CN112953318B - Nonlinear compensation method for permanent magnet synchronous motor driving system inverter - Google Patents
Nonlinear compensation method for permanent magnet synchronous motor driving system inverter Download PDFInfo
- Publication number
- CN112953318B CN112953318B CN202110136391.XA CN202110136391A CN112953318B CN 112953318 B CN112953318 B CN 112953318B CN 202110136391 A CN202110136391 A CN 202110136391A CN 112953318 B CN112953318 B CN 112953318B
- Authority
- CN
- China
- Prior art keywords
- axis
- current
- motor
- inverter
- phase
- 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
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
- H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
- H02P6/14—Electronic commutators
- H02P6/15—Controlling commutation time
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
-
- 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
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
- H02P25/02—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the kind of motor
- H02P25/022—Synchronous motors
-
- 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
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
- H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P80/00—Climate change mitigation technologies for sector-wide applications
- Y02P80/10—Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
A nonlinear compensation method for an inverter of a permanent magnet synchronous motor driving system belongs to the technical field of motor control. The invention aims at the problem that the compensation effect is influenced because zero-axis voltage is not considered in the nonlinear compensation of the existing inverter. The method comprises the following steps: inputting a given slope current to a motor d-axis, collecting a given value of motor d-axis voltage and a feedback value of motor d-axis current, and calculating to obtain a nonlinear relation between d-axis error voltage and the feedback value of motor d-axis current; obtaining zero-axis voltages at different initial electrical angles; obtaining the relation between the nonlinear error voltage and the phase current of the three-phase inverter through iPark conversion, and converting the relation into a continuous fitting function expression; converting the relation between the nonlinear error voltage and the phase current of the three-phase inverter into the relation between equivalent dead time and the phase current; and then space vector pulse width modulation is carried out on the basis of the equivalent dead time three-phase inverter, so that nonlinear compensation of the inverter is realized. The invention can be widely applied to various permanent magnet synchronous motor control systems.
Description
Technical Field
The invention relates to a nonlinear compensation method for an inverter of a permanent magnet synchronous motor driving system, belonging to the technical field of motor control.
Background
The permanent magnet synchronous motor has the advantages of high power factor, high efficiency, good dynamic performance and the like, and is widely applied to the fields of industrial production, traffic, aerospace and the like. With the development of industrial automation, the application requirements of the permanent magnet synchronous motor are increasingly raised. However, the output voltage of the voltage-type driver has an error due to the nonlinear characteristic, and further the control effect of the motor is affected, and the voltage-type driver is particularly significant under the low-speed and light-load working condition. In order to improve the control performance of the motor, it is very important to research a self-learning and compensation method which has strong universality and can accurately identify the nonlinearity of the inverter.
At present, inverter nonlinear compensation methods are roughly classified into three types, namely, function description methods, observer methods and table look-up methods: the function description method is described as a square wave function and a trapezoidal function according to the form of the nonlinear compensation voltage of the inverter, the square wave compensation mode ignores the property that the error voltage changes along with the current, and the trapezoidal compensation mode hardly considers the characteristic that the error voltage changes along with the current nonlinearly in a small current area; the observer method acquires error voltage and compensates the error voltage in real time in the running process of the motor by constructing a nonlinear error voltage observer of the inverter, the compensation precision of the method depends on motor parameters, and parameter change can generate larger influence on the compensation accuracy; the table look-up method is to detect the nonlinear curve of the inverter under the offline condition, and then obtain the compensation voltage by checking the table in real time through the detection current in the running process of the motor, so as to realize the nonlinear compensation of the inverter; the table look-up method is a commonly used method at present, and has the problem that the influence of zero axis voltage is not considered in the nonlinear detection process of the inverter, so that the relation table of the error voltage and the current of the inverter cannot be accurately constructed. Therefore, the zero-axis voltage is considered to be of great significance in the nonlinear compensation of the inverter.
Disclosure of Invention
The invention provides a nonlinear compensation method for an inverter of a permanent magnet synchronous motor driving system, aiming at the problem that zero-axis voltage is not considered to influence the compensation effect in the nonlinear compensation of the existing inverter.
