CN108521244B - Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage - Google Patents

Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage Download PDF

Info

Publication number
CN108521244B
CN108521244B CN201810223578.1A CN201810223578A CN108521244B CN 108521244 B CN108521244 B CN 108521244B CN 201810223578 A CN201810223578 A CN 201810223578A CN 108521244 B CN108521244 B CN 108521244B
Authority
CN
China
Prior art keywords
phase
current
winding
motor
torque
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.)
Active
Application number
CN201810223578.1A
Other languages
Chinese (zh)
Other versions
CN108521244A (en
Inventor
袁野
孙玉坤
黄永红
朱志莹
孟高军
张宽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu University
Kaifeng Power Supply Co of State Grid Henan Electric Power Co Ltd
Original Assignee
Jiangsu University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jiangsu University filed Critical Jiangsu University
Priority to CN201810223578.1A priority Critical patent/CN108521244B/en
Publication of CN108521244A publication Critical patent/CN108521244A/en
Application granted granted Critical
Publication of CN108521244B publication Critical patent/CN108521244B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/05—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation specially adapted for damping motor oscillations, e.g. for reducing hunting
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N15/00—Holding or levitation devices using magnetic attraction or repulsion, not otherwise provided for
    • 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
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/0003—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
    • 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
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/06—Rotor flux based control involving the use of rotor position or rotor speed sensors
    • H02P21/10—Direct field-oriented control; Rotor flux feed-back control
    • 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
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/10—Arrangements for controlling torque ripple, e.g. providing reduced torque ripple

Abstract

The invention relates to a method for suppressing low torque ripple in a wide speed regulation range of a bearingless brushless direct current motor for flywheel energy storage, which belongs to the field of motor control. When the Hall position signal jump marks the beginning of phase change, the phase-off current is reduced to zero, and the phase change is finished, and a measure of switching off the phase and switching on the phase and keeping the phase constant is adopted during the phase change period by PWM modulation in the same step of switching off the phase and not switching the phase. And simultaneously sampling the non-commutation phase current value at the current moment, namely the k moment, and the motor rotating speed, obtaining the reverse electromotive force of the three-phase winding according to the running state of the motor at the current moment, namely the k moment, and finally calculating a predictive control law D by using a current predictive control module, thereby controlling the output of the inverter circuit and controlling the rotation of the motor.

