CN116614035A - Real-time online estimation method for rotor temperature of permanent magnet synchronous motor - Google Patents
Real-time online estimation method for rotor temperature of permanent magnet synchronous motor Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 16
- 238000001816 cooling Methods 0.000 claims abstract description 58
- 230000004907 flux Effects 0.000 claims abstract description 35
- 239000000110 cooling liquid Substances 0.000 claims abstract description 32
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 25
- 238000012937 correction Methods 0.000 claims abstract description 21
- 229910052742 iron Inorganic materials 0.000 claims abstract description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 5
- 239000010949 copper Substances 0.000 claims abstract description 5
- 229910052802 copper Inorganic materials 0.000 claims abstract description 5
- 230000008878 coupling Effects 0.000 claims abstract description 5
- 238000010168 coupling process Methods 0.000 claims abstract description 5
- 238000005859 coupling reaction Methods 0.000 claims abstract description 5
- 238000004804 winding Methods 0.000 claims description 13
- 238000002474 experimental method Methods 0.000 claims description 12
- 230000008859 change Effects 0.000 claims description 11
- 238000010521 absorption reaction Methods 0.000 claims description 9
- 238000005265 energy consumption Methods 0.000 claims description 6
- 238000004088 simulation Methods 0.000 claims description 5
- 238000004422 calculation algorithm Methods 0.000 claims description 4
- 239000002826 coolant Substances 0.000 claims description 3
- 238000012360 testing method Methods 0.000 claims description 2
- 239000000696 magnetic material Substances 0.000 abstract description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005457 optimization Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
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- 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
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/64—Electric machine technologies in electromobility
Abstract
The invention discloses a real-time online estimation method for rotor temperature of a permanent magnet synchronous motor, which comprises the following steps: s1, the sum of iron loss power consumption and copper loss power consumption generated by a motor system is equivalent to the total power consumption absorbed by a motor stator assembly; s2, taking the motor stator assembly as a heat source; s3, taking the dissipation power consumption of cooling air as heat convection loss and the dissipation power consumption of cooling liquid as heat conduction loss, and coupling the two loss parts into the total cooling loss of the motor system; s4, obtaining the temperature characteristic of the motor rotor in the whole environment temperature range under the condition of natural cooling; s5, obtaining the corresponding relation between the motor rotor temperature and the rotor permanent magnet flux linkage, and correcting the motor rotor temperature estimation error generated after the software runs for a long time by setting a motor rotor temperature correction enabling condition. The invention can accurately estimate the temperature of the motor rotor on line in real time, ensure the safety of motor rotation, improve the current output capability and torque output precision of the motor or reduce the cost of manufacturing magnetic materials of the motor.
Description
Technical Field
The invention relates to the technical field of new energy motors, in particular to a real-time online estimation method for rotor temperature of a permanent magnet synchronous motor.
Background
In recent years, the global problems of energy shortage, environmental pollution and the like are faced, the new energy automobile has remarkable advantages in comprehensive energy consumption and tail gas emission compared with the traditional fuel automobile, the energy consumption and the environmental pollution are reduced, the development force on the new energy automobile is increased by governments and host factories in various countries of the world, and meanwhile, the new energy automobile is also favored by vast consumers gradually.
The permanent magnet synchronous motor is used as a preferable object of a main drive motor of a new energy vehicle because of the advantages of high efficiency, high power density, low rotating speed, large torque and the like, the new energy vehicle continuously works under the working condition of high temperature and large load, the rotor magnet steel of the permanent magnet synchronous motor is easy to demagnetize irreversibly, the whole vehicle power is lost, the motor rotor temperature needs to be accurately monitored in real time in order to prevent the whole vehicle power interruption risk caused by the overhigh temperature of the motor rotor, because the motor rotor temperature is sealed and controlled by a narrow structural space, high cost of wireless temperature acquisition equipment and the technology of a permanent magnet synchronous motor rotor temperature algorithm in foreign countries, when the motor stator temperature reaches a certain degree, the motor output power is limited in a conservation mode to indirectly ensure that the rotor is not over-heated, so that the motor performance is not fully exerted, the motor rotor temperature is accurately estimated to directly raise the working threshold of the motor stator temperature, the stator temperature threshold is increased, the current output capability of the motor is strongly related to the volume size of magnetic materials, the motor rotor temperature is accurately estimated to be unchanged with the motor performance, the volume size of the motor magnetic material is reduced, in addition, the motor rotor temperature change can cause the motor torque change to be accurately, and the motor torque can be accurately controlled according to the actual torque change, and the motor torque can be controlled, and the magnet torque can be accurately output, and the motor torque can be controlled.
