Detailed Description
The embodiment of the application provides a flux linkage difference processing method and a motor control device to solve the problem that a device or a converter needs to be additionally arranged in a motor control system to realize the calculation of flux linkage compensation.
In order to make the technical field better understand the scheme of the present application, the following description will be made on the embodiments of the present application with reference to the attached drawings.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein. Furthermore, the terms "comprises," "comprising," or "having," and any variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
With the development and application of more and more electric vehicles. The actual problems are more and more, for example, in hot summer, the ambient temperature is very high (about 40 ℃), when an electric automobile runs, the temperature of a traction motor is more than 85 ℃, and parameters of a motor body, especially a permanent magnetic linkage, are remarkably reduced due to the temperature characteristic of a material, so that the power performance and the high-speed running performance of the motor body are remarkably reduced; on the other hand, the flux linkage needs larger current when the torque is large due to temperature reduction, so that the current output requirement is improved, and the motor and electric drive loss are further increased; thereby increasing the temperature rise of the motor body and inevitably increasing the cooling power output. The reversible temperature characteristics of a magnet when the temperature changes are key factors affecting the magnetism of the magnet. The flux linkage is reduced as the temperature of the permanent magnet material is higher. The degree of influence of temperature on the magnetic chain varies depending on the permanent magnetic material.
After the permanent magnet of the motor is chemically corroded, the magnetic conductivity of the permanent magnet of the motor is weakened, and then the magnetic linkage is weakened or even lower than the initial design value, so that the performance of the output motor is reduced. On the other hand, in the existing motor control, a torque command or a rotation speed command is mainly input into a control loop, an obtained output current command and an actual detection current are controlled in a closed loop mode, and an output voltage control command modulates a driver, so that the torque or the rotation speed of the motor is controlled, as shown in fig. 1, and fig. 1 is a schematic circuit principle diagram of a three-phase motor. The torque is in direct proportion to the flux linkage of the motor, and when the flux linkage of the motor changes, the control system still applies the original flux linkage to cause deviation, so that obvious adverse effect is brought to the stable operation of the torque control of the system, and the stability of the motor is influenced.
Therefore, in order to ensure the performance of the motor under high temperature and complex environment, the motor needs to be controlled correspondingly to cope with the change of the flux linkage. In the prior art, in order to overcome the flux linkage drift problem, a number of researchers calculate the loss of flux linkage through a flux linkage compensation algorithm, and artificially increase the flux linkage. Many compensation algorithms require additional components or converters, but the cost is significantly increased and the performance is reduced.
At present, a hybrid excitation motor and a variable-flux motor develop rapidly, and the hybrid excitation motor can excite a flux linkage through an external excitation coil, so that the purpose of compensating the flux linkage is achieved; a variable flux motor can vary the flux by varying the permanent magnet flux linkage through the D-axis current pulses. Several ways of currently performing flux linkage compensation are described below:
the first is an automatic amplitude modulation type space vector compensation method for overcoming the torque instability provided in chinese patent CN103023415B, and specifically, refer to fig. 2, where fig. 2 is a schematic diagram of the automatic amplitude modulation type space vector compensation method; the main working principle is the way of compensating the non-circular magnetic field trajectory to compensate the magnetic field according to the difference that the stable rotating magnetic field trajectory is circular and the deviated rotating magnetic field trajectory is non-circular, as shown in the square in fig. 2. Firstly, the working current i is obtained in real time through sampling
a、i
b、i
cAnd voltage u
u,u
v,u
wThereby obtaining the actual running flux linkage of electric drive
According to the formula
Acquiring flux linkage compensation voltage value of any rotor position
(
Is a regular circular flux linkage corresponding to the actual running flux linkage of the motor,
is composed of
An amplitude value;
to be a real magnetic linkage
A corresponding space voltage vector;
is a regular circular magnetic linkage
A corresponding space voltage vector); compensating voltage values according to flux linkage
The single chip outputs a driving signal to a rectifying circuit (shown as a dotted line frame in fig. 2) to make the flux linkage of the motor tend to a regular circular flux linkage.
