CN114614709A - Flux-weakening closed-loop control method and device for permanent magnet synchronous motor and vehicle - Google Patents
Flux-weakening closed-loop control method and device for permanent magnet synchronous motor and vehicle Download PDFInfo
- Publication number
- CN114614709A CN114614709A CN202011430398.4A CN202011430398A CN114614709A CN 114614709 A CN114614709 A CN 114614709A CN 202011430398 A CN202011430398 A CN 202011430398A CN 114614709 A CN114614709 A CN 114614709A
- Authority
- CN
- China
- Prior art keywords
- axis
- utilization rate
- current
- regulator
- permanent magnet
- 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.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/0085—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation specially adapted for high speeds, e.g. above nominal speed
- H02P21/0089—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation specially adapted for high speeds, e.g. above nominal speed using field weakening
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/0003—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
The embodiment of the invention discloses a method and a device for flux-weakening closed-loop control of a permanent magnet synchronous motor and a vehicle, relates to the technical field of permanent magnet synchronous motors, can realize flux-weakening closed-loop control adjustment without increasing calculated amount, and has the advantages of strong disturbance rejection capability and high precision. The embodiment of the invention calculates the voltage utilization rate by using the direct axis voltage and the quadrature axis voltage of the permanent magnet synchronous motor, inputs the voltage utilization rate and the target voltage utilization rate determined according to the modulation depth requirement of the system into the weak magnetic ring PI regulator, outputs the dynamic regulation coefficient through the work of the weak magnetic ring PI regulator and is superposed to the Map lookup table input, dynamically regulates the lookup table depth, enables the dq axis current output by the lookup table to be more matched with the current actual working condition, carries out current loop PI regulation on the d axis current component Id and the q axis current component Iq obtained through coordinate transformation, and outputs the direct axis voltage and the quadrature axis voltage of the permanent magnet synchronous motor through the current loop PI regulation, thereby realizing the closed-loop weak magnetic control.
Description
Technical Field
The invention relates to a permanent magnet synchronous motor, in particular to a flux-weakening closed-loop control method and device of the permanent magnet synchronous motor and a vehicle.
Background
The permanent magnet synchronous motor is a motor which uses a permanent magnet to provide excitation, is composed of a stator, a rotor, an end cover and the like, and has good application prospect in the field of electric automobile and train traction. The excitation of the rotor of the permanent magnet synchronous motor is not adjustable, the back electromotive force of the motor is in direct proportion to the rotating speed of the motor, and after the back electromotive force of the motor rises to the maximum value of the voltage of a direct current side along with the rotating speed, the field weakening control needs to be carried out by a method of increasing a direct-axis current component and reducing an alternating-axis current component so as to keep the voltage balance of an armature winding.
The operation of the permanent magnet synchronous motor is limited by the following three aspects, namely, the maximum stator current which can be borne by a motor stator; the maximum output current which can be borne by the inverter power device; and thirdly, limiting the voltage of the direct current bus of the inverter. The above-mentioned limits form a voltage limit ellipse and a current limit circle. When the motor runs at a high speed, better power output capacity needs to be kept, but the intersection range of the voltage limit ellipse and the current limit circle is small, parameters such as motor inductance and flux linkage also have influence on control, and the motor is applied to an electric automobile, so that the working condition is complex, electromagnetic interference is serious, the parameter change of the motor is large, the saturation of a current regulator easily occurs at a high speed, and the system is out of control. Therefore, the quality of the flux-weakening control capability directly affects the control precision, the control efficiency and the system stability of the system.
Disclosure of Invention
The embodiment of the invention provides a flux weakening closed-loop control method for a permanent magnet synchronous motor, which can realize flux weakening control closed-loop adjustment without increasing calculated amount and has the advantages of strong disturbance rejection capability and high precision.
Correspondingly, the embodiment of the invention also provides a flux-weakening closed-loop control device of the permanent magnet synchronous motor and a vehicle, so as to apply the flux-weakening closed-loop control method of the permanent magnet synchronous motor.
In order to solve the above problem, from one aspect of the embodiments of the present invention, an embodiment of the present invention discloses a flux weakening closed-loop control method for a permanent magnet synchronous motor, where the method includes:
determining the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition according to the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor;
taking the difference between the actual voltage utilization rate and the received target voltage utilization rate as the input of a weak magnetic ring PI regulator to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator, wherein the target voltage utilization rate is determined according to the system modulation depth;
according to the motor rotating speed of the permanent magnet synchronous motor, the dynamic adjustment coefficient and the received torque instruction, looking up a table to obtain direct axis table looking-up current and quadrature axis table looking-up current;
obtaining a direct-axis current component and a quadrature-axis current component according to the currently acquired three-phase current of the permanent magnet synchronous motor;
and respectively taking the difference value of the direct-axis lookup table current and the direct-axis current component and the difference value of the quadrature-axis lookup table current and the quadrature-axis current component as the input of a current loop PI regulator to obtain corresponding output so as to update the direct-axis voltage and the quadrature-axis voltage.
Further, according to the direct axis voltage and quadrature axis voltage of the permanent magnet synchronous motor, determining the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition, including:
determining a per unit value of the direct-axis voltage and a per unit value of the quadrature-axis voltage;
calculating the sum of the square of the per-unit value of the direct-axis voltage and the square of the per-unit value of the quadrature-axis voltage;
and opening the square root of the sum of the squares to obtain the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition.
