A method and system for coordinated control of protection, excitation and synchronization under multiple operating conditions

Abstract

The application relates to a multi-working-condition protection, excitation and synchronization collaborative control method and system, and belongs to the field of power protection control. The method comprises the following steps: integrating three-source parameters, the three-source parameters comprising protection system parameters, excitation system parameters and synchronization system parameters, obtaining a normalized state vector based on the three-source parameters; outputting a working condition characteristic matrix based on the normalized state vector and identifying a current dominant working condition; obtaining a control gain matrix, and outputting an optimized control vector through the normalized state vector and the working condition characteristic matrix; converting the optimized control vector into execution parameters and adding dynamic constraints, the execution parameters comprising an excitation voltage set value, a negative sequence current threshold value and a compensation phase difference; monitoring and feeding back execution deviations in real time, and outputting a dynamic constraint coefficient for dynamically constraining the control gain matrix. The application realizes the collaborative control of protection, excitation and synchronization under multi-working conditions.

Description

Technical Field

[0001] This invention belongs to the field of power protection and control technology, specifically relating to a coordinated control method and system for protection, excitation, and synchronization under multiple operating conditions. Background Technology

[0002] The coordinated control of protection, excitation, and synchronizing devices in power systems is a core challenge in ensuring safe grid connection and stable operation of generating units. Traditional technologies employ a "separate design, partial linkage" model: the protection system relies on fixed thresholds, and during transient processes such as unit startup and load surges, it cannot distinguish between faults and disturbances, leading to a high false trip rate; the excitation system uses PID to track the generator terminal voltage, but fails to consider grid voltage fluctuations and synchronization requirements, resulting in excessive grid connection inrush current; although the synchronizing device introduces PID closed-loop regulation of phase difference, its response to rapid frequency changes is lagging, resulting in long grid connection times. In recent years, some improved solutions have attempted to exchange signals through hard-wiring, but these have three fundamental flaws: parameter fragmentation: the parameters of the protection, excitation, and synchronizing systems cannot be analyzed jointly, resulting in fragmentation; rigid operating conditions: fixed control parameters are difficult to adapt to multiple operating conditions such as frequency changes, faults, and grid connection; dynamic mismatch: the lack of an error feedback coordination mechanism easily leads to oscillations. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention provides a coordinated control method and system for protection, excitation, and synchronization under multiple operating conditions.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A coordinated control method for protection, excitation, and synchronization under multiple operating conditions, the implementation of which includes the following steps:

[0006] S1: Integrate the three-source parameters, which include protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters;

[0007] S2: Output the operating condition feature matrix based on the normalized state vector and identify the current dominant operating condition;

[0008] S3: Obtain the control gain matrix, and output the optimized control vector through the normalized state vector and the operating condition feature matrix;

[0009] S4: Convert the optimized control vector into execution parameters and add dynamic constraints. The execution parameters include the excitation voltage setpoint, the negative sequence current threshold, and the compensation phase difference.

[0010] S5: Monitor and provide feedback on execution deviations in real time, and output dynamic constraint coefficients to dynamically constrain the control gain matrix.

[0011] Preferably, step S1 specifically includes:

[0012] The protection system parameters, the excitation system parameters, and the synchronization system parameters are obtained. The protection system parameters include the frequency change rate and the negative sequence current. The excitation system parameters include the grid voltage, the generator terminal voltage, and the voltage change rate. The synchronization system parameters include the phase difference and the slip.

[0013] The normalized state vector is output based on the three source parameters, mathematically described as follows: ,in, For the normalized state vector, The rate of change of frequency, This represents the maximum frequency change rate of the gas turbine. It is a negative sequence current. Rated current, This is the grid voltage. This is the terminal voltage. Rated voltage, The rate of change of voltage. The maximum allowable rate of voltage change, For phase difference, To allow for grid connection phase difference, For slip weights, For slip, This represents the maximum permissible slip.

[0014] Preferably, step S2 specifically includes:

[0015] Pre-training yields the weight matrix and eigenvectors;

[0016] Based on the normalized state vector, the weight matrix, and the feature vector, the operating condition feature matrix is ​​output, mathematically described as follows: ,in, The working condition feature matrix, This is the weight matrix. For feature vectors, For steady-state probability, For the probability of frequently changing operating conditions, For the probability of grid connection, This represents the probability of a faulty operating condition.

[0017] The current dominant operating condition is identified based on the operating condition feature matrix.