The invention discloses a nonlinear compensation method for an inverter of a permanent magnet synchronous motor driving system, which comprises the following steps:
the method comprises the following steps: under the off-line working condition of the motor, inputting given slope current i to a d shaft of the motor through a current loop closed loop dref Then, collecting the d-axis voltage given value u of the motor dref And d-axis current feedback value i of motor dfdb Calculating to obtain d-axis error voltage u derr And d-axis current feedback value i of motor dfdb The non-linear relationship of (a);
step two: calculating the zero-axis voltage u at different initial electrical angles 0 ；
Step three: combined with zero axis voltage u 0 D-axis error voltage u derr And d-axis of motorCurrent feedback value i dfdb The nonlinear relation of the three-phase inverter is converted into a nonlinear error voltage u of the three-phase inverter through iPeak conversion abcerr Phase current i abc The relationship between;
step four: adopting a data fitting algorithm to apply the nonlinear error voltage u of the three-phase inverter abcerr Phase current i abc The relationship between the two is converted into a continuous fitting function expression;
step five: according to the continuous fitting function expression, the nonlinear error voltage u of the three-phase inverter is obtained abcerr Phase current i abc The relation between them is converted into an equivalent dead time T abc Phase current i abc The relationship between; based on equivalent dead time T abc And carrying out space vector pulse width modulation on the three-phase inverter to realize nonlinear compensation of the inverter.
According to the method for compensating for the nonlinearity of the inverter of the permanent magnet synchronous motor drive system of the present invention,
in step one, d-axis error voltage u derr And d-axis current feedback value i of motor dfdb The non-linear relationship of (a) is:
in the formula R d Is the motor resistance, t is the time, Δ t is the time variation, u q Given value for q-axis voltage, i q For the q-axis current feedback value, Δ i is the current increase, given the ramp current i dref The time increases by Δ i every interval Δ t.
According to the inverter nonlinearity compensation method for a permanent magnet synchronous motor drive system of the present invention,
in the third step, based on the symmetry of the three-phase inverter and the motor structure, the nonlinear error voltage u of the three-phase inverter abcerr The calculation method is the same, and a-phase inverter nonlinear error voltage u is obtained by adopting a coordinate transformation mode aerr Phase i of current a a The relationship between them is obtained by solving:
in the formula u qerr Is the q-axis error voltage, θ e Is an initial electrical angle;
i a for phase a current, i q Is a q-axis current, i 0 Zero axis current.
According to the inverter nonlinearity compensation method for a permanent magnet synchronous motor drive system of the present invention,
in the third step, the obtained nonlinear error voltage u of the three-phase inverter is solved abcerr Phase current i abc The relationships between include:
a) when theta is e (30+60k) ° where k is 0,1,2 …; non-linear error voltage u of a-phase inverter aerr Phase i of current a a The relationship between them is:
u aerr (i a )＝u derr (i a /cos(θ e ))cos(θ e )；
b) when theta is e Nonlinear error voltage u of three-phase inverter at (0+60k) ° abcerr Phase current i abc The relationship between them is:
in the formula u x Represents u aerr 、u berr Or u cerr Is a nonlinear error voltage u of the three-phase inverter abcerr Is shown as a separate body; i.e. i x Represents i a 、i b Or i c As phase current i abc Is shown as a separate body; where h is an accumulation variable, and h is 0,1,2 ….
According to the method for compensating for the nonlinearity of the inverter of the permanent magnet synchronous motor drive system of the present invention,
in the fourth step, the process of obtaining the continuous fitting function expression includes:
step one, collecting a d-axis voltage given value u of the motor dref And d-axis current feedback value i of motor dfdb The method comprises the following steps:
inputting given slope current i to d shaft of motor dref Then, set at t 0 To t n Sampling is carried out once every delta t time within a period of time to obtain a d-axis current feedback value i of the motor dfdb And motor d-axis voltage set value u dref Corresponding n +1 sets of data, specifically expressed as (i) j ，u j )，j＝0,1,2…n；
For n +1 group of data (i) j ，u j ) Processing by using Newton quadratic interpolation polynomial to obtain any direct-axis current i d ：i d ＝i dref +i dfdb If i j <i d <i j +1, selection and i d Three adjacent points i j 、i j +1 and i j And +2, calculating to obtain a continuous fitting function expression:
error of fit E m (i d ) Obtaining by interpolation remainder:
where ζ is any constant in the interpolation interval and belongs to [ i ] j ,j j+2 ]M is the order of the interpolation polynomial, m is 2, f (m+1) (ζ) is the m +1 derivative of the fitted function, ω n+1 Is an independent variable related polynomial, omega n+1 ＝(i d -i 0 )(i d -i 1 )…(i d -i n )。
According to the inverter nonlinearity compensation method for a permanent magnet synchronous motor drive system of the present invention,
in step five, equivalent dead time T abc Phase current i abc The relationship between them is:
T s ·u abcerr (i abc )＝T abc (i abc )·U dc ，
in the formula T s For a switching period, U dc Is the dc bus voltage.
