JPH1023730A - Multi-phase stepping motor and drive system thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for facilitating the configuration of an exciting sequece for a multi-phase stepping motor. SOLUTION: This stepping motor is constituted so as to have the number of phases of 6 or more expressed by a×b, where a: odd number of three or more, b: integer of two or more. Phase windings ϕA-ϕO provided at the salient pole of a stator are constituted so as to prepare (b) sets of windings where phase windings of (a) pieces whose phases are shifted by 2 π/a respectively are connected in an annular or star shape, and input terminals C1-C15 of (a×b) pieces are also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyphase stepping motor and its driving system.

[0002]

2. Description of the Related Art As a method of connecting motor windings of a polyphase stepping motor having n phases, a phase difference of 2πi / n (i
Is a positive integer that does not exceed n / 2 and is not a divisor of a). The start and end of the phase winding are connected in series to form a ring, or the start or end of the phase winding There is a method in which the terminals are connected at one point and connected in a star shape, and in the case of a ring shape, each connection point is used as an input terminal, and in the case of a star shape, other than the connection point is used as an input terminal. . And 2n
An input terminal is connected to a drive circuit controlled by the number of switching elements, and each terminal is connected to a positive electrode or a negative electrode of a power supply for each input pulse signal, or is switched so as not to be connected to any of them.

[0003]

As a method of increasing the resolution of a stepping motor, there is a method of increasing the number of motor phases. However, as the number of phases increases, there is a problem that the construction of the excitation sequence becomes complicated.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a polyphase stepping motor and a driving method thereof which can easily construct an excitation sequence of the polyphase motor. It is in.

[0005]

The configuration of the present invention for achieving the above object is as follows. If the number of phases is a × b (a
Is an odd number of 3 or more, and b is an integer of 2 or more. In a stepping motor having 6 or more phases, the phase difference is 2πi / a (i is a positive integer not exceeding a / 2). a
The windings are connected in a ring by sequentially connecting the starting end and the ending of the phase winding which is not a divisor of the above) to form a b winding set having each connection point as an input terminal. The phase difference is 2π /
The start windings or the end ends of the phase windings a are connected in a star shape with one point connected to each other, and b winding sets each having a non-contact as an input terminal are configured. Then, a switching means is connected to the input terminal of the stepping motor, and the input terminal is connected to the positive electrode or the negative electrode of the driving power supply by switching, or the driving circuit of the stepping motor is controlled so as not to be connected to any of the poles. The control is such that the excitation state of an arbitrary ring connection or star connection is switched for each input pulse.

(Operation) Each of the winding sets connected by the switching means forms a torque vector set shifted by 2π / a degrees in electrical angle. When step driving is performed, rotation of π / a is possible in electrical angle, and when half-step driving is performed, rotation of π / 2a is possible in electrical angle. At the same time, each torque vector set is shifted by 2π / (a × b) degrees in electrical angle,
Therefore, when each winding group is regarded as one phase and the excitation state is switched for each winding group, and full-step driving is performed, rotation of π / (a × b) in electrical angle is possible, and half-step driving is performed. Is performed, a rotation of π / (2a × b) is possible in the electrical angle. Accordingly, since the a × b-phase motor can be controlled by combining the excitation sequence of the a-phase motor, the construction of the excitation sequence is facilitated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings by using a 15-phase motor in which a = 5 and b = 3.

As a method for connecting the winding sets, a phase winding having a phase difference of 2πi / a (i is a positive integer not exceeding a / 2 and not a divisor of a) is used. The windings are connected in an annular manner by sequentially connecting the start and end of the phase winding, and each connection point is used as an input terminal, or the winding is connected to the beginning or end of a phase winding having a phase difference of 2π / a. There is a method of connecting in a star shape connected to points and using a non-connection point as an input terminal.

FIG. 1 shows a case where the winding set is formed by a ring connection, and
FIG. 4 is a connection diagram of phase windings of the stepping motor of the present invention when i = 1. φA to φO are input terminals C1 to C1
5 shows phase windings respectively connected to the input terminals C1 to C
Reference numeral 15 is connected to a drive circuit of a stepping motor that controls the input terminals C1 to C15 to be connected to the positive or negative electrode of the drive power supply by switching or not to connect to any of the poles.

