly turn on and off in response to the electromotive force generated in the coil L. For example, as shown in Fig. 8, when the electromotive force falls below the gate trigger voltage v, the switch elements SW1C and SW2C turn off.

[0102] For example, when the switch element SW1C of the coil-terminal short-circuiting unit 40C is turned on by a short-circuit signal input from the short-circuit signal output unit 50C, the switch element SW2C is turned off by an alternating operation.

[0103] Furthermore, when the power supply from the power source 2 to the drive control device 1C is cut off and there is no power supply (operation mode C), both the first diode element D1 and the second diode element D2 of the braking control circuit 43C are turned off, and the switch element SW7C is turned off. At this time, when an electromotive force is generated in the coil L, the switch element SW5C of the short circuit control circuit 44C is turned on, a braking control signal is generated using the electromotive force generated in the coil L, and the switch element SW3C of the short circuit signal output unit 50C is turned on by the braking control signal, and a short circuit signal is generated. As a result, the switch elements SW1C and SW2C of the coil terminal short circuit unit 40C are turned on, and the rotation of the motor 3 is braked (with braking).

[0104] In operation mode C, when the power supply from the power source 2 is cut off, the drive control device 1C brakes the rotation of the motor 3, regardless of whether the motor control unit 20 is driving the motor 3 to rotate or is stopped. In other words, the drive control device 1C brakes the rotation of the motor 3 when the power supply from the power source 2 is cut off, regardless of whether the signal output from the motor braking command unit 22 immediately before the power supply is cut off is a non-braking command signal or a braking command signal.

[0105] Therefore, for example, when the motor 3 stops rotating and the power supply from the power source 2 is cut off, the rotation of the motor 3 caused by an external force can be braked. This makes it possible to suppress forced rotation caused by outside wind when the motor 3 is a fan motor and installed in a user system.

[0106] Next, the operation procedure of the drive control device 1C will be described with reference to Figs. 14 to 16. Fig. 14 is a flowchart (1) for explaining an example of the operation procedure of the drive control device in the second embodiment. Fig. 15 is a flowchart (2) for explaining an example of the operation procedure of the drive control device in the second embodiment, and Fig. 16 is a flowchart (3) for explaining an example of the operation procedure of the drive control device in the second embodiment. Fig. 14 describes the operation of the drive control device 1C when the power supply from the power source 2 is cut off while the motor 3 is being driven to rotate by the drive control device 1C. Note that in the examples shown in Figs. 14 and onwards, the same operations as those described above are denoted by the same reference numerals, and the description thereof will be omitted.

[0107] As shown in FIG. 14, when the electromotive force detection circuit 42C does not detect the electromotive force generated in the coil L (step S404, No), the electromotive force detection circuit 42C continues to determine whether or not the electromotive force is detected as shown in step S404.

[0108] On the other hand, when the electromotive force detection circuit 42C detects the electromotive force generated in the coil L (step S404, Yes), the switch element SW5C of the short circuit control circuit 44C is turned on, and a braking control signal is output (step S405). This turns on the switch element SW3C of the short circuit signal output unit 50C, and a short circuit signal is output (step S406). When the short circuit signal is input to the coil terminal short circuit unit 40C, the switch element SW1C or switch element SW2C of the coil terminal short circuit unit 40C is turned on. Therefore, both ends (terminals A and B) of the coil L are short circuited (step S407). In this case, as described above, the switch elements SW1C and SW2C alternately operate according to the polarity of the electromotive force.

[0109] Furthermore, when the electromotive force generated in the coil L decreases (step S111), the output voltage of the switch element SW5C of the short circuit control circuit 44C decreases (step S412). When the output voltage of the switch element SW5C becomes less than a certain value, the switch element SW3C of the short circuit signal output unit 50C is maintained in the OFF state (step S413), and the switch elements SW1C and SW2C of the coil terminal short circuit unit 40C are maintained in the OFF state (step S414).

[0110] In addition, the operation of the drive control device 1C when braking the motor 3 while power is being supplied from the power source 2 and the drive control device 1C has stopped the rotational drive of the motor 3, and when the motor 3 is forced to rotate by an external force while the drive control device 1C has stopped the rotational drive of the motor 3 and the motor 3 is not rotating, or while the power supply from the power source 2 is cut off, is as shown in Figures 15 and 16.

[0111] In the second embodiment, too, the braking function described above uses the electromotive energy generated in coil L as the power source for braking operation, making it possible to achieve completely independent, power-free operation without the need for a separate power source such as a battery.

[0112] In the second embodiment, the coil terminal short circuit unit 40C is configured to simultaneously realize the functions of a rectifier circuit and a short circuit, so that the components required for short circuiting (braking) between the coils are simple, and can be configured with highly versatile components. In addition, the parasitic diodes of the switch elements Qal and Qbl (MOSFETs) of the motor drive unit 10 are used (shared) as part of the regeneration path of the short circuit current (regenerative current), so that the circuit constituting the regeneration path of the regenerative current can be simplified. Accordingly, the pattern layout on the printed circuit board can be shared between the motor drive unit 10C and the regeneration path of the regenerative current, and the drive control device 1 can be made smaller.

[0113] Furthermore, in the second embodiment as well, no mechanical relay or switch is required to realize the braking function described above, which improves the reliability of the drive control device 1 and extends the product life.

[0114] [Variations] Although the configurations in each embodiment have been described above, the embodiments are not limited thereto. For example, in FIG. 12, the two switch elements SW1C and SW2C of the coil terminal short-circuiting unit 40C are thyristors, but the present invention is not limited thereto. FIG. 17 is a diagram showing a modified example of the coil terminal short-circuiting unit in the second embodiment. As shown in FIG. 17, in the drive control device 1D, a triac is disposed as the switch element (an example of a third short-circuiting element) SW11 between two terminals A and B of the coil L. A short-circuit signal is input to the gate of the switch element SW11 from the short-circuit signal output unit 50C. In this manner, in this modified example, the coil terminal short-circuiting unit 40D is realized by one triac. In this case, the coil terminal short-circuiting unit 40D does not need to be grounded, and the parasitic diodes of the switch elements Qal and Qbl of the motor drive unit 10 do not need to be used in the regenerative path.

[0115] Also, in the second embodiment, an independent coil M for detecting the electromotive force may be used. FIG. 18 is a diagram showing a modified example of a system including a drive control device and a motor in the second embodiment. In the modified example shown in FIG. 18, the drive control device 1E is connected to a motor 3B having a coil M in addition to the coil L to which power is supplied. In the coil terminal short-circuiting unit 40E, switch elements (an example of a third short-circuiting element) SW1E and SW2E, which are thyristors, are arranged in a short-circuit path. In this case, too, the anode of the switch element SW1E and the anode of the switch element (an example of a third signal element) SW3C are connected to the terminal MA of the coil M, and the anode of the switch element SW2E is connected to the terminal MB of the coil M. The braking control unit 30C (not shown) outputs a braking control signal to the short-circuiting signal output unit 50C based on the result of detecting the electromotive force generated in the coil M. Even in this configuration, a detection operation of the electromotive force generated in the independent coil M that does not compete with the control of the coil L for rotational drive can be performed, so that a stable operation can be performed.

[0116] The configuration of each part of the drive control device 1 of the above embodiment is not limited to the above-mentioned configuration. For example, a part or all of the configuration of the braking control unit 30 may be realized by either hardware or software.

[0117] Also, the motor control unit 20 may be driven by a power supply other than the power supply 2. In this case, for example, the motor control unit 20 may be implemented as a semiconductor integrated circuit (IC) separate from a circuit in which the drive control device 1 is mounted. In this way, by driving the motor control unit 20 by a power supply other than the power supply 2, the motor control unit 20 can output a braking command signal even if the power supply from the power supply 2 is interrupted.

[0118] In the above embodiment, the motor control unit 20 determines whether or not to brake the motor 3, but the present invention is not limited to this. For example, the drive control device 1 may be controlled so that an external device other than the motor control unit 20 brakes the motor 3, such as when the user presses an emergency stop button. In this case, a terminal for inputting a braking command from an external device is added to the braking control circuit 43. This allows the motor 3 to be quickly and forcibly stopped when it becomes necessary to stop the motor 3 in an emergency, for example.

[0119] Furthermore, the short-circuit signal output unit is not limited to the configuration of this embodiment. Components other than a thyristor may be included as components. For example, the short-circuit signal output unit may be realized using a mechanical switch (such as a mechanical contact relay). In this case, it is desirable to design the short-circuit signal output unit in consideration of long-term reliability, such as measures against contact failure.

[0120] Moreover, the operation of the drive control device 1 of the above embodiment is not limited to the operations described using Figures 3 to 5. Operations other than those shown in Figures 3 to 5 may be included, and the operations shown in Figures 3 to 5 may be partially performed in parallel.

