Permanent magnet generator flux-weakening voltage-stabilizing strategy for directly regulating and controlling direct-axis current by inputting rotating speed

Abstract

The invention provides a permanent magnet generator flux-weakening voltage-stabilizing strategy for directly regulating and controlling direct-axis current by inputting rotating speed. According to the strategy, the internal relation between the direct-axis current and the maximum voltage-stabilizing rotating speed is analyzed; the problem that the voltage and power output of the permanent magnet synchronous generator is unstable under the wide-range rotating speed change is solved by researching the application of the fuzzy control theory in field weakening control of the permanent magnet synchronous generator and improving the adaptive capacity of the permanent magnet synchronous generator under the complex sudden change working condition. According to the strategy, an accurate relation graph is constructed by constructing a generator mathematical model, inputting direct-axis current and collecting and analyzing the change of the maximum voltage-stabilizing rotating speed under different direct-axis current components; the designed fuzzy controller is embedded into a generator control system, the rotating speed of a prime motor is used as input, the direct-axis current of the generator is used as output, the voltage stabilization performance is evaluated, controller parameters are optimized, the intelligent level is improved, and the nonlinear problem is solved; during testing, sudden change working conditions are input, the voltage stabilization performance of the generator is evaluated, and optimization is carried out.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet generator control, in particular to a permanent magnet generator weak magnetic field voltage stabilization strategy in which an input rotation speed directly controls a direct axis current. Background Art

[0002] With the rapid development of renewable energy, especially wind power, tidal power and other power generation methods that rely on the speed change of the prime mover, higher requirements are placed on the performance of generators; permanent magnet synchronous generators have been widely used in these fields due to their high efficiency, high power density and easy control; however, how to maintain the stability of output voltage and power under a wide range of speed changes is a key technical problem currently faced. Therefore, there is an urgent practical need to study the weak magnetic field voltage stabilization control strategy of permanent magnet synchronous generators.

[0003] The traditional weak-field voltage stabilization control method of permanent magnet synchronous generator mainly relies on voltage feedback to adjust the direct-axis current, but does not take the change of input speed into consideration, which makes it powerless when facing the condition of sudden speed change; especially when the input speed changes rapidly, the traditional method is often difficult to quickly and accurately adjust the electromagnetic state of the generator, which in turn causes fluctuations in output voltage and power, posing a threat to the stable operation of the power system; in the weak-field voltage stabilization control of permanent magnet synchronous generator, the complex relationship between input speed and direct-axis current is difficult to fully describe through an accurate mathematical model, which makes it particularly difficult to introduce input speed as an input variable into the weak-field voltage stabilization control, thus highlighting the limitations of traditional control methods; and in the fuzzy control strategy, with its ability to handle nonlinear characteristics and uncertainties, the fuzzy control strategy is very suitable for the weak-field voltage stabilization control of permanent magnet synchronous generator. The excellent qualitative ability shows significant advantages in controlling complex systems such as permanent magnet synchronous generators; by introducing fuzzy control theory, it can effectively realize fine adjustment of the generator output voltage and power, while reducing the dependence on precise mathematical models, thereby improving the intelligence of the control system and providing strong guarantees for the stable operation of the permanent magnet synchronous generator; for this reason, the applicant has deepened the understanding of the weak magnetic control mechanism of the permanent magnet synchronous generator by exploring the intrinsic connection between the input speed of the prime mover and the weak magnetic current; at the same time, a weak magnetic voltage stabilization strategy for permanent magnet generators that directly controls the direct axis current by input speed is proposed, and fuzzy control theory is applied to the weak magnetic voltage stabilization control of permanent magnet synchronous generators, which provides new ideas and methods for the nonlinear control of complex systems and enriches the research content of control theory. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a permanent magnet generator weak magnetic field stabilization strategy that directly controls the direct-axis current by inputting the speed. By analyzing the intrinsic connection between the direct-axis current and the maximum stabilization speed, studying the application of fuzzy control theory in the weak magnetic field control of permanent magnet synchronous generators and improving the adaptability of permanent magnet synchronous generators under complex and sudden change conditions, a control system is set up to solve the problem of unstable voltage and power output of the permanent magnet generator under a wide range of speed changes.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The weak magnetic field voltage stabilization strategy of a permanent magnet generator with direct-axis current controlled by input speed is characterized in that: the weak magnetic field voltage stabilization strategy of a permanent magnet generator with direct-axis current controlled by input speed under fuzzy control analyzes the intrinsic connection between the direct-axis current and the maximum voltage stabilization speed, studies the application of fuzzy control theory in the weak magnetic field control of permanent magnet synchronous generators, and improves the adaptability of permanent magnet synchronous generators under complex mutation conditions to set up a control system to solve the problem of unstable voltage and power output of the permanent magnet generator under a wide range of speed changes; the analysis of the intrinsic connection between the direct-axis current and the maximum voltage stabilization speed is mainly carried out by constructing a mathematical model of the generator, inputting the direct-axis current, collecting and analyzing the maximum voltage stabilization speed under different direct-axis current components. The change of the maximum voltage stabilization speed is used to construct an accurate relationship map to reveal the intrinsic connection between the direct-axis current and the maximum voltage stabilization speed; the research on the application of fuzzy control theory in the weak magnetic control of permanent magnet synchronous generators is to embed the designed fuzzy controller into the generator control system, with the prime mover speed as input and the generator direct-axis current as output, to evaluate the voltage stabilization performance of the power generation system, and optimize the controller parameters according to the experimental results to improve the intelligence level and the ability to handle nonlinear problems; in terms of improving the adaptability of permanent magnet synchronous generators under complex sudden changes in working conditions, input speed mutations, load changes and other working conditions, evaluate the generator voltage stabilization performance, and continuously optimize the control model.