Further, the method further comprises:
setting the working state and the output amplitude limit value of the weak magnetic ring PI regulator, wherein the working state is working or non-working;
taking the difference between the actual voltage utilization rate and the received target voltage utilization rate as the input of a weak magnetic ring PI regulator to obtain the dynamic regulation coefficient output by the weak magnetic ring PI regulator, wherein the dynamic regulation coefficient comprises the following steps:
taking the difference value between the actual voltage utilization rate and the received target voltage utilization rate as the input of the weak magnetic ring PI regulator;
when the actual voltage utilization rate is less than or equal to the target voltage utilization rate, the weak magnetic ring PI regulator does not work, and the obtained dynamic regulation coefficient is 1;
and when the actual voltage utilization rate is greater than the target voltage utilization rate, the weak magnetic ring PI regulator works, and the actual voltage utilization rate is regulated in the output amplitude limit value to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator.
Further, according to the motor speed of the permanent magnet synchronous motor, the dynamic adjustment coefficient and the received torque instruction, a direct axis table lookup current and a quadrature axis table lookup current are obtained by table lookup, including:
determining the rotating speed of the motor by looking up a table according to the rotating speed of the motor of the permanent magnet synchronous motor and the dynamic adjustment coefficient;
and according to the rotating speed of the motor and the received torque instruction, looking up the table to obtain direct axis table lookup current and quadrature axis table lookup current.
From another aspect of the embodiments of the present invention, an embodiment of the present invention further discloses a flux weakening closed-loop control device for a permanent magnet synchronous motor, the device includes:
the actual voltage utilization rate determining module is used for determining the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition according to the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor;
a dynamic adjustment coefficient obtaining module, configured to use a difference between the actual voltage utilization rate and a received target voltage utilization rate as an input of a weak magnetic ring PI regulator to obtain a dynamic adjustment coefficient output by the weak magnetic ring PI regulator, where the target voltage utilization rate is determined according to a system modulation depth;
the table lookup current obtaining module is used for obtaining direct axis table lookup current and quadrature axis table lookup current by table lookup according to the motor rotating speed of the permanent magnet synchronous motor, the dynamic adjustment coefficient and the received torque instruction;
the current component obtaining module is used for obtaining a direct-axis current component and a quadrature-axis current component according to the currently acquired three-phase current of the permanent magnet synchronous motor;
and the voltage updating module is used for respectively taking the difference value of the direct-axis lookup table current and the direct-axis current component and the difference value of the quadrature-axis lookup table current and the quadrature-axis current component as the input of the current loop PI regulator to obtain corresponding output so as to update the direct-axis voltage and the quadrature-axis voltage.
Further, the actual voltage utilization determining module includes:
a per-unit value determining submodule for determining a per-unit value of the direct-axis voltage and a per-unit value of the quadrature-axis voltage;
the per unit value calculation submodule is used for calculating the sum of the square of the per unit value of the direct-axis voltage and the square of the per unit value of the quadrature-axis voltage;
and the voltage utilization rate calculation submodule is used for opening a square root to the sum of the squares to obtain the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition.
Further, the apparatus further comprises:
the PI regulator setting module is used for setting the working state and the output amplitude limit value of the weak magnetic ring PI regulator, and the working state is working or non-working;
the dynamic adjustment coefficient obtaining module comprises:
the PI regulator input submodule is used for taking the difference value between the actual voltage utilization rate and the received target voltage utilization rate as the input of the weak magnetic ring PI regulator;
the first output result sub-module is used for enabling the weak magnetic ring PI regulator not to work when the actual voltage utilization rate is smaller than or equal to the target voltage utilization rate, and obtaining a dynamic regulation coefficient of 1;
and the second output result submodule is used for working the weak magnetic ring PI regulator when the actual voltage utilization rate is greater than the target voltage utilization rate, and regulating the actual voltage utilization rate within the output amplitude limit value to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator.
Further, the table lookup current obtaining module includes:
the table lookup motor rotating speed determining submodule is used for determining the table lookup motor rotating speed according to the motor rotating speed of the permanent magnet synchronous motor and the dynamic adjusting coefficient;
and the table lookup execution submodule is used for looking up a table according to the table lookup motor rotating speed and the received torque instruction to obtain direct axis table lookup current and quadrature axis table lookup current.
From still another aspect of the embodiments of the present invention, there is also disclosed a vehicle including:
the controller comprises a permanent magnet synchronous motor and a memory for storing controller executable instructions;
the controller is used for executing the flux weakening closed-loop control method of the permanent magnet synchronous motor according to the embodiment of the invention.
The embodiment of the invention has the following advantages:
the embodiment of the invention calculates the voltage utilization rate by using the direct axis voltage and the quadrature axis voltage of the permanent magnet synchronous motor, inputs the voltage utilization rate and the target voltage utilization rate determined according to the modulation depth requirement of the system into the weak magnetic ring PI regulator, outputs the dynamic regulation coefficient through the work of the weak magnetic ring PI regulator and is superposed to the Map lookup table input, dynamically regulates the lookup table depth, enables the dq axis current output by the lookup table to be more matched with the current actual working condition, carries out current loop PI regulation on the d axis current component Id and the q axis current component Iq obtained through coordinate transformation, and outputs the direct axis voltage and the quadrature axis voltage of the permanent magnet synchronous motor through the current loop PI regulation, thereby realizing the closed-loop weak magnetic control.