The winding set W1 is composed of phase windings φD, φ which are shifted by 72 degrees (= 360/5) in electrical angle with respect to the phase winding φA.
The start and end of G, φJ, and φM are sequentially connected. Similarly, the winding set W2 is 48 degrees (= 360 degrees) in electrical angle from the phase winding φA.
× 2/15) The starting and ending ends of the phase windings φF, φI, φL, and φO, which are shifted by 72 degrees in electrical angle with respect to the shifted phase winding φC, are sequentially connected. Phase winding φA
Phase winding φ shifted by 24 degrees (= 360/15) in electrical angle from
Phase windings φE, φ deviated by 72 electrical degrees from B
The start and end of H, φK, and φN are sequentially connected. The phase windings (φA, φ
D, φG, φJ, φM), (φC, φF, φI, φL,
φO), (φB, φE, φH, φK, φN) form torque vectors that are shifted by 72 degrees in electrical angle when a current is passed in the same direction, and each winding set W1, W2,
The corresponding phase winding of W3 forms a torque vector shifted by 24 electrical degrees.

FIG. 2 is an example of a time chart showing an excitation state according to claim 2, wherein A is a forward current of the phase winding φA,
A 'means excitation by current in the opposite direction of the phase winding φA. The same applies to other characters.

In FIG. 1, first, in step 1, the phases A, J ', D, and M' of the winding set W1, the I 'of the winding set W2,
Since the C, L ', and F phases and the B, K', E, and N 'phases of the winding set W3 are respectively excited, a 12-phase excitation state results. next,
In step 2, the excitation of the A phase of the winding set W1 is released and the G phase is excited at the same time, and the excitation states of the winding set 2 and the winding set W3 are not switched. Become. When the process further proceeds to step 3, the excitation of the I 'phase of the winding set W2 is released, and at the same time, the O' phase is excited.
Since the excitation states of the winding set W1 and the winding set W3 are not switched, a 12-phase excitation state is set. Further, in step 4, the H-phase is excited at the same time as the excitation of the B-phase of the winding set W3 is released, and the excitation state of the winding sets W1 and W2 is not switched, so that the 12-phase excitation state is set. Further, in step 5, the winding set W
At the same time when the excitation of the J 'phase of 1 is released, the A' phase is excited, and the excitation state of the winding sets W2 and W3 is not switched, so that the 12-phase excitation state is set. Similarly, in steps 6 to 30, the excitation state of one winding set is switched for each input pulse, and the excitation state of an arbitrary winding set is 3
(= B) Switching is performed every pulse, and the excitation state of an arbitrary winding set is controlled to be switched every 3 (= b) pulses, and the 12-phase excitation state is repeated.

FIG. 3 is a generated vector diagram according to the above-mentioned driving method. As can be seen from the figure, the vectors generated by the winding sets W1, W2 and W3 whose excitation state has been switched in each step are generated by the excitation windings as a result of rotating by 36 degrees (= 180/5) in electrical angle. The composite vector is rotated by 12 degrees (= 180/15), and full-step driving has been achieved.

FIG. 4 is another example of a time chart showing the excitation state according to the present invention, which is different from the above. In the figure, first, in step 1, it is equal to the above step 1,
It becomes a 12-phase excitation state. Next, when the process proceeds to step 2, the G phase of the winding set W1 is excited, and the excitation states of the winding set W2 and the winding set W3 are not switched, so that a 13-phase excitation state is set. When the process further proceeds to step 3, the O 'phase of the winding set W2 is excited, and the excitation states of the winding set W1 and the winding set W3 are not switched, so that a 14-phase excitation state is set. Further, in step 4, the H-phase of the winding set W3 is excited, and the excitation state of the winding sets W1 and W2 is not switched, so that a 15-phase excitation state is set. Further, in step 5, the excitation of the A-phase of the winding set W1 is released, and the excitation states of the winding sets W2 and W3 are not switched, so that a 14-phase excitation state is set. Further, in step 6, the excitation of the I 'phase of the winding set W2 is released, and the excitation states of the winding sets W1 and W3 are not switched, so that a 13-phase excitation state is set. Further, in step 7, the B-phase excitation of the winding set W3 is released, and the excitation state of the winding sets W1 and W2 is not switched, so that a 12-phase excitation state is set. Next, in step 8, the A 'phase of the winding set W1 is excited, and the excitation states of the winding set W2 and the winding set W3 are not switched, so that a 13-phase excitation state is set. Hereinafter, steps 9 to 6 are performed similarly.
Even at 0, the excitation state of one winding set is switched for each input pulse, and the excitation state of an arbitrary winding set is 3 (=
b) It is controlled to switch every pulse, and 12-13
-14-15-14-13 phase excitation is repeated.

