Sensorless control method for high-speed low-carrier-ratio permanent magnet synchronous generator

Abstract

The invention discloses a sensorless control method for a high-speed low-carrier-ratio permanent magnet synchronous generator. The method comprises the following steps: firstly, building a double-loop control system of a controlled permanent magnet synchronous generator comprising a current inner loop and a bus voltage outer loop under the condition of high speed and low carrier wave ratio, selecting an MRAS control strategy as a sensorless control strategy, introducing the MRAS control strategy into the double-loop control system, adjusting parameters of the MRAS control strategy, and controlling the current inner loop and the bus voltage outer loop of the controlled permanent magnet synchronous generator; the double-loop control system is enabled to operate stably; and designing parameters of a controller of the LADRC, and replacing all PI control in a double-loop control system with the LADRC to obtain the sensorless control method of the high-speed low-carrier-ratio permanent magnet synchronous generator based on the LADRC and the MRAS. According to the method, constraint conditions such as high rotating speed, low carrier wave ratio and sensorless control are comprehensively considered, the motor control model when the permanent magnet synchronous motor is used as the generator is constructed, parameter design is carried out in combination with PI control, and a more economical and feasible solution is provided.

Description

Technical Field

[0001] The invention relates to a control method of a permanent magnet synchronous generator, in particular to a sensorless control method of a high-speed and low-carrier ratio permanent magnet synchronous generator. Background Art

[0002] Permanent magnet synchronous generator (PMSG) is small in size, highly reliable and has high power density, so it is widely used in civil aviation and aerospace fields such as passenger aircraft and transport aircraft. Since the aircraft power speed is high, exceeding 10,000 rpm, the fundamental frequency reaches 1 kHz, and the switching frequency of IGBT is generally below 10 kHz, PMSG needs to operate under low carrier ratio conditions. Therefore, high speed and low carrier ratio with a speed greater than 10,000 rpm and a carrier ratio less than 10 is an important working condition for the PMSG system. In terms of control methods, PI control is often used in PMSG vector control systems in engineering. This method has a simple structure and is easy to implement, but the traditional PI controller has poor parameter adaptability and is difficult to achieve good anti-interference ability, resulting in a contradiction between system rapidity and overshoot. In response to the above problems, some advanced control algorithms have been applied to PMSG vector control systems, such as sliding mode control, active disturbance rejection control, and neural network control. For active disturbance rejection control, it has the problem of many parameters and difficulty in setting. On this basis, linear active disturbance rejection control (LADRC) based on bandwidth setting is proposed, which simplifies the controller parameter setting and effectively improves the anti-interference performance of the PMSG system. Compared with PI control, LADRC still needs to design three parameters, and will face disadvantages such as large amount of calculation and unclear relationship between parameters.

[0003] In actual applications, aircraft may need to fly under conditions such as heavy rain, drought, and dust, which are relatively harsh working conditions. While installing speed sensors increases the difficulty of wiring, harsh working conditions will also affect the reliability, sensitivity, and life of speed sensors. Therefore, in order to improve system reliability, ensure high power density, and reduce costs, it is considered to apply sensorless control strategies to motors. In principle, the existing sensorless control methods can be divided into direct calculation method, model reference adaptive method, sliding mode observer method, extended Kalman filter method, and artificial intelligence control method. Among them, the model reference adaptive method (MRAS) takes the equation containing the parameters to be estimated as an adjustable model and the equation without unknown parameters as a reference model. The two models have outputs with the same physical meaning. Therefore, it is considered to combine MRAS with other control methods and apply it to high-speed and low-carrier ratio PMSG systems.

[0004] If the existing control method under low-speed conditions is directly applied to high-speed and low-carrier ratio conditions, the PMSG system will become unstable. As the carrier ratio decreases, the digital control delay of the system will become more serious, and the difficulty of the control method to adjust the system stability will be further increased, and the method may even fail. It is urgent to explore control methods that can be applied to high-speed and low-carrier ratio PMSG systems. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator. Since PI control is the most mature method applied to high-speed, low-carrier ratio conditions, the present invention considers establishing a connection between the obtained control method and PI control, and designs the structure and parameters of the obtained control method based on the PI parameters, thereby adjusting the method to a feasible method under high-speed, low-carrier ratio conditions, and also making parameter calculation easier.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] The sensorless control method of the high-speed low-carrier ratio permanent magnet synchronous generator of the present invention comprises the following steps:

[0008] (1) Building a dual-loop control system for a controlled permanent magnet synchronous generator, wherein the controlled permanent magnet synchronous generator operates under high speed and low carrier ratio conditions, wherein the dual-loop control system includes a current inner loop and a bus voltage outer loop, wherein the current inner loop and the bus voltage outer loop adopt PI control, and the PI control parameters are adjusted to enable the dual-loop control system to operate stably;

[0009] (2) selecting the MRAS control strategy as the sensorless control strategy, introducing the MRAS control strategy into the dual-loop control system, and adjusting the PI control parameters of the MRAS control strategy so that the dual-loop control system operates stably;

[0010] (3) Design the parameters of the LADRC controller and use LADRC to replace all PI controls in the dual-loop control system to obtain a sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS.

[0011] In a preferred embodiment of the present invention, the step (1) is specifically:

[0012] 1.1) Build the current inner loop in the dq rotating coordinate system;

[0013] 1.2) Building the bus voltage outer loop, including:

[0014] The DC end of the three-phase rectifier is connected to the load network, and the voltage signal of the DC end of the three-phase rectifier is collected as the actual value U of the bus voltage.dc , set the reference value of bus voltage is a certain value;

[0015] The bus voltage outer loop converts the bus voltage reference value Subtract the actual value of the bus voltage U dc After being adjusted by the PI controller, the output is used as the q-axis reference current D-axis reference current Still remain suspended;

[0016] 1.3) Connect the permanent magnet synchronous generator to an external engine, and drive the generator to generate electricity through the operation of the engine to supply power to the load network;

[0017] 1.4) Adjust the parameters of the PI controller and the carrier ratio of the vector control module so that the dual-loop control system operates stably.

[0018] In a preferred embodiment of the present invention, step (2) is specifically:

[0019] 2.1) Selecting a reference model and an adjustable model of the MRAS control strategy, determining the input and output of the reference model and the adjustable model respectively, and establishing a framework of the MRAS control strategy;

[0020] 2.2) determining an adaptive law of the control strategy and incorporating the adaptive law into the MRAS control strategy;

[0021] 2.3) Adjust the PI parameters of the MRAS control strategy to ensure stable operation of the dual-loop control system.

[0022] In a preferred embodiment of the present invention, step (3) is specifically:

[0023] 3.1) Simplify the LADRC and make it equivalent to PI control. According to the parameters of the PI control in the current inner loop, the bus voltage outer loop and the MRAS control strategy, the parameters of the LADRC are designed according to the parameter setting method based on bandwidth setting;

[0024] 3.2) The designed LADRC controller replaces the PI controller to obtain the sensorless control method of the high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS.

[0025] The beneficial effect of the present invention is that the present invention comprehensively considers the working conditions of the permanent magnet synchronous motor as a generator under the condition of high speed and low carrier ratio. Under the premise of ensuring the stable operation of the dual-loop system of the high-speed and low-carrier ratio permanent magnet synchronous generator, the observer is designed according to the basic idea of ​​MRAS, thereby introducing a sensorless control strategy. Then the control method is gradually complicated, the LADRC parameters are designed using the parameters of the PI controller, and the LADRC controller is used to replace the PI controller, and the PI control is transitioned to LADRC, gradually exploring and proving the stability of the control system and the feasibility of the control method. The present invention only needs to design two LADRC parameters, α and ω0, so the calculation amount is small. Through α and ω0, four parameters, β1, β2, k and b0, can be further obtained, and the relationship between the parameters is clear. The present invention combines the LADRC method with the sensorless control strategy to improve the practical applicability and external adaptability of the control method.

[0026] Compared with the prior art, the present invention, on the one hand, takes into account the problem of poor performance of low-speed control methods when applied to high-speed conditions. First, the PI algorithm is used to explore a simple control method for a high-speed, low-carrier ratio permanent magnet synchronous generator, and then the method is gradually explored and optimized to ensure the feasibility of the final control method. On the other hand, as a power system applied to the aviation field, the sensorless control strategy is introduced into the system while considering the influence of the external environment, and combined with the LADRC to jointly control the permanent magnet synchronous generator, providing a richer, more stable and better-performing control method for the high-speed, low-carrier ratio permanent magnet synchronous generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a control block diagram of the present invention;

[0028] Figure 2 is a schematic diagram of the MRAS of the present invention;

[0029] Figure 3 It is a schematic diagram of the LADRC controller of the present invention;

[0030] Figure 4 It is a comparison diagram of bus voltage between the method of the present invention and the system using the traditional PI controller;

[0031] Figure 5 It is a comparison diagram of the rotation speed of the method of the present invention and the system using the traditional PI controller;

[0032] Figure 6 It is a comparison diagram of the rotation angle between the method of the present invention and the system using the traditional PI controller. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0034] The present invention sets the permanent magnet synchronous generator under high-speed and low-carrier ratio operating conditions, utilizes the traditional PI-controlled dual-loop motor control system to ensure that the motor operates in a stable state, uses MRAS as a sensorless control strategy, and uses LADRC as the main control method of the dual-loop motor control system to replace PI control. According to the parameters of PI control, the LADRC controller is designed and the parameters are adjusted, thereby reducing the overshoot of output signals such as bus voltage while ensuring system stability, and improving the accuracy of MRAS in observing the motor speed and angle.

[0035] As an embodiment, a sensorless control method for a permanent magnet synchronous generator is provided, and a control block diagram of the entire system is shown as follows: Figure 1 As shown; in this method, sensorless control uses MRAS, and the schematic diagram is as follows Figure 2 As shown; the inner and outer loops in this method both use the LADRC method, and the principle diagram is as follows Figure 3 The method is described in detail using the motor and power electronics semi-physical simulation machine Microbox based on FPGA hardware chip as the permanent magnet synchronous generator module:

[0036] Step 1: construct a dual-loop control system of a controlled permanent magnet synchronous generator under high-speed and low-carrier ratio conditions, including a current inner loop and a bus voltage outer loop, wherein the current inner loop and the bus voltage outer loop adopt PI control, and adjust the PI control parameters to make the dual-loop control system run stably;

[0037] Step 1 specifically includes:

[0038] Step 1.1: Build the current inner loop in the dq rotating coordinate system

[0039] In this embodiment, the reference current of the dq rotating coordinate system is Unconnected, the reference current of the dq rotating coordinate system Including d-axis reference current and q-axis reference current Connect the permanent magnet synchronous generator and the three-phase rectifier, collect the three-phase current of the permanent magnet synchronous generator and obtain the actual current i of the dq rotating coordinate system through coordinate transformation dq , the actual current i in the dq rotating coordinate system dq Including the actual d-axis current i d and the actual q-axis current i q;

[0040] The stator voltage and stator flux equations of the permanent magnet synchronous generator are:

[0041]

[0042] In the formula, u dq , dq 、i dq are the dq axis voltage vector, flux vector and current vector respectively; p is the differential operator; R s is the motor stator resistance; is the electrical angular frequency matrix, ω r is the electrical angular frequency of the motor (rad / s); is the dq axis inductance matrix, let L be the dq axis inductance, then L d =L q =L; ψ = [ψ f 0] T is the dq-axis permanent magnet flux matrix, ψ f is the permanent magnet flux. Simplifying formula (1) yields:

[0043]

[0044] According to formula (2), the current inner loop is constructed; the current inner loop takes the actual current of the dq axis as input and outputs the actual voltage of the dq axis. Subtract the actual current i dq Then it is adjusted by a PI controller, and a PWM wave is generated through a coordinate transformation and a vector control module. The PWM wave is used as a control signal to drive the three-phase rectifier to work.

[0045] Step 1.2: Build the bus voltage outer loop

[0046] The DC end of the three-phase rectifier is connected to a load network, which is composed of multiple resistors and capacitors connected in parallel. The voltage signal of the DC end of the three-phase rectifier is collected as the actual value U of the bus voltage. dc , set the reference value of bus voltage is a certain value;

[0047] The reference value of the bus voltage Subtract the actual value of the bus voltage U dc After being adjusted by the PI controller, the output bus current I dc As the q-axis reference current The d-axis reference current Still remain suspended;

[0048] The actual value of bus voltage U dc and bus current Idc The relationship is:

[0049]

[0050] Where C is the equivalent capacitance of the load network, and R is the equivalent resistance of the load network. dc As the q-axis reference current The bus voltage outer loop is constructed according to formula (3); the bus voltage outer loop takes the reference value and the actual value of the bus voltage as input, and outputs the q-axis reference current;

[0051] The basic structure of the dual-loop control system is obtained by the current inner loop and the bus voltage outer loop;

[0052] Step 1.3, since the permanent magnet synchronous generator needs to input a high speed, in this embodiment, a fuel turbojet engine is connected to the generator in series, and the operation of the engine drives the generator to generate electricity, thereby supplying power to the load network;

[0053] Step 1.4: Adjust the parameters of the PI control and the carrier ratio of the vector control module so that the dual-loop control system operates stably.

[0054] In this embodiment, the parameters of the permanent magnet synchronous generator are shown in Table 1. In addition, for the bus voltage outer loop, the parameters of its PI controller are K P =0.9, K I =130, the PI parameter of the current inner loop is K P =0.05, K I =3.

[0055] Table 1 Permanent magnet synchronous generator parameters

[0056]

[0057] Step 2: Selecting a MRAS (Model Reference Adaptive System) control strategy as the sensorless control strategy, introducing the MRAS control strategy into the control system, and adjusting the parameters of the MRAS control strategy so that the control system operates stably; Step 2 specifically includes:

[0058] Step 2.1, selecting a reference model and an adjustable model of the MRAS control strategy, determining the input and output of the reference model and the adjustable model respectively, and establishing a framework of the control strategy;

[0059] The reference model can be obtained according to the stator flux equation of formula (1):

[0060] ψ dq / L=i dq +[ψ f / L 0]T (4)

[0061] The formula (4) is the reference model, and the actual current i dq As the input of the reference model, ψ dq / L is used as the output of the reference model. Substituting formula (4) into the stator voltage equation of formula (1), we obtain:

[0062]

[0063] The formula (5) is used as an adjustable model, and the actual current i dq and stator voltage u dq That is, the input of the adjustable model, the observed value of the electrical angular frequency ω r is the adjustment amount of the adjustable model, ψ dq / L is the output of the adjustable model;

[0064] Step 2.2, analyze and prove the stability of the MRAS control strategy, determine the adaptive law of the MRAS control strategy and bring the adaptive law into the MRAS control strategy, and write formula (5) in the form of observation quantity:

[0065]

[0066] Subtracting formula (6) from formula (5), the error state equation is:

[0067]

[0068] The error state equation (7) is divided into a linear time-invariant part and a nonlinear time-varying part. The stability of the linear time-invariant part is proved respectively, and the stability of the nonlinear time-varying part is proved by selecting a suitable adaptive law.

[0069] The error state equation (7) is written as follows:

[0070] pe=Be-W (8)

[0071] In the formula, Be is the linear time-invariant part, and -W is the nonlinear time-varying part. If the system is to be asymptotically stable, the linear time-invariant part of formula (8) needs to satisfy Lyapunov's first method, and the nonlinear time-varying part needs to satisfy Popov's integral inequality.

[0072] According to Lyapunov stability, when all eigenvalues ​​λ of the matrix B in formula (8) have negative real parts, the linear time-invariant part is asymptotically stable. That is, the equation Solving for λ=-R s / L±ωr The real part of i,λ is always negative, and the linear time-invariant part is asymptotically stable.

[0073] According to Popov's hyperstability theory, the stability of the nonlinear time-varying part must satisfy

[0074]

[0075] in is a finite positive number, then The nonlinear time-varying part is asymptotically stable. The specific derivation is:

[0076] First, according to the proportional integral form, let for:

[0077]

[0078] Substituting (10) into (9) and decomposing it, we obtain:

[0079]

[0080] With the is also a finite positive number. Assume that g(t) satisfies:

[0081]

[0082] Substitute (14)-(15) into (12) and simplify:

[0083]

[0084] Derivative (15) and similarly assume that F2(e,t) is expressed in the same form, that is:

[0085]

[0086] From (16)-(17), it can be seen that when K1, K2>0, (12)-(13) hold, and then the integral inequality (11) holds, and the nonlinear time-varying part is asymptotically stable.

[0087] Substitute (17) into (10) and simplify it, and use Replace ψ d , q get:

[0088]

[0089] in, is the estimated value of the angular velocity of the generator, K p is the PI control proportional coefficient of the MRAS control strategy, Ki is the PI control integral coefficient of the MRAS control strategy, s is the complex variable of Laplace transform, are the reference values ​​of the d-axis and q-axis flux, respectively. are the observed estimated values ​​of the d-axis and q-axis flux linkages, respectively, and L is the dq-axis inductance.

[0090] The MRAS control strategy is constructed with (4) as the reference model, (5) as the adjustable model, and (18) as the adaptive law.

[0091] Step 2.3: Adjust the PI parameters of the MRAS control strategy to ensure the stability of the dual-loop control system.

[0092] Step 3: According to the PI control in the current inner loop and the bus voltage outer loop, design the parameters of the LADRC controller, use the LADRC to replace all PI controls in the dual-loop control system, and obtain a sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS. Step 3 specifically includes:

[0093] Step 3.1, simplifying the LADRC and making it equivalent to the PI control, and designing the parameters of the LADRC according to the parameters of the PI control in the current inner loop, the bus voltage outer loop and the MRAS control strategy and the parameter setting method based on bandwidth setting;

[0094] Among them, LADRC is first-order, consisting of a first-order linear tracking differentiator LTD, a linear state error feedback control law LSEF, and a linear extended state observer LESO. The expressions of each part are as follows:

[0095] LTD:

[0096]

[0097] LSEF:

[0098]

[0099] LESO:

[0100]

[0101] The input of the entire LADRC link is x; r is the tracking signal of x; T TDis the time constant of the LTD; u0 and k are the output signal and proportional coefficient of the LSEF; b0 is the disturbance compensation coefficient; z1 and z2 are the observed estimated values ​​of the actual output y of the LESO to the controlled object and the total disturbance inside and outside the system respectively; β1 and β2 are the LESO gains; u is the output of the LADRC controller, and y is the output of the controlled object. For different PI controls, the input x, output u and output y of the equivalent LADRC controller are different: in the current inner loop, y=i dq ,in is the dq axis reference voltage; in the bus voltage outer loop, y=U dc In the MRAS control strategy,

[0102] For the bus voltage outer loop of the dual-loop control system, y=U dc , the expressions of LSEF and LESO are simplified to obtain:

[0103]

[0104] Rewrite (23) in the frequency domain and find its transfer function, and then we get:

[0105]

[0106] Where s is the complex variable of Laplace transform; z1(s), z2(s), r(s), U dc (s) are z1, z2, r, and U respectively dc The expression after Laplace transformation is a function of s.

[0107] Perform Laplace transformation on (20)-(21) and combine with (24) to obtain the q-axis reference current The tracking signal r and the actual value U of the bus voltage dc The relationship is:

[0108]

[0109] in, C2(s) is linked to the PI control, namely:

[0110]

[0111] In the formula, K P , K Iare the proportional and integral coefficients of the PI control respectively, T is the period of the low-pass filter, and it can be seen that C2(s) is equivalent to the series connection of the traditional PI controller and the low-pass filter.

[0112] Let variable α = b0(β1+k), simplify (26) to obtain the expression of k and b0:

[0113]

[0114] According to the parameter setting method based on bandwidth setting, let β1 = 2ω0, Substituting (29) into (29) we finally get:

[0115]

[0116] The corresponding parameters of the LADRC are designed by using the PI control parameters in the current inner loop, bus voltage outer loop and MRAS control strategy. That is, according to the PI control parameters in step (1) and step (2), the observer bandwidth ω0 is obtained by selecting a suitable α. Generally, α is selected as an integer power of 10, and it is ensured that ω0 of (30) has at least one positive real number solution, so that the solution is used as ω0 for parameter calculation, and then the parameters β1, β2, k and b0 of the LADRC in the current inner loop, bus voltage outer loop and MRAS control strategy are obtained, and a sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS is obtained.

[0117] Step 3.2, replace the PI controller with the designed LADRC controller to obtain the sensorless control method of the high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS. The model in the above steps is built in the rapid prototype control system using the corresponding algorithm and power electronic components, and then the waveform is recorded in real time in the software EasyGo of the host computer and drawn using the software Matlab to obtain the output curve of the sensorless control of the high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS. This includes the bus voltage outer loop, the actual and observed speed of the motor, and the actual and observed rotation angle of the motor rotor.

[0118] In this embodiment, the parameters of the LADRC controller are shown in Table 2, including the LADRC parameters in the current inner loop, the bus voltage outer loop, and the MRAS observer.

[0119] Table 2 LADRC parameters

[0120]

[0121] Under the condition of high speed and low carrier ratio of permanent magnet synchronous generator, the present invention first adjusts the dual-loop control system to make it run stably, then introduces MRAS, a sensorless control strategy, and proves its feasibility and stability in high-speed and low-carrier ratio PMSG system, designs the corresponding adaptive law, and finally designs the corresponding LADRC controller according to PI parameters. By comparing LADRC with PI, it is shown that the effect of the present invention is better than the traditional method and can be used in the field of aerospace. Its innovation and technical contribution are mainly reflected in the following aspects: (1) A new control method that can be applied to high-speed and low-carrier ratio PMSG is proposed, which can replace the traditional method in engineering; (2) LADRC and MRAS are combined for generator control, so that the method is no longer limited to the motor, and the application scope of sensorless control based on LADRC is expanded; (3) A three-loop control system of current inner loop, bus voltage outer loop and MRAS observation link is constructed, and closed-loop control of dq axis current, bus voltage and motor speed is performed at the same time.

[0122] In order to demonstrate the effectiveness of the method of the present invention, Figure 4 The bus voltage waveform comparison of the control system using LADRC and PI before and after the load network changes in step 1 is shown. It can be seen that whether it is when the system just starts working or after the load network changes around 1.3s, LADRC can maintain the overshoot of the bus voltage within a smaller range, and this range is smaller than the overshoot range when the PI controller is used.

[0123] Figure 5 The comparison between the observed speed and actual speed of the motor using the LADRC and PI methods is shown. It can be seen that although the observed speeds of both methods fluctuate around the actual speed within a certain range, the observed speed of the system using LADRC fluctuates roughly between 1500-2500 rad / s, while the observed speed of the system using PI fluctuates more significantly. Figure 6 The LADRC and PI methods are used to observe the motor rotor position. It can be seen that the LADRC system is more accurate in observing the rotor position, which also corresponds to Figure 5 The observed speed fluctuation corresponding to LADRC is smaller.

[0124] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator, characterized in that: The following steps are involved: (1) Building a dual-loop control system for a controlled permanent magnet synchronous generator, wherein the controlled permanent magnet synchronous generator operates under high speed and low carrier ratio conditions, wherein the dual-loop control system includes a current inner loop and a bus voltage outer loop, wherein the current inner loop and the bus voltage outer loop adopt PI control, and the PI control parameters are adjusted to enable the dual-loop control system to operate stably; (2) selecting the MRAS control strategy as the sensorless control strategy, introducing the MRAS control strategy into the dual-loop control system, and adjusting the PI control parameters of the MRAS control strategy so that the dual-loop control system operates stably; (3) Design the parameters of the LADRC controller and use LADRC to replace all PI controls in the dual-loop control system to obtain a sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS.

2. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 1, characterized in that: The step (1) is specifically: 1.1) Build the current inner loop in the dq rotating coordinate system; 1.2) Building the bus voltage outer loop, including: The DC end of the three-phase rectifier is connected to the load network, and the voltage signal of the DC end of the three-phase rectifier is collected as the actual value U of the bus voltage. dc , set the reference value of bus voltage is a certain value; The bus voltage outer loop converts the bus voltage reference value Subtract the actual value of the bus voltage U dc After being adjusted by the PI controller, the output is used as the q-axis reference current D-axis reference current Still remain suspended; 1.3) Connect the permanent magnet synchronous generator to an external engine, and drive the generator to generate electricity through the operation of the engine to supply power to the load network; 1.4) Adjust the parameters of the PI controller and the carrier ratio of the vector control module so that the dual-loop control system operates stably.

3. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 2 is characterized in that: Step 1.1) is specifically: The reference current of the dq rotating coordinate system Suspended; connect the permanent magnet synchronous generator and the three-phase rectifier, collect the three-phase current of the permanent magnet synchronous generator and obtain the actual current i of the dq rotating coordinate system through coordinate transformation dq ; The stator voltage and stator flux equations of the permanent magnet synchronous generator are: In the formula, u dq , dq 、i dq are the dq axis voltage vector, flux vector and current vector respectively; p is the differential operator; R s is the motor stator resistance; is the electrical angular frequency matrix, ω r is the electrical angular frequency of the motor (rad / s); is the dq axis inductance matrix, let L be the dq axis inductance, then L d =L q =L; ψ = [ψ f 0] T is the dq-axis permanent magnet flux matrix, ψ f is the permanent magnet flux; simplifying formula (1), we get: The current inner loop is constructed according to formula (2), and the current inner loop takes the reference value and actual value of the dq axis current as input and outputs the dq axis reference voltage.

4. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 2 is characterized in that: Step 1.2) is specifically as follows: the actual value of the bus voltage U dc and bus current I dc The relationship is: Where, C is the equivalent capacitance of the load network, R is the equivalent resistance of the load network; the bus current I dc As the q-axis reference current The bus voltage outer loop is constructed according to the formula (3), and the bus voltage outer loop takes the reference value and the actual value of the bus voltage as input and outputs the q-axis reference current.

5. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 1, characterized in that: The step (2) is specifically: 2.1) Selecting a reference model and an adjustable model of the MRAS control strategy, determining the input and output of the reference model and the adjustable model respectively, and establishing a framework of the MRAS control strategy; 2.2) determining an adaptive law of the control strategy and incorporating the adaptive law into the MRAS control strategy; 2.3) Adjust the PI parameters of the MRAS control strategy to ensure stable operation of the dual-loop control system.

6. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 5, characterized in that: In step 2.1), the reference model is obtained according to the stator flux equation: ψ dq / L=i dq +[ψ f / L 0] T (4) Actual current i dq As the input of the reference model, ψ dq / L is used as the output of the reference model; Substituting formula (4) into the stator voltage equation, we obtain: The formula (5) is used as the adjustable model, and the actual current i dq and stator voltage u dq That is, the input of the adjustable model, the observed value of the electrical angular frequency ω r is the adjustment amount of the adjustable model, ψ dq / L is the output of the adjustable model.

7. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 5, characterized in that: The form of the adaptive law in step 2.2) is as follows: in, is the estimated value of the angular velocity of the generator, K p is the PI control proportional coefficient of the MRAS control strategy, K i is the PI control integral coefficient of the MRAS control strategy, s is the complex variable of Laplace transform, are the reference values ​​of the d-axis and q-axis flux linkages, respectively. are the observed estimated values ​​of the d-axis and q-axis flux linkages, respectively, and L is the dq-axis inductance; The MRAS control strategy is constructed with (4) as the reference model, (5) as the adjustable model, and (18) as the adaptive law.

8. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 1, characterized in that: The step (3) is specifically: 3.1) Simplify the LADRC and make it equivalent to PI control. According to the parameters of the PI control in the current inner loop, the bus voltage outer loop and the MRAS control strategy, the parameters of the LADRC are designed according to the parameter setting method based on bandwidth setting; 3.2) The designed LADRC controller replaces the PI controller to obtain the sensorless control method of the high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS.

9. The sensorless control method of a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 8, characterized in that: In step 3.1), LADRC consists of a first-order linear tracking differentiator LTD, a linear state error feedback control law LSEF, and a linear extended state observer LESO. The expressions of each part are as follows: LTD: LSEF: u0=k(r-z1) (20) LESO: The input of the entire LADRC is x; r is the tracking signal of x; T TD is the time constant of the LTD; u0 and k are the output signal and proportional coefficient of the LSEF; b0 is the disturbance compensation coefficient; z1 is the observed estimated value of the actual output y of the LESO to the controlled object, z2 is the observed estimated value of the total disturbance inside and outside the system; β1 and β2 are the LESO gains; u is the output of the LADRC controller; For the dual-loop control system, y=U dc , the expressions of LSEF and LESO are simplified to obtain: Rewrite (23) in the frequency domain and find its transfer function, and then we get: Where s is the complex variable in Laplace transform; Perform Laplace transform on (20)-(21) and combine with (24) to obtain the q-axis reference current The tracking signal r and the actual value U of the bus voltage dc The relationship is: in, C2(s) is linked to PI control, namely: In the formula, K P , K I are the proportional and integral coefficients of PI control respectively, T is the period of the low-pass filter, and it can be seen that C2(s) is equivalent to the series connection of the PI controller and the low-pass filter; Let variable α = b0(β1+k), simplify (26) to obtain the expression of k and b0: According to the parameter tuning method based on bandwidth tuning, let β1 = 2ω0, Substituting (29) into the final result is: Where ω0 is the bandwidth of the linear extended state observer; By using the PI control parameters in the current inner loop, bus voltage outer loop and MRAS control strategy, the corresponding parameters of the LADRC are designed, that is, according to the PI control parameters in step (1) and step (2), the observer bandwidth ω0 is obtained by selecting a suitable α, ω0 is a positive real number, and then the parameters β1, β2, k and b0 of the LADRC in the current inner loop, bus voltage outer loop and MRAS control strategy are obtained, and a sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator based on LADRC and MRAS is obtained.

Images