Description

Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage
Technical Field
The invention relates to a bearing-free brushless direct current motor with wide speed regulation range and low torque ripple suppression, which is suitable for high-performance control of a bearing-free brushless direct current motor for a flywheel battery and belongs to the field of motor control.
Background
With the development of new energy power generation, distributed power systems, hybrid vehicles, aerospace and other fields, energy storage technology has become a worldwide research topic. Among the energy storage technologies, the flywheel battery has received high attention at home and abroad due to the advantages of high power, high efficiency, long service life, high energy storage density, cleanness, no pollution and the like. As one of the core components of the flywheel battery, a driving motor is a focus of research. The brushless direct current motor without the bearing not only has the advantages of high critical rotating speed, good speed regulation performance and simple structure of the brushless direct current motor, but also has the characteristics of low loss and high integration of the magnetic bearing motor. However, like the conventional permanent magnet brushless dc motor, the bearingless brushless dc motor also has inevitable problems: torque ripple due to machining processes and motor control performance. The torque pulsation can bring a series of problems of vibration, noise, resonance and the like, the running safety and reliability of a flywheel battery system are reduced, and the application of the bearingless brushless direct current motor in new energy sources such as flywheel batteries and the like and high-precision fields such as aviation, medical treatment and the like is limited.
In order to suppress torque ripple of a brushless dc motor, domestic and foreign scholars propose control strategies such as a PWM current modulation technique, current hysteresis, adaptive control, and the like. The control strategies mainly control the torque indirectly by a method of controlling current, belong to torque open-loop control, and have slow torque response speed. And the Direct Torque Control (DTC) performs closed-loop control on the torque, and has the advantages of quick dynamic response of the torque, simple structure, strong robustness, easy realization and the like. The DTC utilizes the principles of stator magnetic field orientation and space vectors, directly observes the flux linkage and the torque of the motor under a stator coordinate system by detecting the voltage and the current of the stator, compares the observed value with a given value, obtains a corresponding control signal by a hysteresis controller according to a difference value, and selects a corresponding voltage space vector by integrating the current flux linkage state to realize the direct control of the motor torque. It can be functionally divided into two parts: an observation and control part of the stator flux linkage, which is used for selecting a proper voltage space vector to generate a hexagonal flux linkage in the stator; and a torque observation and control part for realizing instantaneous control of the torque. Because the permanent magnet brushless DC motor is provided with the Hall position sensor, and the flux linkage formed on the motor stator by the voltage space vector determined by the position sensor in the motor operation process is hexagonal, when the DTC is used for the brushless DC motor, on one hand, the flux linkage observation part can be omitted so as to simplify the structure of a control system, and on the other hand, the torque fluctuation of the motor is limited within a specified range by utilizing the high dynamics of the torque control.
The direct torque control strategy of the brushless direct current motor usually adopts a two-phase conduction mode, which can simplify the structure of a control system, but when the motor runs in a high-speed section, the motor can lose the inhibition effect on the phase-change torque ripple as in the traditional pulse width modulation current control.
Disclosure of Invention
In order to solve the problem that the suppression effect of the commutation torque ripple is not ideal when a direct torque control strategy of the bearingless brushless direct current motor operates in a high-speed section, the invention provides a method for suppressing the commutation torque ripple in a wide speed regulation range and in a low torque ripple manner of the bearingless brushless direct current motor.
The technical scheme of the invention is as follows: a method for suppressing the wide speed regulation range and low torque ripple of a bearingless brushless direct current motor for flywheel energy storage comprises the following two control processes: a torque control section and a levitation control section;