The accurate estimation of the temperature of the motor rotor can bring about the improvement of the motor thermal safety and the motor performance or the reduction of the manufacturing cost, and the current main stream motor rotor temperature at home and abroad mainly comprises three directions: (1) According to the thermal resistance modeling method, a CAE simulation tool is used for carrying out hot node division and hot network model construction, so that the parameter calibration workload is high, and the calculation accuracy is greatly affected by the environment; (2) The empirical formula method is used for calculating the temperature of the motor rotor at normal temperature through a traditional empirical formula, and the initial value of the rotor temperature cannot be assigned when the motor is electrified next time; (3) When the counter-potential method is used for measuring the rotor temperature, the motor current is required to be unloaded, and the power of the running vehicle is instantaneously interrupted, so that the driving feeling is influenced, and the method is not applicable to estimation under the actual running working condition of the whole vehicle.
Disclosure of Invention
Aiming at the defects existing in the prior art, the invention provides the real-time online estimation method for the rotor temperature of the permanent magnet synchronous motor, which can meet the estimation requirements of the rotor temperature of the motor under different environment temperatures and variable load working conditions on the premise of not increasing the hardware cost additionally, and has the characteristics of high instantaneity, high precision, strong self-adaptability and the like.
The technical scheme for solving the technical problems is as follows:
a real-time online estimation method for rotor temperature of a permanent magnet synchronous motor comprises the following steps:
s1, the sum of iron loss power consumption and copper loss power consumption generated by a motor system in a task period is equivalent to the total power consumption absorbed by a motor stator assembly;
s2, taking the motor stator assembly as a heat source, wherein the absorption power consumption is equivalent to the sum of cooling air dissipation power consumption, cooling liquid dissipation power consumption and motor rotor absorption power consumption;
s3, taking the dissipation power consumption of cooling air as heat convection loss and the dissipation power consumption of cooling liquid as heat conduction loss, and coupling the two loss parts into the total cooling loss of the motor system;
s4, obtaining temperature characteristics of the motor rotor in the full environment temperature range under the condition of natural cooling through experiments, recording the shutdown time of a motor system and the temperature of the motor rotor at the current power-down time, and calculating to obtain the initial temperature of the motor rotor at the next power-up time;
s5, obtaining the corresponding relation between the motor rotor temperature and the rotor permanent magnet flux linkage through experiments, and correcting the motor rotor temperature estimation error generated after the software runs for a long time by setting a motor rotor temperature correction enabling condition.
Further, the specific step of S3 is as follows:
1) Setting the X coordinate as the temperature T of the motor stator assembly s And the temperature T 'of the motor rotor at the last moment' r Difference delta T sr The Y coordinate is set as the temperature T of the motor stator assembly s And the temperature T of the cooling liquid cool Is a difference DeltaT of (1) sc The Z coordinate is set as the power consumption P of the coupled cooling liquid cool And air cooling power consumption P air Sum P heat The motor system total cooling power consumption two-dimensional table can be constructed, and the motor stator assembly temperature T acquired in a task period is used s Temperature T of cooling liquid cool The temperature T 'of the motor rotor at the last moment' r Obtaining the total cooling power consumption of the motor system by looking up a table;
2) Establishing a motor rotor temperature estimation precision simulation platform, inputting real motor operation data obtained by testing under different conditions into the simulation platform, and estimating a difference delta T of the motor rotor temperature through actually measuring the motor rotor temperature and a model r To correct the two-dimensional table of the motor system total cooling power consumption model to ensure that delta T r The motor rotor temperature estimation precision requirement is met;
further, the step S4 of obtaining the natural cooling characteristic of the temperature of the motor rotor in the full ambient temperature range, and calculating the initial temperature of the motor rotor under the conditions of any ambient temperature and shutdown time length comprises the following specific steps:
1) Obtaining the change relation of the motor rotor temperature along with the downtime in the whole environment temperature range through experiments, and obtaining the slope of a natural cooling line of the motor rotor temperature under different environment temperatures through linear fitting;
2) And calculating the system shutdown time through the time point stored in the non-lost memory when the system is powered down, the temperature of the motor rotor and the time point sent by the whole vehicle controller when the system is powered up, and finally obtaining the initial temperature of the motor rotor at the current power-up time by utilizing the slope of the natural cooling line of the temperature of the motor rotor, the system shutdown time and the temperature of the motor rotor when the system is powered down last time.