The invention has the beneficial effects that: the invention provides a compensation method for nonlinear self-learning of an inverter, which takes zero-axis voltage error into consideration. The method can realize the nonlinear change relation of the nonlinear error voltage of the motor inverter along with the current only through the voltage type inverter without additional detection equipment under the offline working condition, and realize the real-time compensation and correction of the nonlinear error voltage of the inverter when the motor operates on line based on a data fitting method. For a specific voltage type inverter, the method only needs to be used for identifying once, so that compensation can be carried out in the subsequent motor operation, and the nonlinear self-learning process of the inverter does not need to be repeated again.
The method realizes d-axis error voltage characteristic detection based on a d-axis ramp current signal injection mode, then converts the d-axis error voltage characteristic detection into the relation of equivalent dead time along with phase current, and finally detects each phase current in the running process of the motor and compensates the corresponding equivalent dead time to the driving signal of each phase switching tube, namely realizes the nonlinear compensation of the inverter.
The inverter nonlinear self-learning method provided by the method considers the complex nonlinear characteristic of the phase voltage in the full current range, and realizes the accurate extraction of the nonlinear characteristic of the voltage in any current interval based on the injection of the d-axis ramp current signal. Meanwhile, simulation and experiments are combined, the error influence of zero-axis voltage introduced at different rotor positions is disclosed, the zero-axis voltage error in the inverter nonlinear compensation method is avoided through coordinate transformation, and the nonlinear accurate compensation of the inverter in the full current region at any angle can be realized.
The invention is realized based on a voltage-type inverter without additional voltage and current detection hardware. The method is simple and easy to implement, reliable and practical, has good dynamic performance, and can extract the nonlinear voltage error of the full-current inverter of the motor under the offline working condition. The method has great value for improving the control performance of the permanent magnet synchronous motor, and can be widely applied to various permanent magnet synchronous motor control systems.
Drawings
FIG. 1 is a block flow diagram of a method for compensating for non-linearity in an inverter of a PMSM drive system according to the present invention; in the figure, PMSM is a permanent magnet synchronous motor;
FIG. 2 is a 0 reconstruction graph of the three-phase inverter nonlinear error voltage at 0 initial electrical angle without considering zero axis voltage;
FIG. 3 is a 20 reconstruction graph of the three-phase inverter nonlinear error voltage at 20 initial electrical angles without considering zero axis voltage;
FIG. 4 is a 40 ° reconstruction graph of the three-phase inverter nonlinear error voltage at 40 ° initial electrical angle without considering zero axis voltage;
FIG. 5 is a 60 reconstruction graph of three phase inverter nonlinear error voltage at an initial electrical angle of 60 when zero axis voltage is not considered;
FIG. 6 shows the d-axis error voltage and the direct-axis current i in the non-linear self-learning process of the inverter d A graph of (a);
FIG. 7 is a Newton's quadratic interpolation analysis graph of data fitting during the non-linear self-learning process of the inverter;
FIG. 8 is a 0 reconstruction graph of the three phase inverter nonlinear error voltage compensated using the method of the present invention at an initial electrical angle of 30 with zero axis voltage taken into account;
FIG. 9 is a 20 reconstruction graph of the three phase inverter nonlinear error voltage compensated using the method of the present invention at an initial electrical angle of 30 with zero axis voltage taken into account;
FIG. 10 is a 40 reconstruction graph of the three phase inverter nonlinear error voltage compensated using the method of the present invention at an initial electrical angle of 30 with zero axis voltage taken into account;
FIG. 11 is a 60 reconstruction graph of the three phase inverter nonlinear error voltage compensated using the method of the present invention at an initial electrical angle of 30 with zero axis voltage taken into account;
FIG. 12 is a phase A current waveform diagram of a three-phase inverter before compensation;
FIG. 13 is a graph of current waveforms for a three-phase inverter after compensation using the method of the present invention; the compensation voltage is 32.5V/grid;
FIG. 14 is a current harmonic analysis chart before and after compensation by the method of the present invention, which is a harmonic current analysis chart under 10% load at a current frequency of 5 Hz.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.