a torque control section: the error between the given speed n and the actual speed n of the brushless DC motor without bearing is regulated by PID as the given torque Te *Given a torque Te *And the actual torque TeThe error of the motor is subjected to torque regulation, corresponding voltage vectors are selected, and meanwhile, current prediction control is added in combination with a motor rotor position angle theta fed back by a detection device, and finally, torque pulsation of the motor in low-speed, medium-speed and high-speed operation is minimized through the output of an inverter;
a suspension control section: given displacement x, y and error of current vortex sensor actual detection displacement x, y are sent to PID regulator, PID outputs reference suspension force Fx *,Fy *Sending the current to a current set value calculation module of the suspension winding, and outputting a current i through an invertera,b,cAnd finally, controlling the current rotor to stably suspend.
Further, the formula used by the suspension winding current given value calculation module is as follows:
F＝kii+kxx
wherein k isiIs the current stiffness coefficient, kxIs the displacement stiffness coefficient, i is the suspension winding current, x is the rotor unilateral displacement.
Further, the torque control part comprises the following specific processes:
1) the system adopts a control mode of double closed loops of rotating speed and torque, carries out torque control at non-commutation moment, carries out overlapped commutation at commutation moment, and simultaneously adds a current prediction module to calculate the duty ratio;
2) the Hall position signal jump marks the beginning of phase change, and the phase-off current is reduced to zero to mark the end of phase change;
3) the method of overlapped commutation, namely the method of turn-off phase delay turn-off, is adopted, in order to reflect the current of the non-commutation phase on the direct current bus during the delay turn-off period, the measure of turn-off phase and non-commutation phase synchronous PWM modulation are adopted during the commutation period, and the phase is turned on and is constantly switched on;
4) sampling a non-commutation phase current value and a motor rotating speed at the current moment, namely the k moment;
5) obtaining the opposite electromotive force of the three-phase winding according to the running state of the motor at the current moment, namely the k moment;
6) calculating a budget control law D according to the voltage of the three-phase winding end at the current moment, namely the moment k, the back electromotive force of the three-phase winding, the non-commutation current value at the moment k and the predicted value of the non-commutation phase current at the next moment k +1, so as to control the output of the inverter circuit;
7) and repeating the steps 2) to 6) until the phase change is finished, and carrying out torque closed-loop control.
The brushless DC motor without bearing has one set of suspension control winding embedded inside the stator slot of the brushless DC motor to make the suspension magnetic field and the rotating magnetic field share one set of magnetic core circuit. U, V, W is a torque winding of the motor for controlling rotation of the motor. a1, a2, b1, b2, c1 and c2 are suspension windings of the motor, and each set of windings is formed by connecting two windings in series. The torque winding and the suspension winding adopt a concentrated winding mode, and the torque winding adopts a two-phase conduction mode. Because mutual inductance between the concentrated windings is small, and the torque winding and the suspension winding of the common teeth are always conducted at different times, decoupling control between the torque winding and the suspension winding can be achieved. The control of the bearingless brushless dc motor can be divided into a torque control subsystem and a levitation control subsystem.
When the direct torque control strategy of the bearingless brushless direct current motor adopts a two-phase conduction mode, when the motor runs at a high speed section, the reduction rate of the off-phase current is greater than the increase rate of the on-phase current, and the non-commutation current generates current drop, but the direct torque control strategy can not compensate the reduction of the non-commutation phase current. As can be seen from the torque calculation formula, the torque decreases at this time, and torque pulsation occurs. To compensate for the drop in non-commutation phase current, a current predictive control is introduced. The current prediction control uses the non-commutation phase current to keep constant as a prediction reference track so as to control the current change rate of the off-phase and the on-phase to be consistent and establish a prediction model.
