CN111371350A

CN111371350A - Control method of full-magnetic-field direct-current motor system

Info

Publication number: CN111371350A
Application number: CN202010235045.2A
Authority: CN
Inventors: 杨猛
Original assignee: Individual
Current assignee: Yang Meng
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2020-07-03
Anticipated expiration: 2040-03-30
Also published as: WO2021196466A1; CN111371350B

Abstract

The invention discloses a control method of a full-magnetic field direct current motor system, wherein when a rotor magnetic pole is in a process of being approximately overlapped with a stator magnetic pole, a magnetic field generated by a stator winding current is mutually attracted with the magnetic field polarity of the rotor magnetic pole, when the central line of the rotor magnetic pole rotates through the central line of the stator magnetic pole, the current direction is changed, and at the moment, the magnetic field generated by the stator winding current is mutually repelled with the magnetic field polarity of the rotor magnetic pole to push the rotor to continuously rotate forwards.

Description

Control method of full-magnetic-field direct-current motor system

Technical Field

The invention relates to the technical field of motors, in particular to a control method of a full-magnetic-field direct-current motor system.

Background

The motor is a device for converting electric energy into mechanical energy, and is characterized by that it utilizes the electrified coil to produce rotating magnetic field and act on the rotor to form magnetoelectric power rotating torque, and the principle model of D.C. motor in the physics is shown in figure 1, when the coils of two ends are electrified, according to the right-hand spiral rule, it can produce external magnetic induction intensity B whose direction is directed rightward, and the middle rotor can make the magnetic induction line direction in its interior be identical to that of external magnetic induction line to form a shortest closed magnetic line loop, so that the inner rotor can be rotated according to the clockwise direction, and by applying said principle, the inventor designs a brushed D.C. motor with commutator, when the rotor is turned to N-S pole centre and completely aligned, if the stator magnetic field is retained, it can produce strong braking torque for rotor, if it can make the stator be cut off in advance by a small angle in alignment of stator and rotor magnetic pole, the stator magnetic poles are demagnetized, the rotor is not acted by the rotating torque any more, but the rotor can continue to rotate clockwise due to inertia, after rotating a small angle aligned with the angular point, if the current direction of the two solenoids is changed, as shown in fig. 2, the rotor can continue to rotate clockwise forward, so the current direction of the two solenoids is continuously changed, the inner rotor can be rotated without stop, the invention patent application with the publication number of WO2017092174a1 discloses a multi-phase brushless direct current motor and a driving method thereof, wherein a driving module in the motor comprises a controller, an H-bridge single-stage inverter and independent phase coil windings which are sequentially and electrically connected, however, the invention patent application only proposes that each stator winding is independently driven by an H-bridge, the motor driving principle is still based on the principle that sine alternating current generates a rotating magnetic field, and the motor is manufactured by the existing rotating magnetic field principle, the invention patent with the publication number of CN105322748B discloses a current control method of a seven-phase winding permanent magnet synchronous brushless direct current motor, which comprises that a stator adopts 7 slots or multiple slots of 7 and adopts the winding of seven-phase windings, although the invention patent proposes the idea of improving the power density of the motor, the invention patent is only limited to the seven-phase windings, has no general adaptability and has limited improvement of the power density;

the existing brushless direct current motor based on the rotating magnetic field principle only has two thirds of windings which are electrified to do work at any time, and the power density is limited.

Disclosure of Invention

In order to solve the problems, the invention discloses a control method of a full-magnetic-field direct-current motor system.