In a first embodiment, as shown in fig. 1, the present invention provides a method for nonlinear compensation of an inverter of a driving system of a permanent magnet synchronous motor, including a signal injection step, an inverter nonlinear self-learning step, and an inverter nonlinear compensation step, which specifically includes:
the method comprises the following steps: obtaining the nonlinear characteristic of the d-axis inverter: under the off-line working condition of the motor, inputting given slope current i to a d shaft of the motor through a current loop closed loop dref Continuously collecting the given value u of the d-axis voltage of the motor in the current injection process dref And d-axis current feedback value i of motor dfdb Calculating to obtain d-axis error voltage u by substituting motor resistance into operation derr And d-axis current feedback value i of motor dfdb The non-linear relationship of (a);
step two: considering the nonlinear non-saturation characteristic of the inverter, calculating the zero-axis voltage u under different initial electrical angles through a coordinate transformation relation 0 ；
Step three: combined with zero axis voltage u 0 D-axis error voltage u derr And d-axis current feedback value i of motor dfdb The nonlinear relation of the three-phase inverter is converted into a nonlinear error voltage u of the three-phase inverter through iPeak conversion abcerr Phase current i abc The relationship between them;
step four: adopting a data fitting algorithm to apply the nonlinear error voltage u of the three-phase inverter abcerr Phase current i abc The relationship between the continuous fitting function expressions is converted into a continuous fitting function expression which can be stored in the controller;
step five: according to the continuous fitting function expression, the nonlinear error voltage u of the three-phase inverter is obtained abcerr Phase current i abc The relation between them is converted into an equivalent dead time T abc Phase current i abc The relationship between; based on equivalent dead time T abc And carrying out space vector pulse width modulation on the three-phase inverter to realize nonlinear compensation of the inverter.
Further, in the first step of the present embodiment, an error voltage u is introduced to the d-axis due to the non-linearity of the inverter during the signal injection process derr Then the d-axis voltage equation can be expressed as:
u dref ＝i d R d -ω e ψ q +pψ d +u derr ， (1)
wherein i d Is i in FIG. 1 dref And i dfdb Sum, ω e For the electrical angular velocity, psi, of the rotor dq For dq axis flux linkage, p is the differential operator. Since the inverter non-linear self-learning is performed with the motor stationary, ω e ψ q The term is zero while the current ramp injection makes the current change slowly, the differential term p ψ d Is zero.
Given the ramp current i injected, summarized above dref The value is increased in a stepwise manner, so that the d-axis error voltage u is in the process of nonlinear self-learning of the inverter derr And d-axis current feedback value i of motor dfdb The non-linear relationship of (a) is:
in the formula R d Is the motor resistance, t is the time, Δ t is the time variation, u q Given value for q-axis voltage, i q For q-axis current feedback value, Δ i is the current increase, given a ramp current i dref The time increases by Δ i every interval Δ t.
Error voltage u on d axis derr And d-axis current feedback value i of motor dfdb In the non-linear relationship of (2), the function f (x) represents the largest integer no greater than x.
Still further, in the third step of the present embodiment, the three-phase inverter nonlinear characteristics are obtained: and step one, the nonlinear voltage error of the d-axis inverter is obtained through d-axis slope current injection. However, in order to realize the nonlinear compensation of the motor online inverter, the relationship between the nonlinear voltage error of the three-phase inverter and the phase current needs to be obtained. Three-phase inverter nonlinear error voltage u based on symmetry of three-phase inverter and motor structure abcerr The calculation method is the same, taking the relation between the a-phase error voltage and the current as an example, adopting a coordinate transformation mode, and the non-linear error voltage u of the a-phase inverter aerr Phase i of current a a The relationship between them is obtained by solving:
in the formula u qerr Is the q-axis error voltage, θ e Is an initial electrical angle;
i a for phase a current, i q Is a q-axis current, i 0 Is zero axis current.
b-phase inverter non-linear error voltage u berr Phase i of current b b Relation between c-phase inverter nonlinear error voltage u cerr C phase current i c The relationship between them is obtained in the same way. Wherein u is 0 And i 0 Respectively corresponding to the zero axis quantity in the Park/iPad transformation. For a Y-connection winding structure of the motor, the zero-axis current i can be known according to kirchhoff current law 0 Is always zero, however zero axis voltageu 0 The value varies with angle and phase current magnitude.