In the flux weakening control process of the embodiment of the invention, the voltage utilization rate can change along with the fluctuation of parameters such as voltage, temperature and the like of the permanent magnet synchronous motor and the change caused by environmental interference, so that the output of the system can be matched with the real-time working condition by adjusting the voltage utilization rate, and the flux weakening control method has the advantages of strong interference resistance and high precision.
In the flux-weakening control process of the embodiment of the invention, table lookup calculation based on mainstream is adopted, dynamic adjustment is carried out through the voltage utilization rate on the basis of the table lookup calculation, and the Id current component and the Iq current component realize flux-weakening closed loop.
In the flux weakening control process of the embodiment of the invention, the voltage utilization rate is obtained by calculating the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor, the direct-axis voltage and the quadrature-axis voltage are necessary quantities in the control process, the calculated quantity is not increased, and the accuracy dependence on parameters such as motor inductance and flux linkage is low.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a flowchart illustrating the steps of a flux-weakening closed-loop control method for a permanent magnet synchronous motor according to an embodiment of the present invention;
FIG. 2 is a field weakening control schematic of an embodiment of the present invention;
FIG. 3 is a flux weakening control flow diagram of an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of a vehicle according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a flux weakening closed-loop control device of a permanent magnet synchronous motor according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the current general motor control scheme, the three-phase current of a motor is collected and subjected to coordinate transformation to obtain a dq axis current component, a dq axis voltage is obtained through a PI (proportional integral) regulator, and the PWM is used for modulating an output duty ratio through the voltage to perform inversion. In the motor control scheme, two weak magnetic control strategies are provided, one is to calibrate Map table look-up, namely d-axis ammeter table data and q-axis ammeter table data which are needed under the current working condition are calculated according to a torque instruction and a rotating speed table look-up, then d-axis voltage Ud is obtained by a difference value between d-axis current component Id and the d-axis ammeter table data through a PI regulator, and q-axis voltage Uq is obtained by a difference value between q-axis current component Iq and the q-axis ammeter table data through the PI regulator; and secondly, directly calculating a d-axis current component and a q-axis current component through a voltage outer ring, and then carrying out PI regulation on the d-axis current component Id and the q-axis current component Iq obtained through coordinate transformation.
A weak magnetic control mode is carried out based on calibration Map lookup, the calculated amount is small, but the actual operation environment is different from that of the calibration Map, if the bus voltage is different and the temperature difference causes motor parameter change, the lookup data cannot completely match the actual operation condition of the motor, the control precision is insufficient, the weak magnetic control is not closed-loop, and the d-axis current component Id and the q-axis current component Iq cannot be dynamically adjusted. A large number of parameters are introduced for calculation in a mode of directly calculating d-axis current components and q-axis current components through a voltage outer ring, and the calculation depends on motor parameters, but the motor parameters are greatly influenced by the environment, the system is complex, the precision is insufficient, and the universality is poor.
In order to solve the above problems, an embodiment of the present invention provides a method for flux-weakening closed-loop control of a permanent magnet synchronous motor, in which Id current components and Iq current components are calculated by Map lookup, voltage utilization rates are calculated by d-axis voltages and q-axis voltages, the voltage utilization rates represent current modulation depths, and when no overmodulation is considered, and a modulation degree reaches 1, a current loop PI regulator is saturated and a system is out of control, and a weak magnetic loop PI regulator is designed to regulate the voltage utilization rates, and the regulator outputs influence Map lookup, dynamic Id current components and Iq current components, so that a current output voltage vector reaches an expected modulation depth, and meanwhile, the phenomena of insufficient control precision and out of control of system saturation caused by parameter fluctuation are avoided.
Referring to fig. 1, a flowchart illustrating steps of a flux weakening closed-loop control method for a permanent magnet synchronous motor according to an embodiment of the present invention may include the following steps:
step S101, determining the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition according to the direct axis voltage and the quadrature axis voltage of the permanent magnet synchronous motor;
referring to the above description, the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor may be obtained by a PI regulator, and in order to facilitate subsequent calculation and reduce the calculation amount, the embodiment of the present invention performs per unit processing on the entire control system of the permanent magnet synchronous motor, so that the actual voltage utilization rate of the permanent magnet synchronous motor under the current operating condition may be determined directly according to the direct-axis voltage and the quadrature-axis voltage, and the specific implementation steps include:
a substep S101-1 of determining a per unit value of the direct axis voltage and a per unit value of the quadrature axis voltage;
a substep S101-2 of calculating the sum of the square of the per unit value of the direct axis voltage and the square of the per unit value of the quadrature axis voltage;
and a substep S101-3, opening a square root to the sum of the squares to obtain the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition.
And (4) integrating the substep S101-1 to the substep S101-3, wherein the calculation formula of the actual voltage utilization rate is as follows:
in the equation (1), Ud represents a per unit value of the direct-axis voltage, Uq represents a per unit value of the quadrature-axis voltage, and U _ ratio represents the actual voltage utilization rate.
Step S102, taking the difference between the actual voltage utilization rate and the received target voltage utilization rate as the input of a weak magnetic ring PI regulator to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator, wherein the target voltage utilization rate is determined according to the system modulation depth;
after the actual voltage utilization rate is obtained, the embodiment of the invention determines the target voltage utilization rate according to the system modulation depth requirement, for example, the target voltage utilization rate is 0.95. The system modulation depth under different conditions can be different, namely in the closed-loop flux weakening control process each time, the system can receive a target voltage utilization rate, and the target voltage utilization rate is obtained in a command mode, so that the dynamic adjustment coefficient output by the weak magnetic ring PI regulator can better meet the modulation requirement under the current working condition.