The technical scheme of the invention is that the control method of the full-magnetic field direct current motor system comprises a motor body and a motor controller for driving the motor body, wherein a stator and a permanent magnet rotor are arranged in the motor body, a stator magnetic pole and a stator winding are arranged on the stator, a phase sensor is arranged on the motor stator, a phase mark coded disc matched with the phase sensor is arranged on a rotor shaft, and each stator winding corresponds to one group of phase sensors;

particularly, the number of stator magnetic poles required by the internal rotor motor is greater than that of rotor magnetic poles but is not required to be equal to 1.5 times that of the rotor magnetic poles, particularly the number of the stator magnetic poles is allowed to be equal to the number of the rotor magnetic poles +1 and +2, and the number of the stator magnetic poles is also supported to be a prime number;

if the number of the stator windings is prime, the windings of each magnetic pole of the stator must be independently controlled by power;

if the stator windings are complex numbers, the stator windings can be properly connected in series, the series connection number of the windings is the common divisor of the number of the stator windings and the number of the magnetic poles of the rotor, for example, the 6-pole stator windings of the 4-pole rotor, the series connection number is 2, and the 6-pole stator windings can be connected in series to form 3 windings; for another example, the 6-pole rotor 8-pole stator winding has the serial number of 2, and the 8-pole stator winding can be connected in series to form 4 windings;

when the number of the stator windings is a prime number, the torque ripple of the motor is minimum;

for an inner rotor motor, the number of stator poles is greater than the number of rotor poles;

for an outer rotor motor, the number of stator poles is less than the number of rotor poles;

the stator windings are not in star connection or triangular connection, and each stator winding is independently controlled by the power controller;

when the rotor magnetic pole is in the process of being approximately overlapped with the stator magnetic pole, the magnetic field generated by the stator winding current is mutually attracted with the magnetic field polarity of the rotor magnetic pole to drive the rotor to rotate forwards, the stator winding is electrified with reverse current after the central line of the rotor magnetic pole rotates through the central line of the stator magnetic pole, at the moment, the magnetic field generated by the stator winding current is mutually repelled with the magnetic field polarity of the rotor magnetic pole to push the rotor to continuously rotate forwards, and meanwhile, the polarity of the subsequent adjacent rotor magnetic pole is in the process of being approximately overlapped with the magnetic field generated by the current stator winding current, so that the continuous rotation of the motor body is realized;

the motor controller comprises a single chip microcomputer, a direct current bus and a plurality of groups of H bridges, wherein the direct current bus is electrically connected with the plurality of groups of H bridges, a current control element is electrically connected onto the direct current bus and used for managing and conveying current on the direct current bus, the output end of the single chip microcomputer is electrically connected with a switch element of the H bridge, the single chip microcomputer is electrically connected with the phase sensor, the single chip microcomputer receives signals of the phase sensor and drives a switch of a bridge arm of the H bridge, so that the direction control and the on-off control of the current of the stator winding are carried out, and each group of H bridges independently control one stator winding;

when the center line of the rotor magnetic pole coincides with the center line of the stator winding, the phase sensor obtains a rotor phase signal and transmits the rotor phase signal to the single chip microcomputer, and the single chip microcomputer drives the switch of the H-bridge arm after receiving the signal of the phase sensor, so that the commutation control of the stator winding current is realized, a magnetic field generated by the stator winding current and the magnetic field polarity of the rotor magnetic pole are mutually exclusive, and the rotor is pushed to continuously rotate forwards.

Preferably, small-angle power-off dead zones are arranged on the two sides of the center line of the stator winding, when the center line of the rotor magnetic pole enters the range of the power-off dead zones, the motor controller controls the H bridge to power off the stator winding, and after the center line of the rotor magnetic pole passes through the power-off dead zones of the stator winding, the motor controller controls the H bridge to commutate the current of the stator winding;

the invention provides a control method of a full-magnetic field direct current motor system, which has the following beneficial effects that the motor system has a compact structure, the driving principle of the traditional motor through a rotating magnetic field is overturned, the windings of the motor are all involved in driving, and the power density of the motor is greatly improved.

Drawings

Fig. 1 is a schematic view of the rotor of the present invention rotating under the attraction force in an electromagnetic field.

