Three-dimensional space vector modulation strategy and overmodulation processing method for three-phase series-wound motor

Abstract

The application belongs to the technical field of alternating current motor and drive control, and discloses a three-phase series winding motor three-dimensional space vector modulation strategy and over-modulation processing method, in order to improve the control performance of the three-phase series winding motor and provide positive zero sequence current suppression capability, the application proposes a three-dimensional space vector modulation strategy of the three-phase series winding motor based on a space slicing method and an over-modulation strategy thereof, effectively expands the three-dimensional linear modulation area of the series winding motor, provides a simple and effective basic voltage vector selection table, and gives a precise linear modulation area mathematical model. In addition, the corresponding three-dimensional over-modulation method is provided, and the control performance of the series winding motor in the linear modulation area and the over-modulation area is improved.

Description

Technical Field

[0001] This invention belongs to the field of AC motor and drive control technology, and particularly relates to a three-dimensional space vector modulation strategy and overmodulation processing method for a three-phase series winding motor. Background Technology

[0002] A three-phase series-wound motor is fed by four inverter bridge arms, generating sixteen voltage vectors. However, in a three-phase series-wound motor, the presence of zero-sequence current causes these sixteen voltage vectors to be irregularly distributed in three-dimensional space. This irregular three-dimensional space can... αβ-γ The display in a three-dimensional coordinate system makes the space vector modulation strategy very complex. Furthermore, if only the traditional two-dimensional space vector modulation strategy is used to synthesize the reference voltage vector without active control of the zero-sequence current, the total harmonic distortion of the phase current in the series-wound motor will be severe, leading to increased torque ripple and reduced control performance. In a series-wound motor, to implement a three-dimensional space vector modulation strategy, at least three basic voltage vectors are needed to synthesize the three-dimensional reference vector. These basic voltage vectors are the sixteen voltage vectors provided by the four inverter bridge arms. Existing three-dimensional modulation strategies for three-phase series-wound motors are mainly divided into two types: one is a three-dimensional space vector modulation strategy based on the virtual vector method, which synthesizes the reference vector using three voltage vectors containing a zero-sequence voltage component in three-dimensional space. γ A virtual voltage vector in the positive direction of the axis. Alternatively, it can be synthesized using three voltage vectors containing zero-sequence components. γ The virtual voltage vector in the negative axis direction. Then, the voltage vectors used to synthesize the three-dimensional reference vector are respectively... αβ The two fundamental voltage vectors of the plane and γ A virtual voltage vector along the axial direction. (e.g., A. Li, D. Jiang, W. Kong, and R. Qu, "Four-Leg Converter for Reluctance Machine With DC-Biased Sinusoidal Winding Current," IEEE Trans. Power Electron., vol. 34, no. 5, pp. 4569-4580, 2019, doi: 10.1109 / tpel.2018.2864244. (journal article)). However, this method has limitations, as it synthesizes a virtual voltage vector by using three fundamental voltage vectors containing zero-sequence components. γThe virtual vectors in the positive and negative directions of the axis make the three-dimensional linear modulation region conical, limiting the operating domain of the series-winding motor. This method also does not provide a three-dimensional overmodulation strategy. The second method divides the irregular three-dimensional space into 24 small tetrahedrons, achieving three-dimensional space vector modulation. (See, Z. Dong and C. Liu, "Three-Dimension Space Vector Modulation for Three-Phase Series-End Winding Voltage-Source Inverters," IEEE Trans. Ind. Electron., vol. 71, no. 1, pp. 82-92, 2024, doi: 10.1109 / tie.2023.3241399. (Journal article),). In the 24 tetrahedrons, each tetrahedron is composed of one zero voltage vector and three basic voltage vectors. By determining which of the 24 tetrahedrons the reference voltage vector is located in, the three basic voltage vectors used to synthesize the reference voltage vector are obtained. However, this method does not provide a specific expression of the linear modulation region due to the division of the three-dimensional body into tetrahedrons.

[0003] Technical problems to be solved in industrial applications:

[0004] 1. Accurate expression of the linear modulation region:

[0005] In existing methods, such as dividing the three-dimensional space into multiple tetrahedrons to achieve three-dimensional space vector modulation, the mathematical expression of the linear modulation region is not explicitly given. This leads to the inability to accurately determine whether the reference vector is in the linear modulation region, increasing the difficulty of implementing complex control systems.

[0006] In industrial applications, motor control needs to accurately define the linear modulation region to optimize the voltage vector synthesis process. If there is no explicit expression of the linear modulation region, the modulation strategy may not run stably, which will affect the control performance of the series-winding motor.

[0007] 2. Optimization of overmodulation strategy:

[0008] Existing methods do not fully address the overmodulation problem in three-dimensional space vector modulation, especially in high-load or high-output voltage demand scenarios. When the motor enters the overmodulation region, the synthesis accuracy of the reference voltage vector and the dynamic response performance of the system will significantly decrease.

[0009] In practical industrial applications, such as industrial servo systems and electric vehicle drive systems, motors need to operate efficiently and smoothly in the overmodulation region. A lack of overmodulation optimization strategies for three-dimensional space can lead to increased voltage distortion and exacerbated torque ripple, thereby reducing equipment reliability and lifespan. Summary of the Invention

[0010] To address the problems existing in the prior art, this invention provides a three-dimensional space vector modulation strategy and overmodulation processing method for a three-phase series winding motor.

[0011] This invention is implemented as follows: a three-dimensional space vector modulation strategy and overmodulation processing method for a three-phase series-wound motor includes:

[0012] Step 1, in the three-dimensional structure formed by the series winding motor αβ-γ In space, αβ A plane divides a three-dimensional volume into upper and lower halves;

[0013] Step 2, spatial slicing VV αβ , VV γ And the zero voltage vector is included; according to geometric principles, in a spatial slice, the two virtual voltage vectors are... VV αβ , VV γ The zero voltage vector is used to synthesize a three-dimensional reference voltage vector;

[0014] Step 3: The spatial slicing method divides the three-dimensional space into countless two-dimensional slices, and the voltage vector on each slice consists of two virtual voltage vectors. VV αβ and VV γ ;

[0015] Step 4: Execute the three-dimensional modulation strategy.

[0016] Furthermore, the three-dimensional structure formed in the series-wound motor αβ-γ In space, αβ A plane divides a three-dimensional volume into upper and lower halves:

[0017] αβ The plane contains six fundamental voltage vectors and two zero voltage vectors, which form a hexagon; by using any two adjacent fundamental and zero voltage vectors, a plane can be synthesized. αβ Virtual voltage vector in a plane VV αβ According to the volt-second balance principle, αβThe maximum linear modulation region that can be synthesized by six basic voltage vectors and two zero voltage vectors in a plane is a circle with a radius of V dc wherein V dc represents the DC bus value.

[0018] The main principle of space slicing is to use a slice perpendicular to the αβ plane and to cut the irregular three-dimensional space body along the γ axis; in this case, the space slice will contain a virtual voltage vector located in the αβ plane, which is synthesized by any two adjacent vectors of the six basic voltage vectors in the αβ plane, in addition to the zero vector located at the origin.

[0019] The three-dimensional reference vector V ref [ a , b , c ] in the αβ plane and the angle thereof with the α axis can obtain

[0020] (1);

[0021] wherein is the projection of the three-dimensional reference vector in the αβ plane; θ is the angle of the projection of the reference vector in the αβ plane with the α axis; a is the projection of the three-dimensional reference voltage vector in the α axis, b is the projection of the three-dimensional reference voltage vector in the β axis, c is the projection of the three-dimensional reference voltage vector in the γ axis.