The weak magnetic ring PI regulator is also a PI regulator, and it is characterized by that according to the given value and actual output value a control deviation is formed, and the proportion and integral of the deviation are linearly combined to form control quantity, and can be used for controlling controlled object.
After the actual voltage utilization rate and the target voltage utilization rate are obtained, the difference value of the actual voltage utilization rate and the target voltage utilization rate can be used as the input of a newly-added weak magnetic ring PI regulator in the motor control system, and therefore the dynamic regulation coefficient output by the weak magnetic ring PI regulator is obtained.
In an optional embodiment of the present invention, according to a system requirement, in order to balance an output performance of the system and a stability of the system, an operating state and an output limit value of the weak magnetic ring PI regulator are further set in the embodiment of the present invention, and the operating state is operating or not operating. Based on the operating state and the output amplitude limiting value of the weak magnetic ring PI regulator, step S102 may specifically include the following sub-steps:
a substep S102-1, using the difference between the actual voltage utilization rate and the received target voltage utilization rate as the input of the weak magnetic ring PI regulator;
step S102-2, when the actual voltage utilization rate is less than or equal to the target voltage utilization rate, the weak magnetic ring PI regulator does not work, and the obtained dynamic regulation coefficient is 1;
and a substep S102-3, when the actual voltage utilization rate is greater than the target voltage utilization rate, operating the weak magnetic ring PI regulator, and regulating the actual voltage utilization rate within the output amplitude limit value to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator.
Therefore, the weak magnetic ring PI regulator of the embodiment of the invention can determine the working state of the weak magnetic ring PI regulator by comparing the actual voltage utilization rate with the target voltage utilization rate. And when the actual voltage utilization rate is less than or equal to the target voltage utilization rate, the actual voltage utilization rate is not overloaded and accords with the current working condition, at the moment, the weak magnetic ring PI regulator is in a default working state of no regulation, and the output dynamic regulation coefficient is 1. And if the actual voltage utilization rate is greater than the target voltage utilization rate, the actual voltage utilization rate is currently overloaded, the system is in a saturation out-of-control state, and the weak magnetic ring PI regulator regulates the actual voltage utilization rate within the output amplitude limit value to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator.
In the embodiment of the invention, the value range of the dynamic adjustment coefficient is 0-1, the closer the dynamic adjustment coefficient is to 1, the voltage is not fully used under the current working condition, and the closer the dynamic adjustment coefficient is to 1, the utilization rate of the voltage can be increased; on the contrary, the closer the dynamic adjustment coefficient is to 0, the closer the voltage is to the full state under the current working condition is, and the closer the dynamic adjustment coefficient is to 0, the utilization rate of the voltage can be reduced, so that the performance and the stability of the system can be ensured.
Step S103, looking up a table to obtain direct axis table look-up current and quadrature axis table look-up current according to the motor rotating speed of the permanent magnet synchronous motor, the dynamic adjustment coefficient and the received torque instruction;
the embodiment of the invention obtains direct axis lookup table current and quadrature axis lookup table current based on calibration Map lookup, and the calibration Map lookup table records the direct axis current given value and the quadrature axis current given value under different torque instructions and rotating speeds measured by a bench test. In the table, the rotation speed is divided into a plurality of sections according to the division accuracy, for example, the rotation speed is 0-10000 (revolutions per second) with 500 as the division accuracy, the rotation speed is represented as 0, 500, 1000 and 1500 … … in the horizontal row of the table, the torque command is displayed in the row, a range section of the torque can be displayed in each cell, for example, 0-30, 30-60 and 60-90 … …, or specific numerical values can be displayed in each cell, for example, 150, 160, 170 … … and … …
In the prior art, the current value can be determined by looking up a table through Map according to the received torque command and the current rotating speed. However, the embodiment of the present invention is different from the above, the step S103 may specifically include the following table lookup steps:
substep S103-1, determining the rotation speed of the table lookup motor according to the motor rotation speed of the permanent magnet synchronous motor and the dynamic adjustment coefficient;
and a substep S103-2, looking up the table according to the rotation speed of the motor and the received torque instruction to obtain direct axis table lookup current and quadrature axis table lookup current.
When the torque instruction and the current rotating speed are received, the rotating speed is adjusted by adopting a dynamic adjusting coefficient, if the rotating speed is multiplied by the current rotating speed, the current actual table lookup rotating speed is determined, and then the table lookup is carried out according to the table lookup rotating speed and the torque instruction to obtain direct axis table lookup current and quadrature axis table lookup current. In other words, the direct axis lookup table current and the quadrature axis lookup table current according to the embodiment of the present invention are determined after being adjusted by the dynamic adjustment coefficient. The following are exemplified: the current rotating speed is 2000 r/s, the torque instruction indicates that the torque is 250 nm, the dynamic adjustment coefficient is 0.9, namely the table look-up rotating speed is 1800 r/s, and at the moment, the direct-axis current given value and the quadrature-axis current given value corresponding to the rotating speed of 1800 r/s and the torque of 250 nm are respectively used as direct-axis table look-up current and quadrature-axis table look-up current in the table.
Step S104, obtaining a direct-axis current component and a quadrature-axis current component according to the currently acquired three-phase current of the permanent magnet synchronous motor;
as described in the foregoing, after the sensor collects the three-phase current of the permanent magnet synchronous motor, the d-axis current component Id and the q-axis current component Iq can be obtained through Clark and Park coordinate transformation, the direct-axis current component is the d-axis current component Id, and the quadrature-axis current component is the q-axis current component Iq in the embodiment of the present invention. The specific conversion steps of the three-phase current can refer to the prior art, and are not described herein.
Step S105, respectively taking the difference value between the direct-axis lookup table current and the direct-axis current component and the difference value between the quadrature-axis lookup table current and the quadrature-axis current component as the input of a current loop PI regulator to obtain corresponding output so as to update the direct-axis voltage and the quadrature-axis voltage.
In specific implementation, the current loop PI regulator includes a direct axis PI regulator and a quadrature axis PI regulator, and the implementation process of step S105 is as follows:
taking the difference value of the direct-axis lookup table current and the direct-axis current component as the input of the direct-axis PI regulator to obtain the direct-axis voltage of the permanent magnet synchronous motor under the current working condition so as to update the direct-axis voltage;
and taking the difference value of the quadrature axis lookup table current and the quadrature axis current component as the input of the quadrature axis PI regulator to obtain the quadrature axis voltage of the permanent magnet synchronous motor under the current working condition so as to update the quadrature axis voltage.
It can be known from the combination of steps S101 to S105 that, in the embodiment of the present invention, the direct axis voltage and the quadrature axis voltage are updated, so that a closed loop process of the field weakening control is implemented, and in the next field weakening control process, the actual voltage utilization rate is calculated according to the updated direct axis voltage and quadrature axis voltage. That is, the adjustment scheme of the present invention may perform the field weakening control based on the existing direct-axis voltage and quadrature-axis voltage, or may perform the field weakening control based on the updated direct-axis voltage and quadrature-axis voltage of the present invention.
Referring to fig. 2, a field weakening control schematic diagram of an embodiment of the present invention is shown, wherein Torque _ ref represents a Torque command, Motor _ Speed represents a Motor Speed, U _ ratio represents an actual voltage utilization, U _ ratio _ ref represents a target voltage utilization, U _ factor represents a dynamic regulation coefficient, Id _ ref represents a direct axis lookup table current, and Iq _ ref represents an quadrature axis lookup table current.
As shown in fig. 2, a sensor collects three-phase currents of a permanent magnet synchronous motor, the three-phase currents are subjected to coordinate transformation of Clark and Park to obtain a d-axis current component Id and a q-axis current component Iq, and a torque command is subjected to Map lookup to obtain target commands Id _ ref and Iq _ ref of Id and Iq. And taking the difference value between Id _ ref and Id as the input of a d-axis PI regulator, taking the difference value between Iq _ ref and Iq as the input of a q-axis PI regulator, obtaining dq-axis voltages Ud and Uq after the dq-axis PI regulator, carrying out SVPWM (space vector pulse width modulation) after the dq-axis voltages are subjected to Park inverse transformation, outputting the on-off time of a three-phase duty ratio control power device, and finally outputting three-phase current.
On the basis, the weak magnetic closed loop is added, the current actual voltage utilization rate is calculated by using the voltage value output by the dq-axis current PI regulator, the voltage utilization rate reflects the modulation depth, and the voltage utilization rate is changed by the change of a control system caused by the fluctuation of parameters such as voltage and temperature and environmental interference, so that the system output can be matched with the real-time working condition by adjusting the voltage utilization rate. And then, taking the difference value between the U _ ratio _ ref and the U _ ratio determined according to the modulation depth requirement of the system as the input of the weak magnetic ring PI regulator, and outputting the U _ factor through the weak magnetic ring PI regulator. Map table lookup input in the control algorithm is Torque _ ref, Motor _ Speed and U _ factor, which is equivalent to superposition dynamic adjustment on the basis of Map data calibration, and system output performance and system stability are balanced according to system requirements. Setting the working state and the output amplitude of a weak magnetic ring PI regulator, when the actual voltage utilization rate U _ ratio is smaller than U _ ratio _ ref, the weak magnetic ring PI regulator does not work, the output U _ factor is 1, when the actual voltage utilization rate U _ ratio is larger than U _ ratio _ ref, dynamic regulation is carried out, the current values of Id _ ref and Iq _ ref output by table lookup at the moment reflect the current actual working condition, the three-phase current output after current loop control is more accurate, and the output performance and the stability of a system are ensured. Referring to fig. 3, a flux weakening control flow diagram of an embodiment of the present invention is shown, from which the closed loop control process of the present invention is also clearly reflected.
In summary, the embodiments of the present invention have the following advantages:
1) the voltage utilization rate of the embodiment of the invention can change along with the fluctuation of parameters such as voltage, temperature and the like of the permanent magnet synchronous motor and the change caused by environmental interference, so that the output of the system can be matched with the real-time working condition by adjusting the voltage utilization rate, and the invention has the advantages of strong anti-interference capability and high precision.
2) The embodiment of the invention is based on the table look-up calculation of the main flow, dynamic adjustment is carried out on the basis of the table look-up calculation through the voltage utilization rate, the Id current component and the Iq current component realize weak magnetic closed loop, the universality is strong, and the method can be used for the main flow solution of the permanent magnet synchronous motor.
