Variable-speed pumping and storage self-starting control method and system based on state observer

Abstract

The invention discloses a variable-speed pumping and storage self-starting control method and system based on a state observer, and relates to the technical field of variable-speed pumping and storage unit control, and the method comprises the steps: constructing a motor state observer model under a self-starting working condition, selecting a stator flux linkage and a rotor current as observation objects, and building a state observer equation; calculating a positioning angle of vector closed-loop control based on a state observer model; and performing coordinate transformation by using the positioning angle to generate rotor three-phase voltage output, thereby realizing closed-loop self-starting of the variable-speed pumping and storage unit. According to the method, the motor state observer model under the self-starting working condition is constructed, the stator flux linkage and the rotor current are selected as observation objects, the state observer equation is established, and the dynamic state of the motor is accurately estimated in real time; and performing coordinate transformation by using the positioning angle to generate rotor three-phase voltage output, and finally realizing closed-loop self-starting of the variable-speed pumped storage unit.

Description

Technical Field

[0001] The present invention relates to the technical field of variable speed pumped storage unit control, and in particular to a variable speed pumped storage unit self-starting control method and system based on a state observer. Background Art

[0002] As an important component of modern power systems, variable-speed pumped-storage power generation technology has significant advantages in the fields of grid peak regulation and energy storage. Traditional fixed-speed pumped-storage units are widely used due to their simple structure and mature control strategies. However, with the increasing requirements of power systems for flexibility, stability and efficiency, variable-speed pumped-storage units have gradually attracted attention. Variable-speed pumped-storage units have achieved efficient operation under pumping and power generation conditions through doubly-fed asynchronous motors and variable frequency control technology, among which self-starting is one of the key links in the operation of the unit. However, during the self-starting process of variable-speed pumped-storage, due to the complex dynamic characteristics of the system, multiple state variables and strong coupling relationships, traditional control methods (such as simple control based on fixed-speed strategies) are difficult to achieve fast and stable starting. In recent years, control methods based on state observers have gradually become an important research direction for starting control of variable-speed pumped-storage units because they can accurately estimate the system state in real time in complex dynamic environments.

[0003] Although variable-speed pumped storage units have significant advantages over fixed-speed units in terms of control flexibility, the existing technology still has many shortcomings in realizing self-starting control. Traditional methods mostly refer to the starting control strategy of fixed-speed pumped storage units, and fail to give full play to the dynamic performance of variable speed operation. For example, in the starting phase, the system usually relies on the encoder to provide a speed signal, but in the low-speed phase, the encoder has poor stability, resulting in significant signal errors, further affecting the accuracy of starting control. Secondly, in the existing control methods, real-time observation and feedback of motor state variables (such as stator flux and rotor current) are insufficient, which makes the control strategy unable to adapt to the complex dynamic changes in the starting phase. In addition, traditional open-loop or semi-closed-loop control methods are difficult to provide accurate positioning angles, resulting in the control output (such as rotor voltage) unable to achieve efficient matching with the system dynamics, thereby reducing the starting efficiency and increasing the risk of starting failure. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is: the existing variable speed pumped storage self-starting control method has the problems of poor encoder stability and large speed signal error in the low-speed stage, insufficient observation and feedback of motor state variables (such as stator flux and rotor current), inaccurate positioning angle and inability to match system dynamics during the control process, as well as the problem of how to achieve efficient and stable self-starting of the unit.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: a variable speed pumped storage self-starting control method based on a state observer, comprising constructing a motor state observer model under self-starting conditions, selecting stator flux and rotor current as observation objects, and establishing a state observer equation; calculating the positioning angle of vector closed-loop control based on the state observer model; using the positioning angle to perform coordinate transformation, generate a rotor three-phase voltage output, and realize closed-loop self-starting of the variable speed pumped storage unit.