FIG. 5 is a generated vector diagram by the above-mentioned driving method. Vectors generated by each phase are the same as those in FIG. 3 and are omitted, and only the vectors generated by the winding sets and their combined vectors are shown. As can be seen from the drawing, the vector generated by the winding set whose excitation state has been switched in each step is rotated by 18 degrees (= 180/10) in electrical angle, and as a result, the combined vector generated by the excitation winding is 6 degrees. (= 1
80/30), and a half-step drive can be achieved.

FIG. 6 is an example of a time chart showing the excitation state according to the third aspect. Referring to FIG.
Then, it is equal to the above-mentioned step 1 and 12-phase excitation is performed. Next, when the process proceeds to step 2, the G phase of the winding set W1 is excited, and the excitation states of the winding set W2 and the winding set W3 are not switched, so that a 13-phase excitation state is set. When the process further proceeds to step 3, the excitation of the A-phase of the winding set W1 is released and the excitation states of the winding set W2 and the winding set W3 are not switched, so that a 12-phase excitation state is set. Further, in step 4, the O 'phase of the winding set W2 is excited, and the excitation states of the winding sets W1 and W3 are not switched, so that a 13-phase excitation state is set. When the process further proceeds to step 5, the excitation of the I 'phase of the winding set W2 is released, and the excitation states of the winding set W1 and the winding set W3 are not switched, so that a 12-phase excitation state is set. Further, in step 6, the H-phase of the winding set W3 is excited, and the excitation state of the winding sets W1 and W2 is not switched, so that a 13-phase excitation state is set. When the process further proceeds to step 7, the B-phase excitation of the winding set W3 is released and the excitation states of the winding set W1 and the winding set W2 are not switched, so that a 12-phase excitation state is set. Further, in step 8, the A 'phase of the winding set W1 is excited, and the excitation states of the winding sets W2 and W3 are not switched, so that a 13-phase excitation state is set. Similarly, in steps 9 to 60 as well, the excitation state of one winding set is switched for each input pulse, and the excitation state of an arbitrary winding set is switched twice consecutively by the input pulse, and the subsequent 2b- Between two pulses, the excitation state is controlled so as not to change.
The 13-phase excitation state is repeated.

FIG. 7 is a generated vector diagram by the above-mentioned driving method. Vectors generated by each phase are the same as those in FIG. 3 and are omitted, and only the vectors generated by the winding sets and their combined vectors are shown. As can be seen from the figure, the vector generated by the winding set whose excitation state has been switched in each step is 18 degrees (= 180/10) in electrical angle, and as a result, the resultant vector generated by the excitation winding is 6 Degree (=
180/30), and a half-step drive can be achieved.