3) The voltage utilization rate of the embodiment of the invention is obtained by calculating the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor, and the direct-axis voltage and the quadrature-axis voltage are necessary in the control process, the calculated amount is not increased, and the accuracy dependence on parameters such as motor inductance and flux linkage is low.
Based on the same inventive concept, an embodiment of the present invention provides a vehicle, and referring to fig. 4, a schematic structural diagram of the vehicle according to the embodiment of the present invention is shown, where the vehicle includes:
a permanent magnet synchronous machine 401 and a memory 403 for storing instructions executable by the controller 402;
and a controller 402 for executing the field weakening closed-loop control method of the permanent magnet synchronous motor according to the embodiment of the invention.
In concrete implementation, the vehicle adopts the flux weakening closed-loop control method of the permanent magnet synchronous motor to control the permanent magnet synchronous motor, closed-loop dynamic adjustment can be realized, and the control system has high stability, strong interference rejection and high precision.
It should be noted that, for simplicity of description, the method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present invention is not limited by the illustrated order of acts, as some steps may occur in other orders or concurrently in accordance with the embodiments of the present invention. Further, those skilled in the art will appreciate that the embodiments described in the specification are presently preferred and that no particular act is required to implement the invention.
Based on the same inventive concept, an embodiment of the present invention further provides a flux weakening closed-loop control device for a permanent magnet synchronous motor, and referring to fig. 5, a schematic structural diagram of a flux weakening closed-loop control device for a permanent magnet synchronous motor according to an embodiment of the present invention is shown, and the device may include the following modules:
an actual voltage utilization rate determining module 501, configured to determine an actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition according to a direct axis voltage and a quadrature axis voltage of the permanent magnet synchronous motor;
a dynamic adjustment coefficient obtaining module 502, configured to use a difference between the actual voltage utilization rate and the received target voltage utilization rate as an input of a weak magnetic ring PI regulator to obtain a dynamic adjustment coefficient output by the weak magnetic ring PI regulator, where the target voltage utilization rate is determined according to a system modulation depth;
a table lookup current obtaining module 503, configured to obtain a direct axis table lookup current and a quadrature axis table lookup current by table lookup according to the motor rotation speed of the permanent magnet synchronous motor, the dynamic adjustment coefficient, and the received torque instruction;
a current component obtaining module 504, configured to obtain a direct-axis current component and a quadrature-axis current component according to a currently acquired three-phase current of the permanent magnet synchronous motor;
and a voltage updating module 505, configured to take a difference between the direct axis lookup table current and the direct axis current component and a difference between the quadrature axis lookup table current and the quadrature axis current component as inputs of the current loop PI regulator, respectively, to obtain corresponding outputs, so as to update the direct axis voltage and the quadrature axis voltage.
In an optional embodiment of the present invention, the actual voltage utilization determining module 501 includes:
a per-unit value determining submodule for determining a per-unit value of the direct-axis voltage and a per-unit value of the quadrature-axis voltage;
the per unit value calculation submodule is used for calculating the sum of the square of the per unit value of the direct-axis voltage and the square of the per unit value of the quadrature-axis voltage;
and the voltage utilization rate calculation submodule is used for opening a square root to the sum of the squares to obtain the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition.
In an optional embodiment of the present invention, the apparatus further comprises:
the PI regulator setting module is used for setting the working state and the output amplitude limit value of the weak magnetic ring PI regulator, and the working state is working or non-working;
the dynamic adjustment coefficient obtaining module 502 includes:
the PI regulator input sub-module is used for taking the difference value between the actual voltage utilization rate and the received target voltage utilization rate as the input of the weak magnetic ring PI regulator;
the first output result sub-module is used for enabling the weak magnetic ring PI regulator not to work when the actual voltage utilization rate is smaller than or equal to the target voltage utilization rate, and obtaining a dynamic regulation coefficient of 1;
and the second output result submodule is used for working the weak magnetic ring PI regulator when the actual voltage utilization rate is greater than the target voltage utilization rate, and regulating the actual voltage utilization rate within the output amplitude limit value to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator.
In an optional embodiment of the present invention, the table lookup current obtaining module 503 includes:
the table lookup motor rotating speed determining submodule is used for determining the table lookup motor rotating speed according to the motor rotating speed of the permanent magnet synchronous motor and the dynamic adjusting coefficient;
and the table lookup execution submodule is used for looking up a table according to the table lookup motor rotating speed and the received torque instruction to obtain direct axis table lookup current and quadrature axis table lookup current.
To sum up, the embodiment of the present invention calculates the voltage utilization rate by using the direct axis voltage and quadrature axis voltage of the permanent magnet synchronous motor, inputs the voltage utilization rate and the target voltage utilization rate determined according to the modulation depth requirement of the system into the weak magnetic ring PI regulator, outputs the dynamic adjustment coefficient through the work of the weak magnetic ring PI regulator and superimposes the dynamic adjustment coefficient on the Map lookup table input, dynamically adjusts the lookup table depth, so that the dq axis current output by the lookup table more matches the current actual working condition, performs current loop PI adjustment with the d axis current component Id and the q axis current component Iq obtained through coordinate transformation, and outputs the direct axis voltage and the quadrature axis voltage of the permanent magnet synchronous motor through the current loop PI adjustment, thereby realizing the closed-loop weak magnetic control.
In the flux weakening control process of the embodiment of the invention, the voltage utilization rate can change along with the fluctuation of parameters such as voltage, temperature and the like of the permanent magnet synchronous motor and the change caused by environmental interference, so that the output of the system can be matched with the real-time working condition by adjusting the voltage utilization rate, and the flux weakening control method has the advantages of strong interference resistance and high precision.
