CN115765562B - Model-free prediction current control method and device for permanent magnet synchronous motor - Google Patents
Model-free prediction current control method and device for permanent magnet synchronous motor Download PDFInfo
- Publication number
- CN115765562B CN115765562B CN202211167967.XA CN202211167967A CN115765562B CN 115765562 B CN115765562 B CN 115765562B CN 202211167967 A CN202211167967 A CN 202211167967A CN 115765562 B CN115765562 B CN 115765562B
- Authority
- CN
- China
- Prior art keywords
- current
- vector
- voltage vector
- reference voltage
- processing module
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 110
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 35
- 238000012545 processing Methods 0.000 claims description 44
- 230000008569 process Effects 0.000 claims description 19
- 230000003068 static effect Effects 0.000 claims description 13
- 238000004364 calculation method Methods 0.000 claims description 7
- 238000004891 communication Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 8
- 238000005070 sampling Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000010349 pulsation Effects 0.000 description 3
- 238000004590 computer program Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000003044 adaptive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Landscapes
- Control Of Ac Motors In General (AREA)
Abstract
A permanent magnet synchronous motor model-free predictive current control method and device, the method estimates the input voltage gain and the unknown part of the system in the motor super-local model on line according to the voltage vector and the current vector of the preset control period in the past; performing one-beat delay compensation through the current vector at the current moment, the on-line estimated input voltage gain and the unknown part of the system to obtain the current vector at the next moment; combining a motor super-local model, and obtaining a reference voltage vector based on a dead beat principle; according to the reference voltage vector, obtaining a modulation ratio and a reference voltage vector angle; selecting a vector sequence which minimizes current harmonics, and determining a three-phase duty ratio; and constructing a driving signal of each switching tube of the inverter according to the control period and the three-phase duty ratio corresponding to the selected vector sequence. The invention controls according to the super local model, does not depend on any motor parameter, and has extremely strong robustness; simple and easy to realize, and has strong universality.
Description
Technical Field
The application belongs to the technical field of permanent magnet motor transmission control, and particularly relates to a model-free prediction current control method and device for a permanent magnet synchronous motor.
Background
Model predictive control is an online optimization control scheme, and due to the fact that the concept is simple, the constraint of a system is easy to consider, the model predictive control has the advantages of excellent multi-variable control capability and the like, the application of the model predictive control in the field of electric transmission is gradually and deeply developed in recent years.
However, the traditional model predictive control has strong dependence on system model parameters, has poor robustness, and only applies one basic voltage vector in one control period, which results in switching frequency variation and poor steady-state performance.
In order to make the system have good robust and steady-state performance, a simple and practical model-free predictive current control technical scheme which does not depend on motor parameters is needed.
Disclosure of Invention
Therefore, the present application is directed to a model-free predictive current control method and apparatus for permanent magnet synchronous motor, which are used for solving or partially solving the above technical problems.
Based on the above object, a first aspect of the present application provides a model-free predictive current control method for a permanent magnet synchronous motor, including:
obtaining per unit values of the current harmonic effective values of different vector sequences in a preset PWM period by using a calculation formula of the current harmonic effective values;
According to the motor super-local model, utilizing a voltage vector and a current vector of a preset control period in the past to estimate an input voltage gain and a system unknown part on line;
Performing one-beat delay compensation through the current vector at the current moment, the on-line estimated input voltage gain and the unknown part of the system to obtain the current vector at the next moment;
Obtaining a reference voltage vector based on a dead beat principle by utilizing a per unit value of a current harmonic effective value and a current vector at the next moment according to an online estimated input voltage gain and a motor super-local model updated by an unknown part of a system;
According to the reference voltage vector, obtaining a modulation ratio and a reference voltage vector angle;
Selecting a vector sequence which minimizes current harmonics, and determining a three-phase duty ratio;
and constructing a driving signal of each switching tube of the inverter according to the control period and the three-phase duty ratio corresponding to the selected vector sequence.
As a preferable scheme of the model-free predictive current control method of the permanent magnet synchronous motor, the expression of the per unit value of the current harmonic effective value in the preset PWM period is as follows:
where M is the modulation ratio and θ is the reference voltage vector angle.
As a preferable scheme of the model-free predictive current control method of the permanent magnet synchronous motor, a q-axis current reference value is obtained through a speed outer loop PI regulatorUsing the obtained q-axis current reference value/>Given d-axis current reference value/>Rotor position angle theta e obtains current vector reference value/>, under static coordinate systemAnd calculating the modulation ratio M and the reference voltage vector angle theta by combining the current dead beat principle.
As a preferable scheme of the model-free predictive current control method of the permanent magnet synchronous motor, the input voltage gain alpha and the unknown part F of the system are estimated on line, and the variation of the defined current is as follows:
In the method, in the process of the invention, And/>The current values at the k-2, k-1 and k times are respectively; /(I)Control periods from k-2 to k-1, and from k-1 to k times, respectively;
super local model combined with motor The method comprises the following steps:
In the method, in the process of the invention, Is the average voltage vector at the times k-1 to k; /(I)Is the average voltage vector at times k-2 to k-1.
As a preferable scheme of the model-free prediction current control method of the permanent magnet synchronous motor, the expression of one-beat delay compensation is as follows:
the reference voltage vector is obtained based on the dead beat principle as follows:
Wherein T sc is a control period; A voltage vector at the moment k; /(I) Is a reference voltage vector; /(I)A current vector reference value in a static coordinate system;
The expression of the modulation ratio M and the reference voltage vector angle θ is:
Wherein U dc is bus voltage;
the formula for determining the three-phase duty cycle is:
In the method, in the process of the invention, For standardized three-phase reference voltage,/>Is a zero sequence component.