However, the main effect of the solution presented in this patent is that flux linkage deviation repair, such as compensation by boosting for drift caused by temperature rise, requires an additional three-phase PWM rectifier, which significantly increases the cost and hardware complexity of the system. In addition, the solution given in this patent also increases the system losses, thus reducing the operating efficiency of the machine. In addition, the scheme provided by the patent can only compensate the flux linkage state when the power-off is carried out in the previous period, and cannot compensate the flux linkage state to the initial flux linkage state.
The second is a method for controlling field weakening of a permanent magnet synchronous motor for a vehicle provided in chinese patent CN103107764B, which can be specifically seen in fig. 3a and 3b, where fig. 3a is an operation flow chart of the method for controlling field weakening of a permanent magnet synchronous motor for a vehicle, and fig. 3b is an algorithm structure block diagram of the method for controlling field weakening of a permanent magnet synchronous motor for a vehicle. The main working principle of the scheme is that the stator flux linkage offset is obtained through the reference voltage Uref and the actual voltage Ur
Calculating value by stator flux linkage
And offset of
Obtaining a stator flux linkage reference value
Then according to the stator flux linkage
With a first given torque T
refObtaining a second given torque T
e *(ii) a Finally passing through a second given torque T
e *And a stator flux linkage reference value
Obtaining a current command value
Thereby controlling the motor.
As can be seen from fig. 3b, the solution given in the patent requires the addition of a dc voltage sensor, and the voltage magnitude is detected by the dc voltage sensor in real time; detecting the current magnitude in real time through the current sensor; in addition, the scheme provided by the patent mainly compensates flux linkage through the increase of output current, and the increase of the current easily causes overheating of the motor body and is easy to cause flux linkage drift.
In order to solve the problems that devices need to be added and the compensation effect is poor in the two types of compensation flux linkages, the embodiment of the application provides a flux linkage difference processing method for detecting the flux linkage difference, and the flux linkages can be compensated according to the detected flux linkage difference besides detection.
The flux linkage difference processing method provided by the embodiment of the application mainly adopts a method of detecting flux linkage deviation values in a current closed loop mode, takes the flux linkage deviation values as input designation of flux linkage compensation, and performs self-adaptive compensation on drift flux linkages by using the flux linkage adjustable characteristics of a hybrid excitation motor and a variable flux motor to achieve the purpose of motor flux linkage compensation. The flux linkage difference amount processing method according to the embodiment of the present application will be described in detail below.
The method provided by the embodiment of the present application is divided into different application scenarios for different motors, and is described below.
Application scenario 1: i.e. a compensation method for a hybrid excited machine. Referring to fig. 4, fig. 4 is a schematic structural diagram of a hybrid excitation motor according to an embodiment of the present application, and includes a hybrid excitation motor 401, a motor driver 402 for driving the hybrid excitation motor 401, an excitation regulator 403 for regulating a flux linkage by regulating excitation of the hybrid excitation motor 401, and a control device 404, where the control device includes a detection module 4041 and a processing module 4042; the detection module 4041 is mainly used to detect the current of the motor and convert the current into a current value in the DQ coordinate, and for the motor driver 402, the processing module 4042 calculates some parameters according to some algorithms and the parameters detected by the detection module 4041, and inputs the parameters into the motor driver to drive the hybrid excitation motor 401, such as voltage and current. And, the excitation regulator 403 of the hybrid excitation motor can regulate the flux linkage of the motor. It can be seen from the framework that the method of the embodiment of the present application is mainly applied to control of an excitation adjusting module of a hybrid excitation motor, and the flux linkage difference detection and compensation process in this scenario may be that, when the flux linkage of the hybrid excitation motor drifts, the flux linkage difference amount processing method of the embodiment of the present application may be adopted to detect a flux linkage deviation value through current closed loop; and then, the flux linkage deviation value is input to a hybrid excitation motor excitation adjusting module as an input specification of flux linkage compensation, and the flux linkage of the hybrid excitation motor is adjusted through the hybrid excitation motor excitation adjusting module.
