CN110034713A - The control method of permasyn morot vector - Google Patents
The control method of permasyn morot vector Download PDFInfo
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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
- H02P21/18—Estimation of position or speed
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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
- H02P21/24—Vector control not involving the use of rotor position or rotor speed sensors
- H02P21/28—Stator flux based control
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Abstract
本发明提供了一种永磁同步电动机矢量的控制方法，包括以下步骤：S1，利用永磁同步电动机定子电压数学模型，求解出定子电流时间导数的数学模型；S2，将模型离散化，并在角θinj处注入高频电压Vinj，得到永磁同步电动机高频定子电流差模型；S3，根据三角等式变换进一步简化所述永磁同步电动机高频定子电流差模型，求解出所述永磁同步电动机高频定子电流差模型中包含的转子位置；S4，根据所述转子位置控制所述永磁同步电动机进行矢量控制。
The present invention provides a vector control method of a permanent magnet synchronous motor, comprising the following steps: S1, using a permanent magnet synchronous motor stator voltage mathematical model to solve the mathematical model of the time derivative of the stator current; S2, discretizing the model, and in The high-frequency voltage V inj is injected at the angle θ inj to obtain the high-frequency stator current difference model of the permanent magnet synchronous motor; S3, according to the triangular equation transformation, the high-frequency stator current difference model of the permanent magnet synchronous motor is further simplified, and the permanent magnet synchronous motor high-frequency stator current difference model is solved. The rotor position included in the high-frequency stator current difference model of the magnetic synchronous motor; S4, controlling the permanent magnet synchronous motor to perform vector control according to the rotor position.
Description
技术领域technical field
本发明涉及电机控制技术领域，具体为一种永磁同步电动机矢量的控制方法。The invention relates to the technical field of motor control, in particular to a vector control method of a permanent magnet synchronous motor.
背景技术Background technique
永磁同步电动机矢量控制性能很大程度上取决于转子位置信息的准确性。对于电动汽车等对电机控制性能要求较为苛刻的场景，高品质的编码器可满足其需求。但编码器等传感器部件的加入使得机械、电气故障发生概率大大增加，这使得除编码器等位置传感器以外的容错机制——无位置传感器转子位置估计算法显得异常重要。目前大部分无位置传感器算法适用于电机高速运行下的转子位置估计，在静止/低速工况下一般采用高频电压注入的方法，但定子电压、定子电流等的测量误差以及观测器、状态变换器等模块的参数调节准确性很大程度上限制了无位置传感器算法的转子位置估计准确性，无法适应苛刻场景的电机控制性能要求。必须寻求新的永磁同步电动机矢量的控制方法。The performance of permanent magnet synchronous motor vector control largely depends on the accuracy of rotor position information. For scenarios that require more stringent motor control performance, such as electric vehicles, high-quality encoders can meet their needs. However, the addition of sensor components such as encoders greatly increases the probability of mechanical and electrical failures, which makes the position sensorless rotor position estimation algorithm, a fault-tolerant mechanism other than encoders and other position sensors, extremely important. At present, most sensorless algorithms are suitable for rotor position estimation under high-speed operation of the motor. In static/low-speed conditions, the high-frequency voltage injection method is generally used. The accuracy of parameter adjustment of modules such as the controller largely limits the rotor position estimation accuracy of the position sensorless algorithm, and cannot meet the motor control performance requirements of harsh scenarios. A new vector control method of permanent magnet synchronous motor must be sought.
发明内容SUMMARY OF THE INVENTION
鉴于上述情况，有必要提供一种测量参数较少、尽量避免繁琐参数调节过程的无位置传感器转子的控制方法。In view of the above situation, it is necessary to provide a position sensorless rotor control method with less measurement parameters and avoiding cumbersome parameter adjustment process as much as possible.