A second aspect of the present application provides a model-free predictive current control apparatus for a permanent magnet synchronous motor, comprising:
the first processing module is used for obtaining the per unit value of the current harmonic effective value of different vector sequences in a preset PWM period by using a calculation formula of the current harmonic effective value;
The second processing module is used for estimating the input voltage gain and the unknown part of the system on line by utilizing the voltage vector and the current vector of the past preset control period according to the motor super-local model;
The third processing module is used for carrying out one-beat delay compensation through the current vector at the current moment, the on-line estimated input voltage gain and the unknown part of the system to obtain the current vector at the next moment;
The fourth processing module is used for obtaining a reference voltage vector based on a dead beat principle by utilizing a per unit value of a current harmonic effective value and a current vector at the next moment according to an online estimated input voltage gain and a motor super-local model updated by an unknown part of the system;
the fifth processing module is used for acquiring the modulation ratio and the reference voltage vector angle according to the reference voltage vector;
a sixth processing module, configured to select a vector sequence that minimizes current harmonics, and determine a three-phase duty cycle;
And the seventh processing module is used for constructing a driving signal of each switching tube of the inverter according to the control period and the three-phase duty ratio corresponding to the selected vector sequence.
As a preferable scheme of the model-free predictive current control device of the permanent magnet synchronous motor, in the first processing module, the expression of the per unit value of the current harmonic effective value in the preset PWM period is as follows:
where M is the modulation ratio and θ is the reference voltage vector angle.
As a preferable scheme of the model-free predictive current control device of the permanent magnet synchronous motor, in a first processing module, a q-axis current reference value is obtained through a speed outer ring PI regulatorUsing the obtained q-axis current reference value/>Given d-axis current reference value/>Rotor position angle theta e obtains current vector reference value/>, under static coordinate systemAnd calculating the modulation ratio M and the reference voltage vector angle theta by combining the current dead beat principle.
As a preferable scheme of the model-free predictive current control device of the permanent magnet synchronous motor, in the second processing module, the input voltage gain alpha and the unknown part F of the system are estimated on line, and the variation of the defined current is as follows:
In the method, in the process of the invention, And/>The current values at the k-2, k-1 and k times are respectively; /(I)Control periods from k-2 to k-1, and from k-1 to k times, respectively;
super local model combined with motor The method comprises the following steps:
In the method, in the process of the invention, Is the average voltage vector at the times k-1 to k; /(I)Is the average voltage vector at times k-2 to k-1.
As a preferable scheme of the model-free prediction current control device of the permanent magnet synchronous motor, in the third processing module, the expression of one-beat delay compensation is as follows:
In the fourth processing module, the reference voltage vector obtained based on the dead beat principle is:
Wherein T sc is a control period; A voltage vector at the moment k; /(I) Is a reference voltage vector; /(I)Is the current vector reference value in the stationary coordinate system.
As a preferred scheme of the model-free predictive current control device for the permanent magnet synchronous motor, in the fifth processing module, the expression of the modulation ratio M and the reference voltage vector angle θ is as follows:
where U dc is the bus voltage.
As a preferable scheme of the model-free predictive current control device of the permanent magnet synchronous motor, in the sixth processing module, a formula for determining the three-phase duty ratio is as follows:
In the method, in the process of the invention, For standardized three-phase reference voltage,/>Is a zero sequence component.
A third aspect of the present application proposes an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the model-free predictive current control method for a permanent magnet synchronous motor according to the first aspect when executing the program.
A fourth aspect of the present application proposes a non-transitory computer-readable storage medium storing computer instructions for causing a computer to execute implementing the model-free predictive current control method of a permanent magnet synchronous motor according to the first aspect.
From the above, it can be seen that the technical solution provided by the present application obtains the per unit value of the current harmonic effective value of different vector sequences in the preset PWM period by using the calculation formula of the current harmonic effective value; according to the motor super-local model, utilizing a voltage vector and a current vector of a preset control period in the past to estimate an input voltage gain and a system unknown part on line; performing one-beat delay compensation through the current vector at the current moment, the on-line estimated input voltage gain and the unknown part of the system to obtain the current vector at the next moment; obtaining a reference voltage vector based on a dead beat principle by utilizing a per unit value of a current harmonic effective value and a current vector at the next moment according to an online estimated input voltage gain and a motor super-local model updated by an unknown part of a system; according to the reference voltage vector, obtaining a modulation ratio and a reference voltage vector angle; selecting a vector sequence which minimizes current harmonics, and determining a three-phase duty ratio; and constructing a driving signal of each switching tube of the inverter according to the control period and the three-phase duty ratio corresponding to the selected vector sequence. The application controls according to the super local model, does not depend on any motor parameter, and has extremely strong robustness; compared with the traditional scheme, the current harmonic wave is effectively reduced, and the steady-state performance of the system is improved; no priori knowledge of any controlled object is needed, and the method is simple, easy to realize and high in universality; the switching frequency is fixed, and the requirement on the sampling frequency is not high.
Drawings
In order to more clearly illustrate the technical solutions of the present application or related art, the drawings that are required to be used in the description of the embodiments or related art will be briefly described below, and it is apparent that the drawings in the following description are only embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort to those of ordinary skill in the art.