With reference to fig. 2 to fig. 11, the following explains the influence of the zero-axis voltage on the nonlinear self-learning method of the inverter, and provides the correction and compensation method specifically for the ground. The zero axis voltage correction mode in the inverter nonlinear self-learning method is as follows:
the influence of the zero-axis voltage in the nonlinear self-learning of the inverter is considered. From the formula (3), zero axis voltage u is considered to obtain the nonlinear characteristic of the three-phase inverter 0 The calculation formula is as follows,
in the formula u a Is a phase voltage, u b Is a b-phase voltage, u c Is a c-phase voltage, u d Is d-axis voltage, u q Is the q-axis voltage.
Then, the expression (5) of the zero-axis voltage is obtained, i.e. the zero-axis voltage is not constant to zero, but is a variable related to the nonlinear voltage of each phase inverter, as shown in fig. 2.
The relationship between the dq-axis error voltage and the zero-axis error voltage can be obtained from equation (5) and the relationship between the phase error voltage and the phase current.
Compensation strategies for zero axis voltage at different angles. As can be seen from fig. 6 and 7, the d-axis inverter nonlinearity can be obtained by injecting a d-axis ramp signal, and in order to compensate for the three-phase inverter nonlinearity, a zero-axis voltage error value needs to be obtained to realize accurate coordinate transformation of the inverter nonlinearity information. Based on zero axis error voltage u 0 For d-axis position angle θ in equation (3) e And (4) performing classification discussion, and obtaining the change rule of the nonlinear error of the three-phase inverter along with the phase current.
Still further, in the third step of the present embodiment, the non-linear self-learning of the inverter is limited toThe specific angle is made to be free from the zero axis voltage. Error voltage u based on zero axis 0 For the initial electrical angle theta e Carrying out classification discussion, and obtaining the change rule of the nonlinear error of the three-phase inverter along with the phase current; solving the obtained nonlinear error voltage u of the three-phase inverter abcerr Phase current i abc The relationships between include:
a) when theta is e (30+60k) ° where k is 0,1,2 …; satisfy u 0 0 and i 0 When the signal is injected on the d-axis, the signal is 0,
taking phase a as an example, the nonlinear error voltage u of the phase a inverter aerr Phase i of current a a The relationship between them is:
u aerr (i a )＝u derr (i a /cos(θ e ))cos(θ e )；
b) when theta is e (0+60k) ° where k is 0,1,2 …, having u 0 Not equal to 0, and the nonlinear errors of two-phase inverters in three phases are the same. Take theta e For example, phase a at 0 °, equation (3) can be written as an iteration:
with increasing counting variable h, i a Tending toward 0, u is shown in FIGS. 2 to 5 aerr Also tending towards 0.
The nonlinear error voltage u of the three-phase inverter can be obtained by the simultaneous formula (8) abcerr Phase current i abc The relationship between them is:
in the formula u x Represents u aerr 、u berr Or u cerr Is a nonlinear error voltage u of the three-phase inverter abcerr Is shown as a separate body; i all right angle x Represents i a 、i b Or i c Phase current i of abc Is shown as a separate body; where h is an accumulation variable, h is 0,1,2 ….
By self-learning the nonlinearity of the inverter at different angles, reconstructing the nonlinearity of the inverter through a formula (3), and by judging whether the acquired data and the reconstructed data are overlapped, whether the nonlinear self-learning result of the inverter is accurate can be verified, as shown in fig. 2 to 11, and if the zero-axis voltage is not compensated, the nonlinearity of the inverter is influenced by the zero-axis voltage. On the contrary, the correction of the zero-axis voltage error can be realized by self-learning the nonlinearity of the inverter under a specific angle through the formulas (8) and (9).