Fig. 2 is a schematic view of the rotor of the present invention rotated by a repulsive force in an electromagnetic field.

Fig. 3 is a schematic structural diagram of a 4-stage rotor 5 salient pole stator motor of the invention.

Fig. 4 is a schematic structural diagram of a 4-stage rotor 6 salient pole stator motor of the invention.

FIG. 5 is a schematic diagram of the photoelectric switch + code disc of the present invention.

Fig. 6 is an overall schematic diagram of the motor of the present invention.

In the figure, 1, stator magnetic pole; 2. a stator winding; 3. a rotor; 4. a phase marker code disc; 5. a phase sensor; 6. a motor controller; 7. a direct current bus; 8. an H bridge; 9. a single chip microcomputer; 10. a current control element.

Detailed Description

The present invention will be further described with reference to the following examples.

Example (b): 3-6, a 4-level rotor 5 salient pole stator brushless motor is selected to describe the embodiment of the invention, the motor structure is shown in FIG. 3, the schematic diagram of the motor and the motor control system is shown in FIG. 5, the identification mark of the phase mark coded disc 4 is overlapped with the central line of the magnetic pole of the rotor 3, and a dead zone space is reserved; each stator magnetic pole 1 corresponds to 2 phase sensors 5, for example, the a magnetic pole corresponds to two phase sensors 5 of MA1 and MA2, MA1 is located at the center line of the a magnetic pole, the phase difference between MA2 and MA1 is 90 degrees, which is the included angle of the center lines of the two rotor 3 magnetic poles, each phase sensor 5 is connected to the single chip microcomputer 9 of the motor controller 6, the included angle of the opening phase signal of the phase mark coded disc 4 is 87 degrees, that is, when the current of the stator magnetic pole 1 is reversed, a dead zone with an included angle of 3 degrees is left.

Each stator winding 2 pushes the rotor 3 to work by the attraction and repulsion principle of the magnetic pole of the rotor 3, the current direction in the stator winding 2 is controlled by the phase of the rotor 3, as shown in fig. 5, taking the A magnetic pole as an example, taking MA1 as S pole, MA2 as N pole, and setting the rotating direction of the rotor 3 as counterclockwise, the center line of N pole of the rotor 3 already exceeds the center line of the A magnetic pole, the S pole of the rotor 3 is in the process of nearly overlapping with the A magnetic pole, and the N pole of the rotor 3 is away from the A magnetic pole, the instantaneous position of the phase marking coded disc 4 corresponds to MA2 as on, the A magnetic pole is N pole,

the B magnetic pole is in a commutation dead zone, the central line of the B magnetic pole is completely overlapped with the central line of the N level of the rotor 3, the two phase sensors MB1 and MB2 are both in a closed state, the winding of the B magnetic pole is powered off and has no magnetism, when the rotor 3 rotates anticlockwise continuously for 1.5 degrees, the MB2 is powered on, the polarity of the B magnetic pole is an N pole,

for the C pole, the S-pole center line of the rotor 3 already exceeds the C pole center line, but still within the pole overlap region, the C pole phase sensor MC1 is on, MC2 is off, and the polarity of the C pole is S-pole, repelling the S-pole of the rotor 3 that is leaving, and attracting the N-pole of the rotor 3 that is entering the overlap region.

For preventing to produce locking moment or reverse moment between stator magnetic pole 1 and the 3 magnetic poles of rotor, stator winding 2 sets up small-angle outage blind spot around the central line, and when 3 magnetic pole central lines of rotor were in the blind spot within range here, stator winding 2 did not circular telegram, had no effort to 3 magnetic poles of rotor, and rotor 3 passes through the blind spot under the effort of other magnetic poles, just lets in reverse current to the stator after treating 3 magnetic pole central lines of rotor and passing through the blind spot.

