JPH0630592A - Motor - Google Patents

Abstract

PURPOSE:To control precise positioning by the rotation controlling for a minute angle, to control the speed of rotation from the high speed to the sufficiently low speed freely and to perform controlling even at the low-speed rotation by decreasing magnetic flux density so as to reduce iron loss. CONSTITUTION:High-frequency pulse currents having the phase differences are supplied into polyphase windings 1 from inverter power-supply devices 3, 41, 42, 51 and 52. An encoder 8 detects the rotary angle of a rotor 2 in multiple divisions. The detected signal is fed back to a control circuit 6. The inverter power-supply devices are controlled in multiple divisions. Thus, the rotation at the minute angle can be controlled by the increase in number of divisions, and the precise positioning control can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reluctance motor having windings of two or more phases.

[0002]

2. Description of the Related Art Conventionally, it is known to drive an AC motor by a DC power source using an inverter. However, the conventional inverter control is 1
Since the rotation angle of one pulse is controlled, the number of divisions is small and fine position control cannot be performed, and the rotation speed cannot be controlled in a wide range from high speed to sufficiently low speed. Further, in order to reduce the rotation speed, the drive pulse frequency by the inverter must be lowered, but the lower the frequency, the higher the magnetic flux density for producing the same output and the iron loss increases.

[0003]

The present invention eliminates the above drawbacks of the prior art, enables precise positioning control by controlling the rotation of a minute angle, and can freely control the rotation speed from a high speed to a sufficiently low speed. The purpose is to control the iron loss to be low by reducing the magnetic flux density even at low speed rotation.

[0004]

In a reluctance motor having windings of two or more phases, each winding is provided with an inverter for supplying a high-frequency pulse current having a phase difference, and the rotation angle is fed back to the inverter to perform multi-division control. It is characterized by doing so.

[0005]

As described above, the motor of the present invention is provided with an inverter for supplying a high-frequency pulse current having a phase difference to the multiphase winding, and the rotation angle is fed back to the inverter for multidivision control. Therefore, rotation of a minute angle can be controlled by increasing the number of divisions, and precise positioning control can be performed. Further, by supplying high-frequency pulses in multiple divisions to drive, the rotation speed can be freely controlled in an extremely wide range from high speed to sufficiently low speed.
Further, with this high frequency pulse control, the higher the frequency is, the smaller the magnetic flux density is. This has the effect of obtaining an efficient and high output with reduced iron loss. Further, according to the present invention, by forming the magnetic poles, the rotor, or both of them in the multi-divided unevenness, the multi-divided control can be controlled extremely stably and precisely. Further, according to the present invention, since the winding coil is provided with the magnetic energy discharge circuit, high-frequency pulse excitation can be facilitated by enhancing the falling characteristic of the exciting current and decreasing the time constant, and a highly efficient motor can be obtained. .
Further, the output of the inverter is boosted by a transformer and further doubled to rectify the voltage to supply a high voltage to the motor coil. Therefore, the rising characteristic of the high frequency pulse excitation can be improved and the motor can be easily driven with high efficiency. .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment of the drawings. In FIG. 1, reference numeral 1 is a motor coil composed of A phase and B phase, and the rotor 2 is rotated by this magnetic field drive. Reference numeral 3 denotes an inverter DC power supply for driving, which uses a power supply obtained by converting three-phase AC into DC by a rectifier, except in a special case where a battery is used. Reference numerals 41 and 42 denote semiconductor switches for switching the output of the DC power supply 3 on and off to generate a pulse output. MOSFETs are used as high frequency switches and are connected so that each switching pulse is supplied to the motor coil 1. Reference numerals 51 and 52 are smoothing capacitors for storing power source energy, 6 is a control circuit using a microprocessor or the like for switching and driving the FETs 41 and 42 with a required phase difference, and 71 and 72 are in a direction to release magnetic energy in parallel with the coil 1. The connected diode 8 is an encoder for detecting the rotation angle of the rotor 2, and the encoder output is fed back to the control circuit 6 to control the speed.

An encoder 8 for detecting the rotation angle of the rotor 2.
Detects the rotation angle in multiple divisions and feeds back this signal to the control circuit 6 for control. As described above, the control circuit 6 outputs a high-frequency pulse signal having a phase difference of multi-division control from the encoder 8 by the feedback signal of the rotation angle as described above.
Is controlled by a phase difference, for example, a pulse is generated with a phase difference of π / 2, and a rotating magnetic field is generated by exciting the A phase and the B phase of the coil 1, so that the motor can be driven. The pulse width of the pulse current is about 5 to 20 μs. By the minute pulse control, the rotation number of the minute angle can be increased by increasing the division number, and the rotation speed of the rotor 2 can be increased in proportion to the switching frequency of the FETs 41 and 42. It can be controlled at a sufficiently low speed.

The high speed rotation control is proportional to the switching speed of the FETs 41 and 42.
It becomes possible easily by providing. That is, as shown in FIG. 2, the magnetic energy of E = 1 / 2LI ² is stored in the file 1 when the FETs 41 and 42 are switched on, but when the switch is turned off, this is the diodes 71 and 7.
Since it is discharged through 2, the time constant can be remarkably shortened by the sharp fall, and high frequency switching is enabled.