[0121] Although the present invention has been described above based on each embodiment and each modification, it goes without saying that the present invention is not limited to each embodiment and each modification, and various modifications are possible within the scope of the gist of the present invention. Such modifications that do not depart from the scope of the gist are also included in the technical scope of the present invention, and this will be clear to those skilled in the art from the description of the claims. [Explanation of symbols]

[0122] 1, 1A, 1B, 1C, 1D, 1E Drive control device, 2 Power supply, 3, 3B Motor, 10 Motor drive unit, 20 Motor control unit, 21 Motor drive control unit, 22 Motor braking command unit, 30, 30A, 30C Braking control unit, 40, 40B, 40C, 40D, 40E Coil terminal short circuit unit, 41 Power supply interruption detection circuit, 42, 42C, 46 Electromotive force detection circuit, 42a, 46a First electromotive force detection circuit, 42b, 46b Second electromotive force detection circuit, 43, 43C Braking control circuit, 44, 44C Short circuit control circuit, 44a First short circuit control circuit, 44b Second short circuit control circuit, 45 Braking short circuit control circuit, 45a First braking short circuit control circuit, 45b Second braking short circuit control circuit, 50, 50C Short circuit signal output unit, 70 Rotor, 71 Magnet, 80 Stator, 81 teeth, L, M coils, A, B terminals, Qah, Qal, Qbh, Qbl switch elements, Vah, Val, Vbh, Vbl drive control signals, R1 to R9 resistance elements, SW5, SW6, SW7, SW5A, SW6A, SW5C, SW7C switch elements, SW1, SW1B switch elements (an example of a first short-circuit element), SW2, SW2B switch elements (an example of a second short-circuit element), SW1C, SW2C, SW1E, SW2E, SW11 switch elements (an example of a third short-circuit element), SW3 switch element (an example of a first signal element), SW4 switch element (an example of a second signal element), SW3C switch element (an example of a third signal element), D1 first diode element, D2 second diode element, I1, I2 trigger current, i Sw1 ,i Sw2 Short circuit current (regenerative current), iSw1c,iSw2c Short circuit current, Ia, Ib regenerative current

Claims

1. a motor drive unit that energizes a coil of a single-phase motor; a motor control unit that outputs a drive control signal to the motor drive unit to switch a current direction of the coils to be energized by the motor drive unit in a predetermined order; A braking control unit that outputs a braking control signal; a coil terminal short-circuiting unit connected between terminals of the coil and short-circuiting the terminals of the coil in response to a short-circuit signal; a short-circuit signal output section connected to at least one terminal of the coil and the coil terminal short-circuit section, and configured to output the short-circuit signal to the coil terminal short-circuit section when the brake control signal is input; Equipped with the coil terminal short-circuiting unit includes a first short-circuiting element connected between one terminal of the coil and the short-circuiting signal output unit, and a second short-circuiting element connected between the other terminal of the coil and the short-circuiting signal output unit, the coil terminal short-circuit portion includes a first system short-circuit path and a second system short-circuit path each connected between terminals of the coil, the first short-circuit element is disposed in a short-circuit path of the first system, the second short-circuit element is disposed in a short-circuit path of the second system; Drive control device for single-phase motor.

2. A motor drive unit that energizes a coil of a single-phase motor; a motor control unit that outputs a drive control signal to the motor drive unit to switch a current direction of the coils to be energized by the motor drive unit in a predetermined order; A braking control unit that outputs a braking control signal; a coil terminal short-circuiting unit connected between terminals of the coil and short-circuiting the terminals of the coil in response to a short-circuit signal; a short-circuit signal output section connected to at least one terminal of the coil and the coil terminal short-circuit section, and configured to output the short-circuit signal to the coil terminal short-circuit section when the brake control signal is input; Equipped with the coil terminal short-circuiting unit includes a first short-circuiting element connected between one terminal of the coil and the short-circuiting signal output unit, and a second short-circuiting element connected between the other terminal of the coil and the short-circuiting signal output unit, the short circuit signal output unit includes a first signal element connected to one terminal of the coil and the first short circuit element, and a second signal element connected to the other terminal of the coil and the second short circuit element, the first signal element turns on the first short-circuit element to form a first regenerative path in response to a regenerative current flowing through the coil in a first direction; the second signal element turns on the second short-circuit element, thereby forming a second regenerative path in response to a regenerative current flowing through the coil in a second direction; Drive control device for single-phase motor.

3. the coil terminal short-circuit portion includes a first system short-circuit path and a second system short-circuit path each connected between terminals of the coil, the first short-circuit element is disposed in a short-circuit path of the first system, the second short-circuit element is disposed in a short-circuit path of the second system; The drive control device for a single-phase motor according to claim 2.