[0022] Then, the amplitude of the three-dimensional reference vector and the angle thereof with the αβ plane can obtain

[0023] (2);

[0024] wherein is the amplitude of the three-dimensional reference voltage vector; δ is the angle of the reference voltage vector with the αβ plane.

[0025] However, the αβThe virtual voltage vector in the plane does not contain a zero-sequence voltage component. To synthesize a three-dimensional reference voltage vector, a voltage vector containing a zero-sequence component is also needed, that is, a voltage vector containing... γ The voltage vector of the axis component; through analysis, it was found that in the three-dimensional space vector synthesized by the four inverter bridge arms, αβ The upper half of the plane contains four voltage vectors with zero-sequence components; these can be used to synthesize voltage vectors containing zero-sequence components. γ The zero-order virtual vector in the positive direction of the axis; similarly, αβ The four voltage vectors containing zero-sequence components in the lower part of the plane can be used to synthesize voltage vectors containing zero-sequence components. γ A virtual voltage vector in the negative axis direction; however, due to the voltage vector V 10 , V 5. This creates irregularities in three-dimensional bodies, therefore they can be discarded; in this case, in αβ In the upper and lower halves of the plane, any two of the six basic voltage vectors containing zero-sequence components can be used to synthesize a virtual voltage vector containing zero-sequence components. VV γ These virtual voltage vectors form a cone in three-dimensional space; this cone... αβ The projection in the plane is a circle with a radius of 1 / 3 V dc A circle.

[0026] Furthermore, the spatial slicing will VV αβ , VV γ And the zero voltage vector is included; according to geometric principles, in a spatial slice, the two virtual voltage vectors are... VV αβ , VV γ The zero voltage vector is used to synthesize a three-dimensional reference voltage vector:

[0027] They also satisfy the following geometric relationship:

[0028] (3);

[0029] in, T γ Represents a virtual voltage vector containing a zero-sequence component. VV γ The duration of action within a control cycle; T αβ yes αβ Virtual voltage vector in the plane VV αβ The duration of action within a control cycle; Ts To control the cycle; VV αβ , VV γ and three-dimensional reference voltage vector V ref They are respectively

[0030] (4);

[0031] According to equation (3), the boundary of the three-dimensional reference voltage vector in the space slice can be obtained as follows:

[0032] (5);

[0033] in, k Represents the scaling factor.

[0034] Switch to xy The coordinate system can be obtained

[0035] (6);

[0036] It can be seen that the three-dimensional reference voltage vector on the spatial slice is a parametric equation; according to this equation, it can be concluded that the linear modulation region generated by the three-dimensional modulation strategy proposed in this invention is a double frustum; this frustum is... δ =45° is divided into two parts: the frustum region and the cone region.

[0037] Furthermore, the spatial slicing method divides the three-dimensional space into countless two-dimensional slices, and the voltage vector on each slice consists of two virtual voltage vectors. VV αβ and VV γ :

[0038] These virtual voltage vectors cannot be directly output by the inverter; therefore, it is necessary to find the basic voltage vectors used to synthesize these two virtual voltage vectors; for this purpose, the present invention provides a basic voltage vector sector table; the angle obtained from equation (1) θ And determine the location of the three-dimensional reference voltage vector. αβ Four basic voltage vectors can be obtained from the upper or lower half of the plane; then, these four basic voltage vectors are used to synthesize a three-dimensional reference voltage vector.

[0039] Step 5: Execute the three-dimensional overmodulation strategy.

[0040] As shown in equation (6), the linear modulation region is δ =45° is divided into two parts, therefore overmodulation is also performed in these two parts separately; firstly, when the three-dimensional reference voltage vector V ref [a , b , c When 0° ≤ 0° is in the frustum region, i.e., 0° ≤ 0° δ ≤45°; according to equation (1), θ and k It can be obtained; then, according to equation (2), | V ref | can also be obtained. When | V ref |≤ k·V dc The system is considered to be in the linear debugging zone; when | V ref |> k·V dc The system is considered to be in the overmodulation region. Based on the geometric relationship of the three-dimensional reference voltage vector... V ref [ a , b , c The point of intersection with the frustum A ′ can be obtained

[0041] (7);

[0042] in, OA ′ is the intersection of the three-dimensional reference voltage vector and the linear modulation region. OA ′= k · V dc , OB ′ is the new three-dimensional reference voltage vector in αβ Projection on a plane OB ′= OA ′·cos δ .

[0043] Then, A The modulation process was performed in the control algorithm.

[0044] Note that δ =0, overmodulation occurs αβ In the plane, (7) still applies, at this time OB ′= V dc Furthermore, when calculating the new three-dimensional reference voltage vector, the voltage vector in γ The positive and negative directions of the axis need to be determined based on the original three-dimensional reference voltage vector. c Use the symbol to determine;

[0045] When the three-dimensional reference voltage vector is in the conical region, 45° < δ ≤90°. Similarly, according to (1) and (4),θ and k They can be obtained separately; then the magnitude of the three-dimensional reference voltage vector | V ref | can be obtained from (2). When | V ref |> k· V dc The system is in the overmodulation region. Three-dimensional reference voltage vector. V ref [ a , b , c Intersection with the conical surface A ′ can be obtained

[0046] (8);

[0047] in, OB ′ is the new three-dimensional reference voltage vector in αβ Projection on a plane OB ′= V dc / (3tan δ );

[0048] Then, A The modulation process was performed in the control algorithm.

[0049] Another objective of this invention is to provide a three-dimensional space vector modulation strategy and overmodulation processing system for a three-phase series-wound motor, comprising:

[0050] The segmentation module is used to form a three-dimensional segmentation module in a series-wound motor. αβ-γ In space, αβ A plane divides a three-dimensional volume into upper and lower halves;

[0051] The compositing module is used for spatial slicing. VV αβ , VV γ And the zero voltage vector is included; according to geometric principles, in a spatial slice, the two virtual voltage vectors are... VV αβ , VV γ The zero voltage vector is used to synthesize a three-dimensional reference voltage vector;

[0052] The partitioning module is used in the spatial slicing method to divide three-dimensional space into countless two-dimensional slices, with the voltage vector on each slice consisting of two virtual voltage vectors. VV αβ and VV γ ;

[0053] modulation module for three-dimensional modulation and overmodulation strategy.

[0054] Another object of the present application is to provide a computer device comprising a memory and a processor, the memory storing a computer program, the computer program being executed by the processor to make the processor execute the steps of the three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing method.

[0055] Another object of the present application is to provide a computer-readable storage medium storing a computer program, the computer program being executed by a processor to make the processor execute the steps of the three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing method.

[0056] Another object of the present application is to provide an information data processing terminal for implementing the three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing system.

[0057] In combination with the above technical solutions and the technical problems solved, the technical solutions to be protected by the present application have the following advantages and positive effects:

[0058] First, to perfect the three-dimensional space vector modulation strategy for series-winding motors, especially the lack of accurate linear modulation region expression and three-dimensional overmodulation strategy, the present application provides a three-dimensional space vector modulation strategy and three-dimensional overmodulation strategy for three-phase series-winding motors.

[0059] In a three-phase series-winding motor, in order to control the zero-sequence current, the control system needs to synthesize a three-dimensional reference voltage vector, which is denoted as V ref [ a , b , c ]. In order to synthesize the three-dimensional reference voltage vector, more than three basic voltage vectors need to be obtained, and these basic voltage vectors need to be distributed in different planes. In order to obtain the basic voltage vectors, the present application proposes a space slicing method to quickly and effectively obtain the basic voltage vectors.

