CN111181470A - Harmonic suppression method for brushless double-fed motor - Google Patents
Harmonic suppression method for brushless double-fed motor Download PDFInfo
- Publication number
- CN111181470A CN111181470A CN202010149770.8A CN202010149770A CN111181470A CN 111181470 A CN111181470 A CN 111181470A CN 202010149770 A CN202010149770 A CN 202010149770A CN 111181470 A CN111181470 A CN 111181470A
- Authority
- CN
- China
- Prior art keywords
- winding
- stator
- span
- rotor
- windings
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 25
- 230000001629 suppression Effects 0.000 title claims abstract description 22
- 238000004804 winding Methods 0.000 claims abstract description 310
- 230000004907 flux Effects 0.000 claims abstract description 22
- 239000002131 composite material Substances 0.000 claims abstract description 17
- 230000001105 regulatory effect Effects 0.000 claims description 6
- 229910000976 Electrical steel Inorganic materials 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 3
- 238000005315 distribution function Methods 0.000 description 3
- 230000005284 excitation Effects 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
- H02P25/16—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the circuit arrangement or by the kind of wiring
- H02P25/22—Multiple windings; Windings for more than three phases
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
- H02K3/12—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors arranged in slots
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
- H02K3/28—Layout of windings or of connections between windings
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
- H02P29/50—Reduction of harmonics
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
- H02K2201/03—Machines characterised by aspects of the air-gap between rotor and stator
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2203/00—Specific aspects not provided for in the other groups of this subclass relating to the windings
- H02K2203/06—Machines characterised by the wiring leads, i.e. conducting wires for connecting the winding terminations
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P2207/00—Indexing scheme relating to controlling arrangements characterised by the type of motor
- H02P2207/01—Asynchronous machines
Abstract
The invention discloses a harmonic suppression method for a brushless doubly-fed motor, belonging to the technical field of brushless doubly-fed motors and comprising the following steps: s1: three sets of windings with the pole pairs of P1, P2 and P3 respectively form a motor stator winding, and each set of windings are arranged in a composite span manner; s2: selecting the positive directions of flux linkage, current and voltage; s3: the rotor winding is transformed to the stator side through the turn ratio, the turns of the stator winding are equal to those of the rotor winding, and mutual inductance magnetic flux between the windings passes through an air gap; s4: analyzing the characteristics of the air gap magnetic field to obtain the air gap magnetic field waveform; s5: using a four-quadrant frequency converter to regulate the speed of the three sets of stator windings to obtain harmonic magnetomotive force fluctuation amplitude; three groups of windings with adjustable span are adopted to form a stator winding, the span among the power winding, the control winding and the distance adjusting winding and the span among the windings of each winding are gradually shortened in a certain range, so that harmonic magnetic fields are mutually overlapped, the short-distance effect is increased, and the harmonic magnetomotive force intensity is reduced.
Description
Technical Field
The invention relates to the technical field of brushless double-fed motors, in particular to a harmonic suppression method of a brushless double-fed motor.
Background
The double-fed motor is also called AC excitation motor, and it includes motor itself and AC excitation automatic control system. The motor itself is a wound rotor induction motor or a specially designed brushless motor. The double-fed motor is a product combining a motor, a power electronic technology and a numerical control technology, and is a high and new technology product integrating the motor and the power electronic technology.
Two sets of stator windings of alternating current brushless double-fed motor can connect power frequency electric wire netting and variable frequency power supply simultaneously, have synchronous machine and asynchronous machine's operation characteristics simultaneously, and required converter capacity is little, and the operation is reliable, especially in the occasion of higher voltage class, can be by variable frequency power supply's low pressure control high pressure, and energy-conserving effect is showing, compares in the advantage of having brush double-fed motor and has: the structure is simpler, the reliability is enhanced without a brush, the power factor can be adjusted by a control end, and the like. Under the corresponding control end power supply mode, the corresponding operation modes comprise an asynchronous operation mode, a synchronous operation mode, a sub-synchronous mode and a super-synchronous mode. Wherein subsynchronous and supersynchronous are collectively referred to as doubly-fed operating modes. The control end can control the operation mode of the motor, and meanwhile, the power of the control end only accounts for one part of the total power of the motor, so that the energy of a power grid can be absorbed, and meanwhile, the energy can be returned to the power grid, and the capacity of the speed regulating system can be effectively reduced. The brushless double-fed motor has a great application prospect in a speed regulating system. The method has excellent potential in other fields including wind power, water power generation, variable-speed constant-frequency power generation and the like.
However, the research process of the high-voltage brushless double-fed motor is still limited by some technical problems, in the research of the high-voltage brushless double-fed motor, the harmonic content is high, the conductor utilization rate is low, and the harmonic content is a key factor influencing the motor efficiency. The method for suppressing the torque ripple during BDFM operation is large in harmonic suppression difficulty and not directly suppressed by collecting three-phase power currents, designing a power harmonic torque current detection circuit, a power harmonic torque current tracking circuit and a power harmonic torque current compensation circuit.