It can be seen that, in application scenario 1, the embodiment of the present application accurately detects the flux linkage change value without adding an additional sensor, and specifies the change value as the input of hybrid excitation flux linkage compensation, so that the lost flux linkage is compensated by inputting excitation adjusting current to the hybrid excitation motor, and the purpose of stabilizing the external characteristics of the motor is achieved.
Application scenario 2 is described below.
Application scenario 2: a compensation method for a variable reluctance motor. Specifically, referring to fig. 5, fig. 5 is a schematic diagram of an architecture of a variable flux motor according to an embodiment of the present application, including a variable flux motor 501, a motor driver 502, and a control device 503, where the control device 503 includes a processing module 5031 and a detection module 5032, and the detection module 5032 is configured to obtain a current of the variable flux motor and convert the current into a current of a DQ coordinate; of course, the motor driver 502 may be included in the control device 503, and the variable reluctance motor 501 is different in that the variable reluctance motor does not have a separate hybrid excitation motor excitation adjusting module as in the hybrid excitation motor, but compensates the flux linkage of the variable reluctance motor by inputting different parameters to the motor driver 502. Specifically, in the structure, the variable flux motor 501 is connected with a motor driver 502 for driving the variable flux motor, and for the motor driver 502, the processing module calculates some parameters according to some control algorithms and inputs the parameters into the motor driver 502 to drive the variable flux motor 501, and the parameters may be current, voltage and the like. The processing flow of flux linkage drift of the flux varying motor 501 may be that, when the flux linkage drift occurs in the flux varying motor, firstly, a flux linkage deviation value is detected by the flux linkage difference processing method according to the embodiment of the present application, and then, the flux linkage deviation value is used as an input of a vector control algorithm of a motor driver to modify an input parameter of the motor driver, so as to achieve a flux linkage compensation effect on the flux linkage drift of the flux varying motor.
It can be seen that, in application scenario 2, the embodiment of the present application accurately detects the flux linkage change value without adding an additional sensor, uses the change value as a command value for flux linkage adjustment, and controls and adjusts the d-axis stator pulse current through a vector control algorithm to compensate the flux linkage of the flux-varying motor.
The architecture of flux linkage difference processing and adaptive flux linkage compensation of the processing module in the present application is described below, where the architecture is mainly implemented by program codes in a memory, and a specific architecture schematic diagram can be referred to in fig. 6, where fig. 6 is an architecture schematic diagram of flux linkage difference processing in an embodiment of the present application, where deployment of the architecture includes a memory, a CPU, and an I/O device, where the memory mainly stores preset parameters of a motor (i.e., original parameters of the motor when the motor leaves a factory), and the I/O device is mainly connected to the motor and samples three-phase current of the motor and a motor rotation speed; the framework can execute the flux linkage difference detection process by firstly calculating the flux linkage deviation by a CPU through closed-loop regulation according to preset parameters of a motor and acquired three-phase current; the flux linkage compensation process may be that after calculating the flux linkage deviation amount, the CPU adjusts the output excitation current command value according to the flux linkage deviation amount and inputs the value to the motor related module through the I/O device.
Example 1
Referring to fig. 7 and 8, fig. 7 is a diagram illustrating an embodiment of a flux linkage difference processing method according to an embodiment of the present application, and fig. 8 is a general control block diagram illustrating the flux linkage difference processing method according to the embodiment of the present application. As shown in fig. 7, when the system program periodically enters flux linkage observation compensation interruption while the motor is running, the following steps are performed in the interruption:
701. current i of a first period sampled by a D axis under a DQ coordinate is sampled and obtained from a three-phase motordAnd Q-axis sampling current iqAnd calculating to obtain a modulation voltage u according to preset motor parameters of the three-phase motordSum modulation voltage uq*;
The three-phase motor can be various types of motors, such as a hybrid excitation motor and a variable reluctance motor. The current sampling of the three-phase motor is obtained by sampling through I/O equipment, and the acquired three-phase current IabcObtaining a sampling current i through DQ conversiondAnd iq. For the modulation voltage udSum modulation voltage uqPart of the motor control algorithm, indicated by the dashed box in fig. 8, passes through the preset parameters stored in the memory unit and the resulting sampled current idAnd iqCalculating modulation u as input to arithmetic logic of a motor control algorithmd*,uq*。
It should be noted that, for the preset parameters, the equation of the original motor mathematical model is as follows, and the following equation is abbreviated as formula (1):
wherein Rs is equivalent resistance, Lsd,LsqThe inductance is in the dq coordinate system in the initial state; msfAn equivalent excitation inductance generated for the excitation current; omegarThe electrical angular velocity of the motor; u. ofsd,usqIs the motor stator voltage; phiMIs a motor permanent magnet flux linkage; i.e. isdIs stator D-axis current under DQ coordinate system; i.e. isqIs Q axis stator current under DQ coordinate system; i.e. ifIs the excitation current.
Then, after the flux linkage drift occurs, a voltage equation corresponding to the changed motor parameter is called as formula (2) in the following short:
wherein R'sIs equivalent post flux drift resistance, L'sd,L’sqThe inductance after equivalent flux linkage drift in the dq coordinate system; m'sfThe equivalent excitation inductance is generated for the excitation current after flux linkage drift; omegarThe electrical angular velocity of the motor; u. of* sd,u* sqA command value for controlling and outputting the motor stator voltage; phi'MThe value of the flux linkage of the permanent magnet of the motor after the flux linkage drift;
it should be noted that, regarding the parameter S in the formula (2) and the following formulas, please refer to the following description:
s is a differential operator, and the differential of the time domain just corresponds to a complex frequency domain (Laplace transform domain) and then is multiplied by S. It is understood that the original signal is decomposed into a stack of oscillation-damped signals such as \ exp (st), and each component is differentiated, with the result that each component is multiplied by the corresponding S. S (═ d ()/dt), the content in parentheses depends on the following multipliers, such as L × S ═ dL/dt. Further, 1/S is an integral factor, 1/S ═ () dt, and the content in parentheses is determined by the following multiplier, such as K/S ═ (i-r) ═ K ═ ═ i-r (i-r) dt.
The modulation voltage u can be obtained by substituting preset parameters of the motor and the sampled current into the formula (1) and the formula (2)dSum modulation voltage uq*。
702. Will udU, theqA, the said idAnd said iqObtaining D-axis voltage change quantity u by inputting closed-loop adjustmentd1And Q-axis voltage variation ^ uq1;
Wherein the sampled current idAnd iqAnd udSum of uqLater, a voltage change quantity u is obtained by closed-loop regulationd,▽uq. The process is described below, after flux linkage drift occurs, when idAnd iqThe equation with the corresponding parameters unchanged is hereinafter referred to as formula (3):
it can be seen that this equation (3) is obtained on the basis of equation (2), where u ^ udAnd ^ uqCorresponding to the D-axis voltage change amount ^ u in the stepd1And Q-axis voltage variation ^ uq1。
703. U according tod1U ^ uq1The udAnd uqCalculating estimated value i of stator current of D axisd_estAnd Q-axis stator current estimate iq_est;
Wherein, the specific id_estAnd iq_estAs shown in fig. 9, fig. 9 is a block diagram of detecting a closed-loop flux linkage deviation of a current in a flux linkage difference processing method according to an embodiment of the present application. Wherein ^ udAnd ^ uqCalculating the required compensation voltage value by using an initial equation after flux linkage drift, and calculating the estimated value i of the stator currentd_estAnd iq_estThe equation (4) is derived from the formula (1), and is referred to as formula (4) in the following;
where s is a differential operator. Rs is an equivalent resistor in the stator winding of the motor; l issd,LsqEquivalent stator inductances of a d axis and a q axis of a three-phase winding of the motor in a dq coordinate system; phiMIs the product of the number of turns of the motor coil and the magnetic flux of the permanent magnet passing through the motor coil; in this step, the ^ udAnd ^ uqIs u ^ obtained in step 702d1And ^ uq1。
It can be seen that in the flow of fig. 9, the three-phase current i is actually detectedabcI obtained by DQ conversiond,iqAs instruction values are respectively compared with id_est,iq_estMaking a difference value, and respectively using the obtained error values as DQ voltage change value ^ u through a regulatordAnd ^ uqAnd outputting the voltage value to the original model to obtain a formula (3).
704. Will i isd_estAnd said idMake a difference to ^ idThe said iq_estAnd said iqMake a difference to ^ iq。
Wherein in obtaining id_estAnd iq_estThen; in the program controller of the processing module, the detected current id,iqAnd an estimated current id_est,iq_estThe current difference values obtained by difference respectivelydAnd ^ iq。
705. Will be ^ idAnd ^ iqInputting the regulator to obtain the D-axis voltage change amount ^ u of the second periodd2And Q-axis voltage variation ^ uq2。
Wherein the second period is a period subsequent to the first period, and v |, i in the program controller after completion of step 704dAnd ^ iqObtaining ^ u in the next cycle through output of the regulatord2And ^ uq2(ii) a The specific calculation process in the regulator can be seen in the following equation, which is referred to as equation (5) for short:
wherein k ispd,kid,kpq,kiqProportional parameters (k) for dq axes, respectivelypd,kpq) And an integration parameter (k)id,kiq). U ^ obtained at step 705 in the examples of the present applicationd2And ^ uq2Corresponds to ^ u in this formula (5)dAnd ^ uq。
It should be noted that the regulator can have a variety of configurations, such as the regulator can include one of a PI regulator, a fuzzy controller, a stick controller, a synovial controller, and a fuzzy controller. The regulator can be selected according to actual needs,
706. determine ^ u of outputq2If the current value is zero, skipping to the end if the current value is zero; if not, go to step 707.
707. Subtract u by zeroq2Obtaining the difference value ^ u, and determining a command value i of the excitation current of the hybrid excitation motor according to the difference value ^ uf-ref。
Wherein, the if-refAnd the flux linkage difference variation amount corresponds to the hybrid excitation motor. The instruction value if-refThe flux linkage adjusting device can be used for subsequently adjusting the flux linkage of the hybrid excitation motor.
It can be seen that, in embodiment 1, flux linkage deviation is estimated by using the current sampling and the deviation of the original parameter, and accurate estimation of flux linkage drift amount is realized on the premise of not adding any sensor.
It should be noted that the flux linkage difference processing method may further include adaptive compensation for flux linkage of the hybrid excitation motor. Specifically, referring to fig. 10, fig. 10 is a schematic diagram of an algorithm of adaptive flux linkage compensation in a flux linkage difference processing method according to an embodiment of the present application, where for a hybrid excitation motor, a permanent magnet linkage of the motor changes due to a parameter change; brings a difference in measured current from the estimated current, which is manifested in regulator output ^ u in the estimation algorithm_d,▽u_qIs not equal to 0; i.e. u appears_sIs not equal to zero; to make the changing part of the permanent magnet chainCompensated back so that its variation becomes small and approaches 0; here, closed loop control is used, as in fig. 10. U deviation value detected by current closed loopqThe feedback value used as flux linkage compensation is differed from the original command value 0, and the output is regulated by a regulator to be excitation flux linkage current if-ref(ii) a The current is a command value, and is output u through a regulator in difference with the detected exciting currentfAnd comparing with the carrier wave to output PWM so as to regulate the current of the exciting coil. The excitation coil current generates excitation magnetic flux to compensate the lost magnetic flux, and the compensation of the flux linkage is completed.
Optionally, the method for detecting a difference between magnetic flux linkage amounts further includes:
708. will i isf-refAnd the difference is taken with the exciting current sampled from the hybrid excitation motor and is input into an excitation regulator to obtain the modulation voltage.
Wherein, the exciting current can be directly collected from the mixed exciting motor, and the exciting current and the calculated if-refMaking a difference and inputting the difference to the excitation regulator shown in fig. 8 can obtain a regulated voltage output to the excitation driver.
709. And adjusting the excitation coil to compensate the flux linkage through the modulation voltage.
After the modulation voltage is obtained, the magnetic linkage of the hybrid excitation motor can be adjusted by the excitation driver according to the adjustment voltage.
It can be seen that, in embodiment 1, flux linkage deviation is estimated by using the current sampling and the deviation of the original parameter, and accurate estimation of flux linkage drift amount is realized on the premise of not adding any sensor. And the flux linkage deviation value detected by the current closed loop is used as the difference between the feedback value of flux linkage compensation and the original instruction value 0, the output is regulated by a regulator to be an excitation current instruction value, and the excitation flux compensation flux linkage drift amount is generated by the excitation coil current of the hybrid excitation motor. And on the premise of not increasing the current of the three-phase winding of the motor, the flux linkage drift compensation is completed. The motor has the advantages of high efficiency and high safety, and solves the problems that the temperature rise of the motor body is aggravated and the flux linkage drifts more and more when the temperature rise of the motor body is aggravated by increasing the current compensation of the three-phase winding in the prior art.
Example 2
For a variable flux motor, a table corresponding graph of a change value and a d-axis stator pulse current of the variable flux motor is retrieved mainly by detecting a flux linkage change value, so that a variable flux stator current pulse instruction value is determined, the stator current is adjusted according to the variable flux stator current pulse instruction value to send out the d-axis pulse current, and the purpose of motor flux linkage compensation is achieved.
Referring to fig. 11 and 12, fig. 11 is a diagram illustrating an embodiment of a flux linkage difference processing method according to an embodiment of the present application, and fig. 12 is a general control block diagram illustrating the flux linkage difference processing method according to the embodiment of the present application. Wherein, the flux linkage difference detection process of steps 1101 to 1106 is similar to steps 701 to 706 in embodiment 1, and if u is detected in step 706q2If not, jumping to step 1107, and the remaining steps are not described again, the method further includes a adaptive flux linkage compensation process of the variable flux motor:
1107. outputting a variable magnetic flux pulse current command value i by searching a two-dimensional table mapping of the D-axis stator current pulse and ^ u of the variable magnetic flux motord_plus。
However, the difference is that the command value i for the excitation current is obtained by inputting ^ u to the regulator in embodiment 1f-refThe variable magnetic flux pulse current instruction value regulated and output by the variable magnetic flux motor regulator is obtained by a table look-up method. I is describedd_plusThe command value i corresponding to the flux linkage difference variation of the variable reluctance motord_plusThe flux linkage adjusting device can be used for adjusting the flux linkage of the variable-flux motor subsequently.
1108. According to a variable magnetic flux pulse current instruction value id_plusAnd controlling and adjusting the d-axis stator pulse current to compensate flux linkage of the variable flux motor.
When the permanent magnet linkage of the variable reluctance motor changes, the difference between the measured current and the estimated current is brought, and the difference is shown in the output ^ u of the PI regulator in the estimation algorithm_dAnd ^ u_qIs not equal to 0; fig. 13 is a schematic diagram of an algorithm of adaptive variable flux compensation in the flux linkage difference processing method according to the embodiment of the present application, where fig. 13 is a specific calculation process of adaptive variable flux compensation. Wherein the change is reduced in order to compensate for the changed part of the permanent magnet linkageAnd approaches 0; here, closed loop control is used, as in fig. 13. U deviation value detected by current closed loopqAnd (4) making a difference between a feedback value serving as flux linkage compensation and the original command value 0, and outputting a variable flux pulse current command value i by searching a two-dimensional table corresponding map of the variable flux motor D-axis stator current pulse and ^ ud_plusThe D-axis stator pulse current is controlled and adjusted by adjusting the motor winding stator current, and the flux linkage of the permanent magnet material of the variable reluctance motor is changed, so that the drift flux linkage is compensated.
It can be seen that, in the embodiment 2, flux linkage deviation is estimated by using the deviation between the current sampling and the original parameter, and accurate estimation of flux linkage drift amount is realized on the premise of not adding any sensor, which is the same as that in the first embodiment. And the flux linkage deviation value detected by the current closed loop is used as the difference between the feedback value of flux linkage compensation and the original command value 0, the variable flux pulse current command value is regulated and output by the regulator, the d-axis stator pulse current is controlled and regulated, and flux linkage drift compensation is completed on the premise of not increasing the average current of the three-phase winding of the motor. The motor has the advantages of high efficiency and high safety, and solves the problems that the temperature rise of the motor body is aggravated and the flux linkage drifts more and more when the temperature rise of the motor body is aggravated by increasing the current compensation of the three-phase winding in the prior art.
From the above-described embodiments 1 and 2, it can be understood that the present application has the following advantages:
1. the flux linkage deviation is estimated by using the current sampling and the deviation of the original parameters, so that the voltage sensor is reduced, the engineering cost is low, and the estimation precision of the flux linkage deviation is improved.
2. The flux linkage compensation method utilizing the characteristics of the hybrid excitation motor and the variable flux motor does not need to increase the average current of the stator of the motor, and solves the problems that the temperature of the motor is increased and the compensation is more drifted caused by the conventional flux linkage compensation technology.
3. The requirement on the consistency of the external characteristics of the motor is high, and the fatal dependence on a permanent magnet material with high thermal stability is eliminated. The permanent magnet material with low cost and poor thermal stability can be widely used in the field of motors.
In addition, it should be noted that the dynamic flux linkage deviation detection method according to the embodiment of the present application is applicable to all permanent magnet synchronous motors. The method can also be applied to the field of flux linkage drift compensation of other variable flux motors. The specific methods for changing the magnetic flux of other variable-flux motors are different, and the excitation compensation precision is also different. However, the flux linkage deviation amount can be adjusted as a command value for flux linkage adjustment of the flux varying motor.
And the flux linkage difference detected by a dynamic flux linkage deviation detection method can be used as a data basis for motor fault detection by comparing with a limit value. (1) The reversible flux linkage drift amount in the motor process has an upper limit according to the inherent characteristics of the permanent magnet material and the inherent characteristics of the winding, and if the flux linkage drift amount exceeds the upper limit, the reversible flux linkage drift amount can be used as a judgment basis for the occurrence of the irreversible demagnetization fault of the motor. (2) If obvious flux linkage drift occurs in the initial running stage of the motor and on the premise of low temperature rise of the motor, the flux linkage drift can be used as a judgment basis for irreversible demagnetization faults of the motor.
In addition, temperature sensors in the motors on the market are all buried in motor windings, and the temperature of the permanent magnet steel is not directly sampled. The flux linkage difference can be detected by a dynamic flux linkage deviation detection method, the expected flux linkage and flux linkage drift difference is a real-time flux linkage estimated value, and a dynamic temperature estimated value of the permanent magnet material can be obtained according to a relation curve of the permanent magnet material flux linkage and the temperature.
In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product.
The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can store or a data storage device, such as a server, a data center, etc., that is integrated with one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.