[0007] Furthermore, the control system of the permanent magnet generator weak magnetic field stabilization strategy for adjusting the direct-axis current by inputting the speed under the fuzzy control is specially designed for different types of permanent magnet synchronous generators to ensure efficient and stable control under various working conditions, and through a large amount of experimental data, the relationship between the direct-axis current and the maximum voltage stabilization speed is deeply explored and established, providing a solid foundation for the design of the fuzzy controller; at the same time, the fuzzy control theory is introduced to construct a fuzzy controller; the controller can receive the real-time input speed signal of the prime mover, and intelligently output the direct-axis current control instruction according to the preset fuzzy rule set; the design of the fuzzy controller fully considers the complex nonlinear relationship between the direct-axis current and the maximum voltage stabilization speed, ensuring precise weak magnetic field control of the permanent magnet synchronous generator within a wide speed range.

[0008] Furthermore, the data processing of the control system of the permanent magnet generator weak magnetic field stabilization strategy with input speed to control the direct-axis current under fuzzy control is to input different direct-axis current values ​​under different load conditions, and record the corresponding key parameters such as stabilization speed, quadrature-axis current, current amplitude, etc., to form a comprehensive experimental data set, and conduct in-depth analysis of the experimental data to extract the core relationship between the direct-axis current and the maximum stabilization speed, thereby providing strong data support for the subsequent design and optimization of the fuzzy controller.

[0009] Furthermore, the structure of the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control is specifically as follows:

[0010] 1) Input interface: used to receive and process the input speed signal of the prime mover in real time to ensure the accuracy and real-time nature of the data;

[0011] 2) Fuzzy processing unit: converts the received input speed signal into a fuzzy set to provide the necessary input for fuzzy reasoning;

[0012] 3) Fuzzy rule base: stores fuzzy rule sets built based on experimental data. The rule sets define the adjustment strategy of direct-axis current under different input speeds to ensure the accuracy and efficiency of control;

[0013] 4) Fuzzy reasoning engine: Based on the rules in the fuzzy rule base and the fuzzy processed input signal, it performs intelligent reasoning and outputs the corresponding direct-axis current control instructions;

[0014] 5) Output interface: Output the inferred direct-axis current control command to the direct-axis current control module to achieve precise control of the PMSG.

[0015] Furthermore, the control system construction steps of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control are specifically as follows:

[0016] 1) Experimental measurement: Under different load conditions, the maximum voltage-stabilized speed corresponding to different direct-axis current setting values ​​is measured through simulation models or actual experiments to obtain key data;

[0017] 2) Data analysis: Conduct in-depth analysis of the experimental data, construct a data table between the direct-axis current and the maximum voltage-stabilized speed, and reveal their internal relationship;

[0018] 3) Rule conversion: Using professional knowledge and experience, the data table is converted into fuzzy rules and membership functions in the fuzzy rule set, providing a reliable basis for the design of the fuzzy controller.

[0019] Furthermore, the control system setting module of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control includes:

[0020] 1) Voltage monitoring module: monitors the output voltage of PMSG in real time to ensure voltage stability and safety;

[0021] 2) Fuzzy control module: By receiving the input speed signal of the prime mover, it intelligently outputs the direct-axis current control command to achieve precise control of the PMSG;

[0022] 3) Feedback control unit: dynamically adjusts the quadrature axis current according to the difference between the monitored output voltage and the preset voltage to help maintain voltage stability;

[0023] 4) AC and DC axis current closed loop link: Build a closed loop control system for AC and DC axis current to ensure that the system can maintain a stable state under various working conditions;

[0024] 5) Current decoupling module: decouples the current signal into quadrature-axis and direct-axis voltages, facilitating subsequent coordinate transformation and PWM control;

[0025] 6) Coordinate transformation module: converts the control instructions of the AC and DC axis current into voltage components in the motor coordinate system, providing necessary input for PWM control;

[0026] 7) Pulse Width Modulation Module: Generates PWM pulse waves to control IGBT according to the voltage components, achieving precise and efficient control of PMSG.

[0027] Furthermore, the specific steps of the method for using the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control are as follows:

[0028] Step 1: Start and initialize: Start the PMSG and set the initial operating status to ensure that the system is in normal working condition;

[0029] Step 2: Data collection and processing: real-time collection and input of the speed signal of the prime mover into the fuzzy controller to ensure the accuracy and real-time nature of the data;

[0030] Step 3: fuzzy control: the fuzzy controller receives and processes the input speed signal, and outputs a direct-axis current control instruction according to a preset fuzzy rule set;

[0031] Step 4: Direct-axis current adjustment: adjust the direct-axis current according to the output instruction of the fuzzy controller to achieve precise control of the PMSG;

[0032] Step 5: Voltage monitoring and feedback: monitor the output voltage in real time and adjust the quadrature-axis current as needed to maintain voltage stability; ensure that the system remains stable under various operating conditions through the feedback control unit and the AC and DC axis current closed-loop link.

[0033] Furthermore, the electromagnetic induction law in the construction of the fuzzy rule system in the permanent magnet generator weak magnetic field voltage stabilization strategy of input speed control of direct axis current under fuzzy control is reflected in the operation of the permanent magnet synchronous generator as follows: the rotor rotation drives the magnetic flux change, generating a back electromotive force directly proportional to the speed, that is, the output voltage; the formula can be expressed as:

[0034] E=K E ·ω·φ

[0035] Where: E represents electromagnetic induced electromotive force, i.e., back electromotive force;

[0036] K E represents the back electromotive force coefficient;

[0037] ω represents the speed of the prime mover;

[0038] Φ represents magnetic flux.

[0039] Furthermore, the weak magnetic control strategy in the weak magnetic voltage stabilization strategy of the permanent magnet generator with input speed to control the direct axis current under the fuzzy control is optimized to select the weak magnetic control technology set by the limiting bandwidth to dynamically manage the magnetic flux by regulating the direct axis current, thereby controlling the output voltage within a wide speed range; the relationship between the magnetic flux and the direct axis current can be expressed as:

[0040] φ d =L d ·i d

[0041] Where: φ d is the direct-axis magnetic flux;

[0042] L d is the direct-axis inductance;

[0043] i d is the direct axis current.

[0044] The benefits of this application are:

[0045] 1. The weak magnetic field voltage stabilization strategy of permanent magnet generator with input speed control and direct axis current under fuzzy control is specially designed for different types of permanent magnet synchronous generators to ensure efficient and stable control under various working conditions;

[0046] 2. The weak magnetic field voltage stabilization strategy of permanent magnet generator with input speed to control direct axis current under fuzzy control. Through a large amount of experimental data, the relationship between direct axis current and maximum voltage stabilization speed is deeply explored and established, which provides a solid foundation for the design of fuzzy controller.

[0047] 3. The weak magnetic field voltage stabilization strategy of permanent magnet generator with input speed control of direct axis current under fuzzy control introduces fuzzy control theory and constructs a fuzzy controller. The controller can receive the real-time input speed signal of the prime mover and intelligently output the direct axis current control instruction according to the preset fuzzy rule set. The design of the fuzzy controller fully considers the complex nonlinear relationship between the direct axis current and the maximum voltage stabilization speed, ensuring accurate weak magnetic field control of the permanent magnet generator in a wide speed range. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a block diagram of the open-loop system model of the present invention;

[0049] Figure 2 The block diagram of the weak magnetic field voltage stabilization system based on the input speed control direct axis current strategy;

[0050] Figure 3 The test results of the weak magnetic field voltage stabilization system with increasing input speed for controlling the direct axis current based on the input speed.

[0051] Figure 4 The test results of the weak magnetic field voltage stabilization system based on input speed to control the direct axis current when the speed changes suddenly.

[0052] Figure 5 It is the block diagram of variable resistor model;

[0053] Figure 6 The test results of the weak-field voltage stabilization system based on input speed control of direct-axis current under complex working conditions are shown. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0055] The figure shows the weak-field voltage stabilization strategy of a permanent magnet generator that directly controls the direct-axis current by inputting the speed. The figure shows the weak-field voltage stabilization strategy of a permanent magnet generator that controls the direct-axis current by inputting the speed under fuzzy control. By analyzing the intrinsic connection between the direct-axis current and the maximum regulated speed, studying the application of fuzzy control theory in the weak-field control of permanent magnet synchronous generators, and improving the adaptability of permanent magnet synchronous generators under complex and sudden changes in working conditions, a control system is set up to solve the problem of unstable voltage and power output of the permanent magnet generator under a wide range of speed changes. The figure shows the analysis of the intrinsic connection between the direct-axis current and the maximum regulated speed mainly by constructing a mathematical model of the generator, inputting the direct-axis current, collecting and analyzing the maximum regulated speed under different direct-axis current components. The change of voltage and speed is used to construct an accurate relationship map to reveal the intrinsic connection between the direct-axis current and the maximum voltage-stabilizing speed; the application of fuzzy control theory in the weak-field control of permanent magnet synchronous generators is shown in the study, which is to embed the designed fuzzy controller into the generator control system, with the prime mover speed as input and the generator direct-axis current as output, to evaluate the voltage-stabilizing performance of the power generation system, and optimize the controller parameters according to the experimental results to improve the intelligence level and the ability to handle nonlinear problems; in order to improve the adaptability of permanent magnet synchronous generators under complex sudden changes in working conditions, input speed mutations, load changes and other working conditions, evaluate the generator voltage-stabilizing performance, and continuously optimize the control model.