In the flux-weakening control process of the embodiment of the invention, table lookup calculation based on mainstream is adopted, dynamic adjustment is carried out through the voltage utilization rate on the basis of the table lookup calculation, and the Id current component and the Iq current component realize flux-weakening closed loop.
In the flux weakening control process of the embodiment of the invention, the voltage utilization rate is obtained by calculating the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor, the direct-axis voltage and the quadrature-axis voltage are necessary quantities in the control process, the calculated quantity is not increased, and the accuracy dependence on parameters such as motor inductance and flux linkage is low.
It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.
It should also be noted that, in this document, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience of description and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Moreover, relational terms such as "first" and "second" are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions or should not be construed as indicating or implying relative importance. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or terminal equipment comprising the element.
The technical solutions provided by the present application are described in detail above, and the principles and embodiments of the present application are described herein by using specific examples, which are only used to help understanding the present application, and the content of the present description should not be construed as limiting the present application. While various modifications of the illustrative embodiments and applications will be apparent to those skilled in the art based upon this disclosure, it is not necessary or necessary to exhaustively enumerate all embodiments, and all obvious variations and modifications can be resorted to, falling within the scope of the disclosure.
Claims (9)
1. A flux-weakening closed-loop control method for a permanent magnet synchronous motor is characterized by comprising the following steps:
determining the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition according to the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor;
taking the difference between the actual voltage utilization rate and the received target voltage utilization rate as the input of a weak magnetic ring PI regulator to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator, wherein the target voltage utilization rate is determined according to the system modulation depth;
looking up a table to obtain direct axis table look-up current and quadrature axis table look-up current according to the motor rotating speed of the permanent magnet synchronous motor, the dynamic adjustment coefficient and the received torque instruction;
obtaining a direct-axis current component and a quadrature-axis current component according to the currently acquired three-phase current of the permanent magnet synchronous motor;
and respectively taking the difference value of the direct-axis lookup table current and the direct-axis current component and the difference value of the quadrature-axis lookup table current and the quadrature-axis current component as the input of a current loop PI regulator to obtain corresponding output so as to update the direct-axis voltage and the quadrature-axis voltage.
2. The method of claim 1, wherein determining the actual voltage utilization of the PMSM under the current operating conditions according to the DC-to-AC voltage of the PMSM comprises:
determining a per unit value of the direct-axis voltage and a per unit value of the quadrature-axis voltage;
calculating the sum of the square of the per-unit value of the direct-axis voltage and the square of the per-unit value of the quadrature-axis voltage;
and opening the square root of the sum of the squares to obtain the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition.
3. The method of claim 1, further comprising:
setting the working state and the output amplitude limit value of the weak magnetic ring PI regulator, wherein the working state is working or non-working;
taking the difference between the actual voltage utilization rate and the received target voltage utilization rate as the input of a weak magnetic ring PI regulator to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator, wherein the dynamic regulation coefficient comprises the following steps:
taking the difference value between the actual voltage utilization rate and the received target voltage utilization rate as the input of the weak magnetic ring PI regulator;
when the actual voltage utilization rate is less than or equal to the target voltage utilization rate, the weak magnetic ring PI regulator does not work, and the obtained dynamic regulation coefficient is 1;
and when the actual voltage utilization rate is greater than the target voltage utilization rate, the weak magnetic ring PI regulator works, and the actual voltage utilization rate is regulated in the output amplitude limit value to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator.
4. The method of claim 1 or 3, wherein the obtaining of the direct axis lookup table current and the quadrature axis lookup table current by lookup table according to the motor rotation speed of the permanent magnet synchronous motor, the dynamic adjustment coefficient and the received torque command comprises:
determining the rotating speed of the motor by looking up a table according to the rotating speed of the motor of the permanent magnet synchronous motor and the dynamic adjustment coefficient;
and according to the rotating speed of the motor and the received torque instruction, looking up the table to obtain direct axis table lookup current and quadrature axis table lookup current.
5. A flux-weakening closed-loop control device of a permanent magnet synchronous motor is characterized by comprising the following components:
the actual voltage utilization rate determining module is used for determining the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition according to the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor;
a dynamic adjustment coefficient obtaining module, configured to use a difference between the actual voltage utilization rate and a received target voltage utilization rate as an input of a weak magnetic ring PI regulator to obtain a dynamic adjustment coefficient output by the weak magnetic ring PI regulator, where the target voltage utilization rate is determined according to a system modulation depth;
the table lookup current obtaining module is used for obtaining direct axis table lookup current and quadrature axis table lookup current by table lookup according to the motor rotating speed of the permanent magnet synchronous motor, the dynamic adjusting coefficient and the received torque instruction;
the current component obtaining module is used for obtaining a direct-axis current component and a quadrature-axis current component according to the currently acquired three-phase current of the permanent magnet synchronous motor;
and the voltage updating module is used for respectively taking the difference value of the direct-axis lookup table current and the direct-axis current component and the difference value of the quadrature-axis lookup table current and the quadrature-axis current component as the input of the current loop PI regulator to obtain corresponding output so as to update the direct-axis voltage and the quadrature-axis voltage.
6. The apparatus of claim 5, wherein the actual voltage utilization determination module comprises:
a per-unit value determining submodule for determining a per-unit value of the direct-axis voltage and a per-unit value of the quadrature-axis voltage;
the per unit value calculation submodule is used for calculating the sum of the square of the per unit value of the direct-axis voltage and the square of the per unit value of the quadrature-axis voltage;
and the voltage utilization rate calculation submodule is used for opening a square root to the sum of the squares to obtain the actual voltage utilization rate of the permanent magnet synchronous motor under the current working condition.
7. The apparatus of claim 5, further comprising:
the PI regulator setting module is used for setting the working state and the output amplitude limit value of the weak magnetic ring PI regulator, and the working state is working or non-working;
the dynamic adjustment coefficient obtaining module comprises:
the PI regulator input submodule is used for taking the difference value between the actual voltage utilization rate and the received target voltage utilization rate as the input of the weak magnetic ring PI regulator;
the first output result sub-module is used for enabling the weak magnetic ring PI regulator not to work when the actual voltage utilization rate is smaller than or equal to the target voltage utilization rate, and obtaining a dynamic regulation coefficient of 1;
and the second output result submodule is used for working the weak magnetic ring PI regulator when the actual voltage utilization rate is greater than the target voltage utilization rate, and regulating the actual voltage utilization rate within the output amplitude limit value to obtain a dynamic regulation coefficient output by the weak magnetic ring PI regulator.
8. The apparatus of claim 5 or 7, wherein the lookup table current obtaining module comprises:
the table lookup motor rotating speed determining submodule is used for determining the table lookup motor rotating speed according to the motor rotating speed of the permanent magnet synchronous motor and the dynamic adjusting coefficient;
and the table lookup execution submodule is used for looking up a table according to the table lookup motor rotating speed and the received torque instruction to obtain direct axis table lookup current and quadrature axis table lookup current.
9. A vehicle, characterized in that the vehicle comprises:
the controller comprises a permanent magnet synchronous motor and a memory for storing executable instructions of the controller;
the controller is used for executing the flux weakening closed-loop control method of the permanent magnet synchronous motor according to any one of claims 1-4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011430398.4A CN114614709A (en) | 2020-12-09 | 2020-12-09 | Flux-weakening closed-loop control method and device for permanent magnet synchronous motor and vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011430398.4A CN114614709A (en) | 2020-12-09 | 2020-12-09 | Flux-weakening closed-loop control method and device for permanent magnet synchronous motor and vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114614709A true CN114614709A (en) | 2022-06-10 |
Family
ID=81855682
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011430398.4A Pending CN114614709A (en) | 2020-12-09 | 2020-12-09 | Flux-weakening closed-loop control method and device for permanent magnet synchronous motor and vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114614709A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115940731A (en) * | 2022-07-26 | 2023-04-07 | 小米汽车科技有限公司 | Motor efficiency optimization method and device, vehicle and readable storage medium |
-
2020
- 2020-12-09 CN CN202011430398.4A patent/CN114614709A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115940731A (en) * | 2022-07-26 | 2023-04-07 | 小米汽车科技有限公司 | Motor efficiency optimization method and device, vehicle and readable storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108551287B (en) | Torque closed-loop control method for vehicle built-in permanent magnet synchronous motor driving system | |
| JP4531751B2 (en) | Synchronous machine controller | |
| US7586286B2 (en) | Method and apparatus for motor control | |
| US7589486B2 (en) | Control system for multiphase rotary electric machines | |
| CN110890855A (en) | Parameter identification method for permanent magnet synchronous motor of electric vehicle | |
| EP2760127A2 (en) | Method of controlling an AC machine and controller for controlling an AC machine | |
| WO2022133892A1 (en) | Permanent magnet synchronous motor mtpa control method and apparatus, system and device | |
| CN104579083A (en) | Method and system for vector control of permanent magnet synchronous motor | |
| CN110677088B (en) | Control method and control device of permanent magnet synchronous motor | |
| CN112865639B (en) | Electric automobile permanent magnet synchronous motor control system with road condition reproduction function | |
| CN108809185B (en) | Method and system for controlling motor torque of electric automobile | |
| CN108649850B (en) | UDE built-in permanent magnet synchronous motor current control method | |
| CN111740664B (en) | Method for realizing field weakening control of salient pole permanent magnet synchronous motor based on Id=0 | |
| Nishad et al. | Induction motor control using modified indirect field oriented control | |
| CN114614709A (en) | Flux-weakening closed-loop control method and device for permanent magnet synchronous motor and vehicle | |
| CN112821834A (en) | Online parameter identification method and device for permanent magnet synchronous motor | |
| CN109889113B (en) | Permanent magnet motor variable speed scanning control system based on active disturbance rejection control | |
| CN116995981A (en) | Current-voltage vector amplitude angle control method | |
| CN116094383A (en) | Time-varying nonlinear disturbance observer of permanent magnet synchronous motor and current constraint control method | |
| CN114977955A (en) | Global control method and device for permanent magnet synchronous motor and permanent magnet synchronous motor | |
| CN112234894B (en) | Dead-beat direct torque-flux linkage control system and method for variable flux memory motor | |
| CN113644853A (en) | Permanent magnet synchronous motor directional correction system based on Longberger observer | |
| CN109842337B (en) | Flux linkage difference processing method and motor control device | |
| CN111245320B (en) | Control method and control device of synchronous reluctance motor based on power balance | |
| CN111224602B (en) | Control method and control device of permanent magnet synchronous motor based on power balance |
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 |