Five-phase induction motor speed sensorless vector control method, system and terminal

Abstract

The present invention belongs to the field of motor control technology, and discloses a five-phase induction motor speed sensorless vector control method, system and terminal. In the process of digitizing the full-order flux observer algorithm, the bilinear method is used to discretize the state equation of the five-phase induction motor; combining the full-order flux observer and vector control technology, a five-phase induction motor speed sensorless vector control speed regulation system is established. In view of the current domestic technical gap in the speed sensorless vector control of five-phase induction motors, the present invention establishes a five-phase induction motor speed sensorless vector control system based on the full-order flux observer and vector control technology. Experimental results show that the system has good speed regulation performance and speed identification capabilities. In addition, in order to solve the problem that the traditional Euler discretization method will produce a large discrete error, the present invention adopts a more accurate bilinear method to discretize the state equation of the five-phase induction motor, which is suitable for application scenarios with high requirements for speed regulation performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor control, and in particular relates to a speed sensorless vector control method, system and terminal for a five-phase induction motor. Background Art

[0002] Induction motors, due to their low maintenance costs, excellent dynamic response, superior speed-torque characteristics, and high efficiency, are widely used in wind power generation, train traction, automotive industry, and ship propulsion. With the advancement of power electronics technology, power systems have become more flexible than the number of phases in the power supply. This increase in the number of phases also offers numerous benefits for motor drive systems. Compared to traditional three-phase motors, five-phase motors offer lower phase voltage, reduced torque ripple, and higher reliability at the same power output. Currently, five-phase motors are poised to gradually replace traditional three-phase motors.

[0003] Closed-loop speed control is essential in motor control. Speed ​​measurement is generally categorized as either sensored or sensorless. For sensored control, an absolute or incremental encoder is typically connected coaxially to the motor for speed measurement. Because the sampling period of a digital signal processor is typically very short, the speed encoder may produce a non-integer number of pulses within the sampling period. In this case, the calculated speed will deviate from the actual speed, affecting overall system stability. Furthermore, in some harsh operating conditions, installing a speed sensor on the rotating shaft is unsuitable. To address these issues, sensorless control has become a key topic in the AC drive field.

[0004] Currently, speed sensorless control methods can be divided into three main categories: state observation methods based on motor models, high-frequency injection methods, and methods integrated with artificial intelligence theory. High-frequency injection methods require changes to the motor structure, making the process more complex. Methods integrated with artificial intelligence theory have matured in theory, but their application is still in its early stages. State observation methods based on motor models do not require additional hardware circuitry or changes to the motor structure. Based on mature motor modeling theory, they have become the mainstream research method.

[0005] Among the state observation methods based on motor models, the main ones include extended Kalman filters, model reference adaptive systems, and full-order flux observers. Compared with the full-order flux observer, the extended Kalman filter algorithm requires higher computing power from the digital controller due to the large number of matrix operations involved. Compared with the traditional MRAS, the model reference speed identification system based on the full-order flux observer has more advantages because the former uses a voltage-based flux observer as the reference model. This flux observer has pure integral initial value and drift problems, and is heavily dependent on the accurate identification of stator resistance at low speeds. Therefore, the system formed by using the output of this observer as the reference flux is unreliable. The full-order flux observer uses the induction motor itself as the reference model, providing an accurate reference value.

[0006] When digitizing full-order flux observer algorithms, the forward Euler method is often used to discretize the state equations of five-phase induction motors. This method is computationally efficient but suffers from unstable ranges. The construction of a sensorless speed control system for a five-phase induction motor is complex, and research in this area remains limited in China.

[0007] Through the above analysis, the problems and defects of the existing technology are as follows:

[0008] (1) For speed sensor-based control, if an absolute encoder or incremental encoder is coaxially connected to the motor to measure speed, the calculated speed may deviate from the actual speed if not properly installed, affecting the overall stability of the system. Furthermore, speed encoders are significantly affected by environmental factors such as dust, dirt, moisture, vibration, and temperature.

[0009] (2) Among the current speed sensorless control methods, the high-frequency injection method requires changing the motor structure, which is a relatively complicated process, and the application of methods combined with artificial intelligence related theories is still in its initial stage.

[0010] (3) In the traditional model reference adaptive speed identification system, the flux observer has pure integral initial value and drift problems, and is heavily dependent on the accurate identification of the stator resistance at low speeds, which will make the system unreliable. Summary of the Invention

[0011] In response to the problems existing in the prior art, the present invention provides a five-phase induction motor speed sensorless vector control method, system and terminal, and more particularly relates to a five-phase induction motor speed sensorless vector control speed regulation method, system, device and terminal.

[0012] The present invention is implemented as follows: a five-phase induction motor speed sensorless vector control method, the five-phase induction motor speed sensorless vector control method comprising: using a bilinear method to discretize the five-phase induction motor state equation during the digitization process of a full-order flux observer algorithm; combining the full-order flux observer with vector control technology to establish a five-phase induction motor speed sensorless vector control speed regulation system.

[0013] Furthermore, the five-phase induction motor speed sensorless vector control method includes the following steps:

[0014] Step 1: Decouple the five-phase induction motor model using the generalized Clark transform based on the equal power principle to obtain a mathematical model of the five-phase induction motor in a two-phase stationary coordinate system.

[0015] Step 2: Obtain a state equation based on the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system, and discretize the state equation using a bilinear method;

[0016] Step 3: Using the motor body as the reference model and the full-order flux observer as the adjustable model, an adaptive mechanism is constructed to adjust the estimated speed according to the error between the state variables of the two models.

[0017] Step 4: On the control side, an indirect vector control method based on rotor magnetic field orientation is adopted, with the estimated speed as the speed closed-loop control input and the reference voltage as the vector control algorithm input;

[0018] Step 5: Based on the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space, the nearest four-vector SVPWM modulation method is used to suppress the generation of the third harmonic.

[0019] Furthermore, in step 1, the generalized Clark transform based on the equal power principle is selected to decouple the five-phase induction motor model under the natural basis. The generalized Clark transform formula is as follows:

[0020]

[0021] Among them, x αβ is the variable of the fundamental wave space in the two-phase stationary coordinate system, including current, voltage and flux; x αβ3 is the third harmonic spatial variable, x0 is the zero sequence spatial variable, x a～e is a variable under the natural basis.

[0022] The physical quantities of the five-phase induction motor are converted from the five-phase natural coordinate system to the αβ two-phase stationary coordinate system. Since the present invention is mainly targeted at five-phase induction motors with distributed windings, the third harmonic space current of this type of five-phase induction motor does not participate in electromechanical energy conversion and only produces harmonic losses. Therefore, the present invention only considers the fundamental space current to obtain the mathematical model of the five-phase induction motor in the two-phase stationary coordinate system.

[0023]

[0024]

[0025] Among them, R s is the stator resistance, R r is the rotor resistance, L md is the equivalent mutual inductance, L sd is the stator equivalent self-inductance, L rd is the rotor equivalent self-inductance, ω r is the rotor speed, u s is the stator voltage, ψ r is the rotor flux, i s is the stator current, i r is the rotor current, and p represents the differential operator.

[0026] Furthermore, in step 2, based on the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system, the state equation is determined as:

[0027]

[0028] in,

[0029] The state equation is discretized using the bilinear method, then:

[0030]

[0031] Expand using the bilinear method:

[0032]

[0033] Eliminating the coupling terms yields:

[0034]

[0035] in,

[0036] Furthermore, in step 3, the motor body is used as the reference model, and the output state variable is x=[i s ψ r ] T ; The full-order flux observer is used as an adjustable model, and the output state variable is According to the error between the two model state variables, an adaptive mechanism is constructed to adjust the estimated speed. When estimating the speed and the actual speed ω r When approaching, the estimated state variables Gradually converges to the actual value [i s ψ r The stator current error is used to indirectly reflect the error in the rotor flux. When the estimated value of the stator current converges to the actual value, the rotor flux must converge to the actual value, and the estimated speed converges to the actual value. Based on the principle of the model reference adaptive system, the expression for speed identification can be obtained as:

[0037]

[0038] Furthermore, in step 4, the nearest four vector modulation is used as the modulation algorithm of vector control, and the identified speed is used as the input of the speed closed-loop control. After the speed loop, excitation current loop and torque current loop, the reference voltage is obtained. and As input to the vector control algorithm.

[0039] Furthermore, in step 5, for the five-phase H-bridge inverter, define A1 and A4 in the A-phase H-bridge as being turned on as state 1, define A2 and A3 as being turned on as state 0, and use S a The variable represents the switching state of phase A; according to the switching state of the five-phase inverter, the inverter includes 2 5 =32 switching states, then the phase voltage of each phase output by the five-phase inverter is expressed as:

[0040] u x =(2S x -1)U dc ;

[0041] In the case of five-phase symmetrical power supply, after equal amplitude transformation, the fundamental wave synthesis vector U αβ and the third harmonic space synthesis vector U z12 The expression is as follows:

[0042]

[0043] Bring the 32 switching states of the inverter into the fundamental wave synthesis vector U αβ and the third harmonic space synthesis vector U z12 From the expression of , we can obtain the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space.

[0044] The nearest four-vector SVPWM modulation method is used to suppress the generation of third harmonics. By selecting two adjacent large vector voltages and two medium vector voltages to synthesize a reference voltage vector, the synthetic vector in the third harmonic space is made to be 0 through a specific action time ratio.

[0045] Another object of the present invention is to provide a five-phase induction motor speed sensorless vector control system using the five-phase induction motor speed sensorless vector control method. The five-phase induction motor speed sensorless vector control system includes:

[0046] A model decoupling module is used to decouple the five-phase induction motor model using the generalized Clark transformation based on the equal power principle to obtain the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system;

[0047] An equation discretization module is used to obtain a state equation based on a mathematical model of a five-phase induction motor in a two-phase stationary coordinate system and discretize the state equation using a bilinear method;

[0048] The estimated speed regulation module is used to use the motor body as a reference model and the full-order flux observer as an adjustable model, and construct an adaptive mechanism to adjust the estimated speed according to the error between the state variables of the two models;

[0049] A vector control module is used to use the nearest four vector modulation as a modulation algorithm for vector control, use the estimated speed as a speed closed-loop control input, and use the reference voltage as an input for the vector control algorithm;

[0050] The harmonic suppression module is used to draw the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space, and use the nearest four-vector SVPWM modulation method to suppress the generation of the third harmonic.

[0051] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the five-phase induction motor speed sensorless vector control method.

[0052] Another object of the present invention is to provide an information data processing terminal, which is used to implement the five-phase induction motor speed sensorless vector control system.

[0053] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0054] First, addressing the domestic technological gap in sensorless vector control for five-phase induction motors, this invention establishes a sensorless vector control system for five-phase induction motors based on a full-order flux observer and vector control technology, demonstrating strong theoretical and practical value. Furthermore, addressing the significant discretization error inherent in the traditional Euler discretization method, this invention employs a more precise bilinear method to discretize the state equations of the five-phase induction motor, making it suitable for applications requiring high speed regulation performance.

[0055] Second, to achieve better speed regulation performance, the present invention uses a bilinear method to discretize the state equation. Combining a full-order flux observer with vector control technology, the present invention establishes a speed sensorless vector control system for a five-phase induction motor. Experimental results demonstrate that the system exhibits excellent speed regulation performance and speed identification capabilities.

[0056] The present invention also has the following advantages: 1. It eliminates the signal conversion circuitry required for the speed sensor, reducing hardware complexity and costs. 2. It improves the reliability of the speed control system, reduces maintenance requirements, and avoids problems such as speed sensor failure, wear, noise interference, and environmental impact.

[0057] Third, as auxiliary evidence for the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0058] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0059] By eliminating the need for a speed sensor, the present invention can reduce the cost, size, and complexity of a motor drive system and improve its reliability and robustness.

[0060] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad:

[0061] The present invention provides a practical solution for realizing speed sensorless vector control of a five-phase induction motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0063] Figure 1 This is a flow chart of a speed sensorless vector control method for a five-phase induction motor provided by an embodiment of the present invention;

[0064] Figure 2This is a block diagram of a five-phase induction motor speed sensorless vector control system provided by an embodiment of the present invention;

[0065] Figure 3 is a flow chart of a full-order flux observer algorithm provided by an embodiment of the present invention;

[0066] Figure 4 Schematic diagram of a five-phase H-bridge inverter circuit provided by an embodiment of the present invention;

[0067] Figure 5A This is a fundamental wave spatial voltage vector diagram provided by an embodiment of the present invention;

[0068] Figure 5B This is a third harmonic space voltage vector diagram provided by an embodiment of the present invention;

[0069] Figure 6A This is an available vector diagram of the fundamental spatial voltage provided by an embodiment of the present invention;

[0070] Figure 6B This is an available vector diagram of the third harmonic space voltage provided by an embodiment of the present invention;

[0071] Figure 7A This is a fundamental wave spatial synthesis vector diagram provided by an embodiment of the present invention;

[0072] Figure 7B This is a third harmonic spatial synthesis vector diagram provided by an embodiment of the present invention;

[0073] Figure 8 This is a waveform diagram of a no-load experiment provided by an embodiment of the present invention;

[0074] Figure 9 2 is a schematic diagram of the speed regulation performance test results provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0076] In view of the problems existing in the prior art, the present invention provides a five-phase induction motor speed sensorless vector control method, system and terminal. The present invention is described in detail below with reference to the accompanying drawings.

[0077] like Figure 1 As shown, the five-phase induction motor speed sensorless vector control method provided by the embodiment of the present invention includes the following steps:

[0078] S101, decoupling the five-phase induction motor model using the generalized Clark transform based on the equal power principle to obtain a mathematical model of the five-phase induction motor in a two-phase stationary coordinate system;

[0079] S102, obtaining a state equation based on a mathematical model of the five-phase induction motor in a two-phase stationary coordinate system, and discretizing the state equation using a bilinear method;

[0080] S103, using the motor body as a reference model and the full-order flux observer as an adjustable model, constructing an adaptive mechanism to adjust the estimated speed according to the error between the state variables of the two models;

[0081] S104, using the nearest four vector modulation as the modulation algorithm of the vector control, using the estimated speed as the speed closed-loop control input, and using the reference voltage as the vector control algorithm input;

[0082] S105 , drawing a synthetic vector diagram of the fundamental wave space and a synthetic vector diagram of the third harmonic space, and using a nearest four-vector SVPWM modulation method to suppress the generation of the third harmonic.

[0083] As a preferred embodiment, Figure 2 As shown, the five-phase induction motor speed sensorless vector control method provided by the embodiment of the present invention specifically includes the following steps:

[0084] The five-phase induction motor model in the natural basis is a high-order, nonlinear, strongly coupled multivariable system. It is very difficult to control it in the natural coordinate system. Generally, the generalized Clark transformation based on the equal power principle is used to decouple it. The transformation formula is as follows:

[0085]

[0086] Among them, x αβ is the variable of the fundamental wave space in the two-phase stationary coordinate system (such as current, voltage, flux, etc.); x αβ3 is the third harmonic spatial variable; x0 is the zero sequence spatial variable; x a～e is a variable under the natural basis.

[0087] According to the above transformation formula, the physical quantities of the five-phase induction motor are converted from the five-phase natural coordinate system to the αβ two-phase stationary coordinate system, thereby obtaining the mathematical model of the five-phase induction motor in the two-phase stationary coordinate system. Here, only the fundamental wave space is considered:

[0088]

[0089]

[0090] Among them, R s is the stator resistance; Rr is the rotor resistance; L md is the equivalent mutual inductance; L sd is the stator equivalent self-inductance; L rd is the rotor equivalent self-inductance; ω r is the rotor speed; u s is the stator voltage; r is the rotor flux; i s is the stator current; i r is the rotor current; p represents the differential operator.

[0091] According to the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system, its state equation can be written as:

[0092]

[0093] in,

[0094] The state equation is discretized using the bilinear method:

[0095]

[0096] Expand equation (4) using the bilinear method:

[0097]

[0098] Eliminating the coupling term yields:

[0099]

[0100] in,

[0101] Taking the motor body as the reference model, the output state variable is x=[i s ψ r ] T , the full-order flux observer is used as an adjustable model, and the output state variable is According to the error between the two model state variables, an adaptive mechanism is constructed to adjust the estimated speed. When estimating the speed and the actual speed ω r When approaching, the estimated state variables It gradually converges to the actual value [i s ψ rIn actual systems, since the rotor flux cannot be observed intuitively, it is impossible to directly determine whether the estimated value converges to the actual value. However, the transfer function from the stator current to the rotor flux is a first-order inertia link, so the stator current error can indirectly reflect the error in the rotor flux. Therefore, when the estimated value of the stator current converges to the actual value, the rotor flux must also converge to the actual value, and at this time the estimated speed also converges to the actual value. According to the principle of model reference adaptive system, the expression for speed identification is:

[0102]

[0103] The flow chart of the full-order flux observer algorithm provided by the embodiment of the present invention is as follows: Figure 3 shown.

[0104] The identified speed is used as the input of the speed closed-loop control, and the reference voltage is obtained after passing through the speed loop, excitation current loop and torque current loop. and As the input of the vector control algorithm. In order to make the output current closer to the ideal sine wave, the present invention adopts the nearest four vector modulation as the modulation algorithm of the vector control.

[0105] For Figure 4 The five-phase H-bridge inverter shown in the figure defines that A1 and A4 in the A-phase H-bridge are turned on as state "1", and A2 and A3 are turned on as state "0", and S a The variable represents the switching state of phase A, and the same applies to the other four phases. Therefore, according to the switching state of the five-phase inverter, the inverter has 2 5 =32 switching states. The phase voltages of the five-phase inverter output can be expressed by formula (9):

[0106] u x =(2S x -1)U dc (9)

[0107] In the case of five-phase symmetrical power supply, after equal amplitude transformation, the fundamental wave synthesis vector U αβ and the third harmonic space synthesis vector U z12 The expression is as follows:

[0108]

[0109] By bringing the 32 switching states of the inverter into equation (10), we can obtain the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space, as follows: Figure 5A-5B shown.

[0110] Depend on Figure 5A and Figure 5BAs can be seen, the phase voltage vector output by the five-phase inverter is divided into 10 sectors, with four vector types: large vector, medium vector, small vector, and zero vector. The ratio of the large vector, medium vector, and small vector amplitude is 1.618:1:0.618. For the fundamental wave space, the large vector is the 2 / 3 working mode of the five-phase inverter. That is, at a certain moment, the switches 1 and 4 of three adjacent phases of the five H-bridges are turned on, and the switches 2 and 3 are turned off. The switches 1 and 4 of the other two H-bridges are turned off, and the switches 2 and 3 are turned on, or vice versa. The medium vector is the 1 / 4 working mode of the inverter. Similar to the 2 / 3 working mode, the switches 1 and 4 of the four adjacent phases of the H-bridges are turned on, and the switches 2 and 3 are turned off. Only the switches 1 and 4 of one phase of the H-bridge are turned off, and the switches 2 and 3 are turned on, or vice versa. The small vector is the pseudo 2 / 3 working mode of the inverter. Unlike the 2 / 3 working mode, the three phases with switches 1 and 4 turned on are not all adjacent. This will lead to inconsistent directions of the voltage synthesis vector or mutual cancellation of the motor stator flux, which will adversely affect the motor operation. Therefore, the use of small vector synthesis SVPWM should be avoided. For the third harmonic space, its large vector corresponds to the pseudo 2 / 3 working mode of the inverter, the medium vector corresponds to the 1 / 4 working mode of the inverter, and the small vector corresponds to the 2 / 3 working mode of the inverter. Therefore, when the small vector is not used to synthesize the vector in the fundamental space, the large vector is not used for vector synthesis in the third harmonic space. Based on this, the voltage vectors available in the fundamental space and the third harmonic space are as follows: Figures 6A and 6B shown.

[0111] In order to suppress the generation of third harmonics, the nearest four-vector SVPWM (NFV-SVPWM) modulation method is used. The reference voltage vector is synthesized by selecting two adjacent large vector voltages and two medium vector voltages. The synthetic vector in the third harmonic space is made zero through a specific action time ratio, as shown in the following example: Figures 7A and 7B shown.

[0112] like Figures 7A and 7B As shown in FIG, by setting the action time ratio of the large vector to the medium vector in the fundamental wave space to 1.618, the synthetic vector in the third harmonic space can be made 0, thereby reducing the third harmonic.

[0113] The five-phase induction motor speed sensorless vector control system provided by the embodiment of the present invention includes:

[0114] A model decoupling module is used to decouple the five-phase induction motor model using the generalized Clark transformation based on the equal power principle to obtain the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system;

[0115] An equation discretization module is used to obtain a state equation based on a mathematical model of a five-phase induction motor in a two-phase stationary coordinate system and discretize the state equation using a bilinear method;

[0116] The estimated speed regulation module is used to use the motor body as a reference model and the full-order flux observer as an adjustable model, and construct an adaptive mechanism to adjust the estimated speed according to the error between the state variables of the two models;

[0117] Field-oriented control module, for indirect vector control using rotor field orientation, using the estimated speed as the speed closed-loop control input and the reference voltage as the vector control algorithm input;

[0118] The vector control module is used to draw the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space, and use the nearest four-vector SVPWM modulation method to suppress the generation of the third harmonic.

[0119] The present invention has been experimentally verified on a five-phase induction motor with a rated power of 5.5Kw.

[0120] Figure 2 This is a system principle block diagram of the present invention.

[0121] Figure 3 This is the principle block diagram of speed adaptive identification based on full-order flux observer.

[0122] Figure 4 This is the schematic diagram of the inverter circuit.

[0123] Figure 5A 、 5B They are respectively the fundamental wave space voltage vector diagram and the third harmonic space voltage vector diagram.

[0124] Figure 6A 、 6B They are respectively the fundamental wave space available voltage vector diagram and the third harmonic space available voltage vector diagram.

[0125] Figure 7A 、 7B This is a schematic diagram of the fundamental wave space vector synthesis and the third harmonic space voltage vector synthesis in the first sector.

[0126] The embodiment of the present invention sets the speed to 400r / min and the flux amplitude to 0.8Wb, and starts the system at no-load on the physical platform to detect the overall recognition effect of the stator current, rotor flux and rotor speed. The experimental results show that the speed sensorless control system built based on the present invention can accurately identify the stator current, rotor flux and rotor speed. The no-load test waveform is as follows Figure 8 shown.

[0127] The embodiment of the present invention tests the speed regulation performance of the entire system. The speed is first set to 400r / min, then increased to 600r / min, and then reduced back to 400r / min. The experimental results show that the system can still maintain accurate speed identification when the motor is accelerating and decelerating. The experimental results are as follows: Figure 9 shown.

[0128] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art will appreciate that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, or can be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0129] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A five-phase induction motor speed sensorless vector control method, characterized in that: include: In the process of digitizing the full-order flux observer algorithm, the bilinear method is used to discretize the state equation of the five-phase induction motor. Combining full-order flux observer with vector control technology, a five-phase induction motor speed sensorless vector control speed regulation system is established; The five-phase induction motor speed sensorless vector control method comprises the following steps: The state equation is obtained based on the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system, and the state equation is discretized using the bilinear method. According to the mathematical model of the five-phase induction motor in the two-phase stationary coordinate system, the state equation is determined as follows: in, The state equation is discretized using the bilinear method, then: Expand using the bilinear method: Eliminating the coupling terms yields: in, The motor body is used as the reference model and the full-order flux observer is used as the adjustable model. An adaptive mechanism is constructed based on the error between the state variables of the two models to adjust the estimated speed. Taking the motor body as the reference model, the output state variable is x=[i s ψ r ] T ; The full-order flux observer is used as an adjustable model, and the output state variable is According to the error between the two model state variables, an adaptive mechanism is constructed to adjust the estimated speed. When estimating the speed and the actual speed ω r When approaching, the estimated state variables Gradually converges to the actual value [i s ψ r ]; the stator current error is used to indirectly reflect the error of the rotor flux. When the estimated value of the stator current converges to the actual value, the rotor flux must converge to the actual value, and the estimated speed converges to the actual value. According to the principle of model reference adaptive system, the expression of speed identification is:

2. The five-phase induction motor speed sensorless vector control method according to claim 1, characterized in that: The five-phase induction motor speed sensorless vector control method includes the following steps: Step 1: Decouple the five-phase induction motor model using the generalized Clark transform based on the equal power principle to obtain a mathematical model of the five-phase induction motor in a two-phase stationary coordinate system. Step 2: Obtain a state equation based on the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system, and discretize the state equation using a bilinear method; Step 3: Using the motor body as the reference model and the full-order flux observer as the adjustable model, an adaptive mechanism is constructed to adjust the estimated speed according to the error between the state variables of the two models. Step 4: Using an indirect vector control algorithm based on rotor magnetic field orientation, the estimated speed is used as the speed closed-loop control input, and the reference voltage is used as the vector control algorithm input; Step 5: Draw the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space, and use the nearest four-vector SVPWM modulation method to suppress the generation of the third harmonic.

3. The five-phase induction motor speed sensorless vector control method according to claim 2, characterized in that: In step 1, the generalized Clark transform based on the equal power principle is selected to decouple the five-phase induction motor model under the natural basis. The generalized Clark transform formula is as follows: Among them, x αβ is the variable of the fundamental wave space in the two-phase stationary coordinate system, including current, voltage and flux; x αβ3 is the third harmonic spatial variable, x0 is the zero sequence spatial variable, x a～e is a variable under the natural basis; According to the transformation formula, the physical quantities of the five-phase induction motor are converted from the five-phase natural coordinate system to the αβ two-phase stationary coordinate system based on the fundamental wave space, and the mathematical model of the five-phase induction motor in the two-phase stationary coordinate system is obtained; Among them, R s is the stator resistance, R r is the rotor resistance, L md is the equivalent mutual inductance, L sd is the stator equivalent self-inductance, L rd is the rotor equivalent self-inductance, ω r is the rotor speed, u s is the stator voltage, ψ r is the rotor flux, i s is the stator current, i r is the rotor current, and p represents the differential operator.

4. The five-phase induction motor speed sensorless vector control method according to claim 2, wherein: In step 4, the nearest four vector modulation is used as the modulation algorithm of vector control, and the identified speed is used as the input of the speed closed-loop control. After passing through the speed loop, excitation current loop and torque current loop, the reference voltage is obtained. and As input to the vector control algorithm.

5. The five-phase induction motor speed sensorless vector control method according to claim 2, characterized in that: In step 5, for the five-phase H-bridge inverter, define A1 and A4 in the A-phase H-bridge as open as state 1, define A2 and A3 as open as state 0, and use S a The variable represents the switching state of phase A; according to the switching state of the five-phase inverter, the inverter includes 2 5 =32 switching states, then the phase voltage of each phase output by the five-phase inverter is expressed as: you x =(2S x -1)U dc ; In the case of five-phase symmetrical power supply, after equal amplitude transformation, the fundamental wave synthesis vector U αβ and the third harmonic space synthesis vector U z12 The expression is as follows: Bring the 32 switching states of the inverter into the fundamental wave synthesis vector U αβ and the third harmonic space synthesis vector U z12 From the expression of , we can get the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space; The nearest four-vector SVPWM modulation method is used to suppress the generation of third harmonics. By selecting two adjacent large vector voltages and two medium vector voltages to synthesize a reference voltage vector, the synthetic vector in the third harmonic space is made to be 0 through a specific action time ratio.

6. A five-phase induction motor speed sensorless vector control system using the five-phase induction motor speed sensorless vector control method according to any one of claims 1 to 5, characterized in that: The five-phase induction motor speed sensorless vector control system includes: A model decoupling module is used to decouple the five-phase induction motor model using the generalized Clark transformation based on the equal power principle to obtain the mathematical model of the five-phase induction motor in a two-phase stationary coordinate system; An equation discretization module is used to obtain a state equation based on a mathematical model of a five-phase induction motor in a two-phase stationary coordinate system and discretize the state equation using a bilinear method; The estimated speed regulation module is used to use the motor body as a reference model and the full-order flux observer as an adjustable model, and construct an adaptive mechanism to adjust the estimated speed according to the error between the state variables of the two models; A vector control module is used to use the nearest four vector modulation as a modulation algorithm for vector control, use the estimated speed as a speed closed-loop control input, and use the reference voltage as an input for the vector control algorithm; The harmonic suppression module is used to draw the synthetic vector diagram of the fundamental wave space and the synthetic vector diagram of the third harmonic space, and use the nearest four-vector SVPWM modulation method to suppress the generation of the third harmonic.

7. A computer device, characterized in that: The computer device includes a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the processor performs the steps of the five-phase induction motor speed sensorless vector control method according to any one of claims 1 to 5.

8. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the five-phase induction motor speed sensorless vector control system as claimed in claim 6.

Images