[0056] The intrinsic relationship between the direct-axis current and the maximum voltage-regulated speed is analyzed and elaborated according to the parameters of the permanent magnet synchronous motor in Table 1 below;

[0057] Table 1 Permanent magnet synchronous motor parameters

[0058]

[0059]

[0060] According to the law of electromagnetic induction, the magnitude of the electromagnetic induced electromotive force is directly proportional to the rate of change of the magnetic flux; the formula is expressed as:

[0061]

[0062] Where: E represents electromagnetic induced electromotive force, i.e., back electromotive force;

[0063] dφ represents the change in magnetic flux;

[0064] dt represents the change in time;

[0065] In the operating mechanism of the permanent magnet synchronous generator, the rotor rotates and drives the permanent magnet magnetic field to rotate. This dynamic process causes the magnetic flux in the stator coil to change, which in turn induces an induced electromotive force, namely, back electromotive force, in the stator coil; the formula can be further adjusted to:

[0066] E=KE ·ω·φ

[0067] Where: E represents electromagnetic induced electromotive force, i.e., back electromotive force;

[0068] K E represents the back electromotive force coefficient;

[0069] ω represents the speed of the prime mover;

[0070] Φ represents magnetic flux;

[0071] Under the condition of constant magnetic circuit structure, the rate of change of magnetic flux is proportional to the motor speed. Therefore, the magnitude of back electromotive force also increases with the increase of motor speed. At the same time, the magnetic flux itself is deeply affected by the magnetic properties of permanent magnets and the magnetic circuit structure of the motor, which further determines the characteristics of back electromotive force.

[0072] The weak magnetic control technology shown in the figure adjusts the direct-axis current to achieve effective regulation of the motor magnetic flux, thereby flexibly controlling the motor speed; especially when the permanent magnet synchronous motor runs at a speed exceeding the rated speed, in order to maintain voltage balance and promote continuous acceleration of the motor, the air gap magnetic flux needs to be appropriately reduced, which is usually achieved by increasing the direct-axis demagnetization current component; the formula for the relationship between magnetic flux and direct-axis current is expressed as:

[0073] φ d =L d ·i d

[0074] Where: φ d is the direct-axis magnetic flux;

[0075] L d is the direct-axis inductance;

[0076] i d is the direct axis current;

[0077] However, the inherent nonlinear characteristics of the motor, such as saturation effect and hysteresis, may cause the relationship between the direct-axis current and the magnetic flux to deviate from the ideal linear model. In particular, when the direct-axis current is large, the magnetic circuit saturation will significantly change the inductance value, further complicating the mathematical relationship between the two. In order to capture the dynamic relationship between the direct-axis current and the magnetic flux, experimental measurements are usually required. Experimental measurements can provide the magnetic flux data of the motor at different direct-axis current levels, and mathematical relationships can be constructed through data fitting. Although the experimental data-driven method provides the possibility of establishing the relationship between the direct-axis current and the maximum regulated speed, the direct use of the lookup table method has limitations. In contrast, the fuzzy control method shows stronger adaptability, flexibility, and simplified implementation and debugging:

[0078] More adaptable: Fuzzy control can cope with the uncertainty and complexity of the system. Its design is not limited to fixed table data, so it can adapt to changing operating environments and conditions.

[0079] Higher flexibility: Fuzzy control strategies are easy to modify and adjust according to actual needs, and can quickly adapt to different operating scenarios. However, table lookup rules are limited by preset data, difficult to adjust, and have poor real-time responsiveness.

[0080] Simplified implementation and debugging: The design of fuzzy controllers can rely on expert experience and trial and error, and the construction process is relatively intuitive and easy to debug. In contrast, the table lookup method may require a large amount of offline test data to build the lookup table, and the implementation and debugging steps are more cumbersome.

[0081] In summary, when dealing with complex, variable and highly uncertain motor control systems, the fuzzy control method, with its significant advantages, becomes an ideal choice for connecting the prime mover input speed with the weak magnetic control strategy;

[0082] In order to conduct reasonable experiments and obtain sufficient experimental data, we must first build a test system that can control the direct-axis current and the open-loop input speed of the prime mover. The system block diagram is as follows: Figure 1 As shown in the figure, the system first receives the difference between the output voltage and the preset voltage as the input signal, and performs precise calculation through the PI control algorithm to determine the required quadrature-axis current value; after obtaining the quadrature-axis current, the model will also decouple it from the preset direct-axis current, and obtain the voltage components and in the coordinate system through coordinate transformation; finally, the SVPWM module outputs the PWM pulse wave for controlling the IGBT through the voltage components and;

[0083] Using the constructed test model, we can systematically explore the influence of direct-axis current on voltage stability and maximum input speed under different load conditions; during the test, by adjusting the direct-axis current setting value of the input module, the maximum input speed when the voltage remains stable is observed and recorded under various load scenarios, while closely monitoring the real-time changes of the quadrature-axis current; the collection of these experimental data not only provides a reliable basis for evaluating the effect of weak magnetic control, but also lays a solid foundation for the subsequent construction of a permanent magnet motor weak magnetic voltage stabilization model for direct-axis current regulation by input speed under fuzzy control; based on these detailed data, the input variables and output variables of the fuzzy controller can be defined more accurately, and the fuzzy rules and membership functions can be optimized, thereby improving the accuracy and robustness of the control model; as shown in Tables 2 and 3 below, the relationship between the direct-axis current and the maximum voltage stabilization speed is shown for the minimum load and maximum load, respectively.

[0084] Table 2 shows the relationship between the direct-axis current and the maximum voltage-stabilized speed when p=17.8W

[0085]

[0086]

[0087] Table 3 shows the relationship between the direct-axis current and the maximum voltage-stabilized speed when p=40kw

[0088] id Speed iq im 0 4200 -10.78 10.78 -10 4300 -28.82 30.50 -20 4500 -31.62 37.41 -30 4700 -44.61 53.75 -40 5000 -40.48 56.90 -50 5300 -18.94 53.46 -60 5500 -23.82 64.55 -70 5800 -22.95 73.66 -80 6100 -16.58 81.70 -90 6400 -17.33 91.65 -100 6600 -21.27 102.23 -110 7000 -9.264 110.38 -120 7300 -13.12 120.71 -130 7700 -9.874 130.37 -140 8000 -11.54 140.47 -150 8500 -39.3 155.06

[0089] The application of fuzzy control theory in the weak magnetic field control of permanent magnet synchronous generator is studied. Based on the experimental data obtained from the open-loop experiment, the fuzzy logic principle is deeply explored to design an efficient fuzzy controller. The controller clearly sets the input speed as the input variable and the direct-axis current value as the output variable, and accordingly constructs a set of detailed fuzzy rule sets, which can accurately capture and reflect the possible complex nonlinear relationship between the direct-axis current and the maximum voltage-stabilized speed.

[0090] To ensure the performance of the controller, the key parameters of the fuzzy controller were carefully determined; the design of the membership function is particularly critical, which defines the mapping relationship between the input variables and the output variables in the fuzzy space, which directly affects the response characteristics and control accuracy of the controller; through the careful construction of the membership function, the accurate mapping of the input speed to the fuzzy set is achieved, and the membership of the fuzzy set is reasonably allocated; the formulation of fuzzy rules is another core link in the controller design; based on experimental data, combined with professional knowledge and experience, a complete set of fuzzy rules is constructed; these rules describe in detail the adjustment strategy of the direct-axis current value under different input speeds to achieve the desired control effect; after repeated verification and optimization, the effectiveness and accuracy of the fuzzy rules are ensured; the fuzzy controller based on the fuzzy logic principle, through precise parameter setting and rule construction, realizes the accurate reflection of the complex relationship between the direct-axis current and the maximum voltage regulation speed.

[0091] In order to verify the practical application effectiveness of the fuzzy controller, it is integrated into the control system of the permanent magnet synchronous generator, and a permanent magnet generator weak magnetic voltage stabilization model with input speed control of direct axis current under fuzzy control is constructed. The system block diagram is shown in Figure 2 As shown in the figure, a series of real-time control experiments are carried out to comprehensively evaluate the comprehensive performance of the fuzzy controller under different input speed conditions to ensure that it can meet various operating requirements. Increasing input speed scenarios are added to the experiment to comprehensively evaluate the adaptability and robustness of the weak magnetic voltage regulation model based on input speed control of direct-axis current. The real-time data of output voltage is recorded, and in-depth analysis and comparison are carried out to accurately evaluate the control effect of the model and its improvement on system stability and response speed. Figure 3 The test results shown clearly reveal that the weak-field voltage stabilization system based on input speed control of direct-axis current exhibits excellent voltage stability over a wide speed range and the output results are excellent.

[0092] The experiment is designed to improve the adaptability of permanent magnet synchronous generators under complex and sudden working conditions, deeply evaluate the performance of permanent magnet synchronous generators under extreme working conditions, and simulate actual operating conditions with the help of MATLAB test software; the specific design of the experiment is as follows:

[0093] First, the initial operating state is set, and then a sudden change in input speed is introduced at the 1-second node of the simulation time, that is, the speed is rapidly increased from 5000 rpm to 8000 rpm; this setting is intended to simulate the dynamic response of the generator under high speed and rapid speed change conditions to test its stability and control performance; through simulation experiments, the performance of the permanent magnet synchronous generator under extreme working conditions will be comprehensively evaluated, and specific indicators include the stability of output voltage and power, dynamic response speed, and the overall robustness of the system.

[0094] like Figure 4 The test results shown in the figure show that the weak magnetic voltage stabilization system based on the input speed to control the direct-axis current has a relatively small fluctuation amplitude of the output voltage when facing a sudden change in speed, and its maximum voltage difference is only 5.1V, which fully proves that the model has good robustness and adaptability; based on the detailed analysis of the experimental results, the following conclusions can be clearly drawn: the weak magnetic voltage stabilization system based on the input speed to control the direct-axis current has shown good robustness in dealing with sudden changes in speed; specifically, in the simulation experiment, when the input speed is rapidly increased from 5000 rpm to 8000 rpm, the model can still maintain a high degree of stability in the output voltage and power, and has a rapid dynamic response, without obvious fluctuations or instability;

[0095] Next, an adjustable resistive load device is provided; the essential characteristic of a resistive load, i.e., a resistor, is that a fixed ratio relationship is maintained between voltage and current; therefore, the design goal is to create a device that can dynamically reflect and maintain this fixed ratio to replace the traditional fixed resistor, thereby achieving the adjustability of the resistance value;

[0096] like Figure 5 The block diagram shown can be clearly understood that the system includes two terminals for receiving an externally applied voltage; this voltage value is accurately collected by a voltmeter and then divided by a preset target resistance value to determine the required current value; finally, a corresponding current is output through an adjustable current source to ensure that a specific ratio relationship between voltage and current is achieved, thereby effectively simulating or replacing the function of a traditional fixed resistor;

[0097] The figure shows a complex working condition of simulating sudden changes in input speed and load. First, the initial operating state is set, and then a sudden change in input speed is introduced at the 1-second node of the simulation time, that is, the speed is rapidly increased from 5000 rpm to 8000 rpm, and a sudden change in load is introduced at the 1.5-second node, that is, the load is rapidly increased from 20kw to 40kw. This setting is intended to simulate the dynamic response of the generator under the conditions of rapid changes in speed and load, so as to verify its stability and control performance.

[0098] people Figure 6 The test results shown in the figure show that the weak magnetic voltage regulation model based on input speed to control the direct axis current has a relatively small fluctuation range of output voltage when facing a sudden change in speed, and its maximum voltage difference is only 5.1V. When facing a sudden change in load, the maximum voltage difference is only 8.3V, which fully proves that the model has good robustness and adaptability.

[0099] After detailed experimental data analysis, the weak magnetic field voltage stabilization system based on input speed to control the direct-axis current showed the expected robust performance when dealing with rapid changes in speed and load; under the simulated test conditions, the input speed was rapidly increased from 5000 rpm to 8000 rpm, and the load was rapidly increased from 20kW to 40kW. The system successfully maintained a high degree of stability in output voltage and power, and had a rapid dynamic response, with no obvious fluctuations or instability observed; this experimental result fully verified the adaptability and stability of the model under extreme working conditions, indicating that it can effectively cope with complex and changeable situations in actual operation; in addition, the robustness shown by the model provides a solid theoretical basis and practical verification for its practical application in permanent magnet synchronous generator control systems, further enhancing its potential application prospects in the fields of electric transmission and energy conversion.

[0100] The control system of the permanent magnet generator weak magnetic field stabilization strategy with input speed to control direct-axis current under fuzzy control shown in the figure is specially designed for different types of permanent magnet synchronous generators to ensure efficient and stable control under various working conditions. Through a large amount of experimental data, the relationship between direct-axis current and maximum voltage stabilization speed is deeply explored and established, providing a solid foundation for the design of the fuzzy controller. At the same time, fuzzy control theory is introduced to construct a fuzzy controller. The controller can receive the real-time input speed signal of the prime mover and intelligently output the direct-axis current control instruction according to the preset fuzzy rule set. The design of the fuzzy controller fully considers the complex nonlinear relationship between the direct-axis current and the maximum voltage stabilization speed to ensure precise weak magnetic field control of the permanent magnet synchronous generator over a wide speed range.

[0101] The data processing of the control system of the permanent magnet generator weak magnetic field stabilization strategy with input speed to control the direct-axis current under fuzzy control shown is to input different direct-axis current values ​​under different load conditions, and record the corresponding key parameters such as stabilization speed, quadrature-axis current, current amplitude, etc., to form a comprehensive experimental data set, and conduct in-depth analysis of the experimental data to extract the core relationship between the direct-axis current and the maximum stabilization speed, providing strong data support for the design of the subsequent fuzzy controller.

[0102] The structure of the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under fuzzy control is as follows:

[0103] 1) Input interface: used to receive and process the input speed signal of the prime mover in real time to ensure the accuracy and real-time nature of the data;

[0104] 2) Fuzzy processing unit: converts the received input speed signal into a fuzzy set to provide the necessary input for fuzzy reasoning;

[0105] 3) Fuzzy rule base: stores fuzzy rule sets built based on experimental data. The rule sets define the adjustment strategy of direct-axis current under different input speeds to ensure the accuracy and efficiency of control;

[0106] 4) Fuzzy reasoning engine: Based on the rules in the fuzzy rule base and the fuzzy processed input signal, it performs intelligent reasoning and outputs the corresponding direct-axis current control instructions;

[0107] 5) Output interface: Output the inferred direct-axis current control command to the direct-axis current control module to achieve precise control of the PMSG.

[0108] Furthermore, the construction steps of the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control are as follows:

[0109] 1) Experimental measurement: Under different load conditions, the maximum voltage-stabilized speed corresponding to different direct-axis current setting values ​​is measured through simulation models or actual experiments to obtain key data;

[0110] 2) Data analysis: Conduct in-depth analysis of the experimental data, construct a data table between the direct-axis current and the maximum voltage-stabilized speed, and reveal their internal relationship;

[0111] 3) Rule conversion: Using professional knowledge and experience, the data table is converted into fuzzy rules and membership functions in the fuzzy rule set, providing a reliable basis for the design of the fuzzy controller.

[0112] The control system setting modules of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under fuzzy control shown include:

[0113] 1) Voltage monitoring module: monitors the output voltage of PMSG in real time to ensure voltage stability and safety;

[0114] 2) Fuzzy control module: By receiving the input speed signal of the prime mover, it intelligently outputs the direct-axis current control command to achieve precise control of the PMSG;

[0115] 3) Feedback control unit: dynamically adjusts the quadrature axis current according to the difference between the monitored output voltage and the preset voltage to help maintain voltage stability;

[0116] 4) AC and DC axis current closed loop link: Build a closed loop control system for AC and DC axis current to ensure that the system can maintain a stable state under various working conditions;

[0117] 5) Current decoupling module: decouples the current signal into quadrature-axis and direct-axis voltages, facilitating subsequent coordinate transformation and PWM control;

[0118] 6) Coordinate transformation module: converts the control instructions of the AC and DC axis current into voltage components in the motor coordinate system, providing necessary input for PWM control;

[0119] 7) Pulse Width Modulation Module: Generates PWM pulse waves to control IGBT according to the voltage components, achieving precise and efficient control of PMSG.

[0120] The specific steps of the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under fuzzy control are as follows:

[0121] Step 1: Start and initialize: Start the PMSG and set the initial operating status to ensure that the system is in normal working condition;

[0122] Step 2: Data collection and processing: real-time collection and input of the speed signal of the prime mover into the fuzzy controller to ensure the accuracy and real-time nature of the data;

[0123] Step 3: fuzzy control: the fuzzy controller receives and processes the input speed signal, and outputs a direct-axis current control instruction according to a preset fuzzy rule set;

[0124] Step 4: Direct-axis current adjustment: adjust the direct-axis current according to the output instruction of the fuzzy controller to achieve precise control of the PMSG;

[0125] Step 5: Voltage monitoring and feedback: monitor the output voltage in real time and adjust the quadrature-axis current as needed to maintain voltage stability; ensure that the system remains stable under various operating conditions through the feedback control unit and the AC and DC axis current closed-loop link.

[0126] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A permanent magnet generator weak magnetic field voltage stabilization strategy that directly controls the direct axis current by input speed, characterized by: The weak magnetic field voltage stabilization strategy of the permanent magnet generator with input speed to control the direct-axis current under fuzzy control solves the problem of unstable voltage and power output of the permanent magnet generator under wide range of speed changes by analyzing the intrinsic connection between the direct-axis current and the maximum voltage stabilization speed, studying the application of fuzzy control theory in the weak magnetic field control of the permanent magnet synchronous generator and improving the adaptability of the permanent magnet synchronous generator under complex mutation conditions to set up a control system; the analysis of the intrinsic connection between the direct-axis current and the maximum voltage stabilization speed is mainly through constructing a mathematical model of the generator, inputting the direct-axis current, collecting and analyzing the changes in the maximum voltage stabilization speed under different direct-axis current components, so as to construct an accurate relationship map to reveal the intrinsic connection between the direct-axis current and the maximum voltage stabilization speed; the study of the application of fuzzy control theory in the weak magnetic field control of the permanent magnet synchronous generator is to embed the designed fuzzy controller into the generator control system, take the prime mover speed as input and the generator direct-axis current as output, evaluate the voltage stabilization performance of the power generation system, and optimize the controller parameters according to the experimental results to improve the intelligence level and the ability to handle nonlinear problems; in terms of improving the adaptability of the permanent magnet synchronous generator under complex mutation conditions, input speed mutation, load change and other working conditions, evaluate the voltage stabilization performance of the generator, and continuously optimize the control model.

2. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by input speed according to claim 1 is characterized by: The control system of the permanent magnet generator weak magnetic field voltage stabilization strategy of inputting speed to control direct axis current under fuzzy control is specially designed for different types of permanent magnet synchronous generators to ensure efficient and stable control under various working conditions. The relationship between direct axis current and maximum voltage stabilization speed is deeply explored and established through a large amount of experimental data, which provides a solid foundation for the design of the fuzzy controller. At the same time, the fuzzy control theory is introduced to construct the fuzzy controller. The controller can receive the real-time input speed signal of the prime mover and intelligently output the direct-axis current control instruction according to the preset fuzzy rule set; The design of the fuzzy controller fully considers the complex nonlinear relationship between the direct-axis current and the maximum regulated speed, ensuring accurate flux weakening control of the permanent magnet synchronous generator over a wide speed range.

3. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by input speed according to claim 1 is characterized by: The data processing of the control system of the permanent magnet generator weak magnetic field stabilization strategy with input speed to control the direct-axis current under fuzzy control is to input different direct-axis current values ​​under different load conditions, and record the corresponding key parameters such as stabilization speed, quadrature-axis current, current amplitude, etc., to form a comprehensive experimental data set, and conduct in-depth analysis of the experimental data to extract the core relationship between the direct-axis current and the maximum stabilization speed, thereby providing strong data support for the design and optimization of the subsequent fuzzy controller.

4. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by input speed according to claim 1 is characterized by: The structure of the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control is specifically as follows: 1) Input interface: used to receive and process the input speed signal of the prime mover in real time to ensure the accuracy and real-time nature of the data; 2) Fuzzy processing unit: converts the received input speed signal into a fuzzy set to provide the necessary input for fuzzy reasoning; 3) Fuzzy rule base: stores fuzzy rule sets built based on experimental data. The rule sets define the adjustment strategy of direct-axis current under different input speeds to ensure the accuracy and efficiency of control; 4) Fuzzy reasoning engine: Based on the rules in the fuzzy rule base and the fuzzy processed input signal, it performs intelligent reasoning and outputs the corresponding direct-axis current control instructions; 5) Output interface: The inferred direct-axis current control instruction is output to the direct-axis current control module to achieve precise control of the permanent magnet synchronous generator.

5. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by input speed according to claim 1 is characterized by: The construction steps of the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control are specifically as follows: 1) Experimental measurement: Under different load conditions, the maximum voltage-stabilized speed corresponding to different direct-axis current setting values ​​is measured through simulation models or actual experiments to obtain key data; 2) Data analysis: Conduct in-depth analysis of the experimental data, construct a data table between the direct-axis current and the maximum voltage-stabilized speed, and reveal their internal relationship; 3) Rule conversion: Using professional knowledge and experience, the data table is converted into fuzzy rules and membership functions in the fuzzy rule set, providing a reliable basis for the design of the fuzzy controller.

6. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by input speed according to claim 1 is characterized by: The control system setting module of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed regulating direct axis current under the fuzzy control includes: 1) Voltage monitoring module: monitors the output voltage of PMSG in real time to ensure voltage stability and safety; 2) Fuzzy control module: By receiving the input speed signal of the prime mover, it intelligently outputs the direct-axis current control command to achieve precise control of the PMSG; 3) Feedback control unit: dynamically adjusts the quadrature axis current according to the difference between the monitored output voltage and the preset voltage to help maintain voltage stability; 4) AC and DC axis current closed loop link: Build a closed loop control system for AC and DC axis current to ensure that the system can maintain a stable state under various working conditions; 5) Current decoupling module: decouples the current signal into quadrature-axis and direct-axis voltages, facilitating subsequent coordinate transformation and PWM control; 6) Coordinate transformation module: converts the control instructions of the AC and DC axis current into voltage components in the motor coordinate system, providing necessary input for PWM control; 7) Pulse Width Modulation Module: Generates PWM pulse waves to control IGBT according to the voltage components, achieving precise and efficient control of PMSG.

7. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by input speed according to claim 1 is characterized by: The specific steps of the method for using the control system of the permanent magnet generator weak magnetic field voltage stabilization strategy with input speed to control direct axis current under fuzzy control are as follows: Step 1: Start and initialize: Start the PMSG and set the initial operating status to ensure that the system is in normal working condition; Step 2: Data collection and processing: real-time collection and input of the speed signal of the prime mover into the fuzzy controller to ensure the accuracy and real-time nature of the data; Step 3: fuzzy control: the fuzzy controller receives and processes the input speed signal, and outputs a direct-axis current control instruction according to a preset fuzzy rule set; Step 4: Direct axis current adjustment; Adjust the direct-axis current according to the output command of the fuzzy controller to achieve precise control of the PMSG; Step 5: Voltage monitoring and feedback: monitor the output voltage in real time and adjust the quadrature-axis current as needed to maintain voltage stability; ensure that the system remains stable under various operating conditions through the feedback control unit and the AC and DC axis current closed-loop link.

8. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by the input speed according to claim 2 is characterized by: The electromagnetic induction law in the construction of the fuzzy rule system in the permanent magnet generator weak magnetic field voltage stabilization strategy of input speed control of direct axis current under fuzzy control is reflected in the operation of the permanent magnet synchronous generator as follows: the rotor rotation drives the magnetic flux change, generating a back electromotive force directly proportional to the speed, that is, the output voltage; the formula can be expressed as: E=K E ·oh·f Where: E represents electromagnetic induced electromotive force, i.e., back electromotive force; K E represents the back electromotive force coefficient; ω represents the speed of the prime mover; Φ represents magnetic flux.

9. The permanent magnet generator weak magnetic field voltage stabilization strategy of directly controlling the direct axis current by the input speed according to claim 4 is characterized by: The weak magnetic control strategy in the weak magnetic voltage stabilization strategy of the permanent magnet generator with input speed to control the direct axis current under the fuzzy control is optimized to select the weak magnetic control technology set by the limiting bandwidth to dynamically manage the magnetic flux by regulating the direct axis current, thereby controlling the output voltage within a wide speed range; the relationship between the magnetic flux and the direct axis current can be expressed as: f d =L d ·i d Where: φ d is the direct-axis magnetic flux; L d is the direct-axis inductance; i d is the direct axis current.

Images