4. the short circuit signal output unit includes a first signal element connected to one terminal of the coil and the first short circuit element, and a second signal element connected to the other terminal of the coil and the second short circuit element, the first signal element turns on the first short-circuit element to form a first regenerative path in response to a regenerative current flowing through the coil in a first direction; the second signal element turns on the second short-circuit element, thereby forming a second regenerative path in response to a regenerative current flowing through the coil in a second direction; The drive control device for a single-phase motor according to claim 1.

5. 5. The drive control device for a single-phase motor according to claim 1, wherein the coil terminal short-circuiting section directly shorts between terminals of the coil.

6. A motor drive unit that energizes a coil of a single-phase motor; a motor control unit that outputs a drive control signal to the motor drive unit to switch a current direction of the coils to be energized by the motor drive unit in a predetermined order; A braking control unit that outputs a braking control signal; a coil terminal short-circuiting unit connected between terminals of the coil and short-circuiting the terminals of the coil in response to a short-circuit signal; a short-circuit signal output section connected to at least one terminal of the coil and the coil terminal short-circuit section, and configured to output the short-circuit signal to the coil terminal short-circuit section when the brake control signal is input; Equipped with the coil terminal short-circuit unit includes a third system short-circuit path connected between terminals of the coil, and a third short-circuit element disposed in the third system short-circuit path, the short circuit signal output unit includes a third signal element connected to one terminal of the coil and the third short circuit element, The third signal element turns on the third short-circuit element, thereby forming a regenerative path for a regenerative current flowing in both directions through the coil. Drive control device for single-phase motor.

7. The braking control unit includes: a power interruption detection circuit that detects an interruption of power supply from a power source that supplies power to the single-phase motor; When the power supply interruption detection circuit detects an interruption of the power supply while the motor drive unit is driving the motor, the power supply interruption detection circuit outputs the brake control signal.

7. The drive control device for a single-phase motor according to claim 1.

8. The braking control unit includes: When the power supply interruption detection circuit detects an interruption of the power supply and detects an electromotive force generated in the coil while the motor drive unit is stopped from driving the motor, the power supply interruption detection circuit outputs the brake control signal. The drive control device for a single-phase motor according to claim 7.

9. The braking control unit includes: an electromotive force detection circuit that detects an electromotive force generated in the coil; a braking control circuit that switches between braking and non-braking of the single-phase motor in response to a detection result of the power supply interruption detection circuit that detects an interruption of the power supply; a short circuit control circuit that outputs the brake control signal using the electromotive force detected by the electromotive force detection circuit; The drive control device for a single-phase motor according to claim 7 or 8, further comprising:

10. The motor control unit includes: outputting a braking command signal for braking the rotation of the single-phase motor while the motor drive unit is stopped; The braking control unit includes: When the braking command signal is received, the braking control signal is output.

7. The drive control device for a single-phase motor according to claim 1.

11. The braking control unit includes: an electromotive force detection circuit that detects an electromotive force generated in the coil; a braking short-circuit control circuit that receives the braking command signal and outputs the braking control signal using the electromotive force when the electromotive force detection circuit detects the electromotive force; The drive control device for a single-phase motor according to claim 10, further comprising:

12. 11. The drive control device for a single-phase motor according to claim 1, wherein the short-circuit signal output section includes a thyristor.

13. A method for controlling braking of a single-phase motor by a drive control device having a motor drive unit that energizes a coil, comprising: a first step of generating a brake control signal when power supply from a power source that supplies power to the single-phase motor is interrupted and a current is lost in the motor drive unit; a second step of generating a short circuit signal based on the brake control signal; a third step of short-circuiting the terminals of the coil in response to the short-circuit signal; Including, the terminals of the coil are short-circuited by a coil terminal short-circuit portion connected between the terminals of the coil, the short circuit signal is output by a short circuit signal output unit connected to at least one terminal of the coil and the coil terminal short circuit unit; the coil terminal short-circuiting unit includes a first short-circuiting element connected between one terminal of the coil and the short-circuiting signal output unit, and a second short-circuiting element connected between the other terminal of the coil and the short-circuiting signal output unit, the coil terminal short-circuit portion includes a first system short-circuit path and a second system short-circuit path each connected between terminals of the coil, the first short-circuit element is disposed in a short-circuit path of the first system, the second short-circuit element is disposed in a short-circuit path of the second system; A method for controlling braking of a single-phase motor.

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