Further, in the step S5, an intelligent correction algorithm is adopted to eliminate the accumulated error of the motor rotor temperature estimation generated by long-time running of the software, and the specific steps are as follows:
1) Obtaining the corresponding relation between the motor rotor temperature and the motor rotor permanent magnet flux linkage through experiments, and obtaining the motor rotor temperature-rotor permanent magnet flux linkage line slope through linear fitting;
2) Establishing a motor rotor permanent magnet flux observer through a motor voltage equation and a motor flux equation, and calculating a motor rotor correction temperature through the obtained motor rotor permanent magnet flux and flux line slope;
3) Judging the shutdown time of a motor system and the temperature T of a motor stator assembly by designing a motor rotor temperature correction enabling condition s And the temperature T 'of the motor rotor at the last moment' r Absolute value of difference |DeltaT sr The magnitude of the I and the number of motor rotor temperature correction times are used for determining whether the calculated motor rotor correction temperature replaces the motor rotor temperature estimated by the current moment model.
Further, in the step S1, since the motor stator winding is closely attached to the stator core, the temperature of the motor stator winding measured by the temperature sensor is generally approximately equivalent to the temperature of the stator assembly, namely, the formula is satisfied:wherein: p (P) e Iron loss power consumption in a task period; p (P) Cu Copper loss power consumption in a task period; c (C) w Specific heat capacity for motor stator windings; c (C) Fe Specific heat capacity of a stator core of the motor; m is M w The mass of the stator winding of the motor is as follows; m is M Fe The mass of the stator core of the motor is that of the stator core of the motor; delta T s The temperature change of the motor stator assembly in the task period is determined; Δt is the task cycle duration.
Further, after the motor stator assembly absorbs heat, the heat is used as a heat source to radiate the boundary environment, and the heat of the motor stator assembly is consumed by the power P of the cooling liquid cool Power consumption P of air cooling air Motor rotor heat absorption power consumption P r Three parts of consumption are consumed, and in one task period, the instantaneous energy consumption conservation of the system expressed by the following formulas is satisfied between the motor stator assembly and the cooling medium (cooling liquid and air) and between the motor rotor;
the above formula is: (C) w M w +C Fe M Fe )ΔT s ＝(P cool +P air )Δt+C r M r (T r -T′ r ) Wherein: p (P) cool The power consumption of the cooling liquid in the task period is as follows; p (P) air Air cooling power consumption in a task period; c (C) r Specific heat capacity of a motor rotor; m is M r The mass of the motor rotor; t (T) r Calculating the temperature for the motor rotor at the current moment; t'. r The temperature of the motor rotor at the last moment.
The beneficial effects of the invention are as follows:
1. the invention can meet the motor rotor temperature estimation requirements under different environment temperatures and variable load working conditions without increasing hardware cost, and has the characteristics of high real-time performance, high precision, strong self-adaptability and the like.
2. The invention can accurately estimate the temperature of the motor rotor on line in real time, and can improve the current output capability and the torque output precision of the motor or reduce the cost of manufacturing magnetic materials of the motor while ensuring the safety of the motor.
Drawings
FIG. 1 is a schematic illustration of stator and rotor energy consumption of an electric machine system;
FIG. 2 is a diagram of a motor system cooling loss coupling model;
FIG. 3 is a flow chart for off-line optimization of motor rotor temperature estimation accuracy;
FIG. 4 is a schematic diagram of the natural cooling characteristics of the motor rotor at different ambient temperatures;
fig. 5 is a graph of the correspondence between motor rotor temperature and motor rotor permanent magnet flux linkage.
Detailed Description
The invention is further described with reference to the drawings and detailed description.
As shown in fig. 1 to 5, a method for real-time online estimation of rotor temperature of a permanent magnet synchronous motor includes the following steps:
s1, the sum of iron loss power consumption and copper loss power consumption generated by a motor system in a task period is equivalent to the total power consumption absorbed by a motor stator assembly;
s2, taking the motor stator assembly as a heat source, wherein the absorption power consumption is equivalent to the sum of cooling air dissipation power consumption, cooling liquid dissipation power consumption and motor rotor absorption power consumption;
s3, taking the dissipation power consumption of cooling air as heat convection loss and the dissipation power consumption of cooling liquid as heat conduction loss, and coupling the two loss parts into the total cooling loss of the motor system;
s4, obtaining temperature characteristics of the motor rotor in the full environment temperature range under the condition of natural cooling through experiments, recording the shutdown time of a motor system and the temperature of the motor rotor at the current power-down time, and calculating to obtain the initial temperature of the motor rotor at the next power-up time;
s5, obtaining the corresponding relation between the motor rotor temperature and the rotor permanent magnet flux linkage through experiments, and correcting the motor rotor temperature estimation error generated after the software runs for a long time by setting a motor rotor temperature correction enabling condition.
In this embodiment, the sum of the core loss power consumption and the copper loss power consumption generated in the motor system task period is equivalent to the total power consumption of the motor stator assembly for absorbing heat. Because the motor stator winding is closely attached to the stator core, the temperature of the motor stator winding measured by the temperature sensor is generally approximately equivalent to the temperature of the stator assembly, namely, the following formula is satisfied:
wherein P is e Iron loss power consumption in a task period; p (P) Cu Copper loss power consumption in a task period; c (C) w Specific heat capacity for motor stator windings; c (C) Fe Specific heat capacity of a stator core of the motor; m is M w The mass of the stator winding of the motor is as follows; m is M Fe The mass of the stator core of the motor is that of the stator core of the motor; delta T s The temperature change of the motor stator assembly in the task period is determined; Δt is the task cycle duration.
As can be seen from fig. 1, the heat of the motor stator assembly is consumed by the cooling liquid to consume P cool Power consumption P of air cooling air Motor rotor heat absorption power consumption P r Three parts of consumption are consumed, and in one task period, the instantaneous energy consumption conservation of the system expressed by the following formula is satisfied between the motor stator assembly and the cooling medium (cooling liquid and air) and between the motor rotor.
(C w M w +C Fe M Fe )ΔT s ＝(P cool +P air )Δt+C r M r (T r -T′ r )
Formula (C) w M w +C Fe M Fe )ΔT s ＝(P cool +P air )Δt+C r M r (T r -T′ r ) In P cool The power consumption of the cooling liquid in the task period is as follows; p (P) air Air cooling power consumption in a task period; c (C) r Specific heat capacity of a motor rotor; m is M r The mass of the motor rotor; t (T) r Calculating the temperature for the motor rotor at the current moment; t'. r The temperature of the motor rotor at the last moment.
According to formula (C w M w +C Fe M Fe )ΔT s ＝(P cool +P air )Δt+C r M r (T r -T′ r ) It can be seen that, among other parametersIf the power consumption P of the cooling liquid in the task period is obtained under the premise of being known cool And air cooling power consumption P air Then for the rotor temperature T 'at the previous moment' r Continuously superposing to obtain the real-time temperature T of the rotor at the current moment r The following formula is given:
the heat of the motor stator assembly is taken away by the cooling liquid and belongs to heat conduction loss between the motor stator and the cooling liquid, the heat of the motor stator assembly is taken away by air and belongs to heat convection loss between the motor stator assembly and the rotor, and the cooling liquid power consumption P in a task period can be realized cool And air cooling power consumption P air Expressed as:and P air ＝hA air (T s -T′ r )。
Wherein, the liquid crystal display device comprises a liquid crystal display device,in (a): k is the heat conduction coefficient, A s For effective cooling area of stator assembly, T s T is the temperature of the motor stator assembly at the current moment cool The temperature of the cooling liquid is H, and the thickness of the cooling pipeline is H;
P air ＝hA air (T s -T′ r ) In (a): h is a thermal convection coefficient; a is that air Is the air heat convection area between the stator and the rotor of the motor.
Preferably, in the step S4, the natural cooling characteristic of the temperature of the motor rotor in the full ambient temperature range is obtained, and the initial temperature of the motor rotor under the conditions of any ambient temperature and shutdown time length can be calculated, which comprises the following specific steps:
1) Obtaining the change relation of the motor rotor temperature along with the downtime in the whole environment temperature range through experiments, and obtaining the slope of a natural cooling line of the motor rotor temperature under different environment temperatures through linear fitting;
2) And calculating the system shutdown time through the time point stored in the non-lost memory when the system is powered down, the temperature of the motor rotor and the time point sent by the whole vehicle controller when the system is powered up, and finally obtaining the initial temperature of the motor rotor at the current power-up time by utilizing the slope of the natural cooling line of the temperature of the motor rotor, the system shutdown time and the temperature of the motor rotor when the system is powered down last time.