本发明是这样实现的：The present invention is realized in this way:
一种永磁同步电动机矢量的控制方法，包括以下步骤：A vector control method for a permanent magnet synchronous motor, comprising the following steps:
S1，利用永磁同步电动机定子电压数学模型，求解出定子电流时间导数的数学模型；S1, using the mathematical model of the stator voltage of the permanent magnet synchronous motor to solve the mathematical model of the time derivative of the stator current;
S2，将模型离散化，并在角θinj处注入高频电压Vinj，得到永磁同步电动机高频定子电流差模型；S2, discretize the model, and inject the high-frequency voltage V inj at the angle θ inj to obtain the high-frequency stator current difference model of the permanent magnet synchronous motor;
S3，根据三角等式变换进一步简化所述永磁同步电动机高频定子电流差模型，求解出所述永磁同步电动机高频定子电流差模型中包含的转子位置；S3, further simplify the high-frequency stator current difference model of the permanent magnet synchronous motor according to the triangular equation transformation, and solve the rotor position included in the high-frequency stator current difference model of the permanent magnet synchronous motor;
S4，根据所述转子位置控制所述永磁同步电动机进行矢量控制。S4, controlling the permanent magnet synchronous motor to perform vector control according to the rotor position.
本发明的有益效果是：该方法在估计转子位置时无需永磁同步电动机定子绕组的电压信息，因此从根本上避免了定子绕组电压测量误差带来的估计误差，同时，该方法也无需任何观测器、控制器或状态变换器，避免了繁琐的参数调节过程，从而可以提高永磁同步电动机矢量控制性能。The beneficial effects of the present invention are: the method does not need the voltage information of the stator winding of the permanent magnet synchronous motor when estimating the rotor position, so the estimation error caused by the stator winding voltage measurement error is fundamentally avoided, and at the same time, the method does not need any observation. The controller, controller or state converter avoids the tedious parameter adjustment process, thus improving the vector control performance of the permanent magnet synchronous motor.
附图说明Description of drawings
为了更清楚地说明本发明实施方式的技术方案，下面将对实施方式中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本发明的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。In order to explain the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.
图1静止坐标系下半开关频率信号注入解调算法的永磁同步电动机矢量的控制方法的流程图。Fig. 1 is a flow chart of the control method of the permanent magnet synchronous motor vector of the half-switching frequency signal injection demodulation algorithm in the static coordinate system.
图2电压矢量和构成图；Figure 2 Voltage vector and composition diagram;
图3abc参考坐标系中的三相控制信号Va、Vb和Vc以及开关信号Sa、Sb和Sc与电流采样频率及PWM周期的关系图。 Fig . 3 is a graph of the relationship between the three-phase control signals Va, Vb and Vc and the switching signals Sa, Sb and Sc, the current sampling frequency and the PWM period in the abc reference frame.
具体实施方式Detailed ways
为使本发明实施方式的目的、技术方案和优点更加清楚，下面将结合本发明实施方式中的附图，对本发明实施方式中的技术方案进行清楚、完整地描述，显然，所描述的实施方式是本发明一部分实施方式，而不是全部的实施方式。基于本发明中的实施方式，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施方式，都属于本发明保护的范围。因此，以下对在附图中提供的本发明的实施方式的详细描述并非旨在限制要求保护的本发明的范围，而是仅仅表示本发明的选定实施方式。基于本发明中的实施方式，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施方式，都属于本发明保护的范围。In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
请参照图1-3，静止坐标系下本发明实施半开关频率信号注入解调算法的永磁同步电动机矢量的控制方法，包括如下步骤：Please refer to Fig. 1-3, the present invention implements the control method of the permanent magnet synchronous motor vector of the half-switching frequency signal injection demodulation algorithm under the static coordinate system, including the following steps:
S1，利用永磁同步电动机定子电压数学模型，求解出定子电流时间导数的数学模型；S1, using the mathematical model of the stator voltage of the permanent magnet synchronous motor to solve the mathematical model of the time derivative of the stator current;
S2，将模型离散化，并在角θinj处注入高频电压Vinj，得到永磁同步电动机高频定子电流差模型；S2, discretize the model, and inject the high-frequency voltage V inj at the angle θ inj to obtain the high-frequency stator current difference model of the permanent magnet synchronous motor;
S3，根据三角等式变换进一步简化所述永磁同步电动机高频定子电流差模型，求解出所述永磁同步电动机高频定子电流差模型中包含的转子位置；S3, further simplify the high-frequency stator current difference model of the permanent magnet synchronous motor according to the triangular equation transformation, and solve the rotor position included in the high-frequency stator current difference model of the permanent magnet synchronous motor;
S4，根据所述转子位置控制所述永磁同步电动机进行矢量控制。S4, controlling the permanent magnet synchronous motor to perform vector control according to the rotor position.
