JPH03284188A - Motor controller - Google Patents

Abstract

PURPOSE:To obtain optimum torques by making the pulse width of a drive signal variable and by setting the conduction angle of an excitation coil arbitrary within a range of 120-180 deg.. CONSTITUTION:Voltage division resistors R1-R3 are connected so that a predetermined potential may be supplied to the reverse input terminal of a compensator 1c and to that of a comparator 1d. That, in the case of OFF state of transistors Tr1, Tr2, a potential which adjusts the conduction angle to 120 deg. is supplied: while in the case of ON-state, a potential which adjusts the conduction angle to 180 deg. is supplied. Entry of signals to change conduction angles (pulse signals) according this constitution can change the conduction angle of an excitation coil from 120 deg. to 180 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a motor control device suitable for use in drive control of a three-phase DC brushless smoke applied to a vehicle-mounted blower motor or the like.

"Prior Art" Generally, when driving a three-phase direct current bluntless motor, a method is adopted in which each excitation coil of the stator is sequentially switched to flow a square wave drive current.

In this method, the conduction angle of the drive current flowing through each exciting coil is fixed at 120 degrees or 180 degrees. Hereinafter, a driving method with an energization angle of 120 degrees or 180 degrees will be described with reference to the drawings. First, FIG. 5(a) is a diagram showing a stator of a three-phase DC brushless smoke. The stator shown in this figure is composed of Y-connected U-phase, ■-phase, and W-phase excitation coils. In order to supply drive current to the excitation coils of each phase so that the conduction angle becomes 120 degrees, the current is applied in the phase relationship shown in FIG. 5(b). In this way, when the conduction angle is 120 degrees, the drive current flows through the excitation coils of two of the three phases, for example,
When the phase angle is between 60 degrees and 120 degrees, the current flows in the direction of the broken line shown in FIG. 5(a), that is, from the U tll to the V phase.

On the other hand, in order to supply drive current to the excitation coils of each phase at a conduction angle of 180 degrees, the current is applied in the relationship shown in FIG. 6(b). In this case, the drive current always flows through the three excitation coils, and between the two consecutive phase angles of 60 degrees and 120 degrees, the direction of each broken line shown in Fig. 6 (a), Furthermore, current flows from the U phase to the V phase and from the U phase to the W phase.

"Problem to be Solved by the Invention" By the way, in the above-described drive system, if the energization angle of the excitation coil is fixed at 120 degrees, the obtained torque is small, but the drive can be performed with a low current.

On the other hand, if the energization angle of the excitation coil is fixed at 180 degrees, a large torque can be obtained, but on the other hand, a high drive current is required.

However, the current conduction angle of the excitation coil is 120 degrees or 1
Since the motor is fixed at an angle of 80 degrees, there is a drawback that it is not possible to drive the motor under optimal conditions depending on the load condition of the motor.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a motor control device that can be driven under optimal conditions.

"Means for Solving the Problems" This invention (detecting the rotation angle of a 110-meter 17, this rotation 1
drive signal generating means for generating a drive signal train according to excitation timing defined by an angle signal corresponding to f+;
a drive circuit for switching the excitation pole of the stator according to the drive signal and supplying a drive current; It is characterized by being arbitrarily set between 120 degrees and 18[) degrees.

According to Structural Acid, the drive signal generating means changes the pulse width of the drive signal by iiJ and changes the energization angle of the excitation coil by 120 degrees.
You can set it arbitrarily between 180 degrees and 180 degrees. This allows the desired torque to be generated.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of detection circuits 1 to 3 of a motor control device according to an embodiment of the present invention. Note that since the detection circuits 2 and 3 have the same configuration as the detection circuit 1, their illustration is omitted. In the detection circuit 1 shown in this figure, I
A is a pole element that detects the magnetic flux density of the rotating field and outputs it as a fi3 degree signal 1-Tu. Ib1i
It is an operational amplifier that amplifies and outputs the angle signal Hu.

V ref' 1■ref 21J variable reference voltage. This variable reference voltage V'refl and variable reference voltage V r
ef 2 is configured such that its collective voltage varies according to the torque command signal Ts supplied from a control circuit (not shown). These variable reference voltages Vref] Vref2 are potentials with the same absolute value but different polarities, and when receiving the torque command signal Ts that instructs an increase in torque, the variable reference voltage Vref2 is
The potential of f I decreases, and the potential of variable reference potential V rer 2 decreases. The IC is a comparator that compares the magnitude of the angle signal 1-1u supplied to the non-inverting input terminal with the variable reference voltage V ref 1 supplied to the inverting input terminal.

This comparator IC outputs a drive signal Uh when the angle signal Hu is negative. Id is 11 at the inverting input terminal with respect to the variable reference voltage Vref2 supplied to the non-inverting input terminal.
This is a comparator that compares the magnitude of the supplied angle signal Hu.

This comparator +d outputs the drive signal Ul when the angle signal IJu is smaller. Similarly, the detection circuits 2 and 3 output angle signals IT v and T-r, respectively.
Drive signals Vh, Vl and ~Vh, W generated from w
+ is output. These drive signals Uh, [11Wh, W
l is supplied to a drive circuit 4 shown in FIG.

Next, FIG. 2 is a circuit diagram showing the configuration of the drive circuit 4. As shown in FIG.

In this figure, PET, -FET, l are field effect transistors. These field effect transistors P E
'1', ~F, E T 6 are used as power elements and constitute an output stage of this drive circuit 1 .

4゛However, the field effect transistor FET, +~
A positive power supply voltage (10E) is supplied to each drain of PET3, and each source thereof is connected to the drains of field effect transistors FET4 to FETG, respectively. One end of each of the excitation coils of the negative phase, ■ phase, and W phase of the Y-connected stator is connected to each of these connection points. In addition, field effect transistors FET4 to FET
Each of the 6 sources is grounded. Drive signals Uh, Ul, .
, Wh, and Wl are supplied. According to such a configuration, each field effect transistor FET, ~F
Drive signals LJh and V supplied to the gate of E T o
1. ..., Wh, Wl, drive current to each phase (J(
supply. For example, electric field effect)・Lannostar FTεT,
When the drive signals -1Uh and Vl are input to the gates of PET, .

The operation of the motor control device having such a configuration will be explained with reference to FIG. 3. First, when the power is turned on to this motor control device, as shown in FIG. You can get it.

Next, the angle signal 1-T that defines these excitation timings is
11, I-1v, and I-1w, the driving signals Ub, UIWh, and ˜V1 for each phase are generated. Here, for example, if the variable J1 (I1', voltage Vrer I is at the potential of I+V, J in the same figure (A), the energization M of the excitation coil as shown in the same figure (C) Drive signals UI+Vh and Wh having a pulse width of 120 degrees are obtained.

Further, the variable reference voltage V ref 2 is r−V, jt1
7) The drive signals Ul and VIWI at the potential have the same pulse width. In this way, a driving current with an energization angle of 120 degrees is supplied to each of the U-phase, ■-phase, and W-phase excitation coils. (Refer to Figure 5 (B)) Now, a torque command signal Ts is received which instructs an increase in the torque. and each drive signal U as shown in FIG.
h, the pulse width of VhWh increases. As a result, the drive current supplied to each excitation coil increases, making it possible to compensate for the torque that is insufficient as the rotational speed of the rotor increases. Then, when the torque is further increased, the potentials t, -1 of the variable reference voltages V ref I and V ref 2:
r Become an OJ.

As a result, the conduction angle of each exciting coil is 180 degrees (Fig. 6 (
(see b)) and generates maximum torque.

FIG. 4 is a circuit diagram showing a modification of the detection circuit I. In the same figure (A), 5-1 and 5-2 are amplifiers. A level upper/lower rotational speed control signal is input to the amplifiers 5-1, 5-2 in proportion to the rotational speed of the rotor. The difference between the circuit shown in this figure and the one shown in FIG. The configuration is such that a signal is supplied, and its operation is the same as in the embodiment described above.

Further, in the same figure (b), Trl and Tr2 are transistors, R1 to I7. is the voltage dividing resistance. These voltage dividing resistors R1 to R1 connect the inverting input terminal of the comparator 1c and the comparator 1c.
It is connected to the non-inverting input terminal of d so that a predetermined potential is supplied thereto. That is, transistor 'rr I
, 'When Fr 2 is in the off state, the conduction angle is set to 120
On the other hand, in the on state,
A potential that makes the conduction angle 180 degrees is supplied. According to such a configuration, when the energization angle change signal (pulse signal) is input, the energization angle of each exciting coil is changed to 12
Can you change it from 0 degrees to 180 degrees?

Effects of the Invention As explained above, according to the invention, by varying the pulse width of the drive signal, the energization angle of the excitation coil is varied between 120 degrees and 180 degrees.
It is possible to obtain the optimum torque according to the motor load situation.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a detection circuit 1 of a motor control device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing the configuration of a drive circuit 4 in the same embodiment, and FIG. 3 is the same. FIG. 4 is a diagram showing a modified example of the detection circuit, and FIGS. 5 and 6 are diagrams for explaining the conventional example. 1 Pole element, comparator, refl, V ref2 variable reference voltage, drive circuit

Claims (1)

[Claims] In a motor control device that drives and controls a three-phase DC brushless motor that is composed of a stator that is composed of a three-phase excitation coil and a rotor that rotates in response to switching of excitation poles of the stator, the rotation angle of the rotor is controlled. detect,
The stator is equipped with a drive signal generating means that generates a drive signal according to an excitation timing defined by an angle signal corresponding to the rotation angle, and a drive circuit that switches the excitation pole of the stator according to the drive signal and supplies a drive current. , the drive signal generating means varies the pulse width of the drive signal to vary the energization angle of the excitation coil from 120 degrees to 18 degrees.
A motor control device characterized in that it can be set arbitrarily between 0 degrees.