Double-loop coordinated feedback control method for guide vane and power angle of one-pipe multi-machine hydroelectric system

Abstract

The application discloses a guide vane and power angle double-loop coordinated feedback control method of one-pipe multi-machine hydroelectric system, relates to the technical field of hydroelectric unit control, and comprises the following steps: S1, a nonlinear model under the elasticity of water hammer of one-pipe multi-machine is constructed, and a guide vane opening degree and a power angle are selected as double-loop control objects; S2, the double-loop control objects are introduced into original guide vane and power angle control models as additional negative feedback items to obtain a double-loop coordinated feedback control model; S3, a coordinated control theory is introduced, a plurality of guide vane opening degrees and power angles of the multiple units are selected to form guide vane control macro variables and power angle control macro variables respectively, and derivatives are calculated respectively; and S4, the guide vane control macro variables and the derivatives, the power angle control macro variables and the derivatives are substituted into a coordinated control convergence flow field respectively to obtain guide vane and power angle control laws, namely additional negative feedback items, and system control is realized. The application establishes the connection of the multiple units, realizes the timely feedback of the guide vane and power angle changes of the units through the double-loop form, and makes the control effect more optimal.

Description

Technical Field

[0001] This invention relates to the field of hydropower unit control technology, and more specifically to a dual-loop coordinated feedback control method for guide vanes and power angle in a multi-unit hydropower system. Background Technology

[0002] Hydropower stations, as a flexible and rapid-response renewable energy source, play an important role in peak shaving and frequency regulation in modern power systems. In diversion-type hydropower stations, water is transported to the front end of the power plant through a shared pressure steel pipe, and then connected to each turbine generator unit through branch pipes. Such a system is usually called a single-pipe multi-generator system.

[0003] The single-pipe, multi-unit layout is widely used in large-scale cascade power plants. However, this structure exhibits significant hydraulic coupling effects during operation: when a single unit adjusts its guide vane opening or load, it triggers water hammer and pressure pulsation through the shared pressure pipeline, causing power oscillations in other units and, in severe cases, even inducing frequency instability. Especially under scenarios of grid frequency fluctuations or sudden load changes, the dynamic interaction between multiple units further amplifies hydraulic disturbances, threatening the safe and stable operation of the system.

[0004] Existing technologies mostly focus on the optimal control of single units, while neglecting the coordinated control between multiple units. Therefore, there is an urgent need for a coordinated control technology, and to develop a coordinated control method that reduces the impact of hydraulic coupling and improves the output stability of hydropower units. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, this invention discloses a dual-loop coordinated feedback control method for guide vane and power angle in a multi-unit hydropower system. The purpose of this invention is to solve the problem of unsatisfactory control performance in multi-unit systems with hydraulic coupling effects in the existing technology. This invention defines a dual-loop feedback term, introduces coordinated control theory, designs a dual-loop coordinated feedback control model, and provides real-time feedback on changes in guide vane opening and power angle. This invention establishes connections between multiple units, achieving timely feedback of guide vane and power angle changes through a dual-loop configuration, resulting in superior control performance.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A dual-loop coordinated feedback control method for guide vanes and power angle in a multi-machine hydropower system includes the following steps:

[0008] S1. Construct a nonlinear model of elastic water hammer under a single pipe and multiple machines, and select the guide vane opening of the hydraulic part and the power angle of the generator part as the dual-loop control objects in the nonlinear model, and define the dual-loop control objects.

[0009] S2. Introduce a dual-loop control object as an additional negative feedback term into the original guide vane and power angle control model to obtain a dual-loop cooperative feedback control model.

[0010] S3. Introduce the theory of coordinated control, select the guide vane opening and power angle of multiple units to form the guide vane control macro variable and the power angle control macro variable respectively, and obtain the derivatives of the guide vane control macro variable and the power angle control macro variable respectively.

[0011] S4. Substitute the guide vane control macrovariate and its derivative, the power angle control macrovariate and its derivative into the collaborative control convergent manifold to obtain the guide vane and power angle control laws. Then, add the guide vane and power angle control laws into the dual-loop collaborative feedback control model and use the dual-loop collaborative feedback control model to control the multi-machine hydropower system.

[0012] The specific steps are as follows:

[0013] I. Selecting and defining two-loop control objects

[0014] Preferably, in step S1, the nonlinear model is the state equation under elastic water hammer of a multi-unit hydro-turbine generator set, including:

[0015] ;

[0016] in,

[0017] , ,

[0018] In the formula, and State variables for transient hydraulic calculations of branch pipes; This is the normalized value of the hydraulic impact resistance of the branch pipe; The elastic time constant of the branch pipe; This represents the relative value of the static head of the hydropower station. This is a shared head loss coefficient; This represents the relative flow rate of the public pipeline. The head loss coefficient of the branch pipe; The flow rate of the branch pipe; The time constant of the unit's main servo motor; For the unit speed governor control signal; This is the initial value of the guide vane opening; For guide vane opening; This is the guide vane opening at rated load; This is a multi-machine coupling term; The generator's power angle; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; The inertial time constant of the generator set; The mechanical power of the generator; This refers to the generator's output active power. This is the damping factor of the generator; For generator Axial transient electromotive force; This refers to the output excitation voltage of the excitation system. for Shaft synchronous reactance; for Shaft transient reactance; This refers to the terminal voltage. The excitation time constant of the generator; subscript Indicates the first Each branch pipe and its corresponding unit.

[0019] Preferably, in step S1, selecting the guide vane opening of the hydraulic component and the power angle of the generator component as the dual-loop control objects in the nonlinear model includes:

[0020] ;

[0021] ;

[0022] in, For guide vane opening; For time; The time constant of the unit's main servo motor; For the unit speed governor control signal; This is the initial value of the guide vane opening; The generator's power angle; This refers to the synchronous angular velocity of the generator. This represents the generator's angular velocity.

[0023] Preferably, in step S1, defining the dual-loop control object includes:

[0024] ;

[0025] ;

[0026] in, and These are the controlled objects of the guide vane control loop and the power angle control loop, respectively. and These are the functions satisfied by the controlled objects in the guide vane control loop and the power angle control loop, respectively. For guide vane opening; For the unit speed governor control signal; The generator's angular velocity; This refers to the generator's power angle.

[0027] II. Constructing a Dual-Loop Cooperative Feedback Control Model

[0028] Preferably, step S2 includes: taking the control objects of the guide vane control loop and the power angle control loop in the dual-loop control object as the cooperative additional feedback terms of the multi-machine guide vane opening and power angle of the multi-machine system, respectively, and introducing them into the original guide vane and power angle control differential equations to obtain the dual-loop cooperative feedback control model.

[0029] Preferably, in step S2, the dual-loop cooperative feedback control model includes:

[0030] ;

[0031] ;

[0032] in, For guide vane opening; For time; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; This is the initial value of the guide vane opening; The generator's power angle; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; It is the controlled object of the power angle control loop.

[0033] III. Constructing Guide Vane Control Macro Variables and Power Angle Control Macro Variables

[0034] Preferably, in step S3, the guide vane control macrovariable and the power angle control macrovariable are respectively:

[0035] ;

[0036] ;

[0037] in, and These are the macro variables selected for the guide vane and power angle control loops, respectively. For the first Reference value for guide vane opening of the tactical unit; For the first Reference value for the power angle of the generator set; and The first The coordination coefficient between the guide vane opening change and the power angle change of the generator unit; The number of generating units; For the first Guide vane opening of the generator set; For the first The generator power angle of the unit; For the first The difference between the guide vane opening of the generator set and the reference value; For the first The difference between the power angle of the generator set and the reference value.

[0038] Preferably, in step S3, the derivatives of the guide vane control macrovariable and the power angle control macrovariable are respectively:

[0039] ;

[0040] ;

[0041] in, The derivative of the guide vane control macro variable; For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; For guide vane opening; This is the initial value of the guide vane opening; The derivative of the macro variable controlling the power angle; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; It is the controlled object of the power angle control loop.

[0042] IV. Calculation of Guide Vane and Power Angle Control Law

[0043] Preferably, in step S4, substituting the guide vane control macrovariable and its derivative, and the power angle control macrovariable and its derivative into the collaborative control convergent manifold, respectively, includes: substituting each macrovariable and its derivative into the collaborative control convergent manifold. In other words:

[0044] ;

[0045] ;

[0046] in, For macro variables; The derivative of the macro variable; Design parameters for coordination time; and These are the coordinated time design parameters for the guide vane control loop and the power angle control loop, respectively. For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; For guide vane opening; This is the initial value of the guide vane opening; For the first Reference value for guide vane opening of the tactical unit; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; The controlled object of the power angle control loop; For the first The generator power angle of the unit; For the first Reference value for the power angle of the generator set.

[0047] Preferably, in step S4, obtaining the guide vane and power angle control law, which is the output equation for obtaining the cooperative additional feedback term of the guide vane opening and power angle, includes:

[0048] ;

[0049] ;

[0050]

[0051]

[0052] in, and These are the controlled objects of the guide vane control loop and the power angle control loop, respectively. These are the coefficient terms for each parameter; For constant terms; Custom items; For guide vane opening; For the unit speed governor control signal; The generator's power angle; The generator's angular velocity; For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; This is the initial value of the guide vane opening; For the first Reference value for guide vane opening of the tactical unit; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. For the first Reference value for the power angle of the generator set; and These are the coordinated time design parameters for the guide vane control loop and the power angle control loop, respectively.

[0053] As can be seen from the above equation, the output equation of the guide vane control loop includes the guide vane opening, the governor output signal, and a constant term, while the output equation of the power angle control loop includes the power angle, frequency, and a constant term, which is consistent with the above-defined function.

[0054] The beneficial effects of this invention are:

[0055] This invention introduces a cooperative control theory suitable for multi-subsystem joint control. First, guide vane opening and power angle are selected as the control objects in a dual-loop system, and their functional forms are defined. The corresponding control objects are introduced as additional negative feedback terms into the original guide vane and power angle control differential equations, thus improving the original model. By introducing cