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

Abstract

The application discloses a sensorless control method of a high-speed low-carrier-ratio permanent magnet synchronous generator. First, a double-loop control system of a controlled permanent magnet synchronous generator under high-speed low-carrier-ratio conditions is built, including a current inner loop and a bus voltage outer loop, an MRAS control strategy is selected as a sensorless control strategy, the MRAS control strategy is introduced into the double-loop control system, parameters of the MRAS control strategy are adjusted, and the double-loop control system is stably operated; parameters of a controller of LADRC are designed, all PI controls in the double-loop control system are replaced by LADRC, and a sensorless control method of the high-speed low-carrier-ratio permanent magnet synchronous generator based on LADRC and MRAS is obtained. The application comprehensively considers constraint conditions such as high rotating speed, low carrier ratio and sensorless control, constructs a motor control model of the permanent magnet synchronous motor as a generator, and combines PI control to design parameters, so that a more economical and feasible solution is provided.

Description

TECHNICAL FIELD

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

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

[0003] In actual application, the aircraft may need to fly under the conditions of rain, drought and sandstorm, and the working condition is relatively harsh. Installing a speed sensor increases the wiring difficulty, and the harsh working condition also affects the reliability, sensitivity and service life of the speed sensor. Therefore, in order to improve the system reliability, ensure the high power density and reduce the cost, the sensorless control strategy is considered to be applied to the motor. 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 in principle. Among them, the model reference adaptive method (MRAS) takes the equation containing the estimated parameter as the adjustable model, and takes the equation without unknown parameters as the reference model, and the two models have the same physical significance of the output. Therefore, the MRAS is considered to be combined with other control methods and applied to the high-speed low-carrier-ratio PMSG system.

[0004] If the existing control method under low speed condition is directly applied to high speed and low carrier ratio condition, the PMSG system will be unstable, and with the decrease of the carrier ratio, the digital control delay of the system will be more serious, the difficulty of adjusting the stability of the control method system will be further increased, and even the method will fail, so it is urgent to explore a control method which can be applied to high speed and low carrier ratio PMSG system. SUMMARY

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

[0006] The purpose of the present application is achieved by the following technical solutions:

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

[0008] (1) A double-loop control system for the controlled permanent magnet synchronous generator is built, the controlled permanent magnet synchronous generator works under high-speed and low-carrier-ratio conditions, the double-loop control system comprises a current inner loop and a bus voltage outer loop, the current inner loop and the bus voltage outer loop adopt PI control, and the PI control parameters are adjusted to enable the double-loop control system to operate stably;

[0009] (2) The MRAS control strategy is selected as a sensorless control strategy, the MRAS control strategy is introduced into the double-loop control system, and the PI control parameters of the MRAS control strategy are adjusted to enable the double-loop control system to operate stably;

[0010] (3) The parameters of the controller of LADRC are designed, all PI controls in the double-loop control system are replaced by LADRC, and a sensorless control method for a high-speed and low-carrier-ratio permanent magnet synchronous generator based on LADRC and MRAS is obtained.

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

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

[0013] 1.2) Build the bus voltage outer loop, comprising:

[0014] Connect the DC end of the three-phase rectifier to the load network, and collect the voltage signal of the DC end of the three-phase rectifier as the actual value U of the bus voltagedc , set the reference value of bus voltage is a constant value;

[0015] The bus voltage outer ring will subtract the actual value U of the bus voltage from the reference value of the bus voltage dc After passing through the PI controller for adjustment, the output quantity is taken as the q-axis reference current d-axis reference current Still pending;

[0016] 1.3) Connect the permanent magnet synchronous generator with the external engine, drive the generator to generate electricity through the operation of the engine, and 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 double-loop control system operates stably.

[0018] In the preferred scheme of the present application, the step (2) is specifically:

[0019] 2.1) Select the reference model and adjustable model of the MRAS control strategy, determine the input and output of the reference model and adjustable model respectively, and establish the framework of the MRAS control strategy;

[0020] 2.2) Determine the adaptive law of the control strategy and bring the adaptive law into the MRAS control strategy;

[0021] 2.3) Adjust the PI parameters of the MRAS control strategy, so that the double-loop control system operates stably.

[0022] In the preferred scheme of the present application, the step (3) is specifically:

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

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

[0025] The beneficial effects of the present application are: the present application comprehensively considers the working condition 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 double-loop system of the high-speed low-carrier-ratio permanent magnet synchronous generator, an observer is designed according to the basic idea of MRAS, so as to introduce the sensorless control strategy. Then the control method is gradually complicated, the LADRC parameters are designed by using the parameters of the PI controller, and the LADRC controller is used to replace the PI controller, from PI control to LADRC, and the stability of the control system and the feasibility of the control method are gradually explored and proved. The present application only needs to design two LADRC parameters of alpha and omega0, so the calculation amount is small, and four parameters of beta1, beta2, k and b0 can be further obtained through alpha and omega0, and the relationship between the parameters is clear. The present application combines the LADRC method with the sensorless control strategy, and improves the practical applicability and external adaptability of the control method.

[0026] Compared with the prior art, on the one hand, the present application considers the problem that the control method at low speed is poor in performance when applied to high speed, and first adopts the PI algorithm to explore the simple control method of the high-speed low-carrier-ratio permanent magnet synchronous generator, and then gradually explores and optimizes to ensure the feasibility of the final control method; on the other hand, as an electric power system applied to the field of aviation, under the influence of the external environment, the sensorless control strategy is introduced into the system, and is combined with LADRC to control the permanent magnet synchronous generator together, thereby providing a more abundant, more stable and better performance control method for the high-speed low-carrier-ratio permanent magnet synchronous generator. BRIEF DESCRIPTION OF DRAWINGS

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

[0028] Figure 2 is the principle diagram of MRAS of the present application;

[0029] Figure 3 is the principle diagram of the LADRC controller of the present application;

[0030] Figure 4 is the bus voltage comparison diagram of the method of the present application and the system adopting the traditional PI controller;

[0031] Figure 5 is the speed comparison diagram of the method of the present application and the system adopting the traditional PI controller;

[0032] Figure 6 is the rotation angle comparison diagram of the method of the present application and the system adopting the traditional PI controller. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0034] The present invention sets the permanent magnet synchronous generator to operate under high-speed and low-carrier ratio 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 LADRC as the main control method of the dual-loop motor control system to replace PI control. Based on 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 the control block diagram of the entire system is as follows: Figure 1 As shown; In this method, sensorless control adopts MRAS, and the principle 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 As shown. This method is explained in detail using the FPGA-based motor and power electronics hardware-in-the-loop simulator Microbox as the permanent magnet synchronous generator module:

[0036] Step 1: Build a dual-loop control system for 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 ensure stable operation of the dual-loop control system;

[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 q-axis actual current i q;

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

[0041]

[0042] In the formula, u dq , ψ dq , i dq are the dq-axis voltage vector, flux linkage vector and current vector respectively; p is a differential operator; R s is the stator resistance of the motor; is the electrical angular frequency matrix, ω r is the electrical angular frequency (rad / s) of the motor; is the dq-axis inductance matrix, and 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 linkage matrix, ψ f is the permanent magnet flux linkage. Simplifying formula (1) gives:

[0043]

[0044] According to formula (2), the current inner loop is built; the current inner loop takes the actual dq-axis current as input and outputs the actual dq-axis voltage. The current inner loop adjusts the reference current after subtracting the actual current i dq by a PI controller, and generates a PWM wave through a coordinate transformation and a vector control module, and the PWM wave is used as a control signal to drive the three-phase rectifier to work.

[0045] Step 1.2, building a bus voltage outer loop

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

[0047] The reference value of the bus voltage is subtracted from the actual value U dc of the bus voltage, and the output bus current I dc is adjusted by a PI controller, and the output bus current I dc is used as the q-axis reference current The d-axis reference current remains suspended;

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

[0049]

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

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

[0052] Step 1.3, since the permanent magnet synchronous generator needs to input high speed, the fuel turbine engine is connected with the generator in series in this embodiment, and the generator is driven to generate electricity by the operation of the engine, so as to supply power to the load network;

[0053] Step 1.4, adjust the parameters of PI control and the carrier ratio of vector control module, so that the double-loop control system runs stably.

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

[0055] Table 1 Permanent magnet synchronous generator parameters

[0056]

[0057] Step 2, select MRAS (model reference adaptive system) control strategy as a sensorless control strategy, and introduce the MRAS control strategy into the control system, adjust the parameters of the MRAS control strategy, so that the control system runs stably; Step 2 specifically includes:

[0058] Step 2.1, select the reference model and the adjustable model of the MRAS control strategy, determine the input and output of the reference model and the adjustable model respectively, and build the framework of the control strategy;

[0059] The reference model can be obtained according to the stator flux linkage 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 ψ dq / L is the output of the reference model. The formula (4) is substituted into the stator voltage equation of the formula (1) to obtain:

[0062]

[0063] The formula (5) is the adjustable model, and the actual current i dq and the stator voltage u dq The observed value ω r of the electrical angular frequency is the input 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 substitute the adaptive law into the MRAS control strategy, and write the formula (5) into the form of an observation:

[0065]

[0066] Subtract the formula (6) from the formula (5) to obtain the error state equation:

[0067]

[0068] The error state equation (7) is divided into a linear time-invariant part and a nonlinear time-varying part, and 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 in the following form:

[0070] pe=Be-W (8)

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

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

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

[0074]

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

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

[0077]

[0078] Bring (10) into (9) and decompose to get:

[0079]

[0080] is also a finite positive number. Let g(t) satisfy:

[0081]

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

[0083]

[0084] Derive (15) and set F2(e,t) in the same form, that is:

[0085]

[0086] From (16)-(17), when K1,K2>0, (12)-(13) is established, and then the integral inequality in (11) is established, and the nonlinear time-varying part is asymptotically stable.

[0087] Substitute (17) into (10) and simplify, and replace ψ d , ψ q with to get:

[0088]

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

[0090] The MRAS control strategy is built 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 double-loop control system.

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

[0093] Step 3.1, simplify the LADRC and equivalent to the PI control, according to the parameters of the PI control in the current inner loop, bus voltage outer loop and MRAS control strategy, design the parameters of the LADRC according to the parameter tuning method based on bandwidth tuning;

[0094] wherein the LADRC is a first-order, composed of a first-order linear tracking differentiator LTD, a linear state error feedback control law LSEF, and a linear extended state observer LESO, and 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 observation estimation values of the actual output y of the controlled object and the total disturbance inside and outside the system of the LESO 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 of the equivalent LADRC controller and the output y of the controlled object are different: in the current inner loop, y = i dq , wherein 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 double-loop control system, y = U dc , the expression of the LSEF and LESO is simplified to obtain:

[0103]

[0104] (23) is rewritten in the frequency domain, and the transfer function thereof is solved to obtain:

[0105]

[0106] where s is a complex variable of Laplace transform; z1(s), z2(s), r(s) and U dc (s) are z1, z2, r and U dc after Laplace transform, which is a function of s.

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

[0108]

[0109] wherein, C2(s) is related to the PI control, that is:

[0110]

[0111] In the formula, K P , K Irespectively, 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 conventional PI controller and the low-pass filter.

[0112] Let variable α = b0(β1+k), and 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, Substitute (29) to obtain:

[0115]

[0116] Using the PI control parameters in the current inner loop, bus voltage outer loop and MRAS control strategy, the parameters of the corresponding LADRC are designed, that is, according to the PI control parameters in steps (1) and (2), the observer bandwidth ω0 is obtained by selecting a suitable α, generally selecting α as an integer power of 10, and ensuring that ω0 of (30) has at least one positive real solution, so as to use the solution 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 the sensorless control method of the 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 used to build corresponding algorithms and power electronic elements in the rapid prototyping control system, and then the waveforms are recorded in real time in the software EasyGo of the host computer and drawn by the software matlab, that is, the output curve of the sensorless control of the high-speed low carrier ratio permanent magnet synchronous generator based on LADRC and MRAS can be obtained. Which 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, which includes the LADRC parameters in the current inner loop, bus voltage outer loop and MRAS observer.

[0119] Table 2 LADRC parameters

[0120]

[0121] The application firstly adjusts the double-loop control system to make it run stably under the condition of high speed and low carrier ratio of the permanent magnet synchronous generator, then introduces the MRAS sensorless control strategy, and proves the feasibility and stability of the application of the MRAS sensorless control strategy in the high-speed low-carrier-ratio PMSG system, designs the corresponding adaptive law, finally, according to the PI parameter design, the corresponding LADRC controller is designed, the LADRC is compared with the PI, and it is illustrated that the effect of the application is better than that of the traditional method, and the application can be applied to the aerospace field.

[0122] In order to show the effectiveness of the method of the application, Figure 4 The bus voltage waveforms of the control systems adopting the LADRC and the PI before and after the load network change in step 1 are compared, and it can be seen that whether the system just starts to work or after the load network changes at about 1.3s, the overshoot of the bus voltage maintained in a small range by the LADRC is smaller than that by the PI controller.

[0123] Figure 5 The comparison of the observed speed and the actual speed of the motor by the LADRC and the PI is shown. Figure 6 The observation of the rotor position of the motor by the LADRC and the PI is shown. Figure 5 The observation of the rotor position of the motor by the LADRC and the PI is shown.

[0124] The above-mentioned embodiments only express several embodiments of the application, the description is more specific and detailed, but it cannot be understood as the limitation of the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which belong to the protection scope of the application. Therefore, the protection scope of the application should be subject to the appended 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 ensure stable operation of the dual-loop control system; (2) selecting an MRAS control strategy as a 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; The step (3) is specifically as follows: 31) Simplifying the LADRC and converting it into PI control, and designing the parameters of the LADRC according to the parameters of the PI control in the current inner loop, bus voltage outer loop, and MRAS control strategy, using a parameter setting method based on bandwidth setting; 32) 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; In step 31), 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, and 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 ,in is the reference value of the bus voltage, and the expressions of LSEF and LESO are simplified to: Rewrite (23) in the frequency domain and find its transfer function, and we can 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 Regarding the tracking signal r and the actual value U of the bus voltage dc The relationship: in, Connect C2(s) with PI control, that is: Where K P , K I are 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 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 equation, we finally get: Where ω0 is the bandwidth of the linear extended state observer; The corresponding LADRC parameters 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 steps (1) and (2), the observer bandwidth ω0 is obtained by selecting a suitable α, where ω0 is a positive real number. 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.

2. The sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 1, characterized in that: The step (1) is specifically as follows: 11) Build the current inner loop in the dq rotating coordinate system; 12) Building the bus voltage outer loop, including: Connect the DC terminal of the three-phase rectifier to the load network, and collect the voltage signal of the DC terminal of the three-phase rectifier as the actual value of the bus voltage U 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 that, it is adjusted by PI controller and the output is used as the q-axis reference current. d-axis reference current Still remain suspended; 13) Connect the permanent magnet synchronous generator to an external engine, and use the engine to drive the generator to generate electricity and supply power to the load network; 14) Adjusting the parameters of the PI controller and the carrier ratio of the vector control module to ensure stable operation of the dual-loop control system.

3. The sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 2, characterized in that: Step 11) is specifically as follows: The reference current of the dq rotating coordinate system 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: Where u dq , ψ dq 、i dq are the dq axis voltage vector, flux vector and current vector respectively; p is the differential operator; R s is the stator resistance of the motor; is the electrical angular frequency matrix, ω r is the electrical angular frequency of the motor, in 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 the 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 for a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 2, characterized in that: Step 12) 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 actual value of the bus voltage as input and outputs the q-axis reference current.

5. The sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 1, characterized in that: The step (2) is specifically as follows: 21) 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; 22) determining an adaptive law of the control strategy and incorporating the adaptive law into the MRAS control strategy; 23) Adjust the PI parameters of the MRAS control strategy to ensure stable operation of the dual-loop control system.

6. The sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 5, characterized in that: In step 21), 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 the output of the reference model, ψ f is the permanent magnet flux; Substituting formula (4) into the stator voltage equation, we get: 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 electrical angular frequency ω r The observed value is the adjustment amount of the adjustable model, ψ dq / L is the output of the adjustable model, ψ dq is the magnetic flux vector, R s is the stator resistance of the motor, and L is the dq axis inductance.

7. The sensorless control method for a high-speed, low-carrier ratio permanent magnet synchronous generator according to claim 5, characterized in that: The adaptive law in step 22) 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 d-axis and q-axis flux linkages, are the observed estimated values ​​of d-axis and q-axis flux linkages, respectively, and L is the dq-axis inductance; The MRAS control strategy is constructed using formula (4) as the reference model, formula (5) as the adjustable model, and formula (18) as the adaptive law.

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