在步骤S1中，永磁同步电动机定子电压数学模型描述如下：In step S1, the mathematical model of the permanent magnet synchronous motor stator voltage is described as follows:
其中，Vα为永磁同步电动机定子电压在静止坐标系中α轴分量，Vβ为永磁同步电动机定子电压在静止坐标系中β轴分量，Rs为永磁同步电动机定子绕组阻值，Iα为永磁同步电动机定子电流在静止坐标系中α轴分量，Ls为永磁同步电动机定子绕组电感矩阵，Iβ为永磁同步电动机定子电流在静止坐标系中β轴分量，Φr为转子磁链，θr为转子实际位置。Among them, V α is the α-axis component of the permanent magnet synchronous motor stator voltage in the static coordinate system, V β is the β-axis component of the permanent magnet synchronous motor stator voltage in the static coordinate system, R s is the permanent magnet synchronous motor stator winding resistance, I α is the α-axis component of the permanent magnet synchronous motor stator current in the static coordinate system, L s is the permanent magnet synchronous motor stator winding inductance matrix, I β is the β-axis component of the permanent magnet synchronous motor stator current in the static coordinate system, Φ r is the rotor flux linkage, and θ r is the actual position of the rotor.
其中，定子绕组电感矩阵Ls定义为：Among them, the stator winding inductance matrix L s is defined as:
其中，L为定子绕组平均电感，ΔL为定子绕组电感差。Among them, L is the average inductance of the stator winding, and ΔL is the inductance difference of the stator winding.
所述求解出定子电流时间导数的数学模型的步骤包括：对式(1)进行导数运算得到：The step of solving the mathematical model of the time derivative of the stator current includes: performing a derivative operation on the formula (1) to obtain:
其中，ωr为永磁同步电动机定子实际转速，可由定子实际位置求导得到，Ln定义为：Among them, ω r is the actual speed of the permanent magnet synchronous motor stator, which can be derived from the actual position of the stator, and L n is defined as:
通过求解定子电流在(3)和(4)中的时间导数，得到永磁同步电动机定子电流数学模型描述如下：By solving the time derivatives of the stator current in (3) and (4), the mathematical model of the permanent magnet synchronous motor stator current is obtained and described as follows:
其中：in:
在步骤S2中，所述将模型离散化的步骤包括：In step S2, the step of discretizing the model includes:
S21，以(5)为基础，将连续的导数算子用离散化符号代替，得到电流采样周期ΔTk中的电流差ΔI描述如下：S21, based on (5), the continuous derivative operator is replaced by a discretized symbol, and the current difference ΔI in the current sampling period ΔT k is obtained as follows:
请参考图2及图3，电压矢量和由控制器基本控制矢量分别在时刻Tk和Tk+1注入的频率为控制器PWM载波频率一半的高频电压和组成。当电流采样时间间隔足够小时，可认为Tk≈Tk+1，以下假设在两个连续的PWM周期期间成立：Please refer to Figure 2 and Figure 3, the voltage vector and The vector is basically controlled by the controller The high-frequency voltages injected at times T k and T k+1 with a frequency that is half of the PWM carrier frequency of the controller respectively and composition. When the current sampling time interval is small enough, it can be considered that T k ≈ T k+1 , the following assumptions hold during two consecutive PWM cycles:
电机及控制器各项参数保持不变；The parameters of the motor and controller remain unchanged;
基本电流分量呈线性变化；The basic current component changes linearly;
在低速时，转子位置的变化可忽略；At low speed, the change of rotor position is negligible;
在高惯性机械轴中，转子速度的变化可忽略。In high inertia mechanical shafts, the change in rotor speed is negligible.