FIG. 1 is a hardware configuration diagram of a speed regulation control system of a permanent magnet synchronous motor according to an embodiment of the present application;
FIG. 2 is a model-free predictive current control block diagram of a permanent magnet synchronous motor according to an embodiment of the application;
FIG. 3 is an experimental result of dead beat predicted current control with accurate parameters, switching frequency of 5kHz, motor running at 600r/min with rated load;
FIG. 4 is an experimental result of motor operation at 600r/min with rated load using dead beat predictive current control with 1.5 times the inductance error parameter with a switching frequency of 5 kHz;
FIG. 5 is an experimental result of model-free predictive current control with variable sequence space vector modulation, switching frequency of 5kHz, motor operation at 600r/min with rated load;
FIG. 6 is an experimental result of a dead beat predicted current control with accurate parameters, a switching frequency of 5kHz, and a motor operating at 1320r/min with rated load;
FIG. 7 is an experimental result of motor operation at 1320r/min with rated load using dead beat predictive current control with 1.5 times the inductance error parameter with a switching frequency of 5 kHz;
FIG. 8 is an experimental result of model-free predictive current control with variable sequence space vector modulation, a switching frequency of 5kHz, and motor operation at 1320r/min with rated load;
FIG. 9 is an experimental result of dead beat predicted current control with accurate parameters, switching frequency of 5kHz, motor running at 1500r/min with 21 N.m load;
FIG. 10 is an experimental result of motor operation at 1500r/min with 21 N.m load using dead beat predictive current control with 1.5 times the inductance error parameter at a switching frequency of 5 kHz;
FIG. 11 is an experimental result of model-free predictive current control with variable sequence space vector modulation, switching frequency of 5kHz, motor running at 1500r/min with 21 N.m load;
FIG. 12 is a graph comparing current THD for dead-beat predicted current control of accurate parameters, dead-beat predicted current control of 1.5 times inductance error parameters, and variable sequence space vector modulation dead-mode predicted current control at different average modulation ratios;
FIG. 13 is a graph showing experimental results of dead beat predicted current control with accurate parameters, a switching frequency of 5kHz, motor forward and reverse rotation;
FIG. 14 is an experimental result of motor forward and reverse rotation with a switching frequency of 5kHz using dead beat predictive current control with 1.5 times the inductance error parameter;
FIG. 15 is a graph showing experimental results of model-free predictive current control with a switching frequency of 10kHz and motor forward and reverse rotation using variable sequence space vector modulation;
FIG. 16 is an experimental result of motor sudden load rating with 5kHz switching frequency using dead beat predictive current control with accurate parameters;
FIG. 17 is an experimental result of motor sudden load rating with a switching frequency of 5kHz using dead beat predictive current control with 1.5 times the inductance error parameter;
FIG. 18 is an experimental result of model-free predictive current control with switching frequency of 5kHz and motor load rating by employing variable sequence space vector modulation;
FIG. 19 is a block diagram of a model-free predictive current control apparatus for a permanent magnet synchronous motor according to an embodiment of the present application;
Fig. 20 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
The present application will be further described in detail below with reference to specific embodiments and with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present application more apparent.
It should be noted that unless otherwise defined, technical or scientific terms used in the embodiments of the present application should be given the ordinary meaning as understood by one of ordinary skill in the art to which the present application belongs. The use of the terms "comprising" or "including" and the like in embodiments of the present application is intended to cover an element or article appearing before the term and equivalents thereof, which are listed after the term, without excluding other elements or articles.
In the related art, in order to improve the robustness of the parameters of the model predictive control, an on-line identification of the parameters, an observer and a model-free control method are provided. An online parameter identification method based on a least squares method is described in a literature "Performance Improvement of Sensorless Ipmsm Drives in a Low-speed Region Using Online Parameter Identification", and an observer method based on a projection algorithm is also described in a literature "An Improved Deadbeat Current Ccontrol Scheme with a Novel Adaptive Self-tuning Load Model for a Three-phase Pwm Voltage-source Inverter". However, the on-line identification of parameters and the method of adopting observers, while improving the robustness of the parameters, are relatively complex to realize, increase the complexity of the system and are still based on the system model. As an alternative, the related art proposes a model-free control method based on a super local model, and document "Model-Free Predictive Current Control of PMSM Drives Based on Extended State Observer Using Ultralocal Model" describes an extended state observer for observing an unknown part of the system. But this approach requires that the gain of the input voltage be known or empirically derived and requires adjustment of the bandwidth of the observer, which places a limit on its practical application. Clearly, existing model-free control methods still have some drawbacks.
In the related art, in order to improve steady-state performance of model predictive control, the active time of the effective voltage vector is adjusted by inserting a second voltage vector. Although the steady state performance of the system is improved, the method cannot achieve the zero-difference tracking of the reference value. In order to realize error-free tracking reference values, dead beat control is introduced in some methods, such as literature on prediction flux linkage control of induction motor dead speed sensor model based on space vector modulation, and the method only adopts a single 7-segment vector sequence, and current harmonic wave is relatively large during high modulation. In order to reduce the current harmonics, some methods propose hybrid pulse width modulation techniques, such as document "Space-vector-based Hybrid Pulsewidth Modulation Techniques for Reduced Harmonic Distortion and Switching Loss",, but the method is only verified under open loop operation, which is difficult to realize in real time and has weak practicability. As can be seen, there is currently no simple, easy to implement method that significantly reduces current harmonics at full modulation ratio.