Disclosure of Invention
The invention aims to provide a harmonic suppression method of a brushless double-fed motor, which adopts three groups of windings with adjustable span to form a stator winding, gradually shortens the span among a power winding, a control winding and a distance adjusting winding and the span among winding coils in a certain range to enable harmonic magnetic fields to be mutually overlapped, increases a short-distance effect caused by relative position change, reduces the harmonic magnetomotive force strength and solves the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme: the harmonic suppression method of the brushless doubly-fed motor comprises the following steps:
s1: three sets of windings with the pole pair numbers of P1, P2 and P3 respectively form a motor stator winding, wherein the pole pair number is P1 corresponding to a power winding, the pole pair number is P2 corresponding to a control winding, the pole pair number is P3 corresponding to a distance-adjusting winding, and each set of windings are arranged in a composite type span mode;
s2: selecting positive directions of magnetic flux linkage, current and voltage, marking the positive directions of the stator voltage and the current according to the convention of a generator, generating positive magnetic flux linkage by the positive current, fixing the position of a three-phase winding axis of the stator on the space, marking the positive directions of the rotor voltage and the current according to the convention of the generator, generating the positive magnetic flux linkage by the positive current, and offsetting the rotor axis along with the rotation of the rotor;
s3: the rotor winding is transformed to the stator side through the turn ratio, the turns of the stator winding are equal to those of the rotor winding, and mutual inductance magnetic flux between the windings passes through an air gap;
s4: analyzing the characteristics of the air gap magnetic field of the brushless doubly-fed motor in an asynchronous operation mode, and simulating by using finite element calculation software to obtain the waveform of the air gap magnetic field;
s5: the power winding with the number of pole pairs P1 is directly connected with a low-voltage power grid, the control winding is connected with a four-quadrant frequency converter, the four-quadrant frequency converter is connected with a stator winding, a power winding and a distance adjusting winding through a power frequency power supply, and the four-quadrant frequency converter is used for adjusting the speed of three sets of stator windings according to the waveform of an air gap magnetic field in S3;
s6: and (5) adjusting the spacing between the three sets of stator windings according to the waveform of the air gap magnetic field in S3 until the harmonic magnetomotive force fluctuation amplitude is less than 1A/pole.
Further, in S1, the characteristics of the air gap field of the squirrel-cage rotor, the wound rotor, and the hybrid rotor brushless doubly-fed motor in the asynchronous operation mode are analyzed.
Further, in S1, the air gap magnetic field characteristics of the reluctance-type rotor brushless doubly-fed motor in the asynchronous operation mode are analyzed.
Furthermore, the reluctance type rotor brushless double-fed motor adopts silicon steel sheet materials to manufacture a motor rotor.
Furthermore, the power winding coil is arranged at the top of the stator slot, the control winding coil is arranged at the bottom of the stator slot, the distance-adjusting winding coil is arranged between the power winding coil and the control winding coil, and the three stator winding coils are all independently arranged.
Further, the number Z of stator slots is 72, the number Z of rotor slots is 48, the number P1 of power winding pole pairs is 3, the number P2 of control winding pole pairs is 1, and the number P3 of pitch windings is 1, 3, and 5.
Further, the number of slots of each phase of the power winding is 2, the span of an even slot is 10, the span of an odd slot is 8, the number of slots of each phase of the control winding is 6, the span of an even slot is 30, the span of an odd slot is 28, the number of slots of each phase of the pitch-adjusting winding is 2, the span of an even slot is 10, and the span of an odd slot is 8.
Further, the number of slots of each phase of the power winding is 2, the span of an even slot is 10, the span of an odd slot is 8, the number of slots of each phase of the control winding is 6, the span of an even slot is 30, the span of an odd slot is 28, the number of slots of each phase of the pitch-adjusting winding is 4, the span of an even slot is 20, and the span of an odd slot is 18.
Further, the number of slots of each phase of the power winding is 2, the span of an even slot is 10, the span of an odd slot is 8, the number of slots of each phase of the control winding is 6, the span of an even slot is 30, the span of an odd slot is 28, the number of slots of each phase of the pitch-adjusting winding is 6, the span of an even slot is 30, and the span of an odd slot is 28.
Further, S1 includes the following specific steps:
s101: the distance-adjusting winding corresponding to the pole pair number P3 is positioned between the power winding corresponding to the pole pair number P1 and the control winding corresponding to the pole pair number P2;
s102: the composite span part of each set of winding adopts the connection mode of direct connection series connection and reverse connection series connection;
s103: two sets of adjacent stator windings (1) with different pole pairs are indirectly coupled through the rotor.
Compared with the prior art, the invention has the beneficial effects that: the invention provides a harmonic suppression method of a brushless double-fed motor, which adopts three groups of windings with adjustable span to form a stator winding, wherein a distance adjusting winding is positioned between a power winding and a control winding, the distance adjustment is carried out between each set of windings with different or opposite pole pairs, harmonic waves with different intensities are generated in air gaps between adjacent windings in different distances, the harmonic state of the brushless double-fed motor is visually observed according to the waveform of an air gap magnetic field, and the span among the power winding, the control winding and the distance adjusting winding and the span among winding coils are gradually shortened in a certain range so that harmonic magnetic fields are mutually overlapped, thereby increasing a short-distance effect caused by the change of the relative position, reducing the intensity of harmonic magnetomotive force and further suppressing the harmonic wave of the brushless double-fed.
