JP2000125590A - Drive for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive for motor capable of reducing power consumption, and time control with high precision and current feedback with high stability in a motor of two or more phases. SOLUTION: This drive for motor is provided with a current detecting resistor 21, through which current energizing motor windings 16-18 flows, whose ends are commonly connected, a comparator 22 comparing a torque command signal 3 with the voltage generated at the current detecting resistor 21, a reference clock 2 for obtaining a PWM chopping signal, a frequency divider 25, a double-edge detecting and derivative pulse forming circuit 26, a flip-flop circuit 23, a pulse-delay circuit 27 for delaying the output of the flip-flop circuit 23, an energizing control circuit 1 for determining an energized phase, a synchronous rectifying control circuit 24 for controlling the outputs of the flip-flop circuit 23 and the pulse delaying circuit 27, and the output signal of the energizing control circuit 1. It is thus possible to control synchronous rectification at PWM driving, so that the driving transistors 4-6 and 10-12 are not kept in an active state at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor drive having a plurality of motor windings.

[0002]

2. Description of the Related Art A synchronous rectification method (Japanese Patent Application Laid-Open No. 5-221780) is known as a driving method of a motor driving device.

Hereinafter, a synchronous rectification method in a conventional motor driving device will be described with reference to the drawings. FIG. 13 is a configuration diagram of a conventional motor drive device, 87 is an energization control circuit, 88 is a synchronous rectification control circuit, 89 is a two-phase non-overlapping clock, and 4 to 6 and 10 to 12 are drive transistors. Transistors and lower drive transistors,
7-9 and 13-15 are flywheel diodes, 8
3 to 84 are comparators, 19 is a power supply terminal, 85 is RC
A discharge circuit, 81 is a flip-flop, 80 is an inverter, 16 to 18 are motor windings, 20 is a middle point of the motor winding, and 21 is a current detection resistor.

The operation of the motor driving device shown in FIG. 13 will be described below. 1 during the activated phase
One node (eg, node A) is connected to the upper transistor 4
-6 (e.g., upper transistor 4). One node (e.g., node B) is driven low by one of the lower transistors 10-12 (e.g., lower transistor 11);
The other node (for example, node C) is in a floating state with both the upper transistor 6 and the lower transistor 12 turned off. This state is hereinafter referred to as “AB phase” in the text. The coils are then switched in a commutation sequence that maintains current in one of the coils during the switching period.

[0005] Pulse width modulation (hereinafter abbreviated as PWM)
During the period, current is detected at the current sensing resistor 21 and compared to a reference voltage VREF that determines the maximum current that can be generated in the coils 16,17,18. When the current reaches VREF, the comparator 83 changes its output and resets the flip-flop 81. As a result, the inverter 80, the two-phase non-overlapping clock 89, the energization control circuit 8
The switching control of the upper transistors 4, 5, and 6 is performed via 7 to shut off the upper transistors 4, 5, and 6 over all the nodes A, B, and C. At the same time, switch 9
By releasing 0, the RC discharge circuit 85 is enabled, that is, enabled, and the RC discharge circuit 85 generates a time delay, during which the upper transistors 4, 5, and 6 are kept off. When the voltage on the capacitor of the RC discharge circuit 85 drops below the reference voltage VREF, the output of the comparator 84 is inverted and the flip-flop 81 is toggled to turn on the upper drive transistor corresponding to the phase being driven. As a result, the current ramps up,
That is, it rises on the slope. This series of cycles is repeatedly performed.

The description will be continued using the example of the AB phase. First, during the ON period, the current ramps up through the coils 17 and 18 between the nodes A and B, and flows through the upper transistor 4 that is selected to be ON.

Next, when the upper transistor 4 is shut off in the PWM chop cycle operation, the potential of the node A is kept high, and the current in the coils 17 and 18 is maintained in parallel with the lower transistor 10. ,
Flywheel diode 13 must be forward biased. Also, the lower transistor 11 must be kept on to keep node B low. On the other hand, when the PWM chop cycle shuts off the upper transistor 4, the coils 17 and 18 become damping current sources and the energy stored therein must be dissipated. That is, if the voltage to the active drive coil is turned off in the PWM mode,
The flyback energy in the active drive coil is provided by applying a drive current to the lower transistor 10 from a non-rectifying ground return path. That is, when the upper transistor 4 shuts off, the lower transistor 1
When 0 is turned on, the circuit operates as if the coil 17
And 18 are shorted through the two resistors, giving the appearance of no diode. Lower transistor 1
The switching operations of 0, 11, and 12 are achieved by the synchronous rectification control circuit 88 in synchronization with the signal generated by the conduction control circuit 87, as described below.

FIG. 14 is a block diagram showing in detail a part of the control circuit 92 provided in 92 in FIG. FIG. 14 shows only a part of the motor drive circuit for one phase as a part of the control circuit 92, but similar circuits are provided for the remaining phases. Control circuit 92
Is a logic circuit configured to drive the upper driving transistor driving circuit and the lower driving transistor driving circuit in accordance with the energization switching signals of the lines 109 and 110. The other signals input to the control circuit 92 are, as shown in FIG.
8 signal. In order to ensure that the upper drive transistor and the lower drive transistor are not activated at the same time, a two-phase clock 8 with two output signals V103 and V104 exclusively carrying a phase shift clock signal
9 are provided. The two-phase clock 89 operates to turn off the lower transistor when the upper transistor is turned on, and to turn on the lower transistor when the upper transistor is turned off.

[0009]

However, in the above-mentioned conventional configuration, in synchronous rectification during PWM control, PWM is not used.
The time from when the drive transistor on the chop side changes from the conductive state to the non-conductive state until the drive transistor connected in series with the drive transistor star on the PWM chop side changes from the non-conductive state to the conductive state, and PWM.
A circuit that determines the time from when the drive transistor connected in series to the chop-side drive transistor changes from the conductive state to the non-conductive state until the PWM chop-side drive transistor changes from the non-conductive state to the conductive state. Since the delay time of the NAND gate is used, there is a problem that it is difficult to control the time with high accuracy and the variation is large.