In the present embodiment, the above formula is usedIt can be seen that the power consumption P of the cooling liquid in the task period cool Depending on the motor stator assembly temperature T s And the temperature T of the cooling liquid cool Is a difference DeltaT of (1) sc Related to the following.
From the above formula P air ＝hA air (T s -T′ r ) It can be seen that the air-cooling power consumption P in the duty cycle air Depending on the motor stator assembly temperature T s And the temperature T 'of the motor rotor at the last moment' r Is a difference DeltaT of (1) sr Related to the following.
In the embodiment, in order to simplify the complexity of a motor rotor temperature estimation model, reduce the calibration workload and the operation load of a main control chip of a controller, the invention reduces the power consumption P of the cooling liquid cool And air cooling power consumption P air Coupled into a two-dimensional table (as shown in figure 2), the X coordinate is the temperature T of the motor stator assembly s And the temperature T 'of the motor rotor at the last moment' r Difference delta T sr Y coordinates are the temperature T of the motor stator assembly s And the temperature T of the cooling liquid cool Is a difference DeltaT of (1) sc Z coordinate is the power consumption P of the coupled cooling liquid cool And air cooling power consumption P air Sum P heat . From equation (3), the motor rotor temperature T 'at the previous time' r At a certain time, calibrating P heat The value directly influences the estimated value T of the motor rotor at the current moment r . According to the motor rotor temperature estimation optimization flow (shown in figure 3), aiming at the difference delta T between the actual motor rotor temperature measured by the wireless temperature measuring device and the model estimated motor rotor temperature under different environment temperatures and different load working conditions r Offline calibration optimization of Δt in FIG. 2 sr And DeltaT sc Look-up table corresponding P heat Value of DeltaT r And the accuracy estimation requirement is met.
From the above formulaIt can be seen that the rotor temperature T estimated by the current time model during the operation of the motor system r By the rotor temperature value T 'at the previous time' r And (5) continuously iterating operation to obtain the product. Then the whole vehicle parking motor control system is powered down for a period of time and then powered up, the motor rotor has natural cooling (no cooling liquid circulation cooling) in the environment, and the initial temperature T of the motor rotor after the power-up is carried out r_init The estimation needs to be re-performed. The invention designs the motor to be at the temperature of minus 40 ℃ and 60 ℃ in the whole environment temperature range]In the process, the motor is operated at the maximum continuous power at the condition of every 5 ℃ until the rotor temperature is not increased (stable is maintained) for 5 minutes, then the motor control system is powered down and the cooling water is turned off, and the rotor temperature acquisition equipment records the change of the rotor temperature of the motor along with the time (as shown in fig. 4, only the natural cooling temperature change of the rotor at-40 ℃ and 60 ℃ is shown in the diagram, and other temperature lines are omitted). The slope k of the natural cooling temperature lines of the motor rotor with the total 21 temperatures is obtained by carrying out linear fitting on the natural cooling actual temperature lines of the motor rotor with different environmental temperatures c And establishing a one-dimensional slope table of a natural cooling temperature line of the motor rotor corresponding to each environmental temperature.
Preferably, in the step S5, an intelligent correction algorithm is adopted to eliminate the accumulated error of the motor rotor temperature estimation generated by long-time running of the software, and the specific steps are as follows:
1) Obtaining the corresponding relation between the motor rotor temperature and the motor rotor permanent magnet flux linkage through experiments, and obtaining the motor rotor temperature-rotor permanent magnet flux linkage line slope through linear fitting;
2) Establishing a motor rotor permanent magnet flux observer through a motor voltage equation and a motor flux equation, and calculating a motor rotor correction temperature through the obtained motor rotor permanent magnet flux and flux line slope;
3) By designing motor rotor temperature correction enablingJudging the machine halt time length of a motor system and the temperature T of a motor stator assembly s And the temperature T 'of the motor rotor at the last moment' r Absolute value of difference |DeltaT sr The magnitude of the I and the number of motor rotor temperature correction times are used for determining whether the calculated motor rotor correction temperature replaces the motor rotor temperature estimated by the current moment model.
In this embodiment, when the system is powered down, the whole vehicle controller VCU will complete the non-lost storage of the system power down time in real time, while the motor controller IPU will estimate the motor rotor temperature T before the system is powered down r_pd Storing the data in a non-lost memory. When the system is electrified, the whole vehicle controller VCU transmits the last power-down time and the current power-up time of the system to the motor controller IPU through the CAN bus, and the motor controller IPU calculates the shutdown time t of the motor system by comparing the current power-up time and the last power-down time of the system stop 。
Obtaining the slope k of the natural cooling line by checking a one-dimensional table of the slope of the temperature line of the motor rotor c And pass through the formulaCalculating the initial temperature of a motor rotor when the system is electrified, and if the motor system is stopped for a period of time t stop Too long (stable period t of rotor temperature natural cooling when the down time exceeds each ambient temperature w Set as a calibration value), the motor stator and the rotor are considered to be completely naturally cooled, and the initial temperature of the motor rotor after the system is electrified is the stator temperature.