Drawings
FIG. 1 is a stator winding and rotor winding connection diagram of the present invention;
FIG. 2 is a stator winding structure of the present invention;
FIG. 3 is a diagram of the stator windings and four quadrant inverter connections of the present invention;
FIG. 4 is a graph of the magnetic potential distribution produced by a single coil current of the present invention;
FIG. 5 is a diagram illustrating an air-gap magnetic field waveform of a power winding according to a first embodiment of the present invention;
FIG. 6 is a diagram illustrating an air-gap magnetic field waveform of a control winding according to a first embodiment of the present invention;
FIG. 7 is a diagram illustrating an air-gap magnetic field waveform of a pitch winding according to a first embodiment of the present invention;
FIG. 8 is a diagram showing the air-gap magnetic field waveform of the control winding according to the second embodiment of the present invention;
FIG. 9 is a diagram showing the air-gap magnetic field waveform of the power winding according to the third embodiment of the present invention;
FIG. 10 is a diagram showing the air-gap field waveform of the control winding according to the third embodiment of the present invention;
fig. 11 is a flow chart of a harmonic suppression method of the brushless doubly-fed machine according to the present invention.
In the figure: 1. a stator winding; 11. a power winding; 12. a control winding; 13. a distance-adjusting winding; 2. a rotor winding; 3. four-quadrant frequency converter.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
Referring to fig. 1-7, the harmonic suppression method of the brushless doubly-fed motor includes the following steps:
s1: three sets of windings with the pole pair numbers of P1, P2 and P3 respectively form a motor stator winding 1, wherein the pole pair number is P1 corresponding to a power winding 11, the pole pair number is P2 corresponding to a control winding 12, the pole pair number is P3 corresponding to a distance-adjusting winding 13, and each set of windings are arranged in a composite span manner; a power winding 11 coil is arranged at the top of a stator slot, a control winding 12 coil is arranged at the bottom of the stator slot, a distance adjusting winding 13 coil is arranged between the power winding 11 coil and the control winding 12 coil, and the three stator winding 1 coils are all independently arranged; the specific implementation steps of the step are as follows:
s101: the distance-adjusting winding 13 with the number of pole pairs P3 is positioned between the power winding 11 with the number of pole pairs P1 and the control winding 12 with the number of pole pairs P2;
s102: the composite span part of each set of winding adopts the connection mode of direct connection series connection and reverse connection series connection;
s103: two sets of adjacent stator windings 1 with different pole pairs are indirectly coupled through a rotor;
s2: selecting positive directions of magnetic flux linkage, current and voltage, marking the positive directions of the stator voltage and the current according to the convention of a generator, generating positive magnetic flux linkage by the positive current, fixing the position of a three-phase winding axis of the stator on the space, marking the positive directions of the rotor voltage and the current according to the convention of the generator, generating the positive magnetic flux linkage by the positive current, and offsetting the rotor axis along with the rotation of the rotor;
s3: the rotor winding 2 is transformed to the stator side through the turn ratio, the turns of the windings of the stator and the rotor are equal, and mutual inductance magnetic flux between the windings passes through an air gap;
s4: analyzing the characteristics of the air gap magnetic field of the brushless doubly-fed motor in an asynchronous operation mode, and simulating by using finite element calculation software to obtain the waveform of the air gap magnetic field; analyzing the air-gap magnetic field characteristics of the cage-type rotor, the wound rotor and the hybrid rotor brushless double-fed motor in an asynchronous operation mode, and analyzing the air-gap magnetic field characteristics of the reluctance-type rotor brushless double-fed motor in the asynchronous operation mode, wherein the reluctance-type rotor brushless double-fed motor adopts silicon steel sheets to manufacture a motor rotor;
s5: the power winding 11 with the number of pole pairs P1 is directly connected with a low-voltage power grid, the control winding 12 is connected with the four-quadrant frequency converter 3, and the four-quadrant frequency converter 3 is used for regulating the speed of the three sets of stator windings 1 according to the waveform of the air gap magnetic field in S3;
s6: and (5) adjusting the spacing between the three sets of stator windings 1 according to the waveform of the air gap magnetic field in S3 until the harmonic magnetomotive force fluctuation amplitude is less than 1A/pole.
The brushless double-fed motor is characterized in that the number Z of stator slots is 72, the number Z of rotor slots is 48, the number P1 of pole pairs of a power winding 11 is 3, the number P2 of pole pairs of a control winding 12 is 1, the number P3 of pole pairs of a distance-adjusting winding 13 is 3, the number of slots of each phase of the power winding 11 is 2, the span of even-numbered slots is 10, the span of odd-numbered slots is 8, the number of slots of each phase of the control winding 12 is 6, the span of even-numbered slots is 30, the span of odd-numbered slots is 28, the number of slots of each phase of the distance-adjusting winding 13 is 2, the span of even-numbered slots is 10, and the span of odd-numbered slots.