Further, the fitting and storage method of the inverter nonlinear discrete data will be described with reference to fig. 6, 7, and 12 to 14. The fitting and storing method for the discrete data of the nonlinear error voltage of the inverter when the nonlinear self-learning of the inverter is implemented comprises the following steps:
in step four of the present embodiment, the inverter non-linear self-learning data fitting method. Since the inverter nonlinear identification result is discrete, the discrete data is fitted into a continuous function by combining a data fitting algorithm so as to compensate the motor inverter nonlinearity on line. The process of obtaining the continuous fitting function expression includes:
collecting the given value u of the d-axis voltage of the motor in the step one dref And d-axis current feedback value i of motor dfdb The method comprises the following steps:
inputting given slope current i to d shaft of motor dref Then, set at t 0 To t n Sampling is carried out once every delta t time within a period of time to obtain a d-axis current feedback value i of the motor dfdb And motor d-axis voltage set value u dref Corresponding n +1 sets of data, specifically expressed as (i) j ，u j )，j＝0,1,2…n；
For n +1 group of data (i) j ，u j ) Using Newton second-order interpolation polynomial to process any direct-axis current i d ：i d ＝i dref +i dfdb If i is j <i d <i j +1, selection and i d Three adjacent points i j 、i j +1 and i j And +2, calculating to obtain a continuous fitting function expression:
error of fit E m (i d ) Obtaining by interpolation remainder:
where ζ is any constant in the interpolation interval and belongs to [ i ] j ,j j+2 ]M is the order of the interpolation polynomial, m is 2, f (m+1) (ζ) is the m +1 derivative, ω, of the fitting function n+1 Is an independent variable related polynomial, omega n+1 ＝(i d -i 0 )(i d -i 1 )…(i d -i n )。
And further, obtaining a nonlinear compensation strategy of the motor inverter under the online working condition. The nonlinear compensation of the inverter is realized on the basis of nonlinear self-learning of the inverter and data fitting of the nonlinear self-learning.
In step five of the present embodiment, the three-phase error voltage is converted into the equivalent dead time T abc (i abc ) And the method is used for nonlinear compensation of the inverter. One switching period T s Nonlinear error voltage u of internal and three-phase inverter abcerr Equivalent dead time T abc Phase current i abc The relationship between them is:
T s ·u abcerr (i abc )＝T abc (i abc )·U dc ，
in the formula T s For a switching period, U dc Is the dc bus voltage.
The validity of the method provided by the invention is verified. The nonlinear compensation effect of the inverter of the method and the existing method is compared through experiments. And meanwhile, the 5 th harmonic content and the 7 th harmonic content of the phase current before and after the nonlinear compensation of the inverter are analyzed. The current waveform of the compensation method of the present invention is shown in fig. 13, and the fourier analysis result thereof is shown in fig. 14. Analysis can obtain that the inverter nonlinear compensation method based on the inverter nonlinear self-learning provided by the method can effectively reduce 5 and 7 th harmonics of the phase current and can effectively correct the influence of the inverter nonlinearity in the current.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.
Claims (1)
1. A nonlinear compensation method for an inverter of a permanent magnet synchronous motor driving system is characterized by comprising the following steps:
the method comprises the following steps: under the off-line working condition of the motor, inputting given slope current i to a d shaft of the motor through a current loop closed loop dref Then, collecting the d-axis voltage set value u of the motor dref And d-axis current feedback value i of motor dfdb Calculating to obtain d-axis error voltage u derr And d-axis current feedback value i of motor dfdb The non-linear relationship of (a);
step two: calculating zero-axis voltage u under different initial electrical angles 0 ；
Step three: combined with zero axis voltage u 0 D-axis error voltage u derr And d-axis current feedback value i of motor dfdb The nonlinear relation is converted into a three-phase inverter nonlinear error voltage u through iPeak conversion abcerr Phase current i abc The relationship between;
step four: inverting three phases by adopting a data fitting algorithmNon-linear error voltage u of device abcerr Phase current i abc The relationship between the two is converted into a continuous fitting function expression;
step five: according to the continuous fitting function expression, the nonlinear error voltage u of the three-phase inverter is obtained abcerr Phase current i abc The relation between them is converted into an equivalent dead time T abc Phase current i abc The relationship between; based on the equivalent dead time T abc Space vector pulse width modulation is carried out on the three-phase inverter, and nonlinear compensation of the inverter is realized;