In addition, there is a problem that the timing of comparing the maximum current of the motor winding with the reference voltage also causes a delay of the NAND gate, so that the current feedback control may become unstable.

The present invention solves the above-mentioned conventional problems, and realizes highly accurate time control and stable current feedback control. It is an object to provide a motor drive device for a disk media for use.

[0012]

In order to achieve the above object, a motor driving device according to the present invention comprises a plurality of motor windings having one end commonly connected and the other end connected to a power switching circuit for each phase. And a power supply switching circuit comprising a plurality of phases, in which the power supply switching circuit includes a plurality of phases in which an upper drive switching circuit, a motor winding connection point, and a lower drive switching circuit are connected in series from a power supply; And a PWM reference signal generating unit, the PWM reference signal being a set signal, and a comparison logic between a current supplied to the motor winding and a torque command signal being a reset signal.
A flip-flop circuit that generates an M chopping signal; a delay circuit that delays the output of the flip-flop circuit; and the power switching based on an output of the flip-flop circuit, an output of the delay circuit, and an output signal of the conduction control circuit. A synchronous rectification control circuit that supplies a switching signal of an energized phase to the circuit;
The synchronous rectification control circuit switches off the one of the upper and lower drive switching circuits by a reset output of the flip-flop circuit, and then outputs the other of the upper and lower drive switching by an output of the delay circuit having a delay time longer than the reset output. After the circuit is turned on, the upper and lower drive switching circuits that are on are switched off by the set output of the flip-flop circuit, and then the off is performed by the output of the delay circuit having a delay time longer than the set output. Is switched on, and synchronous rectification control is performed so that the upper and lower drive switching circuits are not simultaneously turned on.

According to the above configuration, the PW of the motor driving device is
In synchronous rectification at the time of M, synchronous rectification control can be performed so that upper and lower drive switching circuits are not simultaneously turned on. The configuration of the synchronous rectification control section can be made simple and its setting can be made easy. Further, according to the above configuration, since there is no delay in comparing the maximum current of the motor winding with the reference voltage, current feedback is stable.

Next, it is preferable that the delay circuit is a pulse delay circuit for controlling a delay amount based on a pulse of a reference clock. According to the above configuration, the timing at which one of the upper and lower drive switching circuits is turned on is delay-controlled based on the pulse of the reference clock, so that the synchronous rectification control can be performed so that the upper and lower drive switching circuits are not simultaneously turned on. . Further, according to the above configuration, since there is no delay in comparing the maximum current of the motor winding with the reference voltage, current feedback is stable.

Next, it is preferable that the delay circuit is a CR delay circuit. According to the above configuration, since the timing at which one of the upper and lower drive switching circuits is turned on is delay-controlled based on the CR time constant, synchronous rectification control can be reliably performed so that the upper and lower drive switching circuits are not simultaneously turned on. According to the above configuration, there is no delay in comparing the maximum current of the motor winding with the reference voltage,
Current feedback is stable.

Next, a motor drive device according to the present invention comprises a flywheel diode connected in parallel to the up / down drive switching circuit, and a flywheel diode output detection unit for detecting an output of the flywheel diode. The rectification control circuit detects a voltage generated in a flywheel diode connected in parallel to the upper and lower drive switching circuits by a back electromotive force generated in a motor winding by turning off the upper and lower drive switching circuits. It is preferable that the upper and lower drive switching circuits are turned on after the detection by the unit.

According to the above configuration, after detecting the off of one of the upper and lower drive switching circuits by detecting the output voltage, the other drive switching circuit is turned on, so that the upper and lower drive switching circuits are surely not turned on at the same time. Synchronous rectification control can be performed. Further, according to the above configuration, since there is no delay in comparing the maximum current of the motor winding with the reference voltage, current feedback is stable.

According to another aspect of the present invention, there is provided a motor driving device comprising: a plurality of motor windings having one end connected in common and the other end connected to a power switching circuit for each phase; A power supply switching circuit comprising a plurality of phases, in which a switching circuit is connected in series from a power supply to an upper drive switching circuit, a motor winding connection point and a lower drive switching circuit, and an energization control circuit for controlling an energized motor drive phase In the motor drive device provided with
Compare the triangular wave oscillator with the torque command signal to determine the first PWM
A first comparator that outputs a chopping signal, a second comparator that compares a torque command signal obtained by adding the offset amount with the triangular wave oscillator and outputs a second PWM chopping signal, And a synchronous rectification control circuit for providing a switching signal to the power supply switching circuit based on the output of the comparator and the output signal of the energization control circuit. The synchronous rectification control circuit, in the energized phase, uses the first PWM chopping signal from the first comparator to output the one of the upper and lower drive switching circuits. After switching off, the second P
After the upper and lower drive switching circuits are turned on by the inverted signal of the WM chopping signal, and the upper and lower drive switching circuits are turned off by the inverted signal of the second PWM chopping signal from the second comparator, One of the upper and lower drive switching circuits is switched on by the first PWM chopping signal, and synchronous rectification control is performed so that the upper and lower drive switching circuits are not simultaneously turned on.

According to the above configuration, the timing for turning on and off one of the upper and lower drive switching circuits is set by the triangular wave frequency and the torque command offset voltage.
When it is turned on, it can be made slower than the other drive switching circuit, and when it is turned off, it can be made faster than the other drive switching circuit, and synchronous rectification control can be performed so that the transistors are not turned on at the same time.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a motor driving device according to a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a configuration of a motor driving device according to Embodiment 1 of the present invention, and shows a motor driving device for driving a three-phase full-wave motor. 1 is an energization control circuit, 4 to
Reference numeral 15 denotes a drive switching circuit, 4 to 6 are upper drive transistors, and 10 to 12 are lower drive transistors. 7 to 9 and 13 to 15 are flywheel diodes. 21 is a current detection resistor, 3 is a torque command signal, 2
Is a reference clock, 25 is a frequency dividing circuit, 26 is a both-edge detection differential pulse forming circuit, V1U to W are energization switching signals, 19
Is a power supply, 22 is a comparator, 23 is a flip-flop, 16 to 18 are motor windings, 20 is a middle point of the motor winding, 24 is a first synchronous rectification control circuit, and 27 is a pulse delay circuit.