[0007] As a preferred solution of the variable speed pumped storage self-starting control method based on state observer described in the present invention, wherein: the motor state observer model under the self-starting condition is constructed, including adopting a double closed-loop vector control strategy under the pumping self-starting condition of the variable speed pumped storage unit, the inner loop is the rotor current loop of the motor, and the outer loops are the speed loop and the rotor voltage loop of the motor, respectively, and the control loop is expressed as:

[0008]

[0009] Among them, i rd_ef is the rotor current d-axis reference value, i rq_ef is the q-axis reference value of the rotor current, kp ur is the rotor voltage loop proportional coefficient, ki ur is the rotor voltage loop integral coefficient, u rm_ef is the rotor voltage amplitude reference value, u rm is the actual rotor voltage amplitude, kp ω is the speed loop proportional coefficient, ki ω is the speed loop integral coefficient, ω ref is the speed loop reference value, ω is the actual speed, s is the frequency variable in the Laplace domain, u rd is the rotor voltage d-axis control target value, u rq is the rotor voltage q-axis control target value, kp ir is the rotor current loop proportional coefficient, ki ir is the rotor current loop integral coefficient, i rd is the actual value of the rotor current d-axis, i rq is the actual value of the rotor current q axis, Δu rd is the rotor voltage d-axis decoupling component, Δu rq is the q-axis decoupling component of the rotor voltage; in the self-starting stage, the actual speed of the motor is calculated according to the electrical quantity of the motor, and the doubly fed motor is expressed as:

[0010]

[0011]

[0012] Among them, ψ sd Expressed as the stator flux d-axis component, ψsq Expressed as the q-axis component of the stator flux, ψ rd Expressed as the rotor flux d-axis component, ψ rq Expressed as the q-axis component of the rotor flux, L s Expressed as stator inductance, L m Expressed as mutual inductance, i sd Expressed as the d-axis component of the stator current, i sq Expressed as the q-axis component of the stator current, u sd Expressed as the d-axis component of the stator voltage, u sq Expressed as the q-axis component of the stator voltage, R s is the stator resistance, ω1 is the angular velocity of the selected coordinate system, R r Expressed as rotor resistance.

[0013] As a preferred solution of the variable speed pumped storage self-starting control method based on the state observer of the present invention, wherein: the establishment of the state observer equation includes selecting the stator flux and the rotor current as the observation objects, analyzing the stator flux equation, and expressing it as:

[0014]

[0015] Based on the rotor flux equation, the coupling characteristics of the stator and rotor flux are analyzed and expressed as:

[0016]

[0017] Among them, L r It is expressed as the rotor inductance; based on the rotor voltage equation, the dynamic voltage equation on the rotor side is integrated and expressed as:

[0018]

[0019] Based on the stator voltage equation, the voltage dynamic behavior on the stator side and the interaction between the stator and the rotor are described as follows:

[0020]

[0021] In the self-starting stage, the stator is short-circuited, u sd =u sq =0, expressed as:

[0022]

[0023] The coordinate system is selected to be located at the rotor, then ω1 = ω, and the intermediate variables are calculated, which can be expressed as:

[0024]

[0025] Among them, a represents the first intermediate variable, b represents the second intermediate variable, c represents the third intermediate variable, d represents the fourth intermediate variable, e represents the fifth intermediate variable, and f represents the sixth intermediate variable. The coupled dynamic characteristics of the stator-rotor circuit are constructed and expressed as:

[0026]

[0027] i r =i rd +ji rq

[0028] ψ s =ψ sd +jψ sq

[0029] u r =u rd +ju rq

[0030] Among them, i r is the rotor current, ψ s is the stator flux, u r is the rotor voltage, j is a complex unit; the dynamic model of the stator side is simplified and expressed as:

[0031]

[0032] Construct the state matrix A, input matrix B and output matrix C, expressed as:

[0033]

[0034] Among them, x is the state variable, y is the output variable, and the dependency between the stator and the rotor in the self-starting stage is clearly expressed as:

[0035]

[0036] in, is the time derivative of the state variable x, representing the dynamic behavior of the system, u r is the rotor voltage, and the observer gain matrix is ​​expressed as:

[0037]

[0038] Among them, g1 is the first element of the gain matrix, g2 is the second element of the gain matrix, g3 is the third element of the gain matrix, g4 is the fourth element of the gain matrix, and the state observer equation of the output motor is expressed as:

[0039]

[0040] in, is the estimated value of the state The time derivative of is the estimated state value of the state observer.