The current prediction control needs to control the change rate of the phase current of the turn-on phase and the phase current of the turn-off phase at the same time, so that a method of overlapping phase change, namely turn-off phase delay turn-off, is adopted. In order to reflect the current of the non-commutation phase on the direct current bus during the delay turn-off period, the measures of turning off the phase and turning on the phase for constant conduction by the same-step PWM modulation of the non-commutation phase are adopted during the commutation period. Taking the example that the BA phase is changed to the CA phase when the motor runs at high speed, the B phase is the off phase, the C phase is the on phase, and the A phase is the non-phase-changing phase. Setting the duty ratio of off-phase and on-phase during the overlapped phase change to DB. When the PWM is in an ON state, current flows into the phase A from the phase B and the phase C; when the PWM is in an OFF state, the phase B current freewheels through its lower arm diode, and the phase a current freewheels through its upper arm diode. At this time, the three-phase voltage is:
Figure BDA0001600639310000031
from the three-phase voltage equation, one can obtain:
Figure BDA0001600639310000032
the method comprises the following steps of discretizing:
Figure BDA0001600639310000033
where T is the sampling periodEquation (3) is an expression of the current prediction control during the commutation period of the high-speed section, and its physical meaning is: when the voltage shown in the formula (3) is applied between the two-phase windings of the off-phase B and the non-commutation phase A at the current moment k, the current value on the non-commutation winding at the moment (k +1) can be forced to reach the ideal value i ×(k+1). The predictive control rule is expressed by a control target of keeping the current on the non-commutation phase winding constant during commutation, turning on the phase constant, and applying a duty ratio D represented by formula (3) to the off phaseBCompensation is performed.
Similarly, for the current state during commutation when the motor is operating at low speed, the expression of predictive control in the low speed section can be obtained:
Figure BDA0001600639310000034
the physical significance is as follows: when the voltage shown in the formula (4) is applied between the open-phase C and the non-commutation phase A at the current moment k, the current value on the non-commutation winding at the moment (k +1) can be forced to reach the ideal value i ×(k+1). In the formula DCIs the duty cycle imposed on the on phase. It can be seen that when the motor operates in the low-speed region, the predictive control rule shows that the current on the non-commutation phase winding is kept constant during commutation as a control target, the off-phase is switched off, and the on-phase is applied with the duty ratio D shown in the formula (4)CCompensation is performed.
For the suspension control subsystem, the x-axis actual displacement of the motor rotor output by the x-axis eddy current sensor and the x-axis given reference displacement x are utilized*Comparing, outputting a given suspension force value F of the motor rotor along the x-axis direction through a PID regulatorx *. The same method is used for obtaining a given suspension force value F in the y-axis directiony *Setting the levitation force x-axialx *Given value of y-axis Fy *And a rotor position angle signal detected by the Hall position sensor is input into a suspension force winding current given calculation module, and finally, a suspension winding current is output through a current inverter to control the motor rotor to stably suspend.
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention can effectively inhibit the torque pulsation of the bearingless brushless direct current motor, compensate the falling of non-commutation current when the motor runs at high speed, and control the continuous reduction of torque; when the motor runs at low speed, the rising of the non-commutation current is weakened, and the continuous increase of the control torque is realized.
(2) The invention does not need to consider the high-speed and low-speed running conditions of the motor respectively, and can adopt a uniform torque pulsation method in the whole speed regulation range. Additional hardware circuitry and topology are avoided.
(3) The invention has the advantages of simple direct torque control structure, fast torque response and strong robustness, and also has the advantages of high control precision, strong controllability and the like of current prediction control.
(4) The invention can restrain the torque pulsation of the bearingless brushless DC motor, and meanwhile, the suspension performance of the motor rotor is not influenced, and the motor rotor can be suspended quickly and stably.
Drawings
FIG. 1 is a schematic view of a bearingless brushless DC motor
FIG. 2 direct torque two-point adjustment procedure
FIG. 3 is a schematic diagram of three-phase current waveforms during a phase-change period
FIG. 4 is a schematic diagram of modulation strategy during commutation
FIG. 5 is a schematic diagram of a predictive current compensation method
FIG. 6 is a block diagram of a wide speed range low torque ripple suppression system
Detailed Description
As shown in fig. 1, in the bearingless brushless dc motor, a set of levitation control windings are embedded in stator slots of the brushless dc motor, so that a set of magnetic core circuits are shared by a levitation magnetic field and a rotating magnetic field. U, V, W is a torque winding of the motor for controlling rotation of the motor. The U-phase winding is formed by connecting U1, U2, U3 and U4 in series, the V-phase winding is formed by connecting V1, V2, V3 and V4 in series, and the W-phase winding is formed by connecting W1, W2, W3 and W4 in series. a1, a2, b1, b2, c1 and c2 are suspension windings of the motor, and each set of windings is formed by connecting two windings in series. The torque winding and the suspension winding adopt a concentrated winding mode, and the torque winding adopts a two-phase conduction mode. Because mutual inductance between the concentrated windings is small, and the torque winding and the suspension winding of the common teeth are always conducted at different times, decoupling control between the torque winding and the suspension winding can be achieved. When the rotor rotates to a position angle of 30 degrees, the rotation of the motor is controlled by the conduction of the V and W phases of the torque windings, and the suspension of the rotor is controlled by the conduction of the suspension windings a1 and a 2. When the winding a1 is electrified with current in the direction shown in the figure, the magnetic density at the air gap 1 is increased, and conversely, the magnetic density at the air gap 2 is reduced, so that the balance of the magnetic densities of the air gaps at two sides of the rotor is broken, and the suspension force for displacing the rotor along + x is generated. Similarly, when levitation winding a2 is energized with current as shown, a levitation force is generated that displaces the rotor along + y. Therefore, the rotor is displaced in any direction of the xoy plane by changing the magnitude and direction of the current supplied by the windings a1 and a2, and finally the rotor is stably suspended.
As shown in fig. 2, a direct torque two-point adjustment process in the torque control subsystem. Wherein T isgIs a given torque value, TfIs the feedback value of the actual torque, Δ T is the torque error, TQIs the torque switch signal. Tolerance limits of torque regulators of + -epsilonmAnd a discrete two-point adjusting mode is adopted. At time t1，ΔT≤—εm，TQAnd outputs "1". If TQCombining the rotor position angle signal output by the Hall position sensor, selecting a non-zero voltage space vector, wherein the stator flux linkage rotates forwards, TfIncrease, Δ T increases; to time t2Δ T increases to the upper limit of tolerance + εmI.e. Δ T ≧ epsilonm，TQAnd outputs "0". If TQZero voltage space vector is applied to the machine with the stator flux stationary, TfDecrease, Δ T decreases.
As shown in fig. 3, the motor operates with three-phase current waveforms at different rotational speeds. When the motor operates in the middle speed range (4E)m＝Ubus) And the change rates of the on-phase current and the off-phase current are basically consistent, so that torque fluctuation can not be generated. When the motor is operated in a low-speed section(4Em<Ubus) The rate of rise of the on-phase current is greater than the rate of fall of the off-phase current, the non-commutation current is increased, the torque is increased, in order to reduce the continuous increase of the torque, the zero voltage vector is selected at this time, the on-phase current is chopped, finally, the rates of change of the on-phase current and the off-phase current are consistent, and the torque ripple is suppressed. When the motor is operated in the high-speed section (4E)m>Ubus) The rising rate of the on-phase current is smaller than the falling rate of the off-phase current, the non-phase-commutation phase current falls, the off-phase is uncontrollable, the non-zero voltage vector cannot compensate the reduction of the non-phase-commutation phase current, and the torque ripple occurs.
As shown in fig. 4, the present invention requires simultaneous control of the rate of change of the on-phase and off-phase currents, and thus employs the method of overlapping commutation. In order to reflect the current of the non-commutation phase on the direct current bus during the delay turn-off period, measures of turning off the phase and turning on the phase for constant conduction by PWM modulation of the non-commutation phase in the same step are adopted during the commutation period.