The operation of the motor driving device configured as described above will be described below. Energization switching signal V1U
.About.V1W normally uses a sensor such as a Hall element and is arranged at a position of 120 electrical degrees with respect to the rotation axis of the motor, detects the rotating magnetic field of the motor, and outputs an energization switching signal. In some cases, a back electromotive voltage generated in the coil is used as a conduction switching signal. The energization control circuit 1 switches energization for each phase of the windings 16 to 18 according to an energization switching signal that detects a change in the rotating magnetic field of the motor, and controls the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12.
To the respective bases, a signal switched at a conduction angle of 120 degrees is given. The upper driving transistors 4 to 6 and the lower driving transistors 10 to 12 are respectively connected to the motor winding 1.
6 to 18 and the energization control circuits 1 to 120
A signal for energizing sequentially at each energizing angle of degrees is output.
The output signal of the energization control circuit 1 is input to a first synchronous rectification control circuit 24 that controls a PWM operation and a synchronous rectification operation, and the output signal of the first synchronous rectification control circuit 24 is And lower drive transistor 10
-12 are input to each base.

Next, switching control of the upper driving transistors 4 to 6 and the lower driving transistors 10 to 12 will be described. When the lower drive transistor (for example, 10) of the lower drive transistors 10 to 12 that is energized by the energization switching circuit is turned off by the PWM chop by the first synchronous rectification control circuit 24, the upper drive transistor Among 4 to 6, the upper drive transistor (here, 4) connected in series corresponding to the upper drive transistor (10) performing the PWM chopping operation becomes conductive. Next, when a current flows through the non-conducting lower driving transistor, and the lower driving transistors 10 to 12 (here, 10) on the PWM chop side are turned on again, the lower driving transistor (10) , The upper drive transistor (4 in this case) connected in series becomes non-conductive. Although the first embodiment chops the lower drive transistors 10 to 12, the same operation is performed by chopping the upper drive transistors 4 to 6 and performing synchronous rectification control on the lower drive transistors 10 to 12.

FIG. 2 is a block diagram showing the first synchronous rectification control circuit 24 and the pulse delay circuit 27 shown in FIG.
Is a detailed block diagram of the configuration of FIG. 1, showing only the configuration for a one-phase motor drive transistor circuit. Only one phase is shown, but similar circuits are provided for the remaining phases. By way of example, the phases for the upper drive transistor 4, the lower drive transistor 10, and the motor winding 18 are shown.

1 is an energization control circuit, 4 and 10 are drive transistors, 7 and 13 are flywheel diodes, 21 is a current detection resistor, 3 is a torque command signal, 2 is a reference clock,
25 is a frequency dividing circuit, 26 is a both edge detection differential pulse forming circuit, V1U to V1W are energization switching signals, 19 is a power supply, 22
Is a comparator, 23 is a flip-flop, 18 is a motor winding, 20 is a middle point of the motor winding, 24 is a first synchronous rectification control circuit, and 27 is a pulse delay circuit.

The operation of the motor drive control device of the first embodiment configured as shown in FIG. 2 will be described with reference to FIG. The output signal of the reference clock 2 is V2 in FIG. The signal of V2 is input to the frequency dividing circuit 25, and V25 is output. The rising edge and the falling edge of V25 are detected by the both-edge detecting differential pulse forming circuit 26, and the differential pulse V26 is output. This V26 becomes a set signal of the flip-flop circuit 23.

Next, the current flowing through the motor winding 18 flows through the current detection resistor 21 and causes the current detection resistor 21 to generate a voltage V21. The V21 and the output signal V3 of the torque command signal 3 are input to a comparator 22 which is a comparator. The comparator 22 outputs a reset signal to the flip-flop 23 as indicated by V22 when V21 exceeds V3, that is, when a motor drive current corresponding to the torque command output signal flows through the motor winding 18.

The output V23 of the flip-flop 23 is input to the pulse delay circuit 27, and outputs a delayed pulse V35 for one cycle of V2, which is the output of the reference clock 2. Next, the output signal V35 of the pulse delay circuit 27 and the output signal V23 of the flip-flop 23 are input to the first synchronous rectification control circuit 24. First, V23 and V35 are set to V31 by AND31 in the first synchronous rectification control circuit 24.
Is output. This V31 is a PWM chopping signal.
AND using V1b which is a 0-degree conduction signal as an input signal
32 outputs V32, and the lower drive transistor 1
0 is changed to a conductive state or a non-conductive state. At this time, the timing at which the lower drive transistor 10 changes from the conductive state to the non-conductive state is the timing when the motor drive current corresponding to the torque command output signal flows through the motor winding and is synchronized with the reset signal of the flip-flop 23. It was done. The timing at which the lower drive transistor 10 changes from the non-conductive state to the conductive state is a timing delayed by one cycle of the reference clock from V26 which is the set signal of the flip-flop 23.

Next, V29 and V35 are output by the NOR 29 in the first synchronous rectification control circuit 24.
This V29 and the output signal V1b of the conduction control circuit 1, which is a 120-degree conduction signal of the lower drive transistor circuit, are NAND
30 is input. An inverted output of the NAND30 output signal and the output signal V1a of the conduction control circuit 1, which is a 120-degree conduction signal of the upper drive transistor circuit, is input to the NAND 28, and V28 is output, and the upper drive transistor 4 is turned on or off. Change.