[0060] The three-dimensional space vector modulation strategy proposed by the present application expands the linear modulation region of the series-winding motor by 33.33%; the three-dimensional space vector modulation strategy proposed by the present application gives an accurate mathematical expression of the three-dimensional linear modulation region, which can realize accurate three-dimensional space vector control and overmodulation processing.

[0061] Second, as the auxiliary evidence of the present application, it is also embodied in the following important aspects:

[0062] (1) Compared with the existing star-connected winding motor, the series winding motor has the advantages of high utilization rate of DC bus voltage (the series winding motor can achieve 100% utilization rate of DC bus voltage; while the star winding motor is only 57.7%), strong fault tolerance (three-phase series winding motor has three current freedoms, and can realize fault tolerance operation under one-phase winding open circuit fault; while the star winding motor only has two current freedoms, and cannot operate under one-phase winding open circuit fault), etc., which is very suitable for electric vehicles, ships and other occasions with limited DC bus voltage. In these application occasions, considering the cost, volume and vehicle safety factors of the system, the amplitude of the DC bus voltage usually cannot be too high, which limits the speed operating domain of the motor. By adopting the series winding motor, the speed operating domain of the motor can be effectively expanded.

[0063] The application discloses a three-dimensional linear modulation region expression of a three-phase series winding motor. The linear modulation region of the series winding motor is accurately described by the method, which cannot be obtained in the prior art. In addition, in order to reduce the calculation burden of three-dimensional space vector modulation, a three-dimensional voltage vector lookup table is also proposed to quickly select four active voltage vectors, so that three-dimensional space vector modulation is realized. For the overmodulation region, a three-dimensional overmodulation method based on a geometric model is disclosed, which improves the control performance of the overmodulation region of the series winding motor. The technical scheme of the application can provide a feasible scheme for realizing commercial application of the series winding motor.

[0064] (2) In the existing three-dimensional space vector modulation strategy of the three-phase series winding motor, three voltage vectors containing zero sequence components are usually used to synthesize γ axial components. Under this modulation strategy, the linear modulation region of the series winding motor is two conical shapes, and this method cannot give the expression of the linear modulation region. In addition, in the existing modulation strategy, a large number of trigonometric functions need to be used for duty cycle calculation for different sectors, resulting in a large calculation burden of the system.

[0065] The technical scheme of the application accurately obtains the expression of the linear modulation region by the space slicing method, and expands the linear modulation region from two conical shapes to two circular truncated cones, which expands the linear modulation region by 33.33% and effectively expands the speed operating domain. At the same time, the calculation of the duty cycle does not involve complex trigonometric function calculation, and a specific sector voltage vector lookup table is given, which effectively reduces the calculation burden of the system.

[0066] Thirdly, the technical scheme of the application solves the technical problems of the prior art and achieves significant technical progress in the industrial application

[0067] 1. Analysis of the prior art problems:

[0068] Limitations of complex motor control: Current modulation techniques for three-phase motors are mostly limited to two-dimensional vector modulation strategies. These strategies struggle to provide sufficient voltage modulation capability and dynamic response performance for motors operating under high-performance requirements, such as high rotational speed and wide speed regulation range.

[0069] Inadequate overmodulation processing: Existing overmodulation strategies for series-wound motors lack flexible adjustment methods after entering the overmodulation region, leading to output voltage distortion and affecting the smooth operation of the motor.

[0070] Absence of multi-dimensional space processing: Traditional modulation methods struggle to handle vector distribution problems in three-dimensional space, especially in three-phase series-wound motors, γ Complex voltage control of the shaft component and lack of effective solutions, leading to decreased system efficiency and accuracy.

[0071] 2. Technical innovations and improvements of the invention:

[0072] Three-dimensional space vector modulation: The invention proposes a three-dimensional space-based vector modulation method that combines αβ the plane and γ the shaft in a unified three-dimensional framework, achieving more accurate voltage vector control. Through geometric slicing, complex three-dimensional problems can be simplified into controllable two-dimensional problems, improving computational efficiency.

[0073] Partition processing of the overmodulation region: The invention innovatively divides the linear modulation region and the overmodulation region into a circular cone region and a circular cone region, and designs targeted modulation strategies for different regions to ensure stable voltage control and output in the overmodulation region.

[0074] Adaptive vector adjustment: In overmodulation processing, the invention accurately calculates the intersection of overmodulation vectors through geometric methods and dynamically adjusts based on γ the direction of the shaft, significantly reducing voltage distortion and achieving efficient motor control.

[0075] 3. Significant technical progress:

[0076] Expand the motor speed regulation range: The three-dimensional space voltage vector modulation method of the invention effectively expands the linear speed regulation range of the motor, improving the adaptability of the system in high-voltage demand scenarios.

[0077] Improve modulation accuracy: Through accurate three-dimensional reference voltage vector decomposition and γ shaft direction regulation, the distribution accuracy and dynamic response speed of the voltage vector are significantly improved.

[0078] Enhance system robustness: The flexibility of overmodulation processing significantly reduces the risk of voltage distortion and system instability under high load and rapid dynamic changes.

[0079] 4. Advantages in industrial applications:

[0080] High-performance motor control: The invention is particularly suitable for high-speed, high-precision motor control scenarios such as electric vehicle drive motors and industrial-grade servo systems.

[0081] Energy efficiency optimization: Through more accurate voltage control, the energy efficiency of the motor is significantly improved, meeting the demand for green energy.

[0082] Multi-scenario applicability: The modulation strategy of the invention can be applied to motor and controller design of different topologies, with broad market potential.

[0083] 5. Significant advantages compared to existing technologies:

[0084] Simplification and optimization of complex three-dimensional problems: The invention efficiently maps three-dimensional voltage vector problems to two-dimensional calculations through geometric slicing, solving problems that existing technologies cannot handle.

[0085] Precise control of overmodulation regions: Fine-tuned voltage vector control strategies are designed for different overmodulation regions, overcoming the distortion problem in existing technologies under overmodulation conditions.

[0086] Widespread industrial adaptability: Compared with existing methods, the invention significantly reduces system complexity, is easy to integrate into existing motor controllers, and greatly improves the reliability of the control system.

[0087] 6. Significance of technology promotion:

[0088] The invention not only solves the technical bottleneck of complex modulation in three-phase series winding motors, but also provides a new approach to the application and design of high-performance motors. By improving control efficiency, expanding the speed range, and enhancing system robustness, it provides strong technical support for intelligent manufacturing and green energy industries.

[0089] Fourth, the technical problems and significant progress of the invention:

[0090] Technical problems: 1) Complexity of three-dimensional space voltage vector modulation:

[0091] In three-phase series winding motors, due to the existence of zero-sequence current, voltage vectors are distributed in irregular three-dimensional space. Existing methods lack effective strategies for three-dimensional space vector modulation, making it difficult to accurately generate reference voltage vectors and maintain high-performance operation of the motor.

[0092] 2) Difficulty in dividing linear modulation region and overmodulation region:

[0093] The prior art fails to clearly express the specific geometric range of the three-dimensional linear modulation region, and lacks an adaptive over-modulation strategy. Especially in high output voltage demand scenarios, it cannot effectively handle the over-modulation state, leading to a decline in system performance.

[0094] 3) Current harmonic distortion and torque ripple problems:

[0095] Traditional modulation strategies that do not actively control zero-sequence current are prone to cause severe total harmonic distortion of motor phase current, increase torque ripple, and reduce motor efficiency and stability.

[0096] Significant technical progress:

[0097] 1) Efficient three-dimensional space voltage vector modulation strategy:

[0098] A three-dimensional space slicing method based on three-dimensional αβ-γ coordinate system is proposed, which divides irregular three-dimensional space into two-dimensional slices. By synthesizing virtual voltage vectors VV αβ and VV γ three-dimensional reference voltage vectors, the modulation space is accurately covered, improving modulation accuracy and efficiency.

[0099] 2) Clear expression of linear modulation region:

[0100] Through geometric analysis, a clear division method of linear modulation region and over-modulation region is proposed. The geometric relationship of the reference voltage vector is described by using the cone and cone region model, which provides a clear mathematical basis for over-modulation processing.

[0101] 3) Comprehensive optimization of over-modulation strategy:

[0102] The invention uses different algorithms in different modulation regions (such as cone and cone regions), dynamically adjusts the reference voltage vector to adapt to the over-modulation state, significantly reduces voltage distortion, and improves the stability and efficiency of motor control.

[0103] 4) Reduce harmonic distortion and torque ripple:

[0104] Through active control of zero-sequence current and the use of optimized virtual voltage vector synthesis strategy, the total harmonic distortion of motor phase current is greatly reduced, torque ripple is reduced, and the smoothness of motor operation is improved.

[0105] 5) Universality and robustness:

[0106] The invention is suitable for various complex operating scenarios of series-wound motors, especially in high-power demand and asymmetric load environments, and has excellent robustness and modulation ability, providing high-performance solutions for industrial servo, electric vehicle driving, etc.

[0107] 6) The advancement of the mathematical model:

[0108] The proposed voltage vector relationship (such as formulas (1) to (8)) and the geometric mapping model provide theoretical support for the implementation of motor control algorithms, simplify the complexity of algorithm design, and improve real-time running efficiency.

[0109] Through the above technical scheme, the present application effectively solves the problems of high control complexity, difficult over-modulation processing and insufficient modulation performance of three-phase series winding motor in the prior art, and realizes significant technical progress and industrial value. BRIEF DESCRIPTION OF DRAWINGS

[0110] Figure 1 is a three-dimensional space voltage vector modulation strategy and over-modulation processing method flowchart of a three-phase series winding motor provided by the embodiment of the present application.

[0111] Figure 2 is a three-dimensional space voltage vector modulation strategy and over-modulation processing system structure block diagram of a three-phase series winding motor provided by the embodiment of the present application.

[0112] Figure 3 is a three-phase series winding motor drive topology structure diagram provided by the embodiment of the present application.

[0113] Figure 4 is a three-dimensional voltage vector distribution diagram of a three-phase series winding motor provided by the embodiment of the present application.

[0114] Figure 5 is a space slice diagram provided by the embodiment of the present application.

[0115] Figure 6 is a virtual voltage vector linear modulation area diagram of synthesis of three basic voltage vectors containing zero sequence components provided by the embodiment of the present application.

[0116] Figure 7 is a space slice cross-sectional view provided by the embodiment of the present application.

[0117] Figure 8 is a sector division diagram provided by the embodiment of the present application.

[0118] Figure 9 is an over-modulation schematic diagram provided by the embodiment of the present application.

[0119] Figure 10 is a three-dimensional linear modulation area effect comparison diagram of a three-phase series winding motor provided by the embodiment of the present application.

[0120] Figure 11 is a three-dimensional space voltage vector modulation block diagram of a three-phase series winding motor provided by the embodiment of the present application.

[0121] Figure 12 is a three-dimensional space voltage vector modulation waveform diagram of a three-phase series winding motor provided by an embodiment of the present application, based on a speed of 500 r / min and a load of 1.5 N·m.

[0122] Figure 13 is a dynamic experimental waveform diagram of a three-dimensional space voltage vector modulation of a three-phase series winding motor provided by an embodiment of the present application, based on a speed changing from 600 r / min to -600 r / min and a load of 1 N·m. DETAILED DESCRIPTION

[0123] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0124] Industrial application embodiment 1: efficient control of electric vehicle drive motor

[0125] The drive motor of an electric vehicle needs to provide high efficiency and accurate power output under high speed and heavy load conditions. However, the traditional two-dimensional space voltage vector modulation method has the problems of limited speed range, voltage distortion and unstable control under high speed conditions.

[0126] Objective: to realize efficient control of the drive motor in the high speed region by using the three-dimensional space voltage vector modulation strategy of the present application.

[0127] Technical implementation:

[0128] In the three-dimensional space of the motor αβ plane and γ axis, a reference voltage vector is constructed, and a virtual voltage vector is dynamically adjusted using a geometric slicing method VV αβ and VV γ to meet the voltage requirements under different speeds.

[0129] In the over-modulation region, dynamic voltage vector correction is introduced, and the over-modulation voltage vector is optimized for the circular cone region and the circular cone region respectively to ensure the stability and efficiency of the motor in high speed operation.

[0130] Effect:

[0131] The speed range and control accuracy of the drive motor are improved, and the voltage distortion is significantly reduced.

[0132] The energy efficiency of the motor is improved, and the endurance performance of the electric vehicle is optimized.

[0133] Industrial application embodiment 2: industrial high-performance servo system

[0134] Servo motors in industrial automation production lines need to operate under high dynamic performance and precise positioning conditions, especially in complex load switching and fast response scenarios, requiring high precision and dynamic adaptability of the modulation strategy.

[0135] Application implementation:

[0136] Target realization: The three-dimensional space vector modulation strategy of the application optimizes the control performance of the servo motor.

[0137] Technical realization:

[0138] In a three-phase series-wound servo motor, the three-dimensional vector modulation method is applied, which dynamically adjusts the direction and amplitude of the three-dimensional reference voltage vector by monitoring the load changes in real time.

[0139] In the overmodulation state, the partition optimization strategy of the overmodulation region is used to ensure the response speed and positioning accuracy of the motor under high load switching.

[0140] Effect:

[0141] The dynamic performance and positioning accuracy of the servo motor are improved, and the running efficiency of the production line is improved by about 15%.

[0142] The energy consumption of the motor control system is significantly reduced, providing a high-performance power control solution for intelligent manufacturing.

[0143] As can be seen from the two embodiments, the three-dimensional space vector modulation strategy and overmodulation processing method of the application have wide adaptability in high-performance motor control, especially in scenarios requiring precise dynamic response and high energy efficiency, which can significantly optimize system performance and promote technological progress in related industries.

[0144] As shown in Figure 1 , the three-dimensional space vector modulation strategy and overmodulation processing method of a three-phase series-wound motor provided by the embodiment of the application includes the following steps:

[0145] S101, in the three-dimensional αβ-γ space formed by the series-wound motor, αβ the three-dimensional space is divided into upper and lower half regions by a plane; αβ The voltage vector in the plane does not contain the zero sequence voltage component, i.e. does not contain γ component;

[0146] S102, the space slice includes VV αβ , VV γ and zero voltage vector; according to the geometric principle, in the space slice, two virtual voltage vectors VVαβ , VV γ The zero voltage vector is used to synthesize a three-dimensional reference voltage vector;

[0147] S103, the spatial slicing method divides three-dimensional space into countless two-dimensional slices, and the voltage vector on each slice consists of two virtual voltage vectors. VV αβ and VV γ ;

[0148] S104, three-dimensional overmodulation strategy.

[0149] The three-dimensional structure formed in the series-wound motor provided by the embodiments of the present invention αβ-γ In space, αβ A plane divides a three-dimensional volume into upper and lower halves:

[0150] αβ The plane contains six fundamental voltage vectors and two zero voltage vectors, which form a hexagon; by using any two adjacent fundamental voltage vectors and zero voltage vectors, a plane can be synthesized. αβ Virtual voltage vector in a plane VV αβ According to the volt-second balance principle, αβ The maximum linear modulation region that can be synthesized from the six basic voltage vectors and two zero voltage vectors in a plane is a circle with a radius of . V dc ,in V dc This represents the amplitude of the DC bus voltage.

[0151] The main principle of spatial slicing is to use a perpendicular to αβ Slice the plane, and along γ An axis is used to cut an irregular three-dimensional solid; in this case, the spatial slice will contain a [structure / object] located on [the axis]. αβ The virtual voltage vector of the plane, which is formed by... αβ It is obtained by synthesizing any two adjacent voltage vectors among the six basic voltage vectors on the plane, and also includes the zero voltage vector located at the origin;

[0152] Three-dimensional reference voltage vector V ref [ a, b, c ]exist αβ The projection amplitude of the plane and its relation α The included angle of the axis can be obtained

[0153] (1);

[0154] in, It is a three-dimensional reference voltage vector in αβ Projection of a plane; θ For the reference voltage vector in αβ Projection of a plane and α The included angle of the axis; a It is a three-dimensional reference voltage vector in α Projection of the axis; b It is a three-dimensional reference voltage vector in β Projection of the axis; c It is a three-dimensional reference voltage vector in γ Projection of the axis.

[0155] Then, the magnitude of the three-dimensional reference voltage vector and its relationship with... αβ The included angle of the plane can be obtained

[0156] (2);

[0157] in, It is the magnitude of the three-dimensional reference voltage vector; δ For the reference voltage vector and αβ Angle between two planes.

[0158] However, the space slice contains αβ The virtual voltage vector in the plane does not contain a zero-sequence voltage component. To synthesize a three-dimensional reference voltage vector, a voltage vector containing a zero-sequence component is also needed, that is, a voltage vector containing... γ The voltage vector of the axis component; through analysis, it was found that in the three-dimensional spatial voltage vector synthesized by the four inverter bridge arms, αβ The upper part of the plane contains four voltage vectors with zero-sequence components; these can be used to synthesize voltage vectors containing zero-sequence components. γ The zero-sequence virtual voltage vector in the positive axis direction; similarly, αβ The four voltage vectors containing zero-sequence components in the lower part of the plane can be used to synthesize voltage vectors containing zero-sequence components. γ The virtual voltage vector in the negative axis direction; however, due to the voltage vector V 10 , V 5. This creates irregularities in three-dimensional bodies, therefore they can be discarded; in this case, in αβ In the upper and lower portions of the plane, any two of the six basic voltage vectors containing zero-sequence components can be used to synthesize a virtual voltage vector containing zero-sequence components. VV γ These virtual vectors form a cone in three-dimensional space; this cone... αβ The projection in the plane is a circle with a radius of 1 / 3 V dc A circle.

[0159] The spatial slicing provided in this embodiment of the invention will VV αβ , VV γ And the zero voltage vector is included; according to geometric principles, in a spatial slice, the two virtual voltage vectors are... VV αβ , VV γ The zero voltage vector is used to synthesize a three-dimensional reference voltage vector:

[0160] They also satisfy the following geometric relationship:

[0161] (3);

[0162] in, T γ Represents a virtual voltage vector containing a zero-sequence component. VV γ The duration of action within a control cycle; T αβ yes αβ Virtual voltage vector in VV αβ The duration of action within a control cycle; T s To control the cycle; VV αβ , VV γ and three-dimensional reference voltage vector V ref They are respectively

[0163] (4);

[0164] in, k Represents the scaling factor.

[0165] According to equation (3), the boundary of the three-dimensional reference voltage vector in the space slice can be obtained as follows:

[0166] (5);

[0167] Switch to xy The coordinate system can be obtained

[0168] (6);

[0169] It can be seen that the three-dimensional reference voltage vector on the spatial slice is a parametric equation; according to this equation, it can be concluded that the linear modulation region generated by the three-dimensional modulation strategy proposed in this invention is a double frustum; this frustum is... δ =45° is divided into two parts: the frustum region and the cone region.

[0170] The space slicing method provided by the embodiment of the present application divides three-dimensional space into infinite two-dimensional slices, and the voltage vector on each slice is two virtual voltage vectors VV αβ and VV γ .

[0171] The virtual voltage vectors cannot be directly output by the inverter; therefore, the basic voltage vectors used to synthesize the two virtual voltage vectors need to be found out; for this purpose, the embodiment of the present application provides a basic voltage vector sector table; four basic voltage vectors can be obtained by judging whether the three-dimensional reference voltage vector is located in the upper part or the lower part of the plane through the angle obtained in formula (1) θ αβ and

[0172] The three-dimensional overmodulation strategy provided by the embodiment of the present application is as follows:

[0173] As shown in formula (6), the linear modulation region is divided into two parts by δ =45°, so overmodulation is also performed in the two parts respectively; first, when the three-dimensional reference voltage vector V ref [ a , b , c ] is in the circular cone region, i.e., 0°≤ δ ≤45°; according to formula (1), θ and k can be obtained; then, according to formula (2), V ref can also be obtained. When V ref ≤ k·V dc , the system is considered to be in the linear modulation region; when V ref >, k·V dc , the system is considered to be in the overmodulation region. According to the geometric relationship, the intersection point V ref [ a , b , c ] of the three-dimensional reference voltage vector A and the circular cone can be obtained

[0174] (7);

[0175] wherein, OA ′ is the intersection point of the three-dimensional reference voltage vector and the linear modulation region,​OA k V dc OB is the projection of the new three-dimensional reference voltage vector in the xy-plane, αβ OB OA δ

[0176] Then, A is submitted to the control algorithm to perform the overmodulation process;

[0177] Note that when δ = 0, the overmodulation occurs in the xy-plane, and equation (7) is still applicable, in which case αβ OB V dc In addition, when calculating the new three-dimensional reference voltage vector, the positive or negative direction of the voltage vector in the z-axis needs to be determined according to the sign of γ in the original three-dimensional reference voltage vector; c

[0178] When the three-dimensional reference voltage vector is in the conical region, in which case 45° < θ < 90°. Similarly, according to equations (1) and (4), δ and θ can be obtained, respectively; then the magnitude of the three-dimensional reference voltage vector k ref can be obtained according to equation (2). When V ref , V dc , the system is in the overmodulation region. The three-dimensional reference voltage vector k·V ref [ V , a , b ]and the intersection c of the three-dimensional reference voltage vector with the conical surface can be obtained A

[0179] (8); wherein

[0180] is the projection of the new three-dimensional reference voltage vector in the xy-plane, OB αβ OB V dc / (3 tan δ );

[0181] Then, A is submitted to the control algorithm to perform the overmodulation process. ​​​​​​​​​​​​

[0182] As Figure 2 shown in the figure, the three-dimensional space vector modulation strategy and overmodulation processing system of the three-phase series-winding motor provided by the embodiment of the application comprises:

[0183] a division module, configured to divide a three-dimensional space formed by the series-winding motor into upper and lower half regions by a plane; αβ-γ αβ a synthesis module, configured to synthesize three-dimensional reference voltage vectors by using two virtual voltage vectors

[0184] VV αβ , VV γ and a zero voltage vector in the space slice; VV αβ , VV γ according to geometric principles, in the space slice, the two virtual voltage vectors

[0185] are used to synthesize the three-dimensional reference voltage vector; VV αβ VV γ ;

[0186] a modulation module, configured to implement three-dimensional modulation and overmodulation strategies.