Formula (VI)In (a): t (T) r_init The initial temperature of the motor rotor at the time of system power-on is set; t (T) r_pd The temperature of a motor rotor at the time of system power-down is set; k (k) c The slope of the natural cooling line is the slope of the natural cooling line at different ambient temperatures; t is t stop The system is shut down time; t is t w The motor rotor is naturally cooled and stabilized for a long time.
In the embodiment, the real-time temperature of the motor rotor under different environment temperatures and different load working conditions can be calculated according to S1-S4. Because the software can generate integral accumulated errors after long-time operation, the estimated motor rotor temperature has certain deviation compared with the actual measured rotor temperature. In order to improve the estimation precision of the motor rotor, the invention designs the following steps to reasonably correct the temperature estimation value of the motor rotor.
Obtaining permanent magnet flux linkage psi corresponding to the temperature (20-120 ℃ and 10 ℃ at intervals) of each motor rotor calibrated by a motor factory T As can be seen from fig. 5, the temperature of the motor rotor and the flux linkage of the permanent magnet are approximately in a straight line, and the temperature of the motor rotor corresponding to the flux linkage of the permanent magnet in any temperature interval can be obtained through linearization fitting, specifically as follows:
formula (VI)In (a): psi phi type 20 A permanent magnet flux linkage for the motor rotor at 20 ℃; psi phi type T For the motor rotor temperature T r_amd Permanent magnet flux linkage of (2); k (k) mr A slope is fitted to the motor rotor temperature-flux linkage line.
Establishing a motor voltage equation and a motor flux linkage equation under an alpha and beta coordinate system, and establishing a motor rotor permanent magnet flux linkage observer by utilizing the motor voltage equation and the motor flux linkage equation, wherein the specific contents are as follows:
motor voltage equation:
motor flux linkage equation:
motor rotor permanent magnet flux linkage observer:
formula (VI)In (a): u (U) α 、U β Voltages of an alpha axis and a beta axis respectively; u (U) d 、U q Respectively the d-axis voltage and the q-axis voltage after PI adjustment; i.e α 、i β Currents of an alpha axis and a beta axis respectively; psi phi type α 、ψ β The magnetic links are respectively formed by a motor stator and a motor rotor on an alpha shaft and a beta shaft; r is R s A winding resistor for the stator; θ is the motor rotor angle.
Formula (VI)In (a): l is the inductance of the motor stator; psi phi type f Is the flux linkage of the motor rotor. Formula (VI)In (a): i.e a 、i b 、i c The stator currents are u, v and w three phases respectively; t is t 0 Is one task period duration.
The present invention provides that the following three conditions are satisfied by the formulaCalculating the flux linkage of the permanent magnet of the motor rotor and adding the formula +.>The obtained motor rotor temperature correction value T r_amd Replacing the current time motor rotor temperature estimated value T r 。
The three conditions are specifically as follows:
1. the system is powered down and is powered up again and the machine is stopped for a period of time t stop Is less than the natural cooling stable time t of the motor rotor w ；
2. Temperature T of motor stator assembly at current moment in system operation process s The motor rotor temperature T 'at the last time estimated by the formula (3)' r Absolute value of difference |DeltaT sr I greater than or equal toAt a certain threshold value delta T diff (set to a calibrated value);
3. number of correction times N of motor rotor temperature in running process of system amd Less than or equal to a certain threshold N l (set to a calibrated value).
Finally, it should be explained that: the above embodiments are merely illustrative of the preferred embodiments of the present invention, and not limiting the scope of the present invention; although the invention has been described in detail with reference to the foregoing embodiments, it will be appreciated by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions.