Distribution of magnetic potential generated by a coil current along the circumference of the air gap, wherein 2 thetapFor the span of the coils (in mechanical degrees), the number of turns per coil is N, the current passed is ix, and for simplicity, the stator space coordinate θ is sets(mechanical angle) origin is set on the axis of the coil, where τ is the pole pitch, fx(θs) For the distribution function of the magnetic potential generated by one winding, the magnetic potential generated by the current of one phase winding is:
for the stator power winding 11, the harmonic order of the three-phase composite magnetic potential is:
νp＝(1±6k)pp(k＝0，1，2，…)
wherein p ispFor the pole pair number of the power winding 11, k is the winding coefficient of the fundamental wave of the power winding 11, and v is when k is 0pIs the fundamental magnetic potential of the power winding 11 when v ispWhen v is positive, the harmonic wave and the fundamental wave are in the same directionpWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the power winding 11 is:
wherein k iswpνV for the stator power winding 11pThe winding coefficient of the subharmonic;
similarly, for the stator control winding 12, the harmonic frequency of the three-phase composite magnetic potential is
νc＝(1±6k)pc(k＝0，1，2，…)
pcFor controlling the pole pair number of the winding 12, k is the winding coefficient of the fundamental wave of the control winding 12, and when k is 0, vcTo control the fundamental potential of winding 12, when vcWhen v is positive, the harmonic wave and the fundamental wave are in the same directioncWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the control winding 12 is:
wherein: k is a radical ofwcvV for stator control winding 12cThe winding coefficient of the subharmonic;
for the stator pitch winding 13, the three-phase resultant magnetic potential exists in harmonic order of
νr＝(1±6k)pi(k＝0，1，2，…)
piK is the winding coefficient of the fundamental wave of the distance adjusting winding 13 for the pole pair number of the distance adjusting winding 13, and v is the value when k is 0rFor the fundamental magnetic potential of the distance-adjusting winding 13, when vrWhen v is positive, the harmonic wave and the fundamental wave are in the same directionrWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the distance-adjusting winding 13 is as follows:
wherein: k is a radical ofwrvV for the stator-controllable winding 13rThe winding coefficient of the subharmonic.
Example two
Referring to fig. 8, the method for suppressing harmonic waves of the brushless doubly-fed motor includes the following steps:
s1: three sets of windings with the pole pair numbers of P1, P2 and P3 respectively form a motor stator winding 1, wherein the pole pair number is P1 corresponding to a power winding 11, the pole pair number is P2 corresponding to a control winding 12, the pole pair number is P3 corresponding to a distance-adjusting winding 13, and each set of windings are arranged in a composite span manner; a power winding 11 coil is arranged at the top of a stator slot, a control winding 12 coil is arranged at the bottom of the stator slot, a distance adjusting winding 13 coil is arranged between the power winding 11 coil and the control winding 12 coil, and the three stator winding 1 coils are all independently arranged; the specific implementation steps of the step are as follows:
s101: the distance-adjusting winding 13 with the number of pole pairs P3 is positioned between the power winding 11 with the number of pole pairs P1 and the control winding 12 with the number of pole pairs P2;
s102: the composite span part of each set of winding adopts the connection mode of direct connection series connection and reverse connection series connection;
s103: two sets of adjacent stator windings 1 with different pole pairs are indirectly coupled through a rotor;
s2: selecting positive directions of magnetic flux linkage, current and voltage, marking the positive directions of the stator voltage and the current according to the convention of a generator, generating positive magnetic flux linkage by the positive current, fixing the position of a three-phase winding axis of the stator on the space, marking the positive directions of the rotor voltage and the current according to the convention of the generator, generating the positive magnetic flux linkage by the positive current, and offsetting the rotor axis along with the rotation of the rotor;
s3: the rotor winding 2 is transformed to the stator side through the turn ratio, the turns of the windings of the stator and the rotor are equal, and mutual inductance magnetic flux between the windings passes through an air gap;
s4: analyzing the characteristics of the air gap magnetic field of the brushless doubly-fed motor in an asynchronous operation mode, and simulating by using finite element calculation software to obtain the waveform of the air gap magnetic field; analyzing the air-gap magnetic field characteristics of the cage-type rotor, the wound rotor and the hybrid rotor brushless double-fed motor in an asynchronous operation mode, and analyzing the air-gap magnetic field characteristics of the reluctance-type rotor brushless double-fed motor in the asynchronous operation mode, wherein the reluctance-type rotor brushless double-fed motor adopts silicon steel sheets to manufacture a motor rotor;
s5: the power winding 11 with the number of pole pairs P1 is directly connected with a low-voltage power grid, the control winding 12 is connected with the four-quadrant frequency converter 3, and the four-quadrant frequency converter 3 is used for regulating the speed of the three sets of stator windings 1 according to the waveform of the air gap magnetic field in S3;
s6: and (5) adjusting the spacing between the three sets of stator windings 1 according to the waveform of the air gap magnetic field in S3 until the harmonic magnetomotive force fluctuation amplitude is less than 1A/pole.