A phase mark coded disc 4 is arranged on a motor rotor shaft, coded disc identification marks correspond to the central lines of magnetic poles of each rotor 3, a matched phase sensor 5 is arranged corresponding to the phase mark coded disc 4, a rotor 3 phase section corresponding to the current phase sensor 5 can be obtained through the coded disc identification marks, each stator winding 2 corresponds to one group of phase sensors 5, the phase sensors 5 obtain rotor phase signals and transmit the rotor phase signals to a single chip microcomputer 9 of a motor controller 6, each H bridge 8 unit controls one winding of a motor, the single chip microcomputer 9 receives the signals of the phase sensors 5 and drives switches of bridge arms of the H bridge 8, and reversing control over currents of the stator windings 2 is achieved. When the motor needs to be reversed, the single chip microcomputer 9 controls the on-off of the bridge arms of the H bridge 8 through the direction logic and phase signals transmitted by the encoder, and the on-off signals of the upper bridge arm and the lower bridge arm of each H bridge 8 are exchanged according to the direction logic during reversing.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A control method of a full-magnetic-field direct-current motor system comprises a motor body and a motor controller (6) used for driving the motor body, wherein a stator and a rotor (3) are arranged in the motor body, and the stator is provided with a stator magnetic pole (1) and a stator winding (2), and is characterized in that the rotor (3) is a permanent magnet rotor, a phase sensor (5) is arranged on the stator of the motor body, and a phase mark coded disc (4) matched with the phase sensor (5) is arranged on a shaft of the rotor (3);

when the magnetic pole of the rotor (3) is in the process of being approximately overlapped with the magnetic pole of the stator (1), the magnetic field generated by the current of the stator winding (2) is mutually attracted with the magnetic field polarity of the magnetic pole of the rotor (3) to drive the rotor (3) to rotate forwards, after the central line of the magnetic pole of the rotor (3) rotates through the central line of the magnetic pole of the stator (1), the stator winding (2) is electrified with reverse current, at the moment, the magnetic field generated by the current of the stator winding (2) is mutually repelled with the magnetic field polarity of the magnetic pole of the rotor (3) to push the rotor (3) to continuously rotate forwards, and meanwhile, the polarity of the subsequent adjacent magnetic pole of the rotor (3) is in the process of being approximately overlapped with the magnetic field generated by the current of the stator winding;

the motor controller (6) comprises a single chip microcomputer (9), a direct current bus (7) and H bridges (8), the direct current bus (7) is electrically connected with a plurality of groups of H bridges (8), the output end of the single chip microcomputer (9) is electrically connected with the control end of the H bridges (8), the single chip microcomputer (9) is electrically connected with the phase sensors (5), the single chip microcomputer (9) receives signals of the phase sensors (5) and drives switches of bridge arms of the H bridges (8) so as to control the direction and the opening and closing of currents of the stator windings (2), and each group of H bridges (8) independently control one stator winding (2);

when the center line of the magnetic pole of the rotor (3) is coincident with the center line of the stator winding (2), the phase sensor (5) obtains a phase signal of the rotor (3) and transmits the phase signal to the singlechip (9), and the singlechip (9) drives a switch of a bridge arm of the H bridge (8) after receiving the signal of the phase sensor (5) to realize the reversing control of the current of the stator winding (2), so that the magnetic field generated by the current of the stator winding (2) is mutually exclusive with the magnetic field polarity of the magnetic pole of the rotor (3) and the rotor (3) is pushed to continuously rotate forwards.

2. The control method of the full-magnetic-field direct-current motor system according to claim 1, wherein the stator winding (2) is provided with outage dead zones on two sides of a center line, when the magnetic pole center line of the rotor (3) enters the outage dead zone range, the motor controller (6) controls an H bridge (8) corresponding to the stator winding (2) to cut off the power of the stator winding (2), and after the magnetic pole center line of the rotor (3) passes through the outage dead zone of the stator winding (2), the motor controller (6) controls the H bridge (8) to commutate the current of the stator winding (2).