Claims (6)
1. The real-time online estimation method for the rotor temperature of the permanent magnet synchronous motor is characterized by comprising the following steps of:
s1, the sum of iron loss power consumption and copper loss power consumption generated by a motor system in a task period is equivalent to the total power consumption absorbed by a motor stator assembly;
s2, taking the motor stator assembly as a heat source, wherein the absorption power consumption is equivalent to the sum of cooling air dissipation power consumption, cooling liquid dissipation power consumption and motor rotor absorption power consumption;
s3, taking the dissipation power consumption of cooling air as heat convection loss and the dissipation power consumption of cooling liquid as heat conduction loss, and coupling the two loss parts into the total cooling loss of the motor system;
s4, obtaining temperature characteristics of the motor rotor in the full environment temperature range under the condition of natural cooling through experiments, recording the shutdown time of a motor system and the temperature of the motor rotor at the current power-down time, and calculating to obtain the initial temperature of the motor rotor at the next power-up time;
s5, obtaining the corresponding relation between the motor rotor temperature and the rotor permanent magnet flux linkage through experiments, and correcting the motor rotor temperature estimation error generated after the software runs for a long time by setting a motor rotor temperature correction enabling condition.
2. The method for real-time online estimation of the rotor temperature of the permanent magnet synchronous motor according to claim 1, wherein the specific step S3 is as follows:
1) Setting the X coordinate as the temperature T of the motor stator assembly s And the temperature T 'of the motor rotor at the last moment' r Difference delta T sr The Y coordinate is set as the temperature T of the motor stator assembly s And the temperature T of the cooling liquid cool Is a difference DeltaT of (1) sc The Z coordinate is set as the power consumption P of the coupled cooling liquid cool And air cooling power consumption P air Sum P heat The motor system total cooling power consumption two-dimensional table can be constructed, and the motor stator assembly temperature T acquired in a task period is used s Temperature T of cooling liquid cool The temperature T 'of the motor rotor at the last moment' r Obtaining the total cooling power consumption of the motor system by looking up a table;
2) Establishing a motor rotor temperature estimation precision simulation platform, inputting real motor operation data obtained by testing under different conditions into the simulation platform, and estimating a difference delta T of the motor rotor temperature through actually measuring the motor rotor temperature and a model r To correct the two-dimensional table of the motor system total cooling power consumption model to ensure that delta T r And the requirement on the accuracy of the temperature estimation of the motor rotor is met.
3. The method for real-time online estimation of the rotor temperature of the permanent magnet synchronous motor according to claim 1, wherein the step S4 is to obtain the natural cooling characteristic of the rotor temperature of the motor in the whole ambient temperature range, and calculate the initial temperature of the rotor of the motor under the conditions of any ambient temperature and stop time length, and comprises the following specific steps:
1) Obtaining the change relation of the motor rotor temperature along with the downtime in the whole environment temperature range through experiments, and obtaining the slope of a natural cooling line of the motor rotor temperature under different environment temperatures through linear fitting;
2) And calculating the system shutdown time through the time point stored in the non-lost memory when the system is powered down, the temperature of the motor rotor and the time point sent by the whole vehicle controller when the system is powered up, and finally obtaining the initial temperature of the motor rotor at the current power-up time by utilizing the slope of the natural cooling line of the temperature of the motor rotor, the system shutdown time and the temperature of the motor rotor when the system is powered down last time.
4. The method for real-time online estimation of rotor temperature of permanent magnet synchronous motor according to claim 1, wherein the step S5 is to eliminate the accumulated error of motor rotor temperature estimation generated by long-time running of software by adopting an intelligent correction algorithm, and comprises the following specific steps:
1) Obtaining the corresponding relation between the motor rotor temperature and the motor rotor permanent magnet flux linkage through experiments, and obtaining the motor rotor temperature-rotor permanent magnet flux linkage line slope through linear fitting;
2) Establishing a motor rotor permanent magnet flux observer through a motor voltage equation and a motor flux equation, and calculating a motor rotor correction temperature through the obtained motor rotor permanent magnet flux and flux line slope;
3) Judging the shutdown time of a motor system and the temperature T of a motor stator assembly by designing a motor rotor temperature correction enabling condition s And the temperature T 'of the motor rotor at the last moment' r Absolute value of difference |DeltaT sr The magnitude of the I and the number of motor rotor temperature correction times are used for determining whether the calculated motor rotor correction temperature replaces the motor rotor temperature estimated by the current moment model.
5. The method for real-time online estimation of rotor temperature of permanent magnet synchronous motor according to claim 1, wherein in S1, the motor stator winding is closely attached to the stator core, and the temperature of the motor stator winding measured by the temperature sensor is approximately equivalent to the temperature of the stator assembly, namely, the formula is satisfied:wherein: p (P) e Iron loss power consumption in a task period; p (P) Cu Copper loss power consumption in a task period; c (C) w Specific heat capacity for motor stator windings; c (C) Fe Specific heat capacity of a stator core of the motor; m is M w The mass of the stator winding of the motor is as follows; m is M Fe The mass of the stator core of the motor is that of the stator core of the motor; delta T s The temperature change of the motor stator assembly in the task period is determined; Δt is the task cycle duration.