The brushless double-fed motor is characterized in that the number Z of stator slots is 72, the number Z of rotor slots is 48, the number P1 of pole pairs of a power winding 11 is 3, the number P2 of pole pairs of a control winding 12 is 1, the number P3 of pole pairs of a distance-adjusting winding 13 is 3, the number of slots of each phase of the power winding 11 is 2, the span of even-numbered slots is 10, the span of odd-numbered slots is 8, the number of slots of each phase of the control winding 12 is 6, the span of even-numbered slots is 30, the span of odd-numbered slots is 28, the number of slots of each phase of the distance-adjusting winding 13 is 4, the span of even-numbered slots is 20, and the span of odd-numbered slots.
Distribution of magnetic potential generated by a coil current along the circumference of the air gap, wherein 2 thetapFor the span of the coils (in mechanical degrees), the number of turns per coil is N, the current passed is ix, and for simplicity, the stator space coordinate θ is setsThe (mechanical angle) origin is set on the axis of the coil, wherein,τ is the polar distance, fx(θs) For the distribution function of the magnetic potential generated by one winding, the magnetic potential generated by the current of one phase winding is:
for the stator power winding 11, the harmonic order of the three-phase composite magnetic potential is:
νp＝(1±6k)pp(k＝0，1，2，…)
wherein p ispFor the pole pair number of the power winding 11, k is the winding coefficient of the fundamental wave of the power winding 11, and v is when k is 0pIs the fundamental magnetic potential of the power winding 11 when v ispWhen v is positive, the harmonic wave and the fundamental wave are in the same directionpWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the power winding 11 is:
wherein k iswpνV for the stator power winding 11pThe winding coefficient of the subharmonic;
similarly, for the stator control winding 12, the harmonic frequency of the three-phase composite magnetic potential is
νc＝(1±6k)pc(k＝0，1，2，…)
pcFor controlling the pole pair number of the winding 12, k is the winding coefficient of the fundamental wave of the control winding 12, and when k is 0, vcTo control the fundamental potential of winding 12, when vcWhen v is positive, the harmonic wave and the fundamental wave are in the same directioncWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the control winding 12 is:
wherein: k is a radical ofwcvV for stator control winding 12cThe winding coefficient of the subharmonic;
for the stator pitch winding 13, the three-phase resultant magnetic potential exists in harmonic order of
νr＝(1±6k)pi(k＝0，1，2，…)
piK is the winding coefficient of the fundamental wave of the distance adjusting winding 13 for the pole pair number of the distance adjusting winding 13, and v is the value when k is 0rFor the fundamental magnetic potential of the distance-adjusting winding 13, when vrWhen v is positive, the harmonic wave and the fundamental wave are in the same directionrWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the distance-adjusting winding 13 is as follows:
wherein: k is a radical ofwrvV for the stator-controllable winding 13rThe winding coefficient of the subharmonic.
EXAMPLE III
Referring to fig. 9-11, the harmonic suppression method for the brushless doubly-fed motor includes the following steps:
s1: three sets of windings with the pole pair numbers of P1, P2 and P3 respectively form a motor stator winding 1, wherein the pole pair number is P1 corresponding to a power winding 11, the pole pair number is P2 corresponding to a control winding 12, the pole pair number is P3 corresponding to a distance-adjusting winding 13, and each set of windings are arranged in a composite span manner; a power winding 11 coil is arranged at the top of a stator slot, a control winding 12 coil is arranged at the bottom of the stator slot, a distance adjusting winding 13 coil is arranged between the power winding 11 coil and the control winding 12 coil, and the three stator winding 1 coils are all independently arranged; the specific implementation steps of the step are as follows:
s101: the distance-adjusting winding 13 with the number of pole pairs P3 is positioned between the power winding 11 with the number of pole pairs P1 and the control winding 12 with the number of pole pairs P2;
s102: the composite span part of each set of winding adopts the connection mode of direct connection series connection and reverse connection series connection;
s103: two sets of adjacent stator windings 1 with different pole pairs are indirectly coupled through a rotor;
s2: selecting positive directions of magnetic flux linkage, current and voltage, marking the positive directions of the stator voltage and the current according to the convention of a generator, generating positive magnetic flux linkage by the positive current, fixing the position of a three-phase winding axis of the stator on the space, marking the positive directions of the rotor voltage and the current according to the convention of the generator, generating the positive magnetic flux linkage by the positive current, and offsetting the rotor axis along with the rotation of the rotor;
s3: the rotor winding 2 is transformed to the stator side through the turn ratio, the turns of the windings of the stator and the rotor are equal, and mutual inductance magnetic flux between the windings passes through an air gap;
s4: analyzing the characteristics of the air gap magnetic field of the brushless doubly-fed motor in an asynchronous operation mode, and simulating by using finite element calculation software to obtain the waveform of the air gap magnetic field; analyzing the air-gap magnetic field characteristics of the cage-type rotor, the wound rotor and the hybrid rotor brushless double-fed motor in an asynchronous operation mode, and analyzing the air-gap magnetic field characteristics of the reluctance-type rotor brushless double-fed motor in the asynchronous operation mode, wherein the reluctance-type rotor brushless double-fed motor adopts silicon steel sheets to manufacture a motor rotor;
s5: the power winding 11 with the number of pole pairs P1 is directly connected with a low-voltage power grid, the control winding 12 is connected with the four-quadrant frequency converter 3, and the four-quadrant frequency converter 3 is used for regulating the speed of the three sets of stator windings 1 according to the waveform of the air gap magnetic field in S3;
s6: and (5) adjusting the spacing between the three sets of stator windings 1 according to the waveform of the air gap magnetic field in S3 until the harmonic magnetomotive force fluctuation amplitude is less than 1A/pole.