As shown in fig. 5, the predictive current compensation method employed by the present invention. In an actual control system, in the first control period of a commutation interval, a duty ratio calculated by a predicted current model is not applied, and the change rates of commutation currents cannot be guaranteed to be equal, so that current pulsation of a non-commutation phase cannot be eliminated. The current needs to be compensated, again taking BA-to-CA commutation as an example, ia(k-1)For the non-commutation phase current of the previous cycle, | Δ ibL is the variation of the off-phase current, | Δ icAnd | is the variation of the on-phase current. The specific implementation mode is that the current variation of the on-phase and the off-phase is subjected to difference and then multiplied by a proportionality constant K, and then the obtained numerical value is negatively fed back to the predicted current given end.
As shown in fig. 6, the system block diagram for suppressing the wide speed regulation range and the low torque ripple designed by the invention comprises two parts: a torque control subsystem and a levitation control subsystem. The torque control subsystem adopts a control mode of a rotating speed and torque double closed loop, a given torque value is obtained by setting a rotating speed error through a PID (proportion integration differentiation) controller, and the torque is controlled by a two-point type torque regulator, a voltage vector selection table and an inverter to rotate a motor. Non phase changeTorque control is performed at the time, and phase commutation is performed at the phase commutation time. Meanwhile, a current prediction module is added for calculating the duty ratio. The Hall position signal jump marks the beginning of phase change, and the phase current cut-off is reduced to zero and marks the end of phase change. The suspension control subsystem adopts a displacement closed-loop control mode, and utilizes the x-axial actual displacement of the motor rotor output by the x-axial eddy current sensor and the x-axial given reference displacement x*Comparing, outputting a given suspension force value F of the motor rotor along the x-axis direction through a PID regulatorx *. The same method is used for obtaining a given suspension force value F in the y-axis directiony *Setting the levitation force x-axialx *Given value of y-axis Fy *And a rotor position angle signal detected by the Hall position sensor is input into a suspension force winding current given calculation module, and finally, a suspension winding current is output through a current inverter to control the motor rotor to stably suspend.
In summary, the invention belongs to the field of motor control, and relates to a method for suppressing low torque ripple in a wide speed regulation range of a bearingless brushless direct current motor for flywheel energy storage, which is suitable for high-performance control of the bearingless brushless direct current motor for a flywheel battery. The specific method comprises the following steps: the brushless DC motor without bearing has one set of suspension control winding embedded inside the stator slot of the brushless DC motor to make the suspension magnetic field and the rotating magnetic field share one set of magnetic core circuit. For a torque control system, a direct torque control strategy of a bearingless brushless direct current motor usually adopts a two-phase conduction mode, the structure of the control system is simplified in this way, but when the motor runs at a high speed, the control system and the control system have the same effect of losing the inhibition effect on phase-change torque pulsation as the traditional pulse width modulation control. The current prediction control is added in the traditional direct torque control, the system adopts a control mode of double closed loops of rotating speed and torque, the torque control is carried out at non-commutation moment, overlapping commutation is carried out at commutation moment, and a current prediction module is added for calculating the duty ratio. When the Hall position signal jump marks the beginning of phase change, the phase-off current is reduced to zero, and the phase change is finished, and a measure of switching off the phase and switching on the phase and keeping the phase constant is adopted during the phase change period by PWM modulation in the same step of switching off the phase and not switching the phase. And simultaneously sampling the non-commutation phase current value at the current moment, namely the k moment, and the motor rotating speed, obtaining the reverse electromotive force of the three-phase winding according to the running state of the motor at the current moment, namely the k moment, and finally calculating a predictive control law D by using a current predictive control module, thereby controlling the output of the inverter circuit and controlling the rotation of the motor. And finally, under the condition of not influencing the suspension performance of the rotor, the torque ripple suppression of the bearingless brushless direct current motor in a wide speed regulation range is realized.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (2)