The output signals V32, V28, V in FIG.
As is clear from 1a and V1b, when the lower drive transistor 10 is not performing the PWM chopping operation, the upper drive transistor 4 is turned on or off by the 120 ° turn-on signal of V1a. When the lower drive transistor 10 receives the 120 ° conduction signal of V1b and performs the PWM chopping operation, the upper drive transistor 4 is controlled by synchronous rectification. Here, when the lower drive transistor 10 is in a conductive state, the upper drive transistor 4 is in a non-conductive state, and when the lower drive transistor 10 is in a non-conductive state,
The upper drive transistor 4 becomes conductive. The timing at which the upper drive transistor 4 changes from the conductive state to the non-conductive state is determined by the set signal V2 of the flip-flop 23.
6, and the timing at which the upper drive transistor 4 changes from the non-conductive state to the conductive state is synchronized with V35. This is because the motor drive current corresponding to the torque command output signal flows through the motor winding. This is a timing delayed by one cycle of the reference clock from the reset signal V22 of the flip-flop 23 which is the timing. Therefore, when the lower drive transistor 10 performs the PWM chopping operation, the upper drive transistor 4 performs the synchronous rectification operation, and the state switching of the upper drive or the lower transistor circuit is performed by time control by delay processing according to the reference clock. Can be
At the same time, it can be ensured that no conduction state exists. Furthermore, since the PWM operation can be performed at the timing when the motor drive current corresponding to the torque command output signal flows through the motor winding, the current feedback control can be stabilized.

(Embodiment 2) Next, Embodiment 2 of the motor drive device of the present invention will be described with reference to FIGS.

FIG. 4 shows a configuration of a motor drive device according to a second embodiment of the present invention, and shows a motor drive device for driving a three-phase full-wave motor. 1 is an energization control circuit, 4 to
Reference numeral 15 denotes a drive switching circuit, 4 to 6 are upper drive transistors, and 10 to 12 are lower drive transistors. 7 to 9 and 13 to 15 are flywheel diodes. 21 is a current detection resistor, 3 is a torque command signal, 3
9 is a PWM reference signal, V1U to W are energization switching signals, 19
Is a power supply, 22 is a comparator, 23 is a flip-flop, 16 to 18 are motor windings, 20 is a middle point of the motor windings, 37 is a second synchronous rectification control circuit, and 38 is a CR delay circuit.

The operation of the motor driving device configured as described above will be described. Energization switching signals V1U to V
The operation of 1 W, the energization control circuit 1, the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12, which are referred to by the same reference numerals, are the same as those described in the first embodiment. In other words, the energization switching signals V1U to V1W are usually arranged at 120 electrical degrees with respect to the rotation axis of the motor using a sensor such as a Hall element, detect the rotating magnetic field of the motor, and output the energization switching signal. I do. Also,
In some cases, the back electromotive voltage generated in the coil is used as the energization switching signal. The energization control circuit 1 switches energization for each phase of the windings 16 to 18 in response to an energization switching signal that detects a change in the rotating magnetic field of the motor.
6 and the bases of the lower drive transistors 10 to 12 are supplied with a signal switched at a conduction angle of 120 degrees. The upper drive transistors 4 to 6 and the lower drive transistors 10 to 12 are connected to the motor windings 16 to 18, respectively, and output signals for sequentially energizing the energizing control circuit 1 at every energizing angle of 120 degrees. You. An output signal of the energization control circuit 1 is input to a second synchronous rectification control circuit 37 for controlling a PWM operation and a synchronous rectification operation,
Is output to the bases of the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12.

Next, switching control of the upper driving transistors 4 to 6 and the lower driving transistors 10 to 12 will be described. When the lower drive transistor (for example, 10) energized by the energization switching circuit becomes non-conductive by the PWM chop by the second synchronous rectification control circuit 37 among the lower drive transistors 10 to 12, the upper drive transistor Among 4 to 6, the upper drive transistor (here, 4) connected in series corresponding to the upper drive transistor (10) performing the PWM chopping operation becomes conductive. Next, when a current flows through the non-conducting lower driving transistor, and the lower driving transistors 10 to 12 (here, 10) on the PWM chop side are turned on again, the lower driving transistor (10) , The upper drive transistor (4 in this case) connected in series becomes non-conductive. Although the second embodiment chops the lower drive transistors 10 to 12, the same operation is performed if the upper drive transistors 4 to 6 are chopped and the lower drive transistors 10 to 12 are synchronously rectified.

FIG. 5 is a detailed block diagram of the second synchronous rectification control circuit 37 and the CR delay circuit 38 in the block diagram of FIG. It is shown. Only one phase is shown, but similar circuits are provided for the remaining phases. As an example, the upper driving transistor 4,
The phase diagram for the lower drive transistor 10 and the motor winding 18 is shown.

In FIG. 5, reference numeral 1 denotes an energization control circuit;
0 is a drive transistor, 7 and 13 are flywheel diodes, 21 is a current detection resistor, 3 is a torque command signal, 39
Is a PWM reference signal, V1U to V1W are energization switching signals,
9 is a power supply, 22 is a comparator, 23 is a flip-flop, 18 is a motor winding, 20 is a middle point of the motor winding, 37
Is a synchronous rectification control circuit, and 38 is a CR delay circuit.

The operation of the motor drive control device according to the second embodiment configured as shown in FIG. 5 will be described with reference to FIG. The output signal of the PWM reference signal 39 is V39 in FIG.
It is. The signal of V39 becomes the set signal of the flip-flop circuit 23.

Next, the current flowing through the motor winding 18 flows through the current detection resistor 21 and causes the current detection resistor 21 to generate a voltage V21. The V21 and the output signal V3 of the torque command signal 3 are input to a comparator 22 which is a comparator. The comparator 22 outputs a reset signal to the flip-flop 23 as indicated by V22 when V21 exceeds V3, that is, when a motor drive current corresponding to the torque command output signal flows through the motor winding 18.

The output V23 of the flip-flop 23 is CR
It is input to the delay circuit 38 and outputs a delay pulse V46 determined by the time constant of CR. Next, the output signal V46 of the CR delay circuit 38 and the output signal V2 of the flip-flop 23
3 is input to the second synchronous rectification control circuit 37. First,
V23 and V46 are the ANs in the second synchronous rectification control circuit 37.
V41 is output by D41. This V41 is PWM
A signal V42 is output from an AND 42 which is a chopping signal, and the input signal is V41 and the output signal of the conduction control circuit 1 is V1b which is a 120-degree conduction signal, and the lower drive transistor 10 is turned on or off. Change the state. At this time, the timing when the lower drive transistor 10 changes from the conductive state to the non-conductive state is the timing when the motor drive current corresponding to the torque command output signal flows through the motor winding 18 and the reset signal of the flip-flop 23 Will be synchronized with The timing at which the lower drive transistor 10 changes from the non-conductive state to the conductive state is determined by the set signal V3 of the flip-flop 23.
This is the timing delayed from 9 by the CR time constant of the CR delay circuit 38.

Next, V23 and V46 are output as V47 by the NOR 47 in the second synchronous rectification control circuit 37. The output signal V <b> 1 b of the conduction control circuit 1, which is the V47 and the 120-degree conduction signal of the lower drive transistor, is input to the NAND 40. The NAND40 output signal and an inverted output of the output signal V1a of the conduction control circuit 1, which is a 120-degree conduction signal of the upper driving transistor, are input to the NAND49 and are output to the V49.
Is output to change the upper drive transistor 4 to a conductive state or a non-conductive state.

As described above, the output signals V42, V49, V in FIG.
As is clear from 1a and V1b, when the lower drive transistor 10 is not performing the PWM chopping operation, the upper drive transistor 4 is turned on or off by the 120 ° turn-on signal of V1a. Lower drive transistor 1
When 0 receives the 120 ° conduction signal of V1b and the PWM chopping operation is performed, the upper drive transistor 4 is controlled by synchronous rectification. When the lower drive transistor 10 is conductive, the upper drive transistor 4 is nonconductive, and when the lower drive transistor 10 is nonconductive, the upper drive transistor 4 is conductive. Further, the timing at which the upper drive transistor 4 changes from the conductive state to the non-conductive state is synchronized with the set signal V39 of the flip-flop 23, and the timing at which the upper drive transistor 4 changes from the non-conductive state to the conductive state corresponds to the torque command output signal. This is a timing delayed by a CR time constant from the reset signal V22 of the flip-flop 23, which is the timing when the corresponding motor drive current flows through the motor winding.

Therefore, the lower drive transistor 10 is PWM
During the chop operation, the upper drive transistor 4 performs a synchronous rectification operation, and at the time of switching the state of each of the upper drive transistor and the lower drive transistor circuit, time control can be performed by delay processing according to a delay corresponding to the CR time constant. At the same time, it can be ensured that no conduction state exists. Further, since the PWM operation can be performed at the timing when the motor drive current corresponding to the torque command output signal flows to the motor winding 18, the current feedback control can be stabilized.

Third Embodiment Next, a third embodiment of the motor drive device of the present invention will be described with reference to FIGS.

FIG. 7 shows the structure of a motor driving device according to Embodiment 3 of the present invention, and shows a motor driving device for driving a three-phase full-wave motor. 1 is an energization control circuit, 4 to
Reference numeral 15 denotes a drive switching circuit, 4 to 6 are upper drive transistors, and 10 to 12 are lower drive transistors. 7 to 9 and 13 to 15 are flywheel diodes. 21 is a current detection resistor, 3 is a torque command signal, 3
9 is a PWM reference signal, V1U to V1W are energization switching signals,
19 is a power supply, 22 is a comparator, 23 is a flip-flop, 16 to 18 are motor windings, 20 is a middle point of the motor winding, 50 is a third synchronous rectification control circuit, 38 is a CR delay circuit, and 51 is an output voltage. The detection circuit 52 is an output voltage detection power supply.

The operation of the motor driving device configured as described above will be described. Energization switching signals V1U to V
1W, the energization control circuit 1, the upper drive transistors 4 to 6, and the lower drive transistors 10 to 12, which are denoted by the same reference numerals, are the same as those described in the first embodiment. In other words, the energization switching signals V1U to V1W are usually arranged at 120 electrical degrees with respect to the rotation axis of the motor using a sensor such as a Hall element, detect the rotating magnetic field of the motor, and output the energization switching signal. I do. In some cases, a back electromotive voltage generated in the coil is used as a conduction switching signal. The energization control circuit 1 switches energization for each phase of the windings 16 to 18 according to an energization switching signal that detects a change in the rotating magnetic field of the motor, and switches the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12. A signal switched at a conduction angle of 120 degrees is given to each base. Upper drive transistors 4 to 6 and lower drive transistor 1
Signals 0 to 12 are connected to the motor windings 16 to 18, respectively, and a signal for sequentially energizing the energizing control circuit 1 at every energizing angle of 120 degrees is output. An output signal of the energization control circuit 1 controls a PWM operation and a synchronous rectification operation.
, And the output signal of the third synchronous rectification control circuit 50 is input to each base of the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12.

Next, switching control of the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12 will be described. When the lower drive transistor (for example, 10) energized by the energization switching circuit becomes non-conductive by the PWM chop by the third synchronous rectification control circuit 50 among the lower drive transistors 10 to 12, the upper drive transistor Among 4 to 6, the upper drive transistor (here, 4) connected in series corresponding to the upper drive transistor (10) performing the PWM chopping operation becomes conductive. Next, when a current flows through the non-conducting lower driving transistor, and the lower driving transistors 10 to 12 (here, 10) on the PWM chop side are turned on again, the lower driving transistor (10) , The upper drive transistor (4 in this case) connected in series becomes non-conductive. Although the third embodiment chops the lower drive transistors 10 to 12, the same operation is performed if the upper drive transistors 4 to 6 are chopped and the lower drive transistors 10 to 12 are synchronously rectified.

FIG. 8 is a block diagram showing the third synchronous rectification control circuit 50 and the output voltage detection circuit 5 shown in FIG.
1. A block diagram showing the configuration of the CR delay circuit 38 in detail, and shows only a one-phase motor drive circuit. By way of example, the phases for the upper drive transistor 4, the lower drive transistor 10, and the motor winding 18 are shown.

In FIG. 8, reference numeral 1 denotes an energization control circuit;
0 is a drive transistor, 7 and 13 are flywheel diodes, 21 is a current detection resistor, 3 is a torque command signal, 39
Is a PWM reference signal, V1U to V1W are energization switching signals,
9 is a power supply, 22 is a comparator, 23 is a flip-flop, 18 is a motor winding, 20 is a midpoint of the motor winding, 50
Is a third synchronous rectification control circuit, 38 is a CR delay circuit, 51
Is an output voltage detection circuit.

The operation of the motor drive control device according to the third embodiment configured as shown in FIG. 8 will be described with reference to FIG. The output signal of the PWM reference signal 39 is V39 in FIG.
It is. The signal of V39 becomes the set signal of the flip-flop circuit 23.

Next, the current flowing through the motor winding 18 flows through the current detection resistor 21 and causes the current detection resistor 21 to generate a voltage V21. The V21 and the output signal V3 of the torque command signal 3 are input to a comparator 22 which is a comparator. The comparator 22 outputs a reset signal to the flip-flop 23 as indicated by V22 when V21 exceeds V3, that is, when a motor drive current corresponding to the torque command output signal flows through the motor winding 18.

The output V23 of the flip-flop 23 is CR
The delay pulse 38 is input to the delay circuit 38 and determined by the time constant of CR. Next, the output signal V61 of the CR delay circuit 38 and the output signal V2 of the flip-flop 23
3 is input to the third synchronous rectification control circuit 50. First,
V23 and V61 are the ANs in the third synchronous rectification control circuit 50.
D62 outputs V62. This V62 is PWM
V63 is output by AND63 which is a chopping signal, and the input signal is V62 and the output signal of the conduction control circuit 1 is V1b which is a 120-degree conduction signal, and the lower drive transistor 10 is turned on or off. Change the state. At this time, the timing when the lower drive transistor 10 changes from the conductive state to the non-conductive state is the timing when the motor drive current corresponding to the torque command output signal flows through the motor winding 18 and the reset signal of the flip-flop 23 Will be synchronized with The timing at which the lower drive transistor 10 changes from the non-conductive state to the conductive state is determined by the set signal V3 of the flip-flop 23.
This is the timing delayed from 9 by the CR time constant of the CR delay circuit 38.

Next, V39 is a third synchronous rectification control circuit 50.
Is input as a set signal to the flip-flop circuit 55 in the internal circuit. Then, a back electromotive force is generated at V18, in which the lower drive transistor 10 is turned off in the PWM chopping operation, and a current flows through the flywheel diode 7.

The comparator 6 in the output voltage detection circuit 51
6 compares the voltage generated at V 18 with the voltage V 65 obtained by adding the voltage of the power supply 19, and outputs a reset pulse to the flip-flop 55 when V 18 exceeds V 65.

An inverted output of the output of the flip-flop 55 and an output signal V1b of the conduction control circuit 1, which is a 120-degree conduction signal of the lower drive transistor 10, are input to the NAND 57 and output V57. An inverted signal of the output signal V57 of the NAND 57 and the output signal V1a of the conduction control circuit 1 which is a 120-degree conduction signal of the upper drive transistor is input to the NAND 54, and V54 is output.
Is changed to a conductive state or a non-conductive state.

As described above, the output signals V57, V54, V in FIG.
As is clear from 1a and V1b, when the lower drive transistor 10 is not performing the PWM chopping operation, the upper drive transistor 4 is turned on or off by the 120 ° turn-on signal of V1a. Lower drive transistor 1
When 0 receives the 120 ° conduction signal of V1b and the PWM chopping operation is performed, the upper drive transistor 4 is controlled by synchronous rectification. When the lower drive transistor 10 is conductive, the upper drive transistor 4 is nonconductive, and when the lower drive transistor 10 is nonconductive, the upper drive transistor 4 is conductive. Further, the timing at which the upper drive transistor 4 changes from the conductive state to the non-conductive state is synchronized with the set signal V39 of the flip-flop 23. The timing at which the upper drive transistor 4 changes from the non-conductive state to the conductive state is determined by the timing of the lower drive transistor 1
0 changes from the conductive state to the non-conductive state, a back electromotive force is generated at V18, a current flows through the flywheel diode 7, and a voltage V65 obtained by adding the voltage of V18 to the voltage of the power supply 19
This is the timing at which V18 exceeds V65.

Therefore, the lower drive transistor 10 is PWM
During the chopping operation, the upper driving transistor 4 performs a synchronous rectification operation, and when the state of each of the upper driving transistor and the lower driving transistor is switched, it can be ensured that there is no conduction state at the same time. Furthermore, since the PWM operation can be performed at the timing when the motor drive current corresponding to the torque command output signal flows through the motor winding 18,
Current feedback control can be stabilized.

(Embodiment 4) Next, Embodiment 4 of the motor drive device of the present invention will be described with reference to FIGS.

FIG. 10 shows a configuration of a motor driving device according to the fourth embodiment of the present invention, and shows a motor driving device for driving a three-phase full-wave motor. 1 is an energization control circuit, 4
15 to 15 are drive switching circuits, 4 to 6 are upper drive transistors, and 10 to 12 are lower drive transistors. 7 to 9 and 13 to 15 are flywheel diodes. 3 is a torque command signal, 68 is a triangular wave oscillator,
69 is a torque command offset voltage, 70 to 71 are comparators, V1U to W are energization switching signals, 19 is a power supply,
Reference numeral 18 denotes a motor winding, reference numeral 20 denotes a middle point of the motor winding, and reference numeral 67 denotes a fourth synchronous rectification control circuit.