The brushless double-fed motor is characterized in that the number Z of stator slots is 72, the number Z of rotor slots is 48, the number P1 of pole pairs of a power winding 11 is 3, the number P2 of pole pairs of a control winding 12 is 1, the number P3 of pole pairs of a distance-adjusting winding 13 is 3, the number of slots of each phase of the power winding 11 is 2, the span of even-numbered slots is 10, the span of odd-numbered slots is 8, the number of slots of each phase of the control winding 12 is 6, the span of even-numbered slots is 30, the span of odd-numbered slots is 28, the number of slots of each phase of the distance-adjusting winding 13 is 6, the span of even-numbered slots is 30, and the span of odd-numbered slots.
Distribution of magnetic potential generated by a coil current along the circumference of the air gap, wherein 2 thetapFor the span of the coils (in mechanical degrees), the number of turns per coil is N, the current passed is ix, and for simplicity, the stator space coordinate θ is sets(mechanical Angle) originIs arranged on the axis of the coil, wherein tau is the polar distance, fx(θs) For the distribution function of the magnetic potential generated by one winding, the magnetic potential generated by the current of one phase winding is:
for the stator power winding 11, the harmonic order of the three-phase composite magnetic potential is:
νp＝(1±6k)pp(k＝0，1，2，…)
wherein p ispFor the pole pair number of the power winding 11, k is the winding coefficient of the fundamental wave of the power winding 11, and v is when k is 0pIs the fundamental magnetic potential of the power winding 11 when v ispWhen v is positive, the harmonic wave and the fundamental wave are in the same directionpWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the power winding 11 is:
wherein k iswpνV for the stator power winding 11pThe winding coefficient of the subharmonic;
similarly, for the stator control winding 12, the harmonic frequency of the three-phase composite magnetic potential is
νc＝(1±6k)pc(k＝0，1，2，…)
pcFor controlling the pole pair number of the winding 12, k is the winding coefficient of the fundamental wave of the control winding 12, and when k is 0, vcTo control the fundamental potential of winding 12, when vcWhen v is positive, the harmonic wave and the fundamental wave are in the same directioncWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the control winding 12 is:
wherein: k is a radical ofwcvV for stator control winding 12cThe winding coefficient of the subharmonic;
for the stator pitch winding 13, the three-phase resultant magnetic potential exists in harmonic order of
νr＝(1±6k)pi(k＝0，1，2，…)
piK is the pole pair number of the distance adjusting winding 13, k is the winding coefficient of the fundamental wave of the distance adjusting winding 13, and v is the value when k is 0rFor the fundamental magnetic potential of the distance-adjusting winding 13, when vrWhen v is positive, the harmonic wave and the fundamental wave are in the same directionrWhen the voltage is negative, the harmonic and the fundamental wave are in opposite directions, so the amplitude of the harmonic magnetic potential generated by the current of the distance-adjusting winding 13 is as follows:
wherein: k is a radical ofwrvV for the stator-controllable winding 13rThe winding coefficient of the subharmonic.
In the first, second, and third embodiments, the air gap magnetic field waveform is obtained by using finite element calculation software to perform simulation, and the data is substituted into the formula, so that the amplitude of the harmonic magnetic potential generated by the stator winding 1 current and the amplitude of the harmonic magnetic potential generated by the power winding 11 current are both calculated to be smaller than 1, as shown in table 1.
TABLE 1 statistical table of amplitude of harmonic magnetic potential
In summary, the following steps: the invention provides a harmonic suppression method of a brushless doubly-fed motor, which adopts three groups of windings with adjustable span to form a stator winding 1, wherein a distance adjusting winding 13 is positioned between a power winding 11 and a control winding 12, the distance adjustment between each set of windings different or opposite pole pairs is realized, harmonic waves with different intensities are generated in air gaps between adjacent windings in different distances, the harmonic state of the brushless doubly-fed motor is visually observed according to the air gap magnetic field waveform, the span among the power winding 11, the control winding 12 and the distance adjusting winding 13 and the span among winding coils are gradually shortened in a certain range, so that harmonic magnetic fields are mutually overlapped, a short-distance effect caused by the change of relative positions is increased, the harmonic magnetomotive intensity of the harmonic waves is reduced, and the harmonic of the brushless doubly-fed motor is further suppressed.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical solutions and the inventive concepts of the present invention within the technical scope of the present invention.
Claims (10)
1. The harmonic suppression method of the brushless doubly-fed motor is characterized by comprising the following steps:
s1: three sets of windings with the pole pair numbers of P1, P2 and P3 respectively form a motor stator winding (1), wherein the pole pair number is P1 corresponding to a power winding (11), the pole pair number is P2 corresponding to a control winding (12), the pole pair number is P3 corresponding to a distance-adjusting winding (13), and each set of windings are arranged in a composite span manner;
s2: selecting positive directions of magnetic flux linkage, current and voltage, marking the positive directions of the stator voltage and the current according to the convention of a generator, generating positive magnetic flux linkage by the positive current, fixing the position of a three-phase winding axis of the stator on the space, marking the positive directions of the rotor voltage and the current according to the convention of the generator, generating the positive magnetic flux linkage by the positive current, and offsetting the rotor axis along with the rotation of the rotor;
s3: the rotor winding (2) is transformed to the stator side through the turn ratio, the turns of the windings of the stator and the rotor are equal, and mutual inductance magnetic flux between the windings passes through an air gap;
s4: analyzing the characteristics of the air gap magnetic field of the brushless doubly-fed motor in an asynchronous operation mode, and simulating by using finite element calculation software to obtain the waveform of the air gap magnetic field;
s5: a power winding (11) with the number of pole pairs of P1 is directly connected with a low-voltage power grid, a control winding (12) is connected with a four-quadrant frequency converter (3), and the three sets of stator windings (1) are regulated by using the four-quadrant frequency converter (3) according to the waveform of an air gap magnetic field in S3;
s6: and (4) adjusting the distance between the three sets of stator windings (1) according to the waveform of the air gap magnetic field in S3 until the harmonic magnetomotive force fluctuation amplitude is less than 1A/pole.
2. The harmonic suppression method for the brushless doubly-fed motor as claimed in claim 1, wherein the air-gap magnetic field characteristics of the cage rotor, the wound rotor and the hybrid rotor brushless doubly-fed motor in the asynchronous operation mode are analyzed in S1.
3. The harmonic suppression method for the brushless doubly-fed motor as claimed in claim 1, wherein the air-gap magnetic field characteristics of the reluctance-rotor brushless doubly-fed motor in the asynchronous operation mode are analyzed in S1.
4. The harmonic suppression method of the brushless doubly-fed machine as claimed in claim 3, wherein the reluctance rotor brushless doubly-fed machine is made of silicon steel sheet material.
5. A brushless doubly fed machine harmonic suppression method as claimed in claim 1, characterized in that the power winding (11) coil is placed on top of the stator slot, the control winding (12) coil is placed on bottom of the stator slot, the pitch winding (13) coil is placed between the power winding (11) coil and the control winding (12) coil, and the three stator winding (1) coils are all arranged separately.
6. A harmonic suppression method for brushless doubly fed machine as claimed in claim 1, characterized in that the number of stator slots Z is 72, the number of rotor slots Z is 48, the number of pole pairs P1 of the power winding (11) is 3, the number of pole pairs P2 of the control winding (12) is 1, and the number of pole pairs P3 of the pitch winding (13) is 1, 3 and 5.
7. A brushless doubly fed machine harmonic suppression method as claimed in claim 1, characterized in that the number of slots per phase of the power winding (11) is 2, the even slot span is 10, the odd slot span is 8, the number of slots per phase of the control winding (12) is 6, the even slot span is 30, the odd slot span is 28, the number of slots per phase of the pitch winding (13) is 2, the even slot span is 10, and the odd slot span is 8.
8. A brushless doubly fed machine harmonic suppression method as claimed in claim 1, characterized in that the number of slots per phase of the power winding (11) is 2, the even slot span is 10, the odd slot span is 8, the control winding (12) is 6, the even slot span is 30, the odd slot span is 28, the pitch winding (13) is 4, the even slot span is 20, and the odd slot span is 18.
9. A brushless doubly fed machine harmonic suppression method as claimed in claim 1, characterized in that the number of slots per phase of the power winding (11) is 2, the even slot span is 10, the odd slot span is 8, the control winding (12) is 6, the even slot span is 30, the odd slot span is 28, the pitch winding (13) is 6, the even slot span is 30, and the odd slot span is 28.