in step one, d-axis error voltage u derr And d-axis current feedback value i of motor dfdb The non-linear relationship of (a) is:
in the formula R d Is the motor resistance, t is the time, Δ t is the time variation, u q Given value of q-axis voltage, i q For q-axis current feedback value, Δ i is the current increase, given a ramp current i dref Time increases Δ i per interval Δ t;
in step three, based on the symmetry of the three-phase inverter and the motor structure, the three-phase inverter has a nonlinear error voltage u abcerr The calculation method is the same, and a-phase inverter nonlinear error voltage u is obtained by adopting a coordinate transformation mode aerr Phase i of current a a The relationship between them is obtained by solving the following equation:
in the formula u qerr Is the q-axis error voltage, θ e Is an initial electrical angle;
i a for phase a current, i q Is a q-axis current, i 0 Zero axis current;
in the third step, the obtained nonlinear error voltage u of the three-phase inverter is solved abcerr Phase current i abc The relationships between include:
a) when theta is e (30+60k) ° where k is 0,1,2 …; non-linear error voltage u of a-phase inverter aerr Phase i of current a a The relationship between them is:
u aerr (i a )＝u derr (i a /cos(θ e ))cos(θ e )；
b) when theta is measured e When the voltage is equal to (0+60k) DEG, the nonlinear error voltage u of the three-phase inverter abcerr Phase current i abc The relationship between them is:
in the formula u x Denotes u aerr 、u berr Or u cerr Is a nonlinear error voltage u of the three-phase inverter abcerr The expression of (a); i.e. i x Represents i a 、i b Or i c As phase current i abc The expression of (1); wherein h is an accumulation variable, h is 0,1,2 …;
in the fourth step, the process of obtaining the continuous fitting function expression includes:
step one, collecting a d-axis voltage given value u of the motor dref And d-axis current feedback value i of motor dfdb The method comprises the following steps:
inputting given slope current i to d shaft of motor dref Then, set at t 0 To t n Sampling is carried out once every delta t time within a period of time to obtain a d-axis current feedback value i of the motor dfdb Given value u of d-axis voltage of motor dref Corresponding n +1 sets of data, specifically expressed as (i) j ，u j )，j＝0,1,2…n；
For n +1 group of data (i) j ，u j ) Processing by using Newton quadratic interpolation polynomial to obtain any direct-axis current i d ：i d ＝i dref +i dfdb If i is j <i d <i j +1, select and i d Three adjacent points i j 、i j +1 and i j And +2, calculating to obtain a continuous fitting function expression:
error of fit E m (i d ) Obtaining by interpolation remainder:
where ζ is any constant in the interpolation interval, and ζ belongs to [ i ∈ [) j ,j j+2 ]M is the order of the interpolation polynomial, m is 2, f (m+1) (ζ) is the m +1 derivative, ω, of the fitting function n+1 As an independent variable related polynomial, ω n+1 ＝(i d -i 0 )(i d -i 1 )…(i d -i n )；
In step five, equivalent dead time T abc Phase current i abc The relationship between them is:
T s ·u abcerr (i abc )＝T abc (i abc )·U dc ，
in the formula T s For a switching period, U dc Is the dc bus voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110136391.XA CN112953318B (en) | 2021-02-01 | 2021-02-01 | Nonlinear compensation method for permanent magnet synchronous motor driving system inverter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110136391.XA CN112953318B (en) | 2021-02-01 | 2021-02-01 | Nonlinear compensation method for permanent magnet synchronous motor driving system inverter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112953318A CN112953318A (en) | 2021-06-11 |
| CN112953318B true CN112953318B (en) | 2022-08-30 |
Family
ID=76240669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110136391.XA Active CN112953318B (en) | 2021-02-01 | 2021-02-01 | Nonlinear compensation method for permanent magnet synchronous motor driving system inverter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112953318B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113258845B (en) * | 2021-06-15 | 2022-08-16 | 吉林大学 | Self-learning method for interference characteristic of alternating-current motor voltage source inverter |
| CN113507241B (en) * | 2021-07-16 | 2022-07-22 | 哈尔滨工业大学 | Inverter nonlinear compensation method for permanent magnet synchronous motor driving system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108964501A (en) * | 2017-05-09 | 2018-12-07 | 徐州润泽电气有限公司 | A kind of voltage source inverter control method |
| CN109861622A (en) * | 2019-04-08 | 2019-06-07 | 浙江大学 | Common DC bus opens the low switching frequency control strategy of winding permanent magnet synchronous motor system |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7397675B2 (en) * | 2006-10-18 | 2008-07-08 | Azure Dynamics, Inc. | Inverter-filter non-linearity blanking time and zero current clamping compensation system and method |
