JPS62144590A - Commutatorless motor - Google Patents

Abstract

PURPOSE:To enable output to be increased on operation with simple organization, by detecting the position of a rotor, and by conducting current to the stator windings of two phases and three phases alternately. CONSTITUTION:The output ends of switching elements 1-6 are three-phase- bridge-connected, and are connected to the stator windings 7-12 of isolated neutral star connection. The position of a rotor 13 having magnetic poles is detected by a position detection means 16 consisting of a position detection plate 14 and an electromagnetic conversion element 15. By a control means 17, the switching elements 1-6 are controlled so that electrical conduction to the whole stator windings 7-12 and electrical conduction to two phases only among the windings of three phase may be alternately repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a commutatorless motor used for driving a fan or the like.

2. Description of the Related Art Conventionally, commutatorless motors of this type have been constructed as shown in FIGS. 8 to 11. In the figure, reference numerals 1 to 6 indicate switching elements, the output ends of which are three-phase bridge connected and connected to stator windings 7 to 12 which are star connected with a non-grounded neutral point. The rotor 13 has four magnetic pole pieces, and its position relative to the stator windings 7 to 12 is detected by three magnetoelectric transducers 3o to 32. FIG. 9 is a diagram showing the rotation angle of the rotor 13 and the conduction pattern of the switching elements 1 to 6. The control circuit 33 processes the outputs of the magnetoelectric conversion elements 30 to 32, and
A gate signal is output so that ON''C in the figure becomes conductive, thereby controlling the energization to the stator windings 7 to 12.

FIG. 10 shows the resulting stator magnetic field, and FIG. 11 shows the rotational torque of the motor. 10th
In the figure, stator windings 7 to 12 are arranged at intervals of 60.
When the current is applied in the order shown in Fig. 9, a magnetic field shown by the arrow vector in (2) is generated, and the rotor 13 rotates clockwise by the same angle for every rotation angle %π, and the stator rotating magnetic field and The rotational torque of the electric motor was obtained by the magnetic poles of the rotor 13. Further, as can be seen from FIG. 9, only two phases of the three-phase stator winding were always energized, and the remaining one phase was not energized.

The problem that the invention aims to solve In such a conventional configuration, the supply voltage of the electric motor.

If the structure of the rotor, including the strength of the rotor magnetic poles, and the structure of the stator, including the number of turns of the stator winding, are determined, the maximum output of the motor will be determined accordingly, and if there is any request, the output In order to increase this, it was necessary to increase the power supply voltage, increase the wire diameter of the stator winding, or strengthen the rotor magnetic poles. However, in any case except for changing the power supply voltage, it is necessary to change the structure of the motor itself, so there is a problem in that it is difficult to easily increase the output.

There is also the problem that it is necessary to prepare a variable power supply or the like to change the power supply voltage.

The present invention solves these problems and provides a non-commutator motor that can increase the output without changing the structure of the motor or increasing the power supply voltage. The purpose is to

Means for Solving the Problem In order to solve this problem, the present invention provides a three-phase star-connected stator winding with a neutral point not grounded, a rotor having magnetic poles, and a rotor of the rotor. A control means having a position detecting means for detecting a position, and alternately repeating energization of all the fixed pre-winding wires and energization of only two of the three phases according to the output of the position detection means. It is the result of this.

With this configuration, while the position of the rotor is detected by the position detection means, the control means controls not only two predetermined phases of the three-phase stator winding but also all three phases of the winding in a predetermined direction. Since there is time for energization, the total current flowing into the stator windings increases without changing the power supply voltage, increasing the torque and rotational speed of the motor, and increasing the output.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 7. In the figure, 14 is a position detection plate attached to the rotor 13 so as to rotate in synchronization with the rotor 13. On one side of the plate, N and S poles are magnetized with equal width and 24 poles around the entire circumference. There is. 15 is a magnetoelectric conversion element, and position detection plate 14
Position detection plate 1 is installed at a position where it can detect the magnetic flux of
4 constitute a detection means 16 for detecting the relative position of the rotor 13 with respect to the stator windings 7 to 12. Reference numeral 18 denotes an output determining means for instructing whether to operate in a normal output state or in an increased output state. 17
is a control means for changing the conduction states of the switching elements 1 to 6 in accordance with the output of the output determining means 18 and the output change of the position detecting means 16. FIG. 2 shows the relationship between the output of the position detection means 16, the rotation angle of the rotor 13, and the conduction state of the switching elements 1 to 6 in an operating state in which three-phase energization and two-phase energization are performed alternately to increase the output. This is a diagram. In a normal output state in which two-phase current is always applied, the relationship between the rotation angle of the rotor 130 and the conduction state of the switching elements 1 to 6 is exactly the same as in the conventional example shown in FIG. 9.

In the above configuration, at time t. The magnetic pole of the position detection plate 14 facing the magnetoelectric conversion element 15 changes from the N pole to the S pole.

If the position detection plate 14 changes from the S pole to the N&
If the magnetoelectric transducer 16 is set, time t. The output of the magnetoelectric transducer 15 changes from 1 to 0 in the figure, or 0.
It changes from 1 to 1. In this embodiment, the value changes from 0 to 1, but either value may be used, and the point is that at time t0, the magnetoelectric transducer 1
It is sufficient if the output of 6 changes. The output of the magnetoelectric conversion element 15,
That is, when the output of the position detection means 16 changes, the control means 17 outputs a gate signal that makes the switching elements 1 and 6 conductive, energizes the stator windings 7, 8, 11.12, and the magnetic field generated thereby. The rotor 13 is rotated by. In FIG. 3, the magnetic field is shown by an arrow vector at time t0, and is generated at an intermediate position between the energized two-phase windings. As the rotor 13 rotates, the position detection plate 14 also rotates, and at time t1 when it has rotated by one rotation angle, the magnetic pole facing the magnetoelectric conversion element 15 changes, and the output of the position detection means 16 also changes. from to to tl
Until then, regardless of the output of the output determining means 18, the same 2
The stator windings of the phases are energized, and the magnetic field shown in FIG. 3 and the rotational torque shown in FIG. 4 are the same as in the conventional example. t
At time 1, if the output determining means 18 issues a command to operate in the normal output state, the control means 17 does not change the conduction state of the switching element; however, if the command to operate in the increased output state is issued, The conduction state is changed, switching elements 1, 5, and 6 are brought into conduction, and all three-phase stator windings are energized. At this time, if the impedance of the stator winding of one phase in the case of two-phase energization is (R + iωL), the impedance Z of the stator winding in the case of two-phase energization is Z = 2 (R - 1 - jωL). However, in this case, current flows in from the winding of one of the three phases and current flows out from the winding of the remaining two phases. If Z' is the impedance of the stator winding in three-phase energization, , which is lower than in the case of two-phase energization. Therefore, the current flowing into the stator winding increases compared to the case of two-phase energization, and the resulting magnetic field also becomes stronger. The magnetic field at that time is shown by the arrow vector at time t1 in FIG. As a result of the stronger magnetic field, the motor rotational torque shown by the solid line in the section from rotor diameter π to %π in Figure 4 changes to the torque when two-phase energization continues without changing the conduction state shown by the broken line. The rotor rotation angle %π with increased power output.

It rotates until time t2. At time t2, the position detection means 1e
The output of 2 changes for the second time, and the control means 17 outputs a gate signal that makes the switching elements 1 and 6 conductive.
The phase changes to the energized state, and the output has the same magnitude as the normal output state from the rotor rotation angle 0 to the rotor rotation angle -π, and rotates to the rotor rotation angle -π. During this period, that is, from time t2 to time t3, the same two-phase stator winding is energized regardless of the output of the output determining means 18, and the magnetic field shown in FIG.
The rotational torque shown in the figure is also the same as that of the conventional example. Then time t
3, the output of the position detection means 16 changes for the third time, and the control means 17 does not change the conduction state if the normal output operation state has been instructed by the output determination means 18, but changes it to the output increase state. If operation is instructed, switching elements 1, 2, and 6 are brought into conduction to conduct three-phase current. At this time, current flows from the windings of two of the three phases, and the remaining one
Let Z'' be the impedance of the stator winding in three-phase current flow when current flows out of the phases.

−Z (Z"(Z, τz'<z"<zt, and 2
It is lower than in the case of phase energization and the case of three-phase energization from time t to t2. Therefore, the current flowing into the stator winding increases, the magnetic field becomes stronger, and the rotational torque also increases. The magnetic field at that time is shown by the vector of the arrow at time t3 in FIG. 3, and the torque is shown by the solid line in the range from the rotor rotation angle -π to τπ.

The torque shown by the broken line between the grooves is that when two-phase current is continued. Next, when the output is increased, the rotor rotation angle τ
When it rotates at π2 time t41, the output of the position detection means 16 changes for the fourth time, and the control means 17 outputs a gate signal that makes the switching elements 2 and 6 conductive, and the two-phase energization state is again established.

By repeating (2-phase energization) = (3-phase energization) - (2-phase energization) = (3-phase energization) in this way, the current flowing into the windings is lower than when only 2-phase energization is performed. become more,
As a result, the output of the electric motor increases.

The conduction pattern of the switching elements 1 to 6 is basically a pattern from rotor rotation angle 0 to π, and after π, the rotor 130 rotations continue by repeating the pattern.

Figure 5 shows a comparison of the output when the same prototype machine is operated with 2-phase energization and when 2-phase and 3-phase are energized alternately.
In the figure, the horizontal axis shows torque and the vertical axis shows rotation speed. The solid line indicates alternate 2-phase and 3-phase energization.

The broken line shows the case of only two-phase energization, and the torque is 1.0 (Kp-
cm), the output is approximately 17.5W in the case of two-phase and three-phase alternate energization, and approximately 15.5W in the case of two-phase energization.
4W, the output was increased by about 136%, and the effect was confirmed.

FIG. 6 shows an example of a specific circuit of the main part. Control N means 1
7 consists of a microcomputer 19 and peripheral circuits. The magnetoelectric conversion element 15 is a digital Hall IC.
It outputs a digital signal indicating the rotor position, and the output is directly input to the microcomputer 19. The output determining means 18 is composed of a changeover switch 2o, and according to its output and the output signal from the magnetoelectric transducer 16, the microcomputer 19 determines the switching element to be made conductive and outputs its gate signal.

Next, the operation of the commutatorless motor configured as described above is explained in the seventh section.
This will be explained using the flowchart shown in the figure.

At the same time as the electric motor is turned on, the microcomputer 19 starts receiving the output signals of the magnetoelectric conversion element 15 and the changeover switch 2o in step 21, and at the same time,
The motor starts rotating according to the program procedure shown in the flowchart of FIG. 7 stored in the ROM. First, in step 22, the first two-phase energization gate (time 10
-11 pattern gate signal) is output, and the rotor 13 is rotated. Immediately thereafter, the output of the magnetoelectric transducer 15 is continued to be observed in step 23, and if it changes, the energization pattern is changed to 3-phase energization (the pattern at time t1-12) in step 24, and then normal output is requested in step 26. If output increase operation is requested, in step 26, a gate signal according to the pattern determined in step 24 is output, three-phase energization is performed, and the process moves to step 27. If normal output is requested, the gate signal is not outputted and the process similarly proceeds to step 27 in the same state as 1. In step 27, we continue to observe whether the output of the magnetoelectric transducer 15 has changed again, and if it has changed, in step 28, we change the energization pattern to the next two-phase energization (
The gate signal is changed to time t2-13), and the gate signal is output in step 29. From then on, operation continues by repeating this process. Note that each energization pattern is stored in advance as data in the ROM in the microcomputer 19 in order, and in this example, there are 12 types of data.

Note that in this example, a magnetoelectric transducer was used as the position detection means, but
An optical element such as a photointerrupter may be used, and in that case, the rotor position detection plate may be changed accordingly.

As described above, according to this embodiment, the position of the rotor is detected by one magneto-electric transducer and the position detection plate, and the stator windings are energized alternately between two and three phases. The current flowing into the line increases, making it possible to operate with increased output with a simple structure.

Effects of the Invention As is clear from the description of the embodiments above, according to the present invention, while detecting the position of the rotor by the position detection means,
Since two-phase energization and three-phase energization are performed alternately by the control means, the current flowing into the stator winding increases and the output increases without changing the power supply voltage. Therefore, there is no need to change the motor structure, such as the wire diameter of the stator winding or the strength of the rotor magnetic poles.

The effect is that the output can be increased.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a commutatorless motor according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the conduction state of the switching element, etc., and Fig. 3 shows the magnetic field of the stator winding. 4 is an explanatory diagram of the rotational torque, FIG. 6 is a torque curve, FIG. 6 is a circuit diagram of the main part, and FIG. 7 is a flow chart showing an example of a program for the same operation. Fig. 8 is a schematic configuration diagram of a conventional non-commutator motor, Fig. 9 is an explanatory diagram showing the conduction state of the switching element, etc., Fig. 10 is an explanatory diagram showing the magnetic field of the stator winding, and Fig. 11 is an explanatory diagram showing the magnetic field of the stator winding. The figure is an explanatory diagram of the same rotational torque. 7.8, 9, 10, 11.12... Stator winding, 13... Rotor, 16... Position detection means, 17... Control means . Name of agent: Patent attorney Toshio Nakao and one other person
'1 Figure 2, between 6 t+a@+t, Baj $4 tf! <t
'Bow @ 64 too t+・tu"8"m゛Figure 3 → Rotation j Rotation angle Figure 5 1111 → -Torque 0 mm (ffi) Figure 6 + V Figure 7 Figure 8 Figure 9 1st Figure-1 ◆ Rotation Lee rotation ^

Claims (1)

[Claims] A three-phase star-connected stator winding with a neutral point ungrounded,
It has a rotor having magnetic poles and a position detection means for detecting the position of the rotor, and according to the output of the position detection means,
A non-commutator motor comprising a control means that alternately repeats energization of all of the stator windings and energization of only two of the three phases.