FIG. 8 is an example of a time chart showing an excitation state according to the fourth aspect. In the figure, first, in step 1, the state is the same as step 1 described above, and a 12-phase excitation state is set. Next, when the process proceeds to step 2, the winding set W1
Are released, and the excitation states of the winding set W2 and the winding set W3 are not switched, so that an eight-phase excitation state is achieved.
Further proceeding to step 3, J ', D,
Since the M 'and G phases are excited and the excitation states of the winding set W2 and the winding set W3 are not switched, a 12-phase excitation state is set.
Further, in step 4, the excitation of all phases of the winding set W2 is released, and the excitation states of the winding sets W1 and W3 are not switched, so that an eight-phase excitation state is set. Further, in step 5, the winding set W
2, the C, L ', F, and O' phases are excited, and the excitation states of the winding sets W1 and W3 are not switched, so that a 12-phase excitation state is obtained. Further, in step 6, the excitation of all phases of the winding set W3 is released, and the excitation states of the winding sets W1 and W2 are not switched, so that an eight-phase excitation state is set. Further, in step 7, the K ', E, N', and H phases of the winding set W3 are excited, and the winding set W3 is excited.
Since the excitation states of 1 and W2 are not switched, a 12-phase excitation state is set. Further, in step 8, the excitation of all phases of the winding set W1 is released, and the excitation states of the winding sets W2 and W3 are not switched, so that an eight-phase excitation state is set. Similarly, in steps 9 to 60 as well, the excitation state of an arbitrary winding set is switched twice in succession by an input pulse, and the subsequent 2
During the b-2 pulse, the excitation state is controlled so as not to change. At the time of the switching, there is a state where the winding group is not excited, and the 8-12 phase excitation is repeated.

FIG. 9 is a generated vector diagram by the above driving method. Vectors generated by the respective phases are omitted because they are equivalent to those in FIG. 3, and only the vector generated by the winding set and its composite vector are shown. As can be seen from the drawing, the non-excited state is set at the time of switching the excited state of each arbitrary winding set, and the torque vector is 36 degrees (= 180/180) by the subsequent excitation.
5) As a result of the rotation, the combined vector generated by the excitation winding at each step is rotated by 6 degrees (= 180/30), and the half-step drive can be achieved.

FIG. 10 is an example of a time chart showing the excitation state of claim 5. In the figure, first, in step 1, the state is the same as step 1 described above, and a 12-phase excitation state is set. Next, when the process proceeds to step 2, A of the winding set W1
At the same time as the excitation of the I 'phase of the winding set W2 and the B phase of the winding set W3 is released, the G phase of the winding set W1 and the winding set 2 are released.
O ′ phase and the H phase of the winding set W3 are excited, and then, when the process proceeds to step 3, the J ′ phase of the winding set W1 and the winding set W
At the same time, the excitation of the C phase of the winding set 2 and the K 'phase of the winding set W3 is released, and the A' phase of the winding set W1, the I phase of the winding set W2, and the B 'phase of the winding set W3 are excited. Therefore, a 12-phase excitation state is set. Hereinafter, in steps 4 to 10 as well, 3
The excitation state of the winding sets is controlled so as to be switched simultaneously for each input pulse, and the 12-phase excitation state is repeated.

FIG. 11 is a generated vector diagram by the above-mentioned driving method. Vectors generated by each phase are the same as those in FIG. 3 and are omitted, and only the vectors generated by the winding sets and their combined vectors are shown. As can be seen from the figure, the vector generated by the winding set whose excitation state has been switched in each step is rotated by 36 degrees (= 180/5) in electrical angle. As a result, the resultant vector generated by the excitation winding is 36 degrees. (1
= 180/5), and full-step driving of the 5 (= b) phase motor has been achieved.

FIG. 12 is an example different from the above of the time chart showing the excitation state of the fifth aspect. First, in step 1, the state is the same as step 1 described above, and a 12-phase excitation state is set. Next, in Step 2, the G phase of the winding set W1, the O 'phase of the winding set W2, and the H phase of the winding set W3 are excited, so that a 15-phase excitation state is established. Next, when the process proceeds to step 3, the excitation of the A phase of the winding set W1, the I 'phase of the winding set W2, and the B phase of the winding set W3 is released, resulting in a 12-phase excitation. Next, when the process proceeds to step 4, the winding set W1
A ′ phase, the I phase of the winding set W2 and the B ′ phase of the winding set W3 are excited, so that a 15-phase excitation state is achieved. Similarly, in steps 5 to 20 as well, the excitation state of the three winding sets is controlled so as to be switched for each input pulse.
The 15-phase excitation state is repeated.

FIG. 13 is a generated vector diagram by the above-mentioned driving method. Vectors generated by each phase are the same as those in FIG. 3 and are omitted, and only the vectors generated by the winding sets and their combined vectors are shown. As can be seen from the figure, the vector generated by the winding set whose excitation state has been switched at each step is rotated by 18 degrees (= 180/10) in electrical angle, and as a result, the combined vector generated by each winding is 18 degrees (= 180
/ 10), and half-step driving of the 5 (= b) phase motor has been achieved.

Although not shown, 15
It can be understood that the present invention can be arbitrarily applied to a multi-phase stepping motor other than the phase stepping motor, for example, a 45-phase stepping motor. In addition, a driving method in which a winding set whose excitation state is switched for each input pulse is set to an arbitrary positive number equal to or less than b and a torque vector of the winding set is rotated by a positive number less than 2a of π / 2a is also implemented. It turns out that it is possible.

[0025]

As described above, according to the multi-phase stepping motor and the driving method thereof according to the present invention, the excitation sequence of the 15-phase stepping motor can be realized by combining the excitation sequence of the 5-phase stepping motor. Sequence construction becomes easy. As in the above embodiment, full-step and half-step driving of a 15-phase motor and full-step and half-step driving of a five-phase motor can be easily realized. During high-speed operation, the motor can be driven as a 5-phase motor, and can be driven as a 15-phase motor where high resolution is required.

FIG. 14 shows an equivalent circuit viewed from the power supply at the time of 12-phase excitation according to the above-described embodiment, which is composed of six parallel circuits formed by a winding group in which two phase windings are connected in series. (Where, R: winding resistance per phase, V: power supply voltage, I: rated current). Assuming that the rated current is 0.3 A and the winding resistance per phase is 27 Ω, a power supply having a power supply capacity of 1.8 A or more and a voltage capacity of 16.2 V or more is required as a drive power supply. Power supply, and a general switching element can be used.

Generally, in a stepping motor having a phase number a × b (a is an odd number of 3 or more, b is an integer of 2 or more), a winding set is formed by starting and ending a phase winding having a phase difference of 2π / a. Are sequentially connected to form a ring connection or a star connection, and when an m-phase excitation (m is a common multiple of b and 2), the equivalent circuit viewed from the power supply ideally has m as shown in FIG.
2 × b by a winding group in which / 2b phase windings are connected in series
(Where, I: rated current, R: winding resistance per phase, m: number of exciting phases, b: number of ring connection or star connection). At this time, a power supply having a current capacity of 2 × b × I or more and a voltage capacity of m × I × R / 2 / b or more is required as a drive power supply. By determining b suitable for the power supply capacity and the switching element, driving with a normal power supply and a low-cost and versatile switching element becomes possible.

[Brief description of the drawings]

FIG. 1 is a connection diagram of phase windings of a stepping motor showing an embodiment of a polyphase stepping motor and a driving system thereof according to the present invention.

FIG. 2 is a time chart showing an example of an excited state of the multi-phase stepping motor according to claim 2;

FIG. 3 is a diagram showing generated vectors according to the driving method of the multi-phase stepping motor shown in FIG. 2;

FIG. 4 is a time chart showing another example of the excited state of the multi-phase stepping motor of FIG. 1;

FIG. 5 is a generated vector diagram according to the driving method of the multi-phase stepping motor shown in FIG.

FIG. 6 is a time chart showing an example of an excited state of the multi-phase stepping motor according to claim 3;

FIG. 7 is a generated vector diagram according to the driving method of the multi-phase stepping motor shown in FIG.

FIG. 8 is a time chart showing an example of an excitation state of the multi-phase stepping motor according to claim 4;

FIG. 9 is a diagram showing generated vectors according to the driving method of the polyphase stepping motor shown in FIG.

FIG. 10 is a time chart showing another example of the excited state of the multi-phase stepping motor according to claim 5;

11 is a diagram illustrating generated vectors in the driving method of the multi-phase stepping motor shown in FIG.

FIG. 12 is a time chart showing an example of an excited state of the multi-phase stepping motor according to claim 5;

FIG. 13 is a generated vector diagram according to the driving method of the multi-phase stepping motor shown in FIG.

FIG. 14 is an equivalent circuit viewed from a power supply at the time of 12-phase excitation according to the embodiment of the present invention.

FIG. 15 is an equivalent circuit viewed from a power supply at the time of m-phase excitation according to the embodiment of the present invention.

[Explanation of symbols]

 W1, W2, W3 winding set φA to φO phase winding C1 to C15 Input terminal

Claims (5)

[Claims] In a stepping motor having a phase number of 6 or more represented by a × b (a is an odd number of 3 or more, b is an integer of 2 or more), a phase applied to a stator salient pole is provided. The windings are configured to include b sets of windings in which a phase windings are connected in a ring or star shape with a phase winding shifted by 2π / a, and have a × b input terminals. A multi-phase stepping motor. 2. A phase winding having a phase number of 6 or more represented by a × b (a is an odd number of 3 or more, b is an integer of 2 or more), and a phase winding applied to the stator salient poles. The line is a stepping motor having a winding set in which a phase windings each having a phase shift of 2π / a are connected in a ring or a star, and b sets are provided, and having a × b input terminals. Switching means are individually connected to the a × b input terminals, and the input terminals are connected to the positive electrode or the negative electrode of the driving power supply by switching, or are controlled so as not to be connected to any of the poles. In a stepping motor drive circuit that switches the excitation of the phase winding, the excitation state of one winding set is switched for each input pulse, and the excitation state of an arbitrary winding set is switched for each b input pulse. Are controlled so that , Torque vector due to the winding set is, [pi / a or [pi / 2a rotating polyphase stepping motor driving method which is characterized in that,. 3. A phase winding having a number of phases of 6 or more represented by a × b (a is an odd number of 3 or more, b is an integer of 2 or more), and a phase winding applied to the stator salient poles. The line is a stepping motor having a set of b winding sets in which a phase windings each having a phase shift of 2π / a are connected in a ring or star shape, and having a × b input terminals. A switching means is connected to each of the a × b input terminals, and each input terminal is connected to the positive electrode or the negative electrode of the driving power source by switching, or is controlled so as not to be connected to any of the electrodes. In a stepping motor drive circuit that switches the excitation state of windings, the excitation state of one winding group is switched for each input pulse, and the excitation state of any winding group is switched twice consecutively by an input pulse. Followed by 2b-2 pulses It is controlled so as to repeat that excited state does not change, the its switching, the driving method of a multi-phase stepping motor, characterized in that the torque vector by that the winding set is rotated by [pi / 2a. 4. A phase winding applied to a stator salient pole having a number of phases of 6 or more represented by a × b (a is an odd number of 3 or more, b is an integer of 2 or more). The line is a stepping motor having a set of b winding sets in which a phase windings each having a phase shift of 2π / a are connected in a ring or star shape, and having a × b input terminals. A switching means is connected to each of the a × b input terminals, and each input terminal is connected to the positive electrode or the negative electrode of the driving power source by switching, or is controlled so as not to be connected to any of the electrodes. In a stepping motor drive circuit that switches the excitation state of the windings, the excitation state of one winding set is switched for each input pulse, and the excitation state of any winding set is switched twice consecutively by the input pulse. Subsequent 2b-2 pulses Is controlled so that the excitation state does not change repeatedly. At the time of the switching, there is a state in which the winding group is not excited, and the angles of the torque vectors before and after the winding set differ by π / a. A driving method of a multi-phase stepping motor characterized by the following. 5. A phase winding having a number of phases of 6 or more represented by a × b (a is an odd number of 3 or more, b is an integer of 2 or more), and a phase winding applied to the stator salient poles. The line is a stepping motor having a set of b winding sets in which a phase windings each having a phase shift of 2π / a are connected in a ring or star shape, and having a × b input terminals. A switching means is connected to each of the a × b input terminals, and each of the input terminals is connected to the positive electrode or the negative electrode of the driving power supply by switching, or a phase is controlled so as not to be connected to any of the poles. In the drive circuit of the stepping motor for switching the excitation state of the windings, the excitation state of the b winding sets is controlled so as to be simultaneously switched for each input pulse, and the torque vector by each winding set is π by the switching. /
a, or a π / 2a rotation, for driving a multi-phase stepping motor.