考虑控制器基本控制矢量在角θinj注入高频电压则PWM两周周期之间的高频定子电流差：Consider the controller basic control vector Inject high frequency voltage at angle θ inj Then the high frequency stator current difference between two cycles of PWM:
在步骤S3中，对式(9)进行三角等式变换，简化为：In step S3, the trigonometric equation transformation is performed on equation (9), which is simplified as:
由式(10)可以注意到，静止坐标系中，电流差的α轴和β轴分量都包含有转子位置信息，进一步求解，得到实际转子位置表达式：From equation (10), it can be noticed that in the static coordinate system, the α-axis and β-axis components of the current difference both contain the rotor position information. After further solving, the actual rotor position expression is obtained:
由上述推导得出的实际转子位置θr可近似为生产实际中的电机转子实际位置，由于θinj∈{0,π}，式(11)可进一步简化并得出电机转子实际位置的估计值：The actual rotor position θ r derived from the above can be approximated as the actual position of the motor rotor in production. Since θ inj ∈ {0,π}, Equation (11) can be further simplified and the estimated value of the actual position of the motor rotor can be obtained :
其中， in,
在步骤S4中，根据电机转子实际位置按正弦电流波形给与相电流。所述按正弦电流波形给与相电流的步骤可以选用常规的方式，在此不再累述。In step S4, the phase current is given in a sinusoidal current waveform according to the actual position of the motor rotor. The step of giving the phase current according to the sinusoidal current waveform can be performed in a conventional manner, which will not be repeated here.
以上所述仅为本发明的优选实施方式而已，并不用于限制本发明，对于本领域的技术人员来说，本发明可以有各种更改和变化。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009024835A1 (en) * | 2007-08-20 | 2009-02-26 | Freescale Semiconductor, Inc. | Motor controller for determining a position of a rotor of an ac motor, ac motor system, and method of determining a position of a rotor of an ac motor |
| CN105515488A (en) * | 2016-01-27 | 2016-04-20 | 中国矿业大学 | Method for controlling synchronous motor low speed sensorless based on self-adaptive filter |
| CN106374786A (en) * | 2016-10-11 | 2017-02-01 | 天津深之蓝海洋设备科技有限公司 | Low-rotary-speed control method for non-inductive and brushless direct current motor |
| CN108900131A (en) * | 2018-07-11 | 2018-11-27 | 山东大学 | Durface mounted permanent magnet synchronous motor low speed vector control without position sensor System and method for |
| CN110048654A (en) * | 2019-03-21 | 2019-07-23 | 闽江学院 | Permanent-magnet synchronous motor rotor location estimation method |
-
2019
- 2019-03-21 CN CN201910217895.7A patent/CN110034713B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009024835A1 (en) * | 2007-08-20 | 2009-02-26 | Freescale Semiconductor, Inc. | Motor controller for determining a position of a rotor of an ac motor, ac motor system, and method of determining a position of a rotor of an ac motor |
| CN105515488A (en) * | 2016-01-27 | 2016-04-20 | 中国矿业大学 | Method for controlling synchronous motor low speed sensorless based on self-adaptive filter |
| CN106374786A (en) * | 2016-10-11 | 2017-02-01 | 天津深之蓝海洋设备科技有限公司 | Low-rotary-speed control method for non-inductive and brushless direct current motor |
| CN108900131A (en) * | 2018-07-11 | 2018-11-27 | 山东大学 | Durface mounted permanent magnet synchronous motor low speed vector control without position sensor System and method for |
| CN110048654A (en) * | 2019-03-21 | 2019-07-23 | 闽江学院 | Permanent-magnet synchronous motor rotor location estimation method |
Non-Patent Citations (1)
| Title |
|---|
| 傅睿潇 等: "基于无滤波器高频方波注入的IPMSM无传感器控制策略", 《大电机技术》 * |
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