[0018] Preferably, step S3 specifically includes:

[0019] The control gain matrix is ​​determined through multi-condition simulation optimization.

[0020] The operating condition intensity coefficient is obtained based on the normalized state vector, and the operating condition intensity coefficient includes the frequency intensity coefficient, voltage intensity coefficient and phase intensity coefficient;

[0021] The optimized control vector is output based on the control gain matrix, the operating condition characteristic matrix, and the operating condition intensity coefficient, mathematically described as follows: ,in, This is the correction amount for the excitation voltage setpoint. The correction factor for the protection action threshold. For synchronous phase correction angle, For the control gain matrix, The first characteristic matrix of the working condition row element, For frequency intensity coefficients, Voltage strength coefficient, This is the phase intensity coefficient.

[0022] Preferably, step S4 specifically includes:

[0023] The excitation voltage setpoint is obtained based on the correction amount of the excitation voltage setpoint, and mathematically described as follows: ,in, This is the excitation voltage setpoint. This is the original excitation voltage setting value. To preset the grid connection time, The current time;

[0024] The negative sequence current threshold is obtained based on the protection action threshold correction coefficient, and is mathematically described as follows: ,in, The negative sequence current threshold;

[0025] The compensated phase difference is obtained based on the synchronous phase correction angle, and mathematically described as follows: ,in, To compensate for the phase difference, For the original phase difference, This is the attenuation factor.

[0026] Preferably, step S5 specifically includes:

[0027] The execution deviation is obtained, and the execution deviation includes voltage tracking error, negative sequence current tracking error, and phase difference tracking error;

[0028] The dynamic constraint coefficients are output based on the execution deviation, mathematically described as follows: ,in, For dynamic constraint coefficients, For voltage tracking error, This is for negative sequence current tracking error. For phase difference tracking error, Voltage sensitivity coefficient;

[0029] The control gain matrix is ​​dynamically updated based on the dynamic constraint coefficients, mathematically described as follows: ,in, The updated control gain matrix, This is for element-wise multiplication.

[0030] A multi-condition coordinated control system for protection, excitation, and synchronization, used to execute the aforementioned multi-condition coordinated control method for protection, excitation, and synchronization, includes a data integration module, a condition identification module, a control optimization module, an execution module, and a dynamic constraint module.

[0031] The data integration module is used to integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and to obtain a normalized state vector based on the three-source parameters.

[0032] The working condition identification module is used to output a working condition feature matrix based on the normalized state vector and identify the current dominant working condition.

[0033] The control optimization module is used to obtain the control gain matrix and output the optimized control vector through the normalized state vector and the operating condition feature matrix.

[0034] The execution module is used to convert the optimized control vector into execution parameters and add dynamic constraints. The execution parameters include the excitation voltage setpoint, the negative sequence current threshold, and the compensation phase difference.

[0035] The dynamic constraint module is used to monitor and provide feedback on execution deviations in real time, and outputs dynamic constraint coefficients to dynamically constrain the control gain matrix.

[0036] The beneficial effects of this invention are as follows:

[0037] (1) By integrating the key parameters of the three systems through normalized state vectors, they can be optimized under the same mathematical framework, thus solving the problem of "information silos" in traditional systems.

[0038] (2) It can perform coordinated control through the working condition feature matrix, adapt to various working conditions such as frequency change, fault, and grid connection, and perform coordinated control according to different working conditions. It has strong adaptability and wide application range.

[0039] (3) Establish an error feedback coordination mechanism through dynamic constraint coefficients to monitor and control deviations in the system operation process in real time. Attached Figure Description

[0040] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0041] Figure 1 This is a flowchart illustrating the steps of a coordinated control method for protection, excitation, and synchronization under multiple operating conditions according to the present invention. Detailed Implementation

[0042] To better understand the invention, various aspects of the invention will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of the invention and are not intended to limit the scope of the invention in any way. Throughout the specification, the expression "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the terms "approximately," "about," and similar terms are used as expressions of approximation, not as expressions of degree, and are intended to describe inherent deviations in measured or calculated values ​​that will be recognized by those skilled in the art. Furthermore, the order in which the steps are described in this invention does not necessarily indicate the order in which these steps occur in actual operation, unless otherwise expressly defined or deduced from the context.

[0043] It should also be understood that expressions such as "comprising," "including," "having," "containing," and / or "comprising" are open-ended rather than closed-ended expressions in this specification, indicating the presence of the stated features, elements, and / or components, but not excluding the presence of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not just individual elements in the list. Additionally, when describing embodiments of the invention, the word "may" is used to mean "one or more embodiments of the invention." And the term "exemplary" is intended to refer to examples or illustrations.

[0044] Unless otherwise specified, all terms used herein (including engineering and technical terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that, unless expressly stated herein, terms defined in common dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not in an idealized or overly formalized sense.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] Example 1:

[0047] Please see Figure 1 A coordinated control method for protection, excitation, and synchronization under multiple operating conditions, comprising:

[0048] S1: Integrate the three-source parameters, which include protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters;

[0049] S2: Output the operating condition feature matrix based on the normalized state vector and identify the current dominant operating condition;

[0050] S3: Obtain the control gain matrix, and output the optimized control vector through the normalized state vector and the operating condition feature matrix;

[0051] S4: The optimized control vector is converted into execution parameters and dynamic constraints are added to achieve coordinated control of protection, excitation, and synchronization. The execution parameters include excitation voltage setpoint, negative sequence current threshold, and compensation phase difference.

[0052] S5: Monitor and feedback execution deviations in real time, and output dynamic constraint coefficients to be used to dynamically constrain the control gain matrix in step S3.

[0053] In this embodiment, the normalized state vector is obtained based on the three source parameters, which can be implemented through the following steps:

[0054] S101: The protection system parameters, the excitation system parameters, and the synchronization system parameters are obtained through the protection system, the excitation system, and the synchronization system, respectively. The protection system parameters include the frequency change rate and the negative sequence current. The excitation system parameters include the grid voltage, the generator terminal voltage, and the voltage change rate. The synchronization system parameters include the phase difference and the slip.

[0055] S102: Output the normalized state vector based on the three source parameters, mathematically described as follows: ,in, For the normalized state vector, It represents the rate of change of frequency (i.e., the rate of change of generator terminal voltage frequency, Hz / s). This represents the maximum frequency change rate of the gas turbine. It is a negative sequence current. Rated current, This is the grid voltage. This is the terminal voltage. Rated voltage, This is the rate of change of voltage (i.e., the rate of change of generator terminal voltage, kV / s). The maximum allowable rate of voltage change, This refers to the phase difference (i.e., the phase angle difference between the generator voltage and the grid voltage). To allow for grid connection phase difference, This is the slip weight (typical value 0.3). Slip (i.e., the rate of change of phase difference, ° / s). This represents the maximum permissible slip.

[0056] In this embodiment, the output of the operating condition feature matrix based on the normalized state vector and the identification of the current dominant operating condition can be implemented through the following steps:

[0057] S201: Pre-training yields the weight matrix and eigenvectors;

[0058] Specifically, this involves: collecting historical datasets (100 sets of working condition samples) and inputting them into the dataset. NSV Vectors are generated, and one-hot vector labels are added to each vector (e.g., [0,1,0,0] represents the frequency-varying operating condition); logistic regression is used to solve the problem. The weight matrix is ​​obtained. and the feature vector .

[0059] S202: Output the operating condition feature matrix based on the normalized state vector, the weight matrix, and the feature vector, mathematically described as follows: ,in, The working condition feature matrix, The weight matrix is ​​(4×5). The feature vector is (4×1). For steady-state probability, For the probability of frequently changing operating conditions, For the probability of grid connection, This represents the probability of a faulty operating condition.

[0060] S203: Based on the aforementioned operating condition feature matrix, identify the current dominant operating condition, that is, identify the operating condition with the highest probability of occurrence, which is then considered the dominant operating condition. Example: In this case, the frequency-dependent operating condition dominates (68%).

[0061] In this embodiment, the optimized control vector is output through the normalized state vector and the operating condition feature matrix, which can be implemented through the following steps:

[0062] S301: The control gain matrix is ​​determined through multi-condition simulation optimization, specifically as follows:

[0063] S301-1: Establish a gas turbine model;

[0064] S301-2: Set optimization target: minimize grid-connected inrush current and ensure fault clearing time is less than or equal to preset threshold;

[0065] S301-3: The optimal matrix obtained by the particle swarm optimization algorithm is used as the control gain matrix.

[0066] S302: Obtain the operating condition intensity coefficient based on the normalized state vector. The operating condition intensity coefficient includes a frequency intensity coefficient, a voltage intensity coefficient, and a phase intensity coefficient. The mathematical description of the frequency intensity coefficient is... The mathematical description of the voltage strength coefficient is The mathematical description of the phase intensity coefficient is ,in, The first row of the normalized state vector is the element. This represents the element in the third row of the normalized state vector. This is the element in the 5th row of the normalized state vector;

[0067] S303: Based on the control gain matrix, the operating condition characteristic matrix, and the operating condition intensity coefficient, output the optimized control vector, mathematically described as follows: ,in, This is the correction amount (kV) for the excitation voltage setpoint. The protection action threshold correction coefficient (dimensionless). The synchronous phase correction angle (°) is given. For the control gain matrix (3×4 matrix, That is, the element in the first row and i-th column of the matrix. The first characteristic matrix of the working condition row element, For frequency intensity coefficients, Voltage strength coefficient, This is the phase intensity coefficient.

[0068] In this embodiment, the optimized control vector is transformed into execution parameters and dynamic constraints are added, which can be implemented through the following steps:

[0069] S401: The excitation voltage setpoint is obtained based on the correction amount of the excitation voltage setpoint, mathematically described as follows: ,in, This is the excitation voltage setpoint. This is the original excitation voltage setting value. To preset the grid connection time, For the current time, Used to smoothly approximate the target voltage over time, avoiding step disturbances;

[0070] S402: The negative sequence current threshold is obtained based on the protection action threshold correction coefficient, mathematically described as follows: ,in, The negative sequence current threshold;

[0071] S403: The compensated phase difference is obtained based on the synchronous phase correction angle, mathematically described as follows: ,in, To compensate for the phase difference, For the original phase difference, This is the attenuation factor, typically with a value of 2.0. Used to asymptotically approximate the target phase and suppress oscillations.

[0072] In this embodiment, the output dynamic constraint coefficients are used for the control gain matrix in the dynamic constraint step S3, which can be implemented through the following steps:

[0073] S501: Obtain the execution deviation, which includes voltage tracking error (i.e., the difference between the excitation voltage setpoint obtained by actual monitoring and the excitation voltage setpoint obtained in S4), negative sequence current tracking error (i.e., the difference between the negative sequence current threshold obtained by actual monitoring and the negative sequence current threshold obtained in S4) and phase difference tracking error (i.e., the difference between the compensated phase difference obtained by actual monitoring and the compensated phase difference obtained in S4).

[0074] S502: Output the dynamic constraint coefficients based on the execution deviation, mathematically described as follows: ,in, For dynamic constraint coefficients, For voltage tracking error, This is for negative sequence current tracking error. For phase difference tracking error, This is the voltage sensitivity coefficient (typically 5.0).

[0075] S503: Dynamically update the control gain matrix based on the dynamic constraint coefficients and feed it back to step S3. Mathematically, this is described as follows: ,in, The updated control gain matrix, This is for element-wise multiplication.

[0076] Example 2:

[0077] A coordinated control system for protection, excitation, and synchronization under multiple operating conditions includes a data integration module, an operating condition identification module, a control optimization module, an execution module, and a dynamic constraint module.

[0078] The data integration module is used to integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and to obtain a normalized state vector based on the three-source parameters.

[0079] The working condition identification module is used to output a working condition feature matrix based on the normalized state vector and identify the current dominant working condition.

[0080] The control optimization module is used to obtain the control gain matrix and output the optimized control vector through the normalized state vector and the operating condition feature matrix.

[0081] The execution module is used to convert the optimized control vector into execution parameters and add dynamic constraints to achieve coordinated control of protection, excitation, and synchronization. The execution parameters include excitation voltage setpoint, negative sequence current threshold, and compensation phase difference.

[0082] The dynamic constraint module is used to monitor and provide feedback on execution deviations in real time, and outputs dynamic constraint coefficients for the control gain matrix in the dynamic constraint step S3.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A coordinated control method for protection, excitation, and synchronization under multiple operating conditions, characterized in that, Includes the following steps: S1: Integrate the three-source parameters, which include protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters; S2: Output the operating condition feature matrix based on the normalized state vector and identify the current dominant operating condition; S3: Obtain the control gain matrix, and output the optimized control vector through the normalized state vector and the operating condition feature matrix; S4: Convert the optimized control vector into execution parameters and add dynamic constraints. The execution parameters include the excitation voltage setpoint, the negative sequence current threshold, and the compensation phase difference. S5: Real-time monitoring and feedback of execution deviations, outputting dynamic constraint coefficients to dynamically constrain the control gain matrix; The output of the optimized control vector in step S3 is specifically: the control gain matrix is ​​determined through multi-condition simulation optimization. The operating condition intensity coefficient is obtained based on the normalized state vector, and the operating condition intensity coefficient includes the frequency intensity coefficient, voltage intensity coefficient and phase intensity coefficient; The optimized control vector is output based on the control gain matrix, the operating condition characteristic matrix, and the operating condition intensity coefficient, mathematically described as follows: ,in, This is the correction amount for the excitation voltage setpoint. The correction factor for the protection action threshold. For synchronous phase correction angle, For the control gain matrix, The first characteristic matrix of the working condition row element, For frequency intensity coefficients, Voltage strength coefficient, The phase intensity coefficient, Rated voltage, To allow for grid connection phase difference.

2. The coordinated control method for protection, excitation, and synchronization under multiple operating conditions according to claim 1, characterized in that, Step S1 specifically includes: The protection system parameters, the excitation system parameters, and the synchronization system parameters are obtained. The protection system parameters include the frequency change rate and the negative sequence current. The excitation system parameters include the grid voltage, the generator terminal voltage, and the voltage change rate. The synchronization system parameters include the phase difference and the slip. The normalized state vector is output based on the three source parameters, mathematically described as follows: ,in, For the normalized state vector, The rate of change of frequency, This represents the maximum frequency change rate of the gas turbine. It is a negative sequence current. Rated current, This is the grid voltage. Terminal voltage, Rated voltage, The rate of change of voltage. The maximum allowable rate of voltage change, For phase difference, To allow for grid connection phase difference, For slip weights, For slip, This represents the maximum permissible slip.

3. The coordinated control method for protection, excitation, and synchronization under multiple operating conditions according to claim 2, characterized in that, Step S2 specifically includes: Pre-training yields the weight matrix and eigenvectors; Based on the normalized state vector, the weight matrix, and the feature vector, the operating condition feature matrix is ​​output, mathematically described as follows: ,in, The working condition feature matrix, This is the weight matrix. For feature vectors, For steady-state probability, For the probability of frequently changing operating conditions, For the probability of grid connection, This represents the probability of a faulty operating condition. The current dominant operating condition is identified based on the operating condition feature matrix.

4. The coordinated control method for protection, excitation, and synchronization under multiple operating conditions according to claim 3, characterized in that, Step S4 specifically includes: The excitation voltage setpoint is obtained based on the correction amount of the excitation voltage setpoint, and mathematically described as follows: ,in, This is the excitation voltage setpoint. This is the original excitation voltage setting value. To preset the grid connection time, The current time; The negative sequence current threshold is obtained based on the protection action threshold correction coefficient, and is mathematically described as follows: ,in, The negative sequence current threshold; The compensated phase difference is obtained based on the synchronous phase correction angle, and mathematically described as follows: ,in, To compensate for the phase difference, For the original phase difference, This is the attenuation factor.

5. The coordinated control method for protection, excitation, and synchronization under multiple operating conditions according to claim 4, characterized in that, Step S5 specifically includes: The execution deviation is obtained, and the execution deviation includes voltage tracking error, negative sequence current tracking error, and phase difference tracking error; The dynamic constraint coefficients are output based on the execution deviation, mathematically described as follows: ,in, For dynamic constraint coefficients, For voltage tracking error, This is for negative sequence current tracking error. For phase difference tracking error, Voltage sensitivity coefficient; The control gain matrix is ​​dynamically updated based on the dynamic constraint coefficients, mathematically described as follows: ,in, The updated control gain matrix, This is for element-wise multiplication.

6. A coordinated control system for protection, excitation, and synchronization under multiple operating conditions, characterized in that, The system is applied to the coordinated control method for protection, excitation, and synchronization under multiple operating conditions as described in any one of claims 1-5, and includes a data integration module, an operating condition identification module, a control optimization module, an execution module, and a dynamic constraint module; The data integration module is used to integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and to obtain a normalized state vector based on the three-source parameters. The working condition identification module is used to output a working condition feature matrix based on the normalized state vector and identify the current dominant working condition. The control optimization module is used to obtain the control gain matrix and output the optimized control vector through the normalized state vector and the operating condition feature matrix. The execution module is used to convert the optimized control vector into execution parameters and add dynamic constraints. The execution parameters include the excitation voltage setpoint, the negative sequence current threshold, and the compensation phase difference. The dynamic constraint module is used to monitor and provide feedback on execution deviations in real time, and outputs dynamic constraint coefficients to dynamically constrain the control gain matrix.

Images