6. The method for real-time online estimation of rotor temperature of permanent magnet synchronous motor according to claim 2, wherein the motor stator assembly absorbs heat and then dissipates heat as a heat source to the boundary environment, and the heat of the motor stator assembly is consumed by cooling liquid power P cool Power consumption P of air cooling air Motor rotor heat absorption power consumption P r Three parts of consumption are consumed, and in one task period, the instantaneous energy consumption conservation of the system expressed by the following formulas is satisfied between the motor stator assembly, the cooling medium and the motor rotor:
(C w M w +C Fe M Fe )ΔT s ＝(P cool +P air )Δt+C r M r (T r -T r ')
wherein: p (P) cool The power consumption of the cooling liquid in the task period is as follows; p (P) air Air cooling power consumption in a task period; c (C) r Specific heat capacity of a motor rotor; m is M r The mass of the motor rotor; t (T) r Calculating the temperature for the motor rotor at the current moment; t'. r The temperature of the motor rotor at the last moment.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130028292A1 (en) * | 2011-07-29 | 2013-01-31 | Fanuc Corporation | Temperature detection device that detects temperature of rotor of motor |
| US20170338765A1 (en) * | 2014-09-05 | 2017-11-23 | Crrc Zhuzhou Electric Locomotive Research Institute Co., Ltd. | Rotor temperature monitoring method and system for permanent magnet synchronous motor |
| CN109347405A (en) * | 2018-10-08 | 2019-02-15 | 重庆长安汽车股份有限公司 | A kind of evaluation method and estimating system of motor rotor temperature |
| CN110323994A (en) * | 2019-07-24 | 2019-10-11 | 重庆长安新能源汽车科技有限公司 | Method, system, vehicle and the computer readable storage medium of real-time online estimation motor rotor temperature |
| CN111211719A (en) * | 2018-11-06 | 2020-05-29 | 株洲中车时代电气股份有限公司 | Method and system for estimating temperature of rotor magnetic steel of permanent magnet synchronous motor |
| CN115208281A (en) * | 2022-09-14 | 2022-10-18 | 中汽研汽车检验中心（天津）有限公司 | Thermal model and data processing method thereof, motor model and data processing method thereof |
| CN115833684A (en) * | 2021-12-15 | 2023-03-21 | 宁德时代新能源科技股份有限公司 | Estimation method and device for rotor temperature of permanent magnet synchronous motor and computer equipment |
-
2023
- 2023-05-29 CN CN202310621958.1A patent/CN116614035A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130028292A1 (en) * | 2011-07-29 | 2013-01-31 | Fanuc Corporation | Temperature detection device that detects temperature of rotor of motor |
| US20170338765A1 (en) * | 2014-09-05 | 2017-11-23 | Crrc Zhuzhou Electric Locomotive Research Institute Co., Ltd. | Rotor temperature monitoring method and system for permanent magnet synchronous motor |
| CN109347405A (en) * | 2018-10-08 | 2019-02-15 | 重庆长安汽车股份有限公司 | A kind of evaluation method and estimating system of motor rotor temperature |
| CN111211719A (en) * | 2018-11-06 | 2020-05-29 | 株洲中车时代电气股份有限公司 | Method and system for estimating temperature of rotor magnetic steel of permanent magnet synchronous motor |
| CN110323994A (en) * | 2019-07-24 | 2019-10-11 | 重庆长安新能源汽车科技有限公司 | Method, system, vehicle and the computer readable storage medium of real-time online estimation motor rotor temperature |
| CN115833684A (en) * | 2021-12-15 | 2023-03-21 | 宁德时代新能源科技股份有限公司 | Estimation method and device for rotor temperature of permanent magnet synchronous motor and computer equipment |
| CN115208281A (en) * | 2022-09-14 | 2022-10-18 | 中汽研汽车检验中心（天津）有限公司 | Thermal model and data processing method thereof, motor model and data processing method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 彭志远等: "电动车用永磁同步电机转子温度估算", 重庆理工大学学报( 自然科学), vol. 33, no. 9, 30 September 2019 (2019-09-30), pages 1 - 7 * |
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