[0187] Another object of the application is to provide a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the computer program, when executed by the processor, causes the processor to perform the steps of the three-dimensional space vector modulation strategy and overmodulation processing method of the three-phase series-winding motor.

[0188] Another object of the application is to provide a computer readable storage medium storing a computer program, and the computer program, when executed by a processor, causes the processor to perform the steps of the three-dimensional space vector modulation strategy and overmodulation processing method of the three-phase series-winding motor.

[0189] Another object of the application is to provide an information data processing terminal for implementing the three-dimensional space vector modulation strategy and overmodulation processing system of the three-phase series-winding motor.

[0190] The application is implemented as follows:

[0191] As Figure 3 shown in the figure, the three-phase series-winding motor drive topology comprises: A , B ,​​​C The inverter consists of a three-phase stator winding. It has four bridge arms, namely the bridge arm... L 1. L 2 、L 3 、L Composed of 4 components, the DC bus voltage is V dc To control the zero-sequence current, the control system needs to synthesize a three-dimensional reference voltage vector, which is: V ref [ a , b , c To synthesize this three-dimensional reference voltage vector, more than three basic voltage vectors are needed, and these basic voltage vectors need to be distributed in different planes.

[0192] The sixteen basic voltage vectors generated by a three-phase series-wound motor are distributed as follows: Figure 4 In the irregular three-dimensional bodies shown, they are in αβ The projection of a plane can also be obtained. In three dimensions... αβ-γ In space, αβ A plane divides a three-dimensional volume into upper and lower halves. αβ The plane contains six fundamental voltage vectors and two zero voltage vectors, which form a hexagon. A plane can be synthesized by using any two adjacent fundamental voltage vectors and zero voltage vectors. αβ Virtual voltage vector in a plane VV αβ According to the volt-second balance principle, αβ The maximum linear modulation region that can be synthesized from the six basic voltage vectors and two zero voltage vectors in a plane is a circle with a radius of . V dc .

[0193] The main principle of spatial slicing is to use a perpendicular to αβ Slice the plane, and along γ The axis is used to cut an irregular three-dimensional space volume. In this case, the space slice will contain a [missing information - likely a location]. αβ The virtual voltage vector of the plane, which is formed by... αβ It is obtained by synthesizing any two adjacent voltage vectors among the six basic voltage vectors in the plane. In addition, it includes the zero voltage vector located at the origin, and the spatial slices are as follows: Figure 5 As shown.

[0194] based on Figure 5 Three-dimensional reference voltage vector in αβ The projection amplitude of the plane and its relation α The included angle of the axis can be obtained

[0195] (1);

[0196] wherein, V ref | is the magnitude of the three-dimensional reference voltage vector; δ is the angle of the reference voltage vector with the αβ plane; a is the projection of the three-dimensional reference voltage vector on the α axis; b is the projection of the three-dimensional reference voltage vector on the β axis; c is the projection of the three-dimensional reference voltage vector on the γ axis.

[0197] Then, the magnitude of the three-dimensional reference voltage vector and its angle with the αβ plane can be obtained

[0198] (2);

[0199] wherein, V αβ | is the projection of the three-dimensional reference voltage vector on the αβ plane; θ is the angle of the projection of the reference voltage vector on the αβ plane with the α axis; c is the projection of the three-dimensional reference voltage vector on the γ axis.

[0200] However, the virtual voltage vectors in the αβ plane contained in the space slice do not contain zero-sequence voltage components, and in order to synthesize the three-dimensional reference voltage vector, a voltage vector containing a zero-sequence component is also needed, i.e. a voltage vector containing the γ axis component is also needed. Through analysis, it is found that in the four inverter bridge arm synthesized three-dimensional space vectors, αβ the upper part of the γ plane has four voltage vectors containing zero-sequence components. They can be used to synthesize a zero-sequence virtual voltage vector containing the α β axis positive direction. Similarly, the four voltage vectors containing zero-sequence components in the lower part of the γ plane can be used to synthesize a virtual voltage vector containing the V 10 , V 5 cause the irregularity of the three-dimensional body, so they can be discarded. In this case, in the α βAny two of the six basic voltage vectors with zero-sequence component in the upper and lower half-planes can be used to synthesize a virtual voltage vector with zero-sequence component VV γ These virtual voltage vectors form a cone in three-dimensional space. The projection of this cone in the plane is a circle with a radius of 1 / 3 αβ V dc The synthesized cone is shown in Figure 6

[0201] Then, the space slice proposed by the present application contains VV αβ , VV γ and the zero voltage vector. According to geometric principles, in the space slice, two virtual voltage vectors VV αβ , VV γ and the zero voltage vector can be used to synthesize a three-dimensional reference voltage vector. Meanwhile, they satisfy the following geometric relationships:

[0202] (3);

[0203] wherein, T γ The virtual voltage vector with zero-sequence component VV γ acts for a time of one control period; T αβ is the virtual voltage vector αβ in VV αβ acts for a time of one control period; T s is the control period; VV αβ , VV γ and V ref are respectively

[0204] (4);

[0205] wherein, k represents a proportional factor.

[0206] According to formula (3), the boundary of the three-dimensional reference voltage vector in the space slice is

[0207] (5);

[0208] Converting to xy coordinate system can obtain​​

[0209] (6) ;

[0210] It can be seen that the three-dimensional reference voltage vector on the space slice is a parametric equation. A cross-section of the space slice can be shown in the xy coordinate system as shown in Figure 7 According to the equation, it can be concluded that the linear modulation region generated by the three-dimensional modulation strategy proposed by the application is a double circular truncated cone. The truncated cone is divided into two parts by δ =45°, which are the truncated cone region and the conical region, respectively.

[0211] The space slice method divides the three-dimensional space into countless two-dimensional slices, but the voltage vector on each slice is two virtual voltage vectors VV αβ and VV γ These virtual voltage vectors cannot be directly output by the inverter. Therefore, the basic voltage vectors used to synthesize the two virtual voltage vectors need to be found out. By the angle θ obtained in equation (1), it can be determined whether the three-dimensional reference voltage vector is located in the upper half or the lower half of the αβ plane, that is, the four basic voltage vectors can be obtained, and the sector division is shown in Figure 8 . Among them S 1, S 2, S 3, S 4, S 5, S 6, respectively represent the six sectors divided in the αβ plane, each sector is 60 degrees. N 1, N 2, N 3, N 4, N 5, N 6 represent six sectors containing zero sequence components, each sector is 120 degrees. Then, the four basic voltage vectors are used to synthesize the three-dimensional reference voltage vector. For this purpose, the application provides a basic voltage vector sector table as shown in Table 1.