In view of this, in order to solve the problem that robustness is poor in the traditional dead beat prediction current control scheme, current harmonic wave is relatively large under the high-speed heavy-load equal-height modulation ratio working condition. Based on analysis and deduction of current harmonic wave based on space vector modulation of 4 voltage vector sequences, the invention provides a model-free prediction current control method and device for a permanent magnet synchronous motor according to a first-order super local model.
Referring to fig. 1, the hardware circuit structure according to the embodiment of the invention includes a three-phase voltage source, a three-phase diode rectifier bridge, a direct-current side capacitor, a permanent magnet synchronous motor, a voltage and current sampling circuit, a DSP controller and a driving circuit. The voltage and current sampling circuit respectively collects direct-current side voltage and a phase current of the permanent magnet synchronous motor by using a voltage Hall sensor and a current Hall sensor, and sampling signals enter the DSP controller after passing through the signal conditioning circuit and are converted into digital signals. The DSP controller completes the operation of the model-free predictive current control method of the permanent magnet synchronous motor provided by the embodiment of the invention, outputs six paths of switching pulses, and then obtains final driving signals of six switching tubes of the inverter after passing through the driving circuit.
Referring to fig. 2, a control schematic block diagram of a model-free prediction current control method for a permanent magnet synchronous motor according to an embodiment of the present invention is implemented on a DSP controller of fig. 1 in sequence according to the following steps:
s1, obtaining per unit values of the current harmonic effective values of different vector sequences in a preset PWM period by using a calculation formula of the current harmonic effective values;
S2, according to a motor super-local model, utilizing a voltage vector and a current vector of a preset control period in the past to estimate an input voltage gain and a system unknown part on line;
S3, performing one-beat delay compensation through the current vector at the current moment, the on-line estimated input voltage gain and the unknown part of the system to obtain the current vector at the next moment;
s4, obtaining a reference voltage vector based on a dead beat principle by utilizing a per unit value of a current harmonic effective value and a current vector at the next moment according to an online estimated input voltage gain and a motor super-local model updated by an unknown part of the system;
s5, according to the reference voltage vector, obtaining a modulation ratio and a reference voltage vector angle;
s6, selecting a vector sequence which minimizes current harmonics, and determining a three-phase duty ratio;
S7, constructing a driving signal of each switching tube of the inverter according to a control period and a three-phase duty ratio corresponding to the selected vector sequence.
In this embodiment, the expression of the per unit value of the current harmonic effective value in the preset PWM period is:
where M is the modulation ratio and θ is the reference voltage vector angle.
In this embodiment, the q-axis current reference value is obtained by a speed outer loop PI regulatorUsing the obtained q-axis current reference value/>Given d-axis current reference value/>Rotor position angle theta e obtains current vector reference value/>, under static coordinate systemAnd calculating the modulation ratio M and the reference voltage vector angle theta by combining the current dead beat principle.
In this embodiment, the input voltage gain α and the unknown portion F of the system are estimated online, and the variation of the defined current is:
In the method, in the process of the invention, And/>The current values at the k-2, k-1 and k times are respectively; /(I)Control periods from k-2 to k-1, and from k-1 to k times, respectively;
super local model combined with motor The method comprises the following steps:
In the method, in the process of the invention, Is the average voltage vector at the times k-1 to k; /(I)Is the average voltage vector at times k-2 to k-1.
In this embodiment, in the actual digital control system, there is a beat delay between the output voltage and the command voltage, and in order to eliminate the influence of the beat delay, the current value at time k needs to be compensated, and the current prediction value at time k+1 has the following expression:
in this embodiment, the reference voltage vector obtained based on the dead beat principle is:
Wherein T sc is a control period; A voltage vector at the moment k; /(I) Is a reference voltage vector; /(I)A current vector reference value in a static coordinate system;
The expression of the modulation ratio M and the reference voltage vector angle θ is:
Wherein U dc is bus voltage;
the formula for determining the three-phase duty cycle is:
In the method, in the process of the invention, For standardized three-phase reference voltage,/>Is a zero sequence component.
The effectiveness of the method according to the embodiment of the present invention can be obtained by comparing the three experimental results of fig. 3, fig. 4, fig. 5, fig. 6, fig. 7, fig. 8, fig. 9, fig. 10 and fig. 11, and the THD comparison result of fig. 12. The experimental results are all 5kHz switching frequency, and waveforms from top to bottom are respectively a motor rotating speed, q-axis current, A-phase current and voltage vector sequence. The seq values referred to in the figure are 2.5v,5v,7.5v representing sequences 0127, 012 and 0121, respectively.
The average modulation ratio of fig. 3, 4 and 5 is 0.41, and the three methods all select the sequence 0127, and the steady-state effect of current control is obviously deteriorated by dead beat prediction of error parameters.
The average modulation ratio of fig. 6, 7 and 8 is 0.84. The three kinds of voltage vector sequences selected by the three kinds of methods are different, the dead beat prediction current control method is sequence 0127, and the variable sequence space vector modulation model-free current control method is selected alternately. As can be seen from the figure, the q-axis current pulsation of the model-free current control method of variable sequence space vector modulation is smaller, and the q-axis current pulsation of dead beat prediction current control adopting error parameters is obviously increased.