The operation of the motor driving device configured as described above will be described. Energization switching signals V1U to V
1W, the energization control circuit 1, the upper drive transistors 4 to 6, and the lower drive transistors 10 to 12, which are denoted by the same reference numerals, are the same as those described in the first embodiment. In other words, the energization switching signals V1U to V1W are usually arranged at 120 electrical degrees with respect to the rotation axis of the motor using a sensor such as a Hall element, detect the rotating magnetic field of the motor, and output the energization switching signal. I do. In some cases, a back electromotive voltage generated in the coil is used as a conduction switching signal. The energization control circuit 1 switches energization for each phase of the windings 16 to 18 according to an energization switching signal that detects a change in the rotating magnetic field of the motor, and switches the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12. A signal switched at a conduction angle of 120 degrees is given to each base. Upper drive transistors 4 to 6 and lower drive transistor 1
Motor windings 16 to 18 are connected to 0 to 12, respectively, and the energization control circuit 1 outputs a signal for sequentially energizing every 120-degree energization angle. An output signal of the energization control circuit 1 controls the PWM operation and the synchronous rectification operation.
And the output signal of the fourth synchronous rectification control circuit 67 is input to each base of the upper drive transistors 4 to 6 and the lower drive transistors 10 to 12.

Next, switching control of the upper driving transistors 4 to 6 and the lower driving transistors 10 to 12 will be described. When the lower drive transistor (for example, 10) energized by the energization switching circuit becomes non-conductive by the PWM chop by the fourth synchronous rectification control circuit 67 among the lower drive transistors 10 to 12, the upper drive transistor Among 4 to 6, the upper drive transistor (here, 4) connected in series corresponding to the upper drive transistor (10) performing the PWM chopping operation becomes conductive. Next, when a current flows through the non-conducting lower driving transistor, and the lower driving transistors 10 to 12 (here, 10) on the PWM chop side are turned on again, the lower driving transistor (10) , The upper drive transistor (4 in this case) connected in series becomes non-conductive. Although the third embodiment chops the lower drive transistors 10 to 12, the same operation is performed if the upper drive transistors 4 to 6 are chopped and the lower drive transistors 10 to 12 are synchronously rectified.

FIG. 11 is a detailed block diagram of the fourth synchronous rectification control circuit 67 of the block diagram of FIG. 10, and shows only a one-phase motor drive circuit. Things. As an example, the upper drive transistor 4, the lower drive transistor 10, the motor winding 18
Are shown for the phase.

In FIG. 11, 1 is an energization control circuit, 4 and 10 are drive transistors, 7 and 13 are flywheel diodes, 3 is a torque command signal, 68 is a triangular wave oscillator, 6
9 is a torque command offset voltage, 70 to 71 are comparators, V1U to V1W are energization switching signals, 19 is a power supply,
2 is a comparator, 18 is a motor winding, 20 is a middle point of the motor winding, and 67 is a fourth synchronous rectification control circuit.

The operation of the motor drive control device according to the fourth embodiment configured as shown in FIG. 11 will be described with reference to FIG. The output signal V68 of the triangular wave oscillator 68 and the output signal V3 of the torque command signal 3 are input to the comparator 71, and V71 is output. This V71 is a PWM chopping signal, and V75 is output by an AND75 which receives this V41 and the output signal of the conduction control circuit 1 as a 120 degree conduction signal V1b as an input signal, thereby turning on the lower drive transistor 10. Or to a non-conducting state. At this time, the duty of the conduction state in the lower drive transistor 10 is determined by the output voltage value V3 of the torque command signal with respect to the output signal V68 of the triangular wave oscillator. Further, a voltage V69 obtained by adding the offset voltage 69 to the output signal V68 of the triangular wave oscillator 68 and the output signal V3 of the torque command signal 3 is input to the comparator 70, and V70 is output. An output signal V1b of the energization control circuit 1, which is a 120-degree energization signal of the lower drive transistor, is input as a reset signal of the flip-flop 80 in the fourth synchronous rectification control circuit 67, and is used as a drive signal of the lower drive transistor 10. An inverted output V76 of a certain V75 is input as a set signal of the flip-flop 80. The output signal V80 of the flip-flop is a mask signal that the upper drive transistor 4 can be driven only during the period in which the lower drive transistor 10 performs the PWM chopping operation in the synchronous rectification control. The inverted output of V80 and V70 is N
The signal is input to AND79 and V79 is output. NAND7
9 and the inverted output of the output signal V1a of the conduction control circuit 1, which is a 120-degree conduction signal of the upper drive transistor, are input to the NAND 78 and V78 is output, and the upper drive transistor 4 changes to a conductive state or a non-conductive state. Let it.

As described above, the output signals V75, V78,
As is clear from V1a and V1b, when the lower drive transistor 10 is not performing the PWM chopping operation, the upper drive transistor 4 is turned on or off by the 120 ° turn-on signal of V1a. When the lower drive transistor 10 receives the 120 ° conduction signal of V1b and performs a PWM chopping operation, the upper drive transistor 4 is controlled by synchronous rectification. When the lower drive transistor 10 is conductive, the upper drive transistor 4 is nonconductive, and when the lower drive transistor 10 is nonconductive, the upper drive transistor 4 is conductive.

Therefore, the lower drive transistor 10 is PWM
The upper driving transistor 4 performs a synchronous rectification operation during the chop operation, and performs time control by delay processing according to the oscillation frequency of the triangular wave oscillator 68 and the offset voltage 69 when switching the state of each of the upper driving transistor and the lower driving transistor. And at the same time ensure that no conduction state exists.

In each of the embodiments described above, the lower drive transistor circuit is described as a PWM chop circuit. However, the upper drive transistor circuit may be configured as a PWM chop circuit. Nor.

[0067]

According to the motor driving device of the present invention, the above-described first to fourth configurations realize low power consumption driving in the synchronous rectification by PWM, and the driving transistor on the PWM chop side changes from the conductive state. It is possible to accurately control the time from when the state changes to the non-conducting state to when the driving transistor connected in series to the driving transistor on the PWM chop side changes from the non-conducting state to the conducting state. Further, according to the motor drive device of the present invention, the drive transistor connected to the PWM chop side is turned off when the state of the drive transistor connected in series to the drive transistor on the PWM chop side changes from the conductive state to the non-conductive state. It is possible to accurately control the time from when the state changes to the conduction state.