[0212] Table 1 Basic voltage vector sector table

[0213] V αβ ]]> ​ V γ ]]> ​ 1 V 11 V 9]]> ​ 3 V 14 V 8]]> ​ 1 V 11 V 9]]> ​ 1 V 8 V 12 ]]> ​ 1 V 11 V 9]]> ​ 4 V 3 V 1]]> ​ 2 V 9 V 13 ]]> ​ 1 V 8 V 12 ]]> ​ 2 V 9 V 13 ]]> ​ 4 V 3 V 1 ]]> ​ 2 <![CDATA[ V 9 V 13 ]]> 5 V 1 V 7 ]]> ​ 3 V 13 V 4]]> ​ 1 V 8 V 12 ]]> ​ 3 V 13 V 4]]> ​ 2 <![CDATA[ V 12 V 14 ]]> 3 V 13 V 4]]> ​ 5 V 1 V 7]]> ​ 4 V 4 V 6]]> ​ 2 V 12 V 14 ]]> ​ 4 V 4 V 6]]> ​ 5 V 1 V 7]]> ​ 4 V 4 V 6]]> ​ 6 V 7 V 3]]> ​ 5 V 6 V 2]]> ​ 2 V 12 V 14 ]]> ​ 5 V 6 V 2]]> ​ 3 V 14 V 8]]> ​ 5 V 6 V 2]]> ​ 6 V 7 V 3]]> ​ 6 V 2 V 11 ]]> ​ 3 V 14 V 8]]> ​ 6 V 2 V 11 ]]> ​ 6 V 7 V 3]]> ​ 6 V 2 V 11 ]]> ​ 4 V 3 V 1]]> ​

[0214] In order to well control when the series winding motor enters overmodulation, the application also provides a three-dimensional overmodulation strategy. As shown in equation (6), the linear modulation region is divided into two parts by δ =45°, so overmodulation is also performed in these two parts. First, when the three-dimensional reference voltage vector Vref [ a , b , c ] is in the circular-toroid region, i.e. 0°≤ δ ≤45°. According to equation (1), θ and k can are obtained. Then, according to equation (2), V ref may also be obtained. When V ref ≤ k·V dc , the system is considered to be in the linear modulation region. When V ref > k·V dc , the system is considered to be in the overmodulation region. According to the geometric relationship of Figure 9 , the intersection point V ref [ a , b , c ] of the three-dimensional reference voltage vector A and the circular-toroid can be obtained

[0215] (7);

[0216] where OA ′ is the intersection point of the three-dimensional reference voltage vector and the linear modulation region; OA ′= k · V dc ; OB ′ is the projection of the new three-dimensional reference voltage vector on the αβ plane, OB ′= OA ′·cos δ .

[0217] Then, A ′ is submitted to the control algorithm to perform overmodulation processing.

[0218] Note that when δ =0, overmodulation occurs in the αβ plane, and equation (7) is still applicable, in which case OB ′= V dc . In addition, when calculating the new three-dimensional reference voltage vector, the positive and negative directions of the voltage vector on the γ axis need to be determined according to the positive and negative signs of c in the original three-dimensional reference voltage vector.

[0219] When the three-dimensional reference voltage vector is in the conical region, at this time 45°<δ ≤ 90°. Similarly, according to formula (1) and formula (4), θ and k The amplitude of the three-dimensional reference voltage vector can be obtained respectively; then V ref The amplitude of the three-dimensional reference voltage vector can be obtained according to formula (2). When V ref > k·V dc The system is in the overmodulation region. According to the geometric relationship as shown in formula (3), the three-dimensional reference voltage vector Figure 9 V ref [ a , b , c ] and the intersection of the circular cone surface A ′ can be obtained

[0220] (8);

[0221] wherein, OB ′ is the projection of the new three-dimensional reference voltage vector on the αβ plane; OB ′= V dc / (3tan δ );

[0222] Then, A ′ is submitted to the control algorithm to perform overmodulation processing.

[0223] The three-dimensional linear modulation region generated by the three-dimensional space voltage vector modulation algorithm proposed in the present application is compared with the linear modulation region generated by the existing method as shown in formula (5), and it can be seen that the linear modulation region generated by the algorithm proposed in the present application is a double circular cone, and the existing method is a double circular cone, and the linear modulation region is expanded by 33.33%. Figure 10

[0224] The execution process of the whole control algorithm is as shown in formula (6). First, the current motor speed Figure 11 is collected, and the reference motor speed n is set n ref ;

[0225] The speed deviation control calculation is performed through the speed loop PI controller, and the result is projected to the dq plane to obtain the reference current i q ref ;

[0226] The reference current i d ref 、i ​​0 ref is zero;

[0227] collecting the current phase currents i A , i B , i C , through the Clark transformation, the results are projected to the α-β-0 plane, get i α , i β and i 0 ;

[0228] i α , i β through the Park transformation, and the results are projected to the d-q-0 plane, get the current d-q plane current i d , i q and i 0 ;

[0229] by reference to the current i q ref , i d ref and i 0 ref and the current d-q-0 plane i d , i q 、i 0， by PI controller to get the reference voltage u q ref , u d ref 、u 0 ref ;

[0230] u q ref , u d ref 、u 0 ref ​​The Anti-Park transformation is used to obtain u α ref 、 u β ref 、u 0 ref ;

[0231] The u α ref 、 u β ref 、u 0 ref The input three-dimensional modulation module generates the PWM waveform of the bridge arm to drive the three-phase series winding motor to run, and finally verifies on an experimental platform. Based on the verification of the steady-state performance of the proposed algorithm under the condition of a rotating speed of 500r / min and a load of 1.5N·m, the experimental waveforms of the rotating speed, the torque, the phase current, αβ-γ The axial current and the bridge arm current are shown in Figure 12 Then, in order to verify the dynamic performance, the dynamic performance of the proposed algorithm is verified under the condition of a rotating speed changing from 600r / min to-600r / min and a load of 1N·m, and the experimental waveforms of the rotating speed, the torque, the phase current and the phase current are shown in Figure 13 .

[0232] In order to verify the technical scheme of the application, the scheme is verified in detail in the laboratory. A 1kW three-phase series winding motor driving experiment platform is built in the laboratory. The effectiveness of the modulation algorithm proposed in the application is verified through the three-phase series winding motor driving experiment platform. The related experimental results are also embodied in the technical scheme of the application.

[0233] The three-dimensional space vector modulation strategy and overmodulation processing method for series winding motors proposed in the application can be verified and tested on the three-phase series winding motor driving experiment platform. The experimental hardware platform is composed of a three-phase series winding motor, a dSPACE 1202, an upper computer, a programmable power supply and a magnetic powder brake. The series winding motor parameters are as follows: the number of pole pairs is 4; the resistance is 1.52Ω; d The axial inductance is 3.77mH; q The axial inductance is 3.77mH; the zero sequence inductance is 1.55mH; the rotor flux is 0.129Wb; the third rotor flux harmonic is 0.0059Wb; the rated rotating speed is 2500rpm; the rated torque is 4N·m; and the sampling frequency is 10kHz.

[0234] The three-phase series winding motor driving experiment platform tests the operation performance of the application under steady state and dynamic state. The speed is set to 500 r / min under steady state, and the load is 1.5 N·m, the obtained speed, torque, phase current, αβ-γ The experimental waveforms of shaft current and bridge arm current are shown in Figure 12 Under dynamic condition, the speed of the series winding motor changes from 600 r / min to-600 r / min, and the load 1 N·m remains unchanged, the obtained motor speed, torque, phase current and phase current amplification experimental waveforms are shown in Figure 13 The div represents each grid, for example, 50 ms / div represents that the time width of each grid in the figure is 50 ms, and it can be seen from the figure that the modulation strategy proposed in the application can effectively suppress the zero sequence current under steady state, so that the three-phase current of the motor is good in sinusoidal. Under dynamic condition, the response speed is fast, and the given speed value can be quickly tracked.

[0235] It should be noted that the embodiments of the application can be realized by hardware, software or a combination of software and hardware. The hardware part can be realized by special logic; the software part can be stored in the memory and executed by the appropriate instruction execution system, such as microprocessor or special designed hardware. Those skilled in the art can understand that the above-mentioned devices and methods can be realized by computer executable instructions and / or included in processor control code, for example, such code is provided on carrier medium such as magnetic disk, CD or DVD-ROM, programmable memory such as read-only memory (firmware) or data carrier such as optical or electronic signal carrier. The device of the application and its modules can be realized by hardware circuit such as ultra large scale integrated circuit or gate array, semiconductor such as logic chip, transistor, or programmable hardware device such as field programmable gate array, programmable logic device, etc., can also be realized by software executed by various types of processors, and can also be realized by the combination of the above hardware circuit and software, such as firmware.

[0236] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed by the application, as long as it is within the spirit and principle of the application, should be covered within the protection scope of the application.

Claims

1. A three-phase series-wound motor three-dimensional space vector modulation strategy and overmodulation processing method, characterized in that, The method comprises the following steps: Step 1, in the three-dimensional αβ-γ space formed by the series-winding motor, the αβ plane divides the three-dimensional space into upper and lower halves; Step 2, the space slice will include the VV αβ , VV γ and zero voltage vector; according to geometric principles, in the space slice, two virtual voltage vectors VV αβ , VV γ and zero voltage vector are used to synthesize a three-dimensional reference voltage vector V ref [a, b, c]; Step 3, the space slicing method divides the three-dimensional space into an infinite number of two-dimensional slices, and the voltage vector on each slice is two virtual voltage vectors VV αβ and VV γ ; Step 4, three-dimensional modulation execution and overmodulation strategy processing; The space sector includes both virtual voltage vectors VV αβ , VV γ and the zero voltage vector; according to geometric principles, in the space sector, both virtual voltage vectors VV αβ , VV γ and the zero voltage vector are used to synthesize a three-dimensional reference voltage vector: Meanwhile, the following geometric relationship is satisfied: （3）， where T γ Virtual voltage vector VV γ In the action time of one control period; T αβ Virtual voltage vector VV αβ In the action time of one control period; T s Control period; VV αβ , VV γ And V ref Respectively （4）， According to equation (3), the three-dimensional reference voltage vector V ref [a, b, c] at the boundary of the spatial slice is （5）， Conversion to the xy coordinate system can obtain （6）； The three-dimensional αβ-γ space formed by the series-winding motor is divided into upper and lower halves by the αβ plane; The αβ plane contains six basic voltage vectors and two zero voltage vectors, which form a hexagon; a virtual voltage vector VV in the αβ plane can be synthesized by using any two adjacent basic voltage vectors and zero voltage vectors among the voltage vectors αβ ; according to the voltage-second balance principle, the maximum linear modulation region that can be synthesized by the six basic voltage vectors and the two zero voltage vectors in the αβ plane is a circle with a radius of V dc ; Three-dimensional reference voltage vector V ref The projection amplitude of [a, b, c] in the αβ plane and its angle with the α axis can be obtained （1）； where |V αβ is the projection of the three-dimensional reference voltage vector on the αβ plane; θ is the angle between the projection of the three-dimensional reference voltage vector on the αβ plane and the α axis; a is the projection of the three-dimensional reference voltage vector on the α axis, b is the projection of the three-dimensional reference voltage vector on the β axis, and c is the projection of the three-dimensional reference voltage vector on the γ axis Then, the three-dimensional reference voltage vector V ref The magnitude of [a, b, c] and its angle with the αβ plane can be obtained （2）； where |V ref is the magnitude of the three-dimensional reference voltage vector; and δ is the angle between the reference voltage vector and the αβ plane.

2. The method of claim 1, wherein the three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing method is characterized by, The space slicing method divides the three-dimensional space into an infinite number of two-dimensional slices, and the voltage vector on each slice is two virtual voltage vectors VV αβ and VV γ : The angle θ obtained in formula (1) is used to determine whether the three-dimensional reference voltage vector is located in the upper half or the lower half of the αβ plane, so as to obtain four basic voltage vectors; Then, the four basic voltage vectors are used to synthesize the three-dimensional reference voltage vector.

3. The method of claim 1, wherein the three-dimensional space vector modulation strategy and overmodulation process for a three-phase series-winding motor is characterized by, The three-dimensional modulation execution and overmodulation strategy processing: As shown in equation (6), the linear modulation region is divided into two parts by δ = 45°, so the overmodulation is also performed in the two parts respectively; first when the three-dimensional reference voltage vector V ref [a, b, c] is in the circular cone region, i.e. 0°≤δ≤45°; according to equation (1), θ can be obtained; then, according to equation (2), |V ref | can also be obtained; when |V ref |≤k·V dc , the system is considered to be in the linear modulation region; when |V ref |>k·V dc , the system is considered to be in the overmodulation region, and according to the geometric relationship, the intersection point A' of the three-dimensional reference voltage vector V ref [a, b, c] and the circular cone can be obtained (7) ； wherein OA' = k-V dc OB' = OA' cos δ; Then, A' is submitted to the control algorithm to perform overmodulation processing. Note that when δ = 0, overmodulation occurs in the αβ plane, and equation (7) is still applicable, in which case OB' = V dc ; moreover, when calculating the new three-dimensional reference voltage vector, the positive or negative direction of the voltage vector in the γ axis needs to be determined according to the sign of c in the original three-dimensional reference voltage vector; When the three-dimensional reference voltage vector is in the conical region, i.e. 45° < δ ≤ 90°, θ can be obtained according to formula (1) respectively; then the amplitude |V ref | of the three-dimensional reference voltage vector can be obtained according to formula (2); when |V ref | > k · V dc , the system is in the overmodulation region; the three-dimensional reference voltage vector V ref [a, b, c] can be obtained according to formula (3); the intersection A' of the three-dimensional reference voltage vector V [α, β, γ] and the conical surface can be obtained (8) ； wherein OB' = V dc (3 tan δ); Then, A' is submitted to the control algorithm to perform overmodulation processing.

4. A three-phase series-wound motor three-dimensional space vector modulation strategy and overmodulation processing system for implementing the three-phase series-wound motor three-dimensional space vector modulation strategy and overmodulation processing method according to any one of claims 1-3, characterized in that, The three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing system comprises: A segmentation module is configured to divide the three-dimensional space formed by the series-winding motor into upper and lower halves by the αβ plane; a synthesis module for synthesizing the VV αβ , VV γ and zero voltage vectors are included; according to geometric principles, in the space section, two virtual voltage vectors VV αβ , VV γ and zero voltage vectors are used to synthesize a three-dimensional reference voltage vector; The dividing module is used for dividing three-dimensional space into infinite two-dimensional slices by space slicing method, and the voltage vector on each slice is two virtual voltage vectors VV αβ and VV γ ; A modulation module is configured to perform three-dimensional overmodulation strategy.

5. A computer device, comprising: The computer device comprises a memory and a processor, and the memory stores a computer program, which, when executed by the processor, causes the processor to execute the steps of the three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing method according to any one of claims 1-4.

6. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to execute the steps of the three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing method according to any one of claims 1-3.

7. An information data processing terminal, characterized by The information data processing terminal is configured to implement the three-phase series-winding motor three-dimensional space vector modulation strategy and overmodulation processing system according to claim 4.

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