The average modulation ratio of fig. 9, 10 and 11 was 0.945. The q-axis current pulsation of the model-free current control method of the variable sequence space vector modulation is minimum, and the A-phase current is more sinusoidal. The current THD of the dead beat prediction current control method adopting accurate parameters is 3.7935%, the current THD of the dead beat prediction current control method adopting error parameters is 11.8611%, and the current THD of the model-free current control method adopting variable sequence space vector modulation is 2.4749%. Compared with a dead beat prediction current control method adopting accurate parameters, the model-free current control method adopting variable sequence space vector modulation has the advantages that the current THD is reduced by 34.8%, and more excellent steady state performance and robustness are shown.
Fig. 12 is a summary of the current THD at different modulation ratios for the three methods. Compared with the prior art, the model-free current control method for variable sequence space vector modulation according to the embodiment of the invention does not depend on motor parameters, has good robustness, and has the minimum current THD under the full modulation ratio; at high modulation ratios, the decrease in current THD is more pronounced.
FIGS. 13, 14 and 15 show experimental waveforms for three methods of motor from +1500r/min to-1500 r/min; fig. 16, 17 and 18 show experimental waveforms of the motor suddenly loaded at the rated rotation speed by three methods, and it can be seen that the model-free current control method of variable sequence space vector modulation has stable forward and reverse switching, q-axis current can rapidly and accurately track q-axis current reference values, and has strong anti-interference capability, excellent robustness and good dynamic performance.
In summary, in this embodiment, the entire system adopts the series control structure, and the q-axis current reference valueObtained by a speed outer loop PI regulator. According to the obtained q-axis current reference value/>Given d-axis current reference value/>Rotor position angle theta e obtains current vector reference value/>, under static coordinate systemAnd calculating the modulation ratio M and the reference voltage vector angle theta by combining the current dead beat principle. According to the super local model, the input voltage gain alpha and the system unknown part F are estimated on line by using the voltage vector and the current vector of the past preset control period. According to current vector/>Performing one-beat delay compensation on the input voltage gain alpha estimated on line and the unknown part F of the system to obtain a current vector/>, at the moment k+1The reference voltage vector/>, based on the dead beat principle, can be solved by utilizing the per unit value of the current harmonic effective value and the current vector at the next moment and according to the online estimated input voltage gain alpha and the motor super-local model updated by the unknown part F of the systemAccording to the reference voltage vector/>The modulation ratio M and the reference voltage vector angle θ are found. Further, a vector sequence that minimizes current harmonics is selected and a three-phase duty cycle d a,b,c is determined. And constructing a driving signal of each switching tube of the inverter according to a control period corresponding to the selected vector sequence and the three-phase duty ratio d a,b,c. The embodiment of the invention solves the problems that the traditional dead beat prediction current control scheme depends on motor parameters and has poor robustness and the problem that the current harmonic wave is relatively large under the working condition of high-speed heavy-load equal-height modulation ratio by adopting a single 7-segment vector sequence. The embodiment of the invention uses a super local model of the motor, the model can be updated on line based on the voltage and the current in the past control period, the voltage vector reference value is synthesized according to the dead beat principle, one vector sequence is expanded to three vector sequences during space vector synthesis, and a method for on-line selecting the vector sequence which minimizes the current harmonic wave is provided. Compared with the traditional dead beat prediction current control, the embodiment of the invention has strong robustness to parameter variation, can obtain smaller current harmonic waves under the full modulation ratio, and can reduce the current THD by more than 30% under the high modulation ratio.
It should be noted that, the method of the embodiment of the present application may be performed by a single device, for example, a computer or a server. The method of the embodiment can also be applied to a distributed scene, and is completed by mutually matching a plurality of devices. In the case of such a distributed scenario, one of the devices may perform only one or more steps of the method of an embodiment of the present application, the devices interacting with each other to accomplish the method.
It should be noted that the foregoing describes some embodiments of the present application. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments described above and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.
Referring to fig. 19, based on the same inventive concept, the present application also provides a model-free predictive current control device for a permanent magnet synchronous motor, corresponding to the method of any of the above embodiments, including:
The first processing module 1 is used for obtaining per unit values of the current harmonic effective values of different vector sequences in a preset PWM period by using a calculation formula of the current harmonic effective values;
The second processing module 2 is used for estimating the input voltage gain and the unknown part of the system on line by utilizing the voltage vector and the current vector of the past preset control period according to the motor super-local model;
The third processing module 3 is configured to perform one-beat delay compensation through the current vector at the current time, the input voltage gain estimated online, and the unknown part of the system, so as to obtain a current vector at the next time;
The fourth processing module 4 is configured to obtain a reference voltage vector based on a dead beat principle by using a per unit value of a current harmonic effective value and a current vector at a next moment according to an online estimated input voltage gain and an updated motor super-local model of an unknown part of the system;
A fifth processing module 5, configured to obtain a modulation ratio and a reference voltage vector angle according to the reference voltage vector;
a sixth processing module 6, configured to select a vector sequence that minimizes current harmonics, and determine a three-phase duty cycle;
and a seventh processing module 7, configured to construct a driving signal of each switching tube of the inverter according to the control period and the three-phase duty ratio corresponding to the selected vector sequence.
In this embodiment, in the first processing module 1, the expression of the per unit value of the current harmonic effective value in the preset PWM period is:
where M is the modulation ratio and θ is the reference voltage vector angle.
In the present embodiment, in the first processing module 1, the q-axis current reference value is obtained through the speed outer loop PI regulatorUsing the obtained q-axis current reference value/>Given d-axis current reference value/>Rotor position angle theta e obtains current vector reference value/>, under static coordinate systemAnd calculating the modulation ratio M and the reference voltage vector angle theta by combining the current dead beat principle.