According to the motor driving apparatus of the present invention, in the above time control, it is not necessary to use the delay processing by the NAND circuit, which has conventionally been a problem, and the timing is controlled by the clock, the CR time constant, the output voltage detection, and the triangular wave frequency. The time can be set easily, accurately, and the variation can be reduced. Also,
With the first to third configurations, there is no delay in the time for comparing the maximum current of the motor winding with the reference voltage.
The current feedback is stable and a constant current can be supplied to the motor, and high-precision rotation control of the motor can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of a three-phase full-wave motor drive device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of a first synchronous rectification control circuit 24 and a pulse delay circuit 27 in the block diagram of FIG.

FIG. 3 is a timing chart illustrating the operation of the three-phase full-wave motor driving device according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a three-phase full-wave motor drive device according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a detailed configuration of a second synchronous rectification control circuit 37 and a CR delay circuit 38 in the block diagram of FIG.

FIG. 6 is a timing chart illustrating the operation of the three-phase full-wave motor driving device according to the second embodiment of the present invention.

FIG. 7 is a block diagram of a three-phase full-wave motor driving device according to a third embodiment of the present invention.

8 is a block diagram showing a detailed configuration of a third synchronous rectification control circuit 50, an output voltage detection circuit 51, and a CR delay circuit 38 in the block diagram of FIG.

FIG. 9 is a timing chart illustrating the operation of the three-phase full-wave motor driving device according to the third embodiment of the present invention.

FIG. 10 is a block diagram of a three-phase full-wave motor driving device according to a fourth embodiment of the present invention.

FIG. 11 is a block diagram showing a detailed configuration of a fourth synchronous rectification control circuit 67 in the block diagram of FIG. 10;

FIG. 12 is a timing chart illustrating the operation of the three-phase full-wave motor driving device according to the third embodiment of the present invention.

FIG. 13 is a block diagram of a conventional three-phase full-wave motor driving device.

14 is a control circuit 92 provided in 92 in FIG.
Block diagram detailing part of

[Explanation of symbols]

 1,87 energization control circuit 2 reference clock 3 torque command signal 4-6 upper drive transistor 10-12 lower drive transistor 7-9,13-15 flywheel diode 16-18 motor winding 19 power supply 20 motor winding middle point Reference Signs List 21 Current detection resistor 22, 70, 71, 83, 84 Comparator 23, 81 Flip-flop circuit 24 First synchronous rectification control circuit 37 Second synchronous rectification control circuit 50 Third synchronous rectification control circuit 67 Fourth synchronous rectification Control circuit 88 Synchronous rectification control circuit 25 Divider circuit 26 Both edges detection differential pulse forming circuit 27 Pulse delay circuit 38, 85 CR delay circuit 39 PWM reference signal 51 Output voltage detection circuit 52 Output voltage detection power supply 68 Triangular wave oscillator 69 Offset voltage 89 2-phase clock generator 90 Switch 91 CR charge Use power

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) JJ29 LL22 LL24 LL41

Claims (5)

[Claims] 1. A multi-phase motor winding, one end of which is connected in common and the other end of which is connected to a power switching circuit of each phase, the power switching circuit, wherein an upper drive switching circuit and a motor are connected in series from a power supply. A power supply switching circuit including a plurality of phases in which a winding connection point and a lower drive switching circuit are connected; and a motor drive device including an energization control circuit for controlling an energized phase of the motor drive. A flip-flop circuit that generates a PWM chopping signal using the PWM reference signal as a set signal, a comparison logic between a current supplied to the motor winding and a torque command signal as a reset signal, and a delay for delaying an output of the flip-flop circuit Circuit, an output of the flip-flop circuit, an output of the delay circuit, and an output of the conduction control circuit. A synchronous rectification control circuit that supplies a switching signal of an energized phase to the power supply switching circuit based on a signal. After switching off the drive switching circuit, the output of the delay circuit having a delay time than the reset output, the upper and lower drive switching circuit is switched on, the set output of the flip-flop circuit,
After switching off the other upper and lower drive switching circuits that are on, the upper and lower drive switching circuits that are off by the output of the delay circuit having a delay time from the set output are switched on, A motor drive device, wherein synchronous rectification control is performed so that the upper and lower drive switching circuits are not simultaneously turned on. 2. The pulse delay circuit according to claim 1, wherein the delay circuit controls a delay amount based on a pulse of a reference clock.
A motor drive device according to claim 1. 3. The motor driving device according to claim 1, wherein the delay circuit is a CR delay circuit. 4. A flywheel diode connected in parallel to the vertical drive switching circuit, and a flywheel diode output detection unit for detecting an output of the flywheel diode, wherein the synchronous rectification control circuit is configured to control the one of the upper and lower sides. After the flywheel diode output detector detects a voltage generated in a flywheel diode connected in parallel with the upper and lower drive switching circuits due to a back electromotive force generated in the motor winding due to the turning off of the drive switching circuit, The motor drive device according to claim 1, wherein the drive switching circuit is turned on. 5. A multi-phase motor winding, one end of which is commonly connected and the other end of which is connected to a power switching circuit of each phase, the power switching circuit, and an upper drive switching circuit and a motor connected in series from a power supply. In a power supply switching circuit having a plurality of phases in which a winding connection point and a lower drive switching circuit are connected, and a motor drive device having an energization control circuit for controlling a motor energized phase, a triangular wave oscillator and a torque command signal are transmitted. First PWM in comparison
A first comparator that outputs a chopping signal, a second comparator that compares a torque command signal obtained by adding the offset amount with the triangular wave oscillator and outputs a second PWM chopping signal, A synchronous rectification control circuit that supplies a switching signal to the power supply switching circuit based on the output of the comparator and the output signal of the energization control circuit, and the second PWM chopping signal is the first PWM chopping signal because of the offset amount. The synchronous rectification control circuit, in the energized phase, uses the first PWM chopping signal from the first comparator to output the one of the upper and lower drive switching circuits. After switching off the second PWM chopping The upper and lower drive switching circuits are turned on by an inverted signal of the signal, and the upper and lower drive switching circuits are turned off by an inverted signal of the second PWM chopping signal from the second comparator. A motor drive device, wherein one of the upper and lower drive switching circuits is turned on by one PWM chopping signal, and synchronous rectification control is performed so that the upper and lower drive switching circuits are not turned on at the same time.