1. A method for suppressing the wide speed regulation range and low torque ripple of a bearingless brushless direct current motor for flywheel energy storage is characterized by comprising the following two control processes: a torque control section and a levitation control section;
a torque control section: the error between the given speed n and the actual speed n of the brushless DC motor without bearing is regulated by PID as the given torque Te *Given a torque Te *And the actual torque TeThe error of the motor is processed by a torque regulator to select a corresponding voltage vector, and simultaneously combined with a motor rotor position angle theta fed back by a detection device, current prediction control is added, and finally the motor is enabled to be at a low speed, a medium speed, a low speed and a medium speed through the output of an inverter,Minimizing high speed operation torque ripple;
a suspension control section: given displacement x, y and error of current vortex sensor actual detection displacement x, y are sent to PID regulator, PID outputs reference suspension force Fx *、Fy *Sending the current to a current set value calculation module of the suspension winding, and outputting a current i through an invertera,b,cFinally, controlling the current rotor to stably suspend;
the formula used by the suspension winding current given value calculation module is as follows:
F＝kii+kxa
wherein k isiIs the current stiffness coefficient, kxIs the displacement stiffness coefficient, i is the suspension winding current, a is the rotor unilateral displacement;
the torque control part comprises the following specific processes:
1) the system adopts a control mode of double closed loops of rotating speed and torque, carries out torque control at non-commutation moment, carries out overlapped commutation at commutation moment, and simultaneously adds a current prediction module to calculate the duty ratio;
2) the Hall position signal jump marks the beginning of phase change, and the phase-off current is reduced to zero to mark the end of phase change;
3) the method of overlapped commutation, namely the method of turn-off phase delay turn-off, is adopted, in order to reflect the current of the non-commutation phase on the direct current bus during the delay turn-off period, the measure of turn-off phase and non-commutation phase synchronous PWM modulation are adopted during the commutation period, and the phase is turned on and is constantly switched on;
4) sampling a non-commutation phase current value and a motor rotating speed at the current moment, namely the k moment;
5) obtaining the opposite electromotive force of the three-phase winding according to the running state of the motor at the current moment, namely the k moment;
6) calculating a budget control law D according to the voltage of the three-phase winding end at the current moment, namely the moment k, the back electromotive force of the three-phase winding, the non-commutation current value at the moment k and the predicted value of the non-commutation phase current at the next moment k +1, so as to control the output of the inverter circuit;
7) repeating the steps 2) to 6) until the phase change is finished, and carrying out torque closed-loop control;
in step 6), the following current prediction model is used to calculate the prediction control law D:
a) expression of current prediction control during commutation in the high-speed section:
Figure FDA0002293173970000011
b) expression of current prediction control during low-speed section commutation:
Figure FDA0002293173970000021
wherein, U(k)Is the voltage applied between the two phase windings of the off-phase and the non-commutation phase at time k, R is the stator winding resistance, i(k)Is the non-commutation winding current at time k, i(k+1)Is the non-commutation winding current at the time k +1, L is the stator self-inductance, T is the sampling period, E(k)Three-phase back electromotive force amplitude at time k, UbusIs the dc bus voltage;
the brushless direct current motor without the bearing is characterized in that a set of suspension control winding is embedded in a stator slot of the brushless direct current motor, so that a suspension magnetic field and a rotating magnetic field share a set of iron core magnetic circuit, wherein U, V, W is a torque winding of the motor and is used for controlling the rotation of the motor; the U-phase winding is formed by connecting U1, U2, U3 and U4 in series, the V-phase winding is formed by connecting V1, V2, V3 and V4 in series, and the W-phase winding is formed by connecting W1, W2, W3 and W4 in series; a1, a2, b1, b2, c1 and c2 are suspension windings of the motor, and each set of winding is formed by connecting two windings in series; the torque winding and the suspension winding are both in a concentrated winding mode, the torque winding adopts a two-phase conduction mode, mutual inductance between the concentrated windings is small, and the torque winding and the suspension winding of the common teeth are not conducted at the same time, so that decoupling control between the torque winding and the suspension winding is realized.
2. The method for suppressing the wide speed regulation range and low torque ripple of the brushless direct current motor for the flywheel energy storage as claimed in claim 1, wherein when the a1 winding is energized, the magnetic density at the air gap 1 is increased, and conversely, the magnetic density at the air gap 2 is decreased, thereby breaking the balance of the air gap magnetic densities at two sides of the rotor and generating the suspension force which makes the rotor displace along + x; similarly, when the levitation winding a2 is energized, a levitation force for displacing the rotor in + y direction is generated, so that the rotor is displaced in any direction of the xoy plane by changing the magnitude and direction of the current applied to the windings a1 and a2, and finally the rotor is stably levitated.
CN201810223578.1A 2018-03-19 2018-03-19 Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage Active CN108521244B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810223578.1A CN108521244B (en) 2018-03-19 2018-03-19 Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810223578.1A CN108521244B (en) 2018-03-19 2018-03-19 Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage

Publications (2)

Publication Number Publication Date
CN108521244A CN108521244A (en) 2018-09-11
CN108521244B true CN108521244B (en) 2020-05-05

Family

ID=63433441

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810223578.1A Active CN108521244B (en) 2018-03-19 2018-03-19 Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage

Country Status (1)

Country Link
CN (1) CN108521244B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111464094B (en) * 2020-05-13 2021-10-26 吉林大学 Brushless direct current motor model prediction controller and construction method thereof
CN114389495B (en) * 2021-03-25 2023-10-20 南京航空航天大学 Improved direct torque control strategy for bearingless sheet motor
CN113572390A (en) * 2021-05-07 2021-10-29 联合汽车电子有限公司 Driving method for noise suppression of brushless direct current motor
CN113541539A (en) * 2021-06-11 2021-10-22 东莞理工学院 Method for suppressing torque ripple of brushless DC motor
CN115028118B (en) * 2022-08-11 2022-12-13 天津赛象科技股份有限公司 Servo module type omnibearing driving mechanism and method and automatic guide vehicle

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104967378B (en) * 2015-05-27 2018-10-23 北京金风科创风电设备有限公司 Method and device for suppressing vibration and noise of wind driven generator
CN107017810B (en) * 2017-04-24 2023-04-07 东南大学盐城新能源汽车研究院 Permanent magnet synchronous motor weight-free model prediction torque control system and method
CN107645256A (en) * 2017-07-17 2018-01-30 中国矿业大学 Permagnetic synchronous motor weak magnetic control system and its method based on torque prediction control

Also Published As

Publication number Publication date
CN108521244A (en) 2018-09-11

Similar Documents

Publication Publication Date Title
CN108521244B (en) Bearing-free brushless direct current motor wide speed regulation range and low torque ripple suppression method for flywheel energy storage
Fang et al. Torque ripple reduction in BLDC torque motor with nonideal back EMF
Xia et al. Torque ripple reduction in brushless DC drives based on reference current optimization using integral variable structure control
Zhang et al. Fault-tolerant sensorless control of a five-phase FTFSCW-IPM motor based on a wide-speed strong-robustness sliding mode observer
CN101635555B (en) Motor control device, motor control system, motor control module and refrigerating unit
Zhang et al. Fast commutation error compensation method of sensorless control for MSCMG BLDC motor with nonideal back EMF
JP2007525137A (en) Position sensorless control algorithm for AC machines
Lu et al. Reduction of unbalanced axial magnetic force in postfault operation of a novel six-phase double-stator axial-flux PM machine using model predictive control
Wang et al. The output voltage control strategy for DSEG with controlled rectification based on conduction angle estimation
Gu et al. Matlab/simulink based modeling and simulation of fuzzy PI control for PMSM
Cao et al. Braking torque control strategy for brushless DC motor with a noninductive hybrid energy storage topology
Jo et al. Rotor field-oriented V/f drive system implementation with oscillation suppression compensator in induction motors
Huang et al. Commutation Torque Ripple Suppression in Three Phase Brushless DC Motor Using Open-end Winding
Wang et al. Minimum field current increment control for doubly salient electro-magnetic generator with improved dynamic performance
CN101383573B (en) Direct suspending power control method for permanent magnet type non-bearing motor
CN114744655B (en) Control method and topology device of flywheel energy storage system
CN114123928B (en) N-phase doubly salient motor optimal current control method based on N+1 bridge arm
CN112234894B (en) Dead-beat direct torque-flux linkage control system and method for variable flux memory motor
Akrami et al. Comparison of Flatness-based Control and Field-Oriented Control for PMSMs in Automotive Water Pump Application
Chen et al. SOSM direct torque and direct suspension force control for double stator Bearingless switched reluctance motor
CN114785234A (en) Switched reluctance motor torque distribution function sectional control method based on fuzzy control
Khudhair et al. A discrete-time controller for the reduction of commutation torque ripple in bldcm drives
Sun et al. Torque ripple suppression control of bearingless brushless DC motor in wide speed regulation range
Boulghasoul et al. Real time implementation of fuzzy adaption mechanism for MRAS sensorless indirect vector control of induction motor
JP2006020454A (en) Controller for permanent magnet synchronous motor

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
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right
TR01 Transfer of patent right

Effective date of registration: 20220805

Address after: 475000 Electric Power Mansion, Jinming Road, Kaifeng City, Henan

Patentee after: KAIFENG POWER SUPPLY COMPANY, STATE GRID HENAN ELECTRIC POWER Co.,Ltd.

Patentee after: JIANGSU University

Address before: Zhenjiang City, Jiangsu Province, 212013 Jingkou District Road No. 301

Patentee before: JIANGSU University