FIG. 3 shows a motor stator 9 and rotor 2.
In the enlarged detailed view of FIG. 6, the stator 9 is a six-phase pole 91, 9
2, 93, 94, 95, and 96 are provided, and the coil 1 is wound around each of them. Further, eight minute divided fine concavities and convexities 9a are formed at the tip of each pole, and minute concavities and convexities 2a with a slight phase shift are also formed on the outer circumference of the rotor 2, which is used as a reluctance type. A multi-phase pulse current is applied to the winding coil 1 of each of the poles 91 to 96 for control, and a minute angle rotation control in which the number of divisions is increased by minute pulse control of a pulse width of the pulse current of about 5 to 20 μs. You can
As described above, this minute angle rotation control forms the multi-divided minute unevenness 9a on each pole and the minute unevenness 2a on the rotor 2 as well, whereby the angle control becomes accurate and the number of angle divisions can be further increased. This enables precise position control and speed control. For example, the division angle of the 8-division 6-pole shown is 360 ° / 48 = 7.5 °, which is 7.5.
When supplying a pulse of 20 μs at ° / 1 Pulse,
The rotation speed is 62500 RPM. Therefore, by controlling the rotation angle feedback so that the rotation angle is divided into multiple divisions and one rotation is performed at 480 pulses, the division angle is 0.75 ° /
The rotation speed becomes 6250 RPM at 1 pulse, and further divided into 0.075 ° / 1 pulse at 625 RPM.
Can be controlled. Such multi-division control can be easily and precisely controlled by forming minute unevenness of the pole, and the control angle is 0.75 ° / 1 by the multi-division control.
From Pulse to 0.075 ° / 1 Pulse, the rotation speed can be freely controlled from a high speed rotation of 62500 RPM to a sufficiently low speed of 625 RPM. Further, when a silicon steel sheet with a silicon content of 6.5 to 6.7% having a small magnetic anisotropy and magnetostriction is used for the motor coil and a silicon steel sheet having a thickness of 0.1 mm is used, the iron loss is W≈4B ² Al ( R / μL) × 10
It is ^-9 , and the magnetic flux density B for obtaining the same output is as shown in the table below, and it is understood that the higher the frequency f, the smaller the magnetic flux density B, the smaller the iron loss, and the higher the efficiency. According to this, according to the present invention, a high frequency pulse of about 5 to 20 μs is usually used, so that the magnetic flux density B is 1/1 of the conventional value.
It can be reduced to about 10, and iron loss can be reduced to improve efficiency.

FIG. 4 shows another embodiment of the inverter circuit.
The pulse current is transformer-coupled, boosted, and output. Reference numeral 10 is the step-up transformer, which transforms the pulse voltage to about 500 to 800 V to make the motor coil 1
The required power can be easily input by supplying the power. In FIG. 5, the output of the transformer 10 is further high-voltage rectified by the voltage doubler rectifier circuit 11 and supplied. By supplying such a high voltage pulse current, the rising characteristics of the exciting current can be improved and the time constant can be reduced to facilitate the high frequency pulse excitation, and the motor can be driven with high efficiency.

[0011]

As described above, the motor of the present invention is provided with an inverter for supplying a high-frequency pulse current having a phase difference to the multiphase winding, and the rotation angle is fed back to the inverter to control the motor in multiple divisions. Because it was
By increasing the number of divisions, it is possible to control the rotation of a minute angle and perform precise positioning control. Further, by supplying high-frequency pulses in multiple divisions to drive, the rotation speed can be freely controlled in an extremely wide range from high speed to sufficiently low speed. Further, with this high-frequency pulse control, the higher the frequency, the smaller the magnetic flux density, which has the effect of obtaining an efficient and high output with reduced iron loss.

Further, according to the present invention, since the magnetic pole, the rotor, or both of them are formed in multi-divided unevenness, the multi-divided control can be controlled extremely stably and precisely. Further, according to the present invention, since the winding coil is provided with the magnetic energy discharge circuit, the falling characteristic of the exciting current is enhanced and the time constant is reduced to facilitate the high frequency pulse excitation, and a highly efficient motor can be obtained. Further, the output of the inverter is boosted by a transformer and further doubled to rectify the voltage to supply a high voltage to the motor coil. Therefore, the rising characteristic of the high frequency pulse excitation can be improved and the motor can be easily driven with high efficiency. .

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of its waveform.

3 is an enlarged structural view of another embodiment of a portion of FIG. 1. FIG.

[Figure 4]

FIG. 5 is a circuit diagram of another embodiment of another part of FIG.

[Explanation of symbols]

 1 Winding coil 2 Rotor 3 DC power supply 41,42 FET 51,52 Capacitor 6 Control circuit 71,72 Diode 8 Encoder 9 Stator 91-96 Magnetic poles 9a, 2a Divided unevenness 10 Step-up transformer 11 Double voltage rectification circuit

Claims (5)

[Claims] 1. In a reluctance motor having windings of two or more phases, each winding is provided with an inverter for supplying a high-frequency pulse current having a phase difference, and the rotation angle is fed back to the inverter for multi-division control. A motor characterized by that. 2. The motor according to claim 1, wherein the winding coil is provided with a magnetic energy discharge circuit. 3. The motor according to claim 1, wherein the magnetic pole or the rotor is formed in a multi-divided concavo-convex pattern. 4. The motor according to claim 1, further comprising an inverter for transformer-coupling and outputting the high-frequency pulse current. 5. The motor according to claim 1, further comprising an inverter which couples the high frequency pulse current with a transformer and doubles and rectifies the output of the transformer.