In this embodiment, in the second processing module 2, the input voltage gain α and the unknown portion F of the system are estimated online, and the variation of the defined current is:
/>
In the method, in the process of the invention, And/>The current values at the k-2, k-1 and k times are respectively; /(I)Control periods from k-2 to k-1, and from k-1 to k times, respectively;
super local model combined with motor The method comprises the following steps:
In the method, in the process of the invention, Is the average voltage vector at the times k-1 to k; /(I)Is the average voltage vector at times k-2 to k-1.
In the present embodiment, in the third processing module 3, the expression of one-beat delay compensation is:
In the fourth processing module 4, the reference voltage vector is obtained based on the dead beat principle as follows:
Wherein T sc is a control period; A voltage vector at the moment k; /(I) Is a reference voltage vector; /(I)Is the current vector reference value in the stationary coordinate system.
In the present embodiment, in the fifth processing module 5, the expression of the modulation ratio M and the reference voltage vector angle θ is:
where U dc is the bus voltage.
In this embodiment, in the sixth processing module 6, the formula for determining the three-phase duty ratio is:
In the method, in the process of the invention, For standardized three-phase reference voltage,/>Is a zero sequence component.
For convenience of description, the above devices are described as being functionally divided into various modules, respectively. Of course, the functions of each module may be implemented in the same piece or pieces of software and/or hardware when implementing the present application.
The device of the above embodiment is used for implementing the model-free prediction current control method of the corresponding permanent magnet synchronous motor in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described herein.
Based on the same inventive concept, the application also provides an electronic device corresponding to the method of any embodiment, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor realizes the model-free predictive current control method of the permanent magnet synchronous motor of any embodiment when executing the program.
Fig. 20 is a schematic diagram showing a hardware structure of a more specific electronic device according to the present embodiment, where the device may include: a processor 1010, a memory 1020, an input/output interface 1030, a communication interface 1040, and a bus 1050. Wherein processor 1010, memory 1020, input/output interface 1030, and communication interface 1040 implement communication connections therebetween within the device via a bus 1050.
The processor 1010 may be implemented by a general-purpose CPU (Central Processing Unit ), a microprocessor, an Application SPECIFIC INTEGRATED Circuit (ASIC), or one or more integrated circuits, etc. for executing related programs to implement the technical solutions provided in the embodiments of the present disclosure.
The Memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory ), static storage, dynamic storage, etc. Memory 1020 may store an operating system and other application programs, and when the embodiments of the present specification are implemented in software or firmware, the associated program code is stored in memory 1020 and executed by processor 1010.
The input/output interface 1030 is used to connect with an input/output module for inputting and outputting information. The input/output module may be configured as a component in a device (not shown) or may be external to the device to provide corresponding functionality. Wherein the input devices may include a keyboard, mouse, touch screen, microphone, various types of sensors, etc., and the output devices may include a display, speaker, vibrator, indicator lights, etc.
Communication interface 1040 is used to connect communication modules (not shown) to enable communication interactions of the present device with other devices. The communication module may implement communication through a wired manner (such as USB, network cable, etc.), or may implement communication through a wireless manner (such as mobile network, WIFI, bluetooth, etc.).
Bus 1050 includes a path for transferring information between components of the device (e.g., processor 1010, memory 1020, input/output interface 1030, and communication interface 1040).
It should be noted that although the above-described device only shows processor 1010, memory 1020, input/output interface 1030, communication interface 1040, and bus 1050, in an implementation, the device may include other components necessary to achieve proper operation. Furthermore, it will be understood by those skilled in the art that the above-described apparatus may include only the components necessary to implement the embodiments of the present description, and not all the components shown in the drawings.
The electronic device of the foregoing embodiment is configured to implement the model-free prediction current control method of the corresponding permanent magnet synchronous motor in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described herein.
Based on the same inventive concept, the present application also provides a non-transitory computer readable storage medium corresponding to the method of any embodiment, wherein the non-transitory computer readable storage medium stores computer instructions for causing the computer to execute the permanent magnet synchronous motor model-free prediction current control method according to any embodiment.
The computer readable media of the present embodiments, including both permanent and non-permanent, removable and non-removable media, may be used to implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device.
The storage medium of the foregoing embodiment stores computer instructions for causing the computer to execute the model-free prediction current control method of the permanent magnet synchronous motor according to any one of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described herein.
Those of ordinary skill in the art will appreciate that: the discussion of any of the embodiments above is merely exemplary and is not intended to suggest that the scope of the application (including the claims) is limited to these examples; the technical features of the above embodiments or in the different embodiments may also be combined within the idea of the application, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the application as described above, which are not provided in detail for the sake of brevity.
Additionally, well-known power/ground connections to Integrated Circuit (IC) chips and other components may or may not be shown within the provided figures, in order to simplify the illustration and discussion, and so as not to obscure the embodiments of the present application. Furthermore, the devices may be shown in block diagram form in order to avoid obscuring the embodiments of the present application, and also in view of the fact that specifics with respect to implementation of such block diagram devices are highly dependent upon the platform within which the embodiments of the present application are to be implemented (i.e., such specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the application, it should be apparent to one skilled in the art that embodiments of the application can be practiced without, or with variation of, these specific details. Accordingly, the description is to be regarded as illustrative in nature and not as restrictive.