[0041] As a preferred solution of the variable speed pumped storage self-starting control method based on the state observer of the present invention, wherein: the calculation of the positioning angle of the vector closed-loop control includes performing closed-loop self-starting control based on the state observer of the motor, obtaining the positioning angle of the vector closed-loop control used in the self-starting stage, and adjusting the dynamic characteristics of the state matrix A according to the pole left shift k configuration parameters of the observer, which is expressed as:

[0042] |λI-A|=|λ'I-(A-GC)|=|(λ-k)I-(A-GC)|

[0043] Among them, λ is the eigenvalue, which represents the target position of the observer pole, I is the unit matrix, λ' is the adjusted target eigenvalue, and the output gain matrix element is expressed as:

[0044] g1=2k

[0045] g2=0

[0046]

[0047] g4=0

[0048] Based on the established doubly-fed motor state observer, the motor flux and rotor current are observed by the motor rotor voltage and current actually sampled.

[0049] As a preferred solution of the variable speed pumped storage self-starting control method based on the state observer of the present invention, wherein: the positioning angle of the vector closed-loop control is calculated, and the rotation angular velocity of the motor is calculated according to the observation result of the observer and the actual rotor current sampling value, which is expressed as:

[0050]

[0051] Among them, k p is the proportional gain coefficient, k i is the integral gain coefficient, is the estimated d-axis component of the rotor current, is the estimated q-axis component of the stator flux, is the estimated q-axis component of the rotor current, is the estimated value d-axis component of the stator flux. According to the observation result of the flux by the observer, the positioning angle of the vector closed-loop control in the self-starting stage is calculated, which is expressed as:

[0052]

[0053] Among them, θ is the positioning angle using vector closed-loop control during the self-starting stage.

[0054] As a preferred solution of the variable speed pumped storage self-starting control method based on the state observer of the present invention, wherein: the generating of the rotor three-phase voltage output includes performing coordinate transformation on the detected rotor three-phase current according to the positioning angle obtained by the observer, and obtaining the d and q axis components i of the rotor current rd 、i rq ;change i rd 、i rq Bring it into the rotor current control loop and output the rotor voltage d and q-axis control target value u rd 、u rq .

[0055] As a preferred solution of the variable speed pumped storage self-starting control method based on the state observer of the present invention, wherein: the generating of the rotor three-phase voltage output also includes coordinate transformation of the rotor voltage control target value based on the positioning angle to obtain the three-phase rotor voltage u ra 、u rb 、u rc , which is the output voltage of the AC excitation system, controls the variable-speed pumped storage unit to complete the closed-loop self-start under pumping conditions.

[0056] Another object of the present invention is to provide a variable speed pumped storage self-starting control system based on a state observer, which can generate a rotor three-phase voltage output by utilizing the positioning angle for coordinate transformation, thereby realizing closed-loop self-starting of the variable speed pumped storage unit, and solving the problem of low efficiency of the current variable speed pumped storage self-starting control technology.

[0057] As a preferred solution of the variable speed pumped storage self-starting control system based on the state observer described in the present invention, it includes: an equation establishment module, an angle calculation module, and a closed-loop self-starting module; the equation establishment module is used to construct a motor state observer model under the self-starting condition, select the stator flux and the rotor current as the observation objects, and establish the state observer equation; the angle calculation module is used to calculate the positioning angle of the vector closed-loop control based on the state observer model; the closed-loop self-starting module is used to use the positioning angle to perform coordinate transformation, generate the rotor three-phase voltage output, and realize the closed-loop self-starting of the variable speed pumped storage unit.

[0058] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement a step of a variable speed pumped storage self-starting control method based on a state observer.

[0059] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a variable-speed pumped storage self-starting control method based on a state observer.

[0060] Beneficial effects of the present invention: The variable speed pumped storage self-starting control method based on state observer provided by the present invention constructs a motor state observer model under self-starting conditions, selects stator flux and rotor current as observation objects, and establishes state observer equations, thereby realizing real-time and accurate estimation of the dynamic state of the motor; by calculating the positioning angle of vector closed-loop control based on the state observer model, the control target value of the rotor current is determined, thereby realizing precise control of the running direction of the motor; by using the positioning angle for coordinate transformation, the rotor three-phase voltage output is generated, and finally the closed-loop self-starting of the variable speed pumped storage unit is realized. The present invention achieves better results in terms of accuracy, efficiency and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0062] Figure 1 An overall flow chart of a variable speed pumped storage self-starting control method based on a state observer provided in the first embodiment of the present invention.

[0063] Figure 2 An overall flow chart of a variable speed pumped storage self-starting control system based on a state observer provided in the third embodiment of the present invention. DETAILED DESCRIPTION

[0064] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0065] Example 1, reference Figure 1 , which is an embodiment of the present invention, provides a variable speed pumped storage self-starting control method based on a state observer, comprising:

[0066] S1: Construct a motor state observer model under self-starting conditions, select stator flux and rotor current as observation objects, and establish the state observer equation.

[0067] Furthermore, the motor state observer model under the self-starting condition is constructed, including the use of a double closed-loop vector control strategy under the pumping self-starting condition of the variable speed pumped storage unit. The inner loop is the rotor current loop of the motor, and the outer loops are the speed loop and the rotor voltage loop of the motor. The control loop is expressed as:

[0068]

[0069] Among them, i rd_ef is the rotor current d-axis reference value, i rq_ef is the q-axis reference value of the rotor current, kp ur is the rotor voltage loop proportional coefficient, ki ur is the rotor voltage loop integral coefficient, u rm_ef is the rotor voltage amplitude reference value, u rm is the actual rotor voltage amplitude, kp ω is the speed loop proportional coefficient, ki ω is the speed loop integral coefficient, ω ref is the speed loop reference value, ω is the actual speed, s is the frequency variable in the Laplace domain, u rd is the rotor voltage d-axis control target value, u rq is the rotor voltage q-axis control target value, kp ir is the rotor current loop proportional coefficient, ki ir is the rotor current loop integral coefficient, i rd is the actual value of the rotor current d-axis, i rq is the actual value of the rotor current q axis, Δu rd is the rotor voltage d-axis decoupling component, Δu rq is the q-axis decoupling component of the rotor voltage; in the self-starting stage, the actual speed of the motor is calculated according to the electrical quantity of the motor, and the doubly fed motor is expressed as:

[0070]

[0071]

[0072] Among them, ψ sd Expressed as the stator flux d-axis component, ψ sq Expressed as the q-axis component of the stator flux, ψ rd Expressed as the rotor flux d-axis component, ψ rq Expressed as the q-axis component of the rotor flux, L s Expressed as stator inductance, L m Expressed as mutual inductance, i sd Expressed as the d-axis component of the stator current, i sq Expressed as the q-axis component of the stator current, u sd Expressed as the d-axis component of the stator voltage, u sqExpressed as the q-axis component of the stator voltage, R s is the stator resistance, ω1 is the angular velocity of the selected coordinate system, R r Expressed as rotor resistance.

[0073] It should be noted that establishing the state observer equation includes selecting the stator flux and the rotor current as the observation objects and analyzing the stator flux equation, which can be expressed as:

[0074]

[0075] Based on the rotor flux equation, the coupling characteristics of the stator and rotor flux are analyzed and expressed as:

[0076]

[0077] Among them, L r It is expressed as the rotor inductance; based on the rotor voltage equation, the dynamic voltage equation on the rotor side is integrated and expressed as:

[0078]

[0079] Based on the stator voltage equation, the voltage dynamic behavior on the stator side and the interaction between the stator and the rotor are described as follows:

[0080]

[0081] In the self-starting stage, the stator is short-circuited, u sd =u sq =0, expressed as:

[0082]

[0083] The coordinate system is selected to be located at the rotor, then ω1 = ω, and the intermediate variables are calculated, which can be expressed as:

[0084]

[0085] Among them, a represents the first intermediate variable, b represents the second intermediate variable, c represents the third intermediate variable, d represents the fourth intermediate variable, e represents the fifth intermediate variable, and f represents the sixth intermediate variable. The coupled dynamic characteristics of the stator-rotor circuit are constructed and expressed as:

[0086]

[0087] i r =i rd +ji rq

[0088] ψ s =ψ sd +jψ sq

[0089] u r =u rd +ju rq

[0090] Among them, i r is the rotor current, ψ s is the stator flux, u r is the rotor voltage, j is a complex unit; the dynamic model of the stator side is simplified and expressed as:

[0091]

[0092] Construct the state matrix A, input matrix B and output matrix C, expressed as:

[0093]

[0094] C = [1 0]

[0095]

[0096] y=i r

[0097] Among them, x is the state variable, y is the output variable, and the dependency between the stator and the rotor in the self-starting stage is clearly expressed as:

[0098]

[0099] in, is the time derivative of the state variable x, representing the dynamic behavior of the system, u r is the rotor voltage, and the observer gain matrix is ​​expressed as:

[0100]

[0101] Among them, g1 is the first element of the gain matrix, g2 is the second element of the gain matrix, g3 is the third element of the gain matrix, g4 is the fourth element of the gain matrix, and the state observer equation of the output motor is expressed as:

[0102]

[0103] in, is the estimated value of the state The time derivative of is the estimated state value of the state observer.

[0104] It should also be noted that the selection of stator flux and rotor current as observation objects can capture the core dynamic variables of the motor during the startup phase, effectively reflect the magnetic coupling and current characteristics of the motor, and realize real-time observation of the rotor current and stator flux through the construction of a state observer. This provides dynamic state support for subsequent precise control, eliminates the dependence on low-speed encoders during the startup phase, avoids instability caused by encoder errors in the low-speed segment, improves the robustness and accuracy of state estimation, ensures the stable operation of the motor in a complex dynamic environment, and provides comprehensive and accurate basic data support for the control model in subsequent steps.

[0105] S2: Based on the state observer model, calculate the positioning angle of the vector closed-loop control.

[0106] Furthermore, the calculation of the positioning angle of the vector closed-loop control includes performing closed-loop self-starting control based on the state observer of the motor, obtaining the positioning angle of the vector closed-loop control in the self-starting stage, and adjusting the dynamic characteristics of the state matrix A according to the left shift k configuration parameters of the observer pole, which is expressed as:

[0107] |λI-A|=|λ'I-(A-GC)|=|(λ-k)I-(A-GC)|

[0108] Among them, λ is the eigenvalue, which represents the target position of the observer pole, I is the unit matrix, λ' is the adjusted target eigenvalue, and the output gain matrix element is expressed as:

[0109] g1=2k

[0110] g2=0

[0111]

[0112] g4=0

[0113] Based on the established doubly-fed motor state observer, the motor flux and rotor current are observed by the motor rotor voltage and current actually sampled.

[0114] It should be noted that the calculation of the positioning angle of the vector closed-loop control also includes calculating the rotation angular velocity of the motor according to the observation results of the observer and the actual rotor current sampling value, which is expressed as:

[0115]

[0116] Among them, k p is the proportional gain coefficient, k i is the integral gain coefficient, is the estimated d-axis component of the rotor current, is the estimated q-axis component of the stator flux, is the estimated q-axis component of the rotor current, is the estimated value d-axis component of the stator flux. According to the observation result of the flux by the observer, the positioning angle of the vector closed-loop control in the self-starting stage is calculated, which is expressed as:

[0117]

[0118] Among them, θ is the positioning angle using vector closed-loop control during the self-starting stage.

[0119] It should also be noted that through precise positioning angle calculation, the performance of vector control is optimized, so that the system can quickly enter stable operation during the self-starting stage; the oscillation problem caused by positioning angle error in traditional control methods is avoided, and the speed and stability of startup are improved; conditions are created for the realization of closed-loop vector control, making the output of the control loop more accurate and dynamically responsive.

[0120] S3: Use the positioning angle to perform coordinate transformation, generate the rotor three-phase voltage output, and realize the closed-loop self-starting of the variable-speed pumped storage unit.

[0121] Furthermore, generating the rotor three-phase voltage output includes performing coordinate transformation on the detected rotor three-phase current according to the positioning angle obtained by the observer to obtain the d-axis and q-axis components i of the rotor current. rd 、i rq ;change i rd 、i rq Bring it into the rotor current control loop and output the rotor voltage d and q-axis control target value u rd 、u rq .

[0122] It should be noted that generating the rotor three-phase voltage output also includes performing coordinate transformation on the rotor voltage control target value based on the positioning angle to obtain the three-phase rotor voltage u ra 、u rb 、u rc , which is the output voltage of the AC excitation system, controls the variable-speed pumped storage unit to complete the closed-loop self-start under pumping conditions.

[0123] It should also be noted that the application of closed-loop control ensures the real-time and accuracy of the system's dynamic response; coordinate transformation reduces the error between voltage output and rotor dynamics, fully utilizes the dynamic characteristics of the variable-speed unit, and improves starting efficiency; by accurately generating the rotor's three-phase voltage, the variable-speed pumped storage unit successfully achieves a self-starting process from stationary to stable operation, greatly improving the reliability and efficiency of operation.

[0124] Embodiment 2 is an embodiment of the present invention, which provides a variable speed pumped storage self-starting control method based on a state observer. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0125] First, a variable speed doubly fed generator (DFIG) was selected as the experimental object to simulate the operating characteristics of the pumped storage unit. The system parameters included stator inductance, rotor inductance, mutual inductance, rotor resistance and stator resistance, and actual rated values ​​were used to ensure the universality and representativeness of the experiment. A state observer model was constructed in the experiment, which selected stator flux and rotor current as the core observation objects, and designed a vector closed-loop control system based on this.

[0126] Firstly, the state equation is established according to the electrical parameters of the motor, and the stator flux and rotor current are selected as the observed quantities. The dual closed-loop vector control strategy is used to realize the dynamic feedback of the observer, in which the inner loop is the rotor current control loop and the outer loop is the speed and voltage control loop. In the design process of the observer, the proportional gain and integral gain are adjusted through experiments to optimize the dynamic response performance of the observer. Based on the observation results of the state observer, the positioning angle of the vector closed-loop control is calculated. The positioning angle is obtained through the dynamic relationship between the rotor flux and the stator flux, and is used as the basic parameter of the coordinate transformation. Combined with the closed-loop control algorithm, the deviation of the rotor current reference value is adjusted in real time through the proportional-integral controller to ensure that the dynamic output of the rotor voltage accurately matches the actual demand. The three-phase current of the rotor is transformed by the positioning angle to generate the current component. The rotor current component outputs the target voltage through the control loop, and generates the rotor three-phase voltage signal through the inverse transformation. Finally, the rotor voltage signal is transmitted to the AC excitation system to realize the closed-loop control of the pumped storage unit under the self-starting condition.

[0127] The experiment conducted six groups of tests under different working conditions, including different settings of the initial speed value from static to 1500RPM, and tests under various external disturbance conditions. The changes in the rotor current, rotor voltage and speed were recorded. All data were collected through high-precision sensors to ensure the accuracy of the data. In the acceleration stage from static to 1500RPM, the system can achieve stable operation in a short time, and under external disturbance conditions, the deviation between the actual speed and the estimated value is maintained within ±0.1%. This result shows that the dynamic control strategy using real-time feedback from the state observer significantly improves the system's anti-interference ability and response speed. Through the construction of the state observer and the combination of closed-loop control, the system can achieve fast and stable self-starting. Compared with the prior art, the present invention improves the motor starting efficiency and operating stability.

[0128] Example 3, reference Figure 2, which is an embodiment of the present invention, provides a variable speed pumped storage self-starting control system based on a state observer, including an equation building module, an angle calculation module, and a closed-loop self-starting module.

[0129] The equation establishment module is used to construct the motor state observer model under the self-starting condition, select the stator flux and the rotor current as the observation objects, and establish the state observer equation; the angle calculation module is used to calculate the positioning angle of the vector closed-loop control based on the state observer model; the closed-loop self-starting module is used to use the positioning angle for coordinate transformation, generate the rotor three-phase voltage output, and realize the closed-loop self-starting of the variable-speed pumped storage unit.

[0130] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0131] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0132] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0133] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc. It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not limited. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

[0134] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A variable speed pumped storage self-starting control method based on a state observer, characterized in that: include: Construct a motor state observer model under self-starting conditions, select stator flux and rotor current as observation objects, and establish the state observer equation; Based on the state observer model, the positioning angle of the vector closed-loop control is calculated; The positioning angle is used to perform coordinate transformation to generate the rotor three-phase voltage output and realize the closed-loop self-starting of the variable-speed pumped storage unit.

2. The variable speed pumped storage self-starting control method based on a state observer as claimed in claim 1, characterized in that: The motor state observer model under the self-starting condition is constructed by adopting a double closed-loop vector control strategy under the pumping self-starting condition of the variable speed pumped storage unit, wherein the inner loop is the rotor current loop of the motor, and the outer loops are the speed loop and the rotor voltage loop of the motor, respectively. The control loop is expressed as: Among them, i rd_ef is the rotor current d-axis reference value, i rq_ef is the q-axis reference value of the rotor current, kp ur is the rotor voltage loop proportional coefficient, ki ur is the rotor voltage loop integral coefficient, u rm_ef is the rotor voltage amplitude reference value, u rm is the actual rotor voltage amplitude, kp ω is the speed loop proportional coefficient, ki ω is the speed loop integral coefficient, ω ref is the speed loop reference value, ω is the actual speed, s is the frequency variable in the Laplace domain, u rd is the rotor voltage d-axis control target value, u rq is the rotor voltage q-axis control target value, kp ir is the rotor current loop proportional coefficient, ki ir is the rotor current loop integral coefficient, i rd is the actual value of the rotor current d-axis, i rq is the actual value of the rotor current q axis, Δu rd is the rotor voltage d-axis decoupling component, Δu rq is the q-axis decoupling component of the rotor voltage; In the self-starting stage, the actual speed of the motor is calculated based on the electrical quantity of the motor, and the doubly fed motor is expressed as: Among them, ψ sd Expressed as the stator flux d-axis component, ψ sq Expressed as the q-axis component of the stator flux, ψ rd Expressed as the rotor flux d-axis component, ψ rq Expressed as the q-axis component of the rotor flux, L s Expressed as stator inductance, L m Expressed as mutual inductance, i sd Expressed as the d-axis component of the stator current, i sq Expressed as the q-axis component of the stator current, u sd Expressed as the d-axis component of the stator voltage, u sq Expressed as the q-axis component of the stator voltage, R s is the stator resistance, ω1 is the angular velocity of the selected coordinate system, R r Expressed as rotor resistance.

3. The variable speed pumped storage self-starting control method based on state observer as claimed in claim 2, characterized in that: The establishment of the state observer equation includes selecting the stator flux and the rotor current as observation objects, analyzing the stator flux equation, and expressing it as: Based on the rotor flux equation, the coupling characteristics of the stator and rotor flux are analyzed and expressed as: Among them, L r It is expressed as rotor inductance; Based on the input rotor voltage equation, the dynamic voltage equation on the rotor side is integrated and expressed as: Based on the stator voltage equation, the voltage dynamic behavior on the stator side and the interaction between the stator and the rotor are described as follows: In the self-starting stage, the stator is short-circuited, u sd =u sq =0, expressed as: The coordinate system is selected to be located at the rotor, then ω1 = ω, and the intermediate variables are calculated, which can be expressed as: Among them, a represents the first intermediate variable, b represents the second intermediate variable, c represents the third intermediate variable, d represents the fourth intermediate variable, e represents the fifth intermediate variable, and f represents the sixth intermediate variable. The coupled dynamic characteristics of the stator-rotor circuit are constructed and expressed as: i r =to rd +ji rq ψ s =ψ sd +jψ sq you r =u rd +you rq Among them, i r is the rotor current, ψ s is the stator flux, u r is the rotor voltage, j is a complex unit; The dynamic model of the stator side is simplified as follows: Construct the state matrix A, input matrix B and output matrix C, expressed as: C＝[10] y=i r Among them, x is the state variable, y is the output variable, and the dependency between the stator and the rotor in the self-starting stage is clearly expressed as: in, is the time derivative of the state variable x, representing the dynamic behavior of the system, u r is the rotor voltage, and the observer gain matrix is ​​expressed as: Among them, g1 is the first element of the gain matrix, g2 is the second element of the gain matrix, g3 is the third element of the gain matrix, g4 is the fourth element of the gain matrix, and the state observer equation of the output motor is expressed as: in, is the estimated value of the state The time derivative of is the estimated state value of the state observer.

4. The variable speed pumped storage self-starting control method based on state observer as claimed in claim 3, characterized in that: The calculation of the positioning angle of the vector closed-loop control includes performing closed-loop self-starting control based on the state observer of the motor, obtaining the positioning angle of the vector closed-loop control in the self-starting stage, configuring the parameters according to the pole left shift k of the observer, and adjusting the dynamic characteristics of the state matrix A, which is expressed as: |λI-A|=Iλ′I-(A-GC)|=I(λ-k)I-(A-GC)| Among them, λ is the eigenvalue, which represents the target position of the observer pole, I is the unit matrix, λ′ is the adjusted target eigenvalue, and the output gain matrix element is expressed as: g1=2k g2＝0 g4＝0 Based on the established doubly-fed motor state observer, the motor flux and rotor current are observed by the motor rotor voltage and current actually sampled.

5. The variable speed pumped storage self-starting control method based on state observer according to claim 4, characterized in that: The calculation of the positioning angle of the vector closed-loop control also includes calculating the rotation angular velocity of the motor according to the observation result of the observer and the actual rotor current sampling value, which is expressed as: Among them, k p is the proportional gain coefficient, k i is the integral gain coefficient, is the estimated d-axis component of the rotor current, is the estimated q-axis component of the stator flux, is the estimated q-axis component of the rotor current, is the estimated value d-axis component of the stator flux. According to the observation result of the flux by the observer, the positioning angle of the vector closed-loop control in the self-starting stage is calculated, which is expressed as: Among them, θ is the positioning angle using vector closed-loop control during the self-starting stage.

6. The variable speed pumped storage self-starting control method based on state observer according to claim 5, characterized in that: The generating of the rotor three-phase voltage output includes performing coordinate transformation on the detected rotor three-phase current according to the positioning angle obtained by the observer to obtain the d-axis and q-axis components i of the rotor current. rd 、i rq ; will i rd 、i rq Bring it into the rotor current control loop and output the rotor voltage d and q-axis control target value u rd 、u rq .

7. The variable speed pumped storage self-starting control method based on state observer according to claim 6, characterized in that: The generating of the rotor three-phase voltage output further includes performing coordinate transformation on the rotor voltage control target value based on the positioning angle to obtain the three-phase rotor voltage u ra 、u rb 、u rc , which is the output voltage of the AC excitation system, controls the variable-speed pumped storage unit to complete the closed-loop self-start under pumping conditions.

8. A system using the variable speed pumped storage self-starting control method based on a state observer as claimed in any one of claims 1 to 7, characterized in that: Including equation building module, angle calculation module, closed-loop self-starting module; The equation building module is used to build a motor state observer model under the self-starting condition, select the stator flux and the rotor current as the observation objects, and build the state observer equation; The angle calculation module is used to calculate the positioning angle of the vector closed-loop control based on the state observer model; The closed-loop self-starting module is used to perform coordinate transformation using the positioning angle, generate a rotor three-phase voltage output, and realize closed-loop self-starting of the variable-speed pumped storage unit.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the variable speed pumped storage self-starting control method based on a state observer are implemented as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the variable speed pumped storage self-starting control method based on a state observer are implemented as described in any one of claims 1 to 7.

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