| CN101826804B (en) * | 2010-05-21 | 2012-06-20 | 哈尔滨工业大学 | Control method of parallel-type permanent magnet direct-drive wind power converter in wind driven generation system |
| TWI426699B (en) * | 2011-02-21 | 2014-02-11 | Univ Nat Taiwan Science Tech | Driving controller of synchronous motor and the driving control method thereof |
| CN104320027B (en) * | 2014-09-25 | 2016-08-24 | 南京航空航天大学 | The control method of the open permanent-magnet electric generator system of parallel winding |
| JP2017169251A (en) * | 2016-03-14 | 2017-09-21 | 株式会社明電舎 | Zero-phase current suppression controller of open winding induction machine |
| CN108183648B (en) * | 2018-01-24 | 2020-04-24 | 武汉理工大学 | Permanent magnet synchronous motor parameter identification method based on inverter nonlinear compensation |
| CN111030534B (en) * | 2019-12-20 | 2021-07-13 | 东南大学 | Parameter identification method for permanent magnet synchronous motor in steady-state operation mode |
-
2021
- 2021-02-01 CN CN202110136391.XA patent/CN112953318B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108964501A (en) * | 2017-05-09 | 2018-12-07 | 徐州润泽电气有限公司 | A kind of voltage source inverter control method |
| CN109861622A (en) * | 2019-04-08 | 2019-06-07 | 浙江大学 | Common DC bus opens the low switching frequency control strategy of winding permanent magnet synchronous motor system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112953318A (en) | 2021-06-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5492192B2 (en) | AC motor control device | |
| CN110971163B (en) | Synchronous reluctance motor low-torque-ripple sensorless control method | |
| CN112953318B (en) | Nonlinear compensation method for permanent magnet synchronous motor driving system inverter | |
| CN112953359B (en) | Method and system for modulating current harmonic minimum pulse width of double three-phase permanent magnet synchronous motor | |
| CN103731079A (en) | Permanent magnet motor system with shared bus structure and open winding and control method for suppressing zero-sequence current | |
| JP2010068653A (en) | Inverter control apparatus and motor drive system | |
| CN110011359B (en) | Grid-connected inverter parameter identification method under finite set model prediction control | |
| CN108988725B (en) | Permanent magnet synchronous motor current harmonic suppression system and method adopting improved complex vector PI controller | |
| WO2022134772A1 (en) | Control method for permanent magnet auxiliary synchronous reluctance motor | |
| WO2021114993A1 (en) | Position-sensorless control method and system for permanent magnet synchronous motor | |
| CN114079399B (en) | Grid-connected inverter current loop control system and method based on linear active disturbance rejection control | |
| Wang et al. | Zero-Sequence Voltage Error Elimination-Based Offline VSI Nonlinearity Identification for PMSM Drives | |
| CN116667722A (en) | Nine-phase open winding permanent magnet synchronous motor model prediction robust control method | |
| CN113067505B (en) | Method for compensating voltage vector in control process of permanent magnet synchronous motor | |
| CN109560741A (en) | It is a kind of based on the permanent magnet synchronous motor system of measurement Error Compensation device and compensation method | |
| CN111682814B (en) | Method and device for determining external characteristic parameters of motor system, electronic equipment and medium | |
| CN115411991B (en) | Inverter nonlinear self-learning method of synchronous reluctance motor driver | |
| CN114301361B (en) | Control method of electrolytic capacitor-free permanent magnet synchronous motor driving system based on bus current control | |
| CN115622468A (en) | Permanent magnet synchronous motor current loop control method and device based on cascade sliding mode resonance | |
| Zhu et al. | Current harmonic elimination method for asymmetric dual three‐phase permanent magnet synchronous motor | |
| Pengcheng et al. | Offline parameter identification strategy of permanent magnet synchronous motor considering the inverter nonlinearities | |
| CN113381655B (en) | Method for eliminating sampling delay error in motor system controlled by single current sensor | |
| CN114123904B (en) | Predictive current increment control method suitable for operation of permanent magnet synchronous motor in high-speed region | |
| CN111193447B (en) | Torque ripple suppression method of open-winding permanent magnet synchronous motor | |
| CN113965129A (en) | Compensation method for current measurement offset error of permanent magnet synchronous motor control system |
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 | ||
| CB03 | Change of inventor or designer information |
Inventor after: Wang Qiwei Inventor after: Wang Gaolin Inventor after: Zhang Guoqiang Inventor after: Zhao Nannan Inventor after: Xu Dianguo Inventor before: Wang Gaolin Inventor before: Wang Qiwei Inventor before: Zhang Guoqiang Inventor before: Zhao Nannan Inventor before: Xu Dianguo |
|
| CB03 | Change of inventor or designer information |