While the application has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of those embodiments will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.
The present embodiments are intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, and the like, which are within the spirit and principles of the embodiments of the application, are intended to be included within the scope of the application.
Claims (2)
1. A model-free predictive current control method for a permanent magnet synchronous motor comprises the following steps:
obtaining per unit values of the current harmonic effective values of different vector sequences in a preset PWM period by using a calculation formula of the current harmonic effective values;
According to the motor super-local model, utilizing a voltage vector and a current vector of a preset control period in the past to estimate an input voltage gain and a system unknown part on line;
Performing one-beat delay compensation through the current vector at the current moment, the on-line estimated input voltage gain and the unknown part of the system to obtain the current vector at the next moment;
Obtaining a reference voltage vector based on a dead beat principle by utilizing a per unit value of a current harmonic effective value and a current vector at the next moment according to an online estimated input voltage gain and a motor super-local model updated by an unknown part of a system;
According to the reference voltage vector, obtaining a modulation ratio and a reference voltage vector angle;
Selecting a vector sequence which minimizes current harmonics, and determining a three-phase duty ratio;
Constructing a driving signal of each switching tube of the inverter according to a control period and a three-phase duty ratio corresponding to the selected vector sequence;
The expression of the per unit value of the current harmonic effective value in the preset PWM period is:
Wherein M is modulation ratio, θ is reference voltage vector angle;
obtaining q-axis current reference value through speed outer loop PI regulator Using the obtained q-axis current reference value/>Given d-axis current reference value/>Rotor position angle theta e obtains current vector reference value/>, under static coordinate systemCalculating a modulation ratio M and a reference voltage vector angle theta by combining a current dead beat principle;
the input voltage gain alpha and the unknown part F of the system are estimated on line, and the variation of the defined current is as follows:
In the method, in the process of the invention, And/>The current values at the k-2, k-1 and k times are respectively; /(I)Control periods from k-2 to k-1, and from k-1 to k times, respectively;
super local model combined with motor The method comprises the following steps:
In the method, in the process of the invention, Is the average voltage vector at the times k-1 to k; /(I)Is the average voltage vector at times k-2 to k-1;
the expression for one beat delay compensation is:
the reference voltage vector is obtained based on the dead beat principle as follows:
Wherein T sc is a control period; A voltage vector at the moment k; /(I) Is a reference voltage vector; /(I)A current vector reference value in a static coordinate system;
The expression of the modulation ratio M and the reference voltage vector angle θ is:
Wherein U dc is bus voltage;
the formula for determining the three-phase duty cycle is:
In the method, in the process of the invention, For standardized three-phase reference voltage,/>Is a zero sequence component.
2. A model-free predictive current control device for a permanent magnet synchronous motor, comprising:
the first processing module is used for obtaining the per unit value of the current harmonic effective value of different vector sequences in a preset PWM period by using a calculation formula of the current harmonic effective value;
The second processing module is used for estimating the input voltage gain and the unknown part of the system on line by utilizing the voltage vector and the current vector of the past preset control period according to the motor super-local model;
The third processing module is used for carrying out one-beat delay compensation through the current vector at the current moment, the on-line estimated input voltage gain and the unknown part of the system to obtain the current vector at the next moment;
The fourth processing module is used for obtaining a reference voltage vector based on a dead beat principle by utilizing a per unit value of a current harmonic effective value and a current vector at the next moment according to an online estimated input voltage gain and a motor super-local model updated by an unknown part of the system;
the fifth processing module is used for acquiring the modulation ratio and the reference voltage vector angle according to the reference voltage vector;
a sixth processing module, configured to select a vector sequence that minimizes current harmonics, and determine a three-phase duty cycle;
The seventh processing module is used for constructing a driving signal of each switching tube of the inverter according to a control period and a three-phase duty ratio corresponding to the selected vector sequence;
in the first processing module, the expression of the per unit value of the current harmonic effective value in the preset PWM period is as follows:
Wherein M is modulation ratio, θ is reference voltage vector angle;
In the first processing module, a q-axis current reference value is obtained through a speed outer loop PI regulator Using the obtained q-axis current reference value/>Given d-axis current reference value/>Rotor position angle theta e obtains current vector reference value/>, under static coordinate systemCalculating a modulation ratio M and a reference voltage vector angle theta by combining a current dead beat principle;
in the second processing module, the input voltage gain alpha and the unknown part F of the system are estimated on line, and the variation of the defined current is as follows:
In the method, in the process of the invention, And/>The current values at the k-2, k-1 and k times are respectively; /(I)Control periods from k-2 to k-1, and from k-1 to k times, respectively;
super local model combined with motor The method comprises the following steps:
In the method, in the process of the invention, Is the average voltage vector at the times k-1 to k; /(I)Is the average voltage vector at times k-2 to k-1;
in the third processing module, the expression of one-beat delay compensation is:
In the fourth processing module, the reference voltage vector obtained based on the dead beat principle is:
Wherein T sc is a control period; A voltage vector at the moment k; /(I) Is a reference voltage vector; /(I)A current vector reference value in a static coordinate system;
in the fifth processing module, the expression of the modulation ratio M and the reference voltage vector angle θ is:
Wherein U dc is bus voltage;
In the sixth processing module, the formula for determining the three-phase duty ratio is:
In the method, in the process of the invention, For standardized three-phase reference voltage,/>Is a zero sequence component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211167967.XA CN115765562B (en) | 2022-09-23 | 2022-09-23 | Model-free prediction current control method and device for permanent magnet synchronous motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211167967.XA CN115765562B (en) | 2022-09-23 | 2022-09-23 | Model-free prediction current control method and device for permanent magnet synchronous motor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115765562A CN115765562A (en) | 2023-03-07 |
| CN115765562B true CN115765562B (en) | 2024-06-11 |
Family
ID=85351911
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211167967.XA Active CN115765562B (en) | 2022-09-23 | 2022-09-23 | Model-free prediction current control method and device for permanent magnet synchronous motor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115765562B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109039189A (en) * | 2018-07-17 | 2018-12-18 | 东南大学 | Two vector prediction control system of permanent magnet synchronous motor and method based on geometric method |
| CN109347387A (en) * | 2018-11-07 | 2019-02-15 | 珠海格力电器股份有限公司 | Motor control method and control device based on model prediction |
| CN110868111A (en) * | 2019-10-22 | 2020-03-06 | 北方工业大学 | Permanent magnet synchronous motor model prediction control method based on discrete space vector modulation |
| CN113746391A (en) * | 2021-08-26 | 2021-12-03 | 华北电力大学 | Control method and device for permanent magnet synchronous motor, electronic equipment and storage medium |
| WO2022192352A1 (en) * | 2021-03-09 | 2022-09-15 | Magna International Inc. | Multi-critic based enhanced vector control optimization with multi-q learning for motor control |
-
2022
- 2022-09-23 CN CN202211167967.XA patent/CN115765562B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109039189A (en) * | 2018-07-17 | 2018-12-18 | 东南大学 | Two vector prediction control system of permanent magnet synchronous motor and method based on geometric method |
| CN109347387A (en) * | 2018-11-07 | 2019-02-15 | 珠海格力电器股份有限公司 | Motor control method and control device based on model prediction |
| CN110868111A (en) * | 2019-10-22 | 2020-03-06 | 北方工业大学 | Permanent magnet synchronous motor model prediction control method based on discrete space vector modulation |
| WO2022192352A1 (en) * | 2021-03-09 | 2022-09-15 | Magna International Inc. | Multi-critic based enhanced vector control optimization with multi-q learning for motor control |
| CN113746391A (en) * | 2021-08-26 | 2021-12-03 | 华北电力大学 | Control method and device for permanent magnet synchronous motor, electronic equipment and storage medium |
Non-Patent Citations (2)
| Title |
|---|
| Venkata Yaramasu et al..Modulated Model Predictive Torque and Current Control of Squirrel Cage Induction Generator-Based Wind Power Generation System.《2020 IEEE 21st Workshop on Control and Modeling for Power Electronics (COMPEL)》.2020,第1-11页. * |
| 张朝阳.轨道交通永磁同步牵引系统调制策略与控制技术研究.《电工技术学报》.2020,正文第22页第1段-第23页最后1段. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115765562A (en) | 2023-03-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | Position sensorless permanent magnet synchronous machine drives—A review | |
| Zhang et al. | Performance evaluation of two-vector-based model predictive current control of PMSM drives | |
| Zhang et al. | Multiple-AVF cross-feedback-network-based position error harmonic fluctuation elimination for sensorless IPMSM drives | |
| Wang et al. | Quadrature PLL-based high-order sliding-mode observer for IPMSM sensorless control with online MTPA control strategy | |
| Lin et al. | Model-free predictive current control for interior permanent-magnet synchronous motor drives based on current difference detection technique | |
| US9401656B2 (en) | Method of controlling power conversion apparatus | |
| JP5907294B2 (en) | Power converter | |
| Chen et al. | Low complexity dual-vector model predictive current control for surface-mounted permanent magnet synchronous motor drives | |
| CN110880895B (en) | Method for determining q-axis current compensation value of permanent magnet synchronous motor and method for suppressing pulsation | |
| CN111969914B (en) | Dead beat current prediction control method and equipment for permanent magnet synchronous motor and storage medium | |
| CN110912480A (en) | Permanent magnet synchronous motor model-free predictive control method based on extended state observer | |
| Yang et al. | Predictive current control and field-weakening operation of SPMSM drives without motor parameters and DC voltage | |
| CN110868111A (en) | Permanent magnet synchronous motor model prediction control method based on discrete space vector modulation | |
| KR20140113260A (en) | Motor control device | |
| Agustin et al. | A synchronized current difference updating technique for model-free predictive current control of PMSM drives | |
| Chen et al. | Band-based multi-step predictive torque control strategy for PMSM drives | |
| CN112332736B (en) | Asynchronous motor dead beat prediction current control method and device based on current difference | |
| CN115765562B (en) | Model-free prediction current control method and device for permanent magnet synchronous motor | |
| JP6604436B2 (en) | Motor control device and control method | |
| CN113746391A (en) | Control method and device for permanent magnet synchronous motor, electronic equipment and storage medium | |
| Ma et al. | Dichotomy solution based model predictive control for permanent magnet linear synchronous motors | |
| Stando et al. | Sensorless predictive torque control of induction motor drive operating in wide speed range—Simulation study | |
| KR101214443B1 (en) | A Output Control System Of Inverter Using Phase Angle Compensation And A Output Control Method Thereof | |
| CN117060803A (en) | Variable-period generalized double-vector model prediction current control method and related equipment | |
| Zhang et al. | A novel three-vectors-based model predictive flux control of induction motor drives |
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 |