10. A harmonic suppression method for brushless doubly fed machine as claimed in claim 1, characterized in that S1 includes the following specific steps:
s101: the distance-adjusting winding (13) corresponding to the pole pair number P3 is positioned between the power winding (11) corresponding to the pole pair number P1 and the control winding (12) corresponding to the pole pair number P2;
s102: the composite span part of each set of winding adopts the connection mode of direct connection series connection and reverse connection series connection;
s103: two sets of adjacent stator windings (1) with different pole pairs are indirectly coupled through the rotor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010149770.8A CN111181470A (en) | 2020-03-06 | 2020-03-06 | Harmonic suppression method for brushless double-fed motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010149770.8A CN111181470A (en) | 2020-03-06 | 2020-03-06 | Harmonic suppression method for brushless double-fed motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111181470A true CN111181470A (en) | 2020-05-19 |
Family
ID=70648450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010149770.8A Pending CN111181470A (en) | 2020-03-06 | 2020-03-06 | Harmonic suppression method for brushless double-fed motor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111181470A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112117876A (en) * | 2020-09-15 | 2020-12-22 | 合肥工业大学 | High-synchronization speed difference modulation brushless double-fed motor |
| CN112865637A (en) * | 2021-01-25 | 2021-05-28 | 华中科技大学 | Torque ripple suppression device and method for brushless double-fed independent power generation system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2891456Y (en) * | 2006-03-21 | 2007-04-18 | 广东华拿东方能源有限公司 | Internal feeding brushless variable speed AC motor |
| US20140145541A1 (en) * | 2011-07-15 | 2014-05-29 | Wind Technologies Limited | Brushless doubly fed machines |
| CN109286258A (en) * | 2018-11-30 | 2019-01-29 | 武汉若可电气有限公司 | A kind of alternating-current brushless double feedback electric engine wound rotor winding and preparation method thereof |
| CN208955775U (en) * | 2018-11-13 | 2019-06-07 | 哈尔滨理工大学 | A kind of high-voltage brushless double feedback electric engine |
| WO2019174627A1 (en) * | 2018-03-15 | 2019-09-19 | 东南大学 | Equivalent air gap model for motor |
-
2020
- 2020-03-06 CN CN202010149770.8A patent/CN111181470A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2891456Y (en) * | 2006-03-21 | 2007-04-18 | 广东华拿东方能源有限公司 | Internal feeding brushless variable speed AC motor |
| US20140145541A1 (en) * | 2011-07-15 | 2014-05-29 | Wind Technologies Limited | Brushless doubly fed machines |
| WO2019174627A1 (en) * | 2018-03-15 | 2019-09-19 | 东南大学 | Equivalent air gap model for motor |
| CN208955775U (en) * | 2018-11-13 | 2019-06-07 | 哈尔滨理工大学 | A kind of high-voltage brushless double feedback electric engine |
| CN109286258A (en) * | 2018-11-30 | 2019-01-29 | 武汉若可电气有限公司 | A kind of alternating-current brushless double feedback electric engine wound rotor winding and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| SALMAN ABDI ET AL.: "A new stator back iron design for brushless doubly fed machines", 《2017 20TH INTERNATIONAL CONFERENCE ON ELECTRICAL MACHINES AND SYSTEMS (ICEMS)》, 5 October 2017 (2017-10-05), pages 1 - 6 * |
| 胡必武 等: "无刷双馈电机的定子绕组比较研究", 《微特电机》, no. 9, 30 September 2007 (2007-09-30), pages 10 - 11 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112117876A (en) * | 2020-09-15 | 2020-12-22 | 合肥工业大学 | High-synchronization speed difference modulation brushless double-fed motor |
| CN112865637A (en) * | 2021-01-25 | 2021-05-28 | 华中科技大学 | Torque ripple suppression device and method for brushless double-fed independent power generation system |
| CN112865637B (en) * | 2021-01-25 | 2022-03-11 | 华中科技大学 | Torque ripple suppression device and method for brushless double-fed independent power generation system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Cao et al. | Influence of leading design parameters on the force performance of a complementary and modular linear flux-switching permanent-magnet motor | |
| CN101640423B (en) | Generator system for wind power generation and variable speed control method | |
| US8928199B2 (en) | Wound rotor brushless doubly-fed motor | |
| CN102801266B (en) | Brushless double-fed motor wound rotor winding and manufacturing method thereof | |
| CN111181470A (en) | Harmonic suppression method for brushless double-fed motor | |
| Boldea et al. | Fractional kVA rating PWM converter doubly fed variable speed electric generator systems: An overview in 2020 | |
| CN107994816A (en) | A kind of electric system and its optimal control method | |
| Zhang et al. | A brushless doubly fed generator based on permanent magnet field modulation | |
| Hazra et al. | Power conversion with a magnetically-geared permanent magnet generator for low-speed wave energy converter | |
| Alnajjar et al. | Medium-speed synchronous reluctance generator as efficient, reliabile and low-cost solution for power generation in modern wind turbines | |
| Shao et al. | Design of a twelve-phase flux-switching permanent magnet machine for wind power generation | |
| Hofmann et al. | Optimal control of doubly-fed full-controlled induction wind generator with high efficiency | |
| CN202798399U (en) | Wound rotor winding for brushless doubly-fed motor | |
| Li et al. | Quantitive Harmonic Analysis and Force Ripple Suppression of a Parallel Complementary Modular Linear Reluctance machine | |
| US11621598B2 (en) | Torque density pseudo six-phase induction machine | |
| Abdoos et al. | Optimal Design of an Exterior-Rotor Permanent Magnet Generator for Wind Power Applications | |
| Shao et al. | A comparative study on nine-and twelve-phase flux-switching permanent-magnet wind generators | |
| Xiong et al. | Development of a multi-pitch unequal-turn-coil wound rotor for the brushless doubly-fed generator | |
| CN206099573U (en) | A. C. brushless double -fed motor | |
| Yao et al. | Voltage stabilization analysis of a harmonic excitation generator employing armature current auxiliary self-excitation scheme under variable load conditions | |
| Tatsuta et al. | Studies on characteristics of PMSGs used for current-source type wind farm composed of series-connected wind generators | |
| David et al. | Rotor-Tied Configuration of DFIG Wind Turbines for Improving Reactive Power Support Capability | |
| CN114400798B (en) | Single-winding direct-current excitation brushless double-fed motor and control circuit thereof | |
| EP3920406A1 (en) | Wind turbine electrical power generating system and method | |
| CN114123712B (en) | Voltage converter based on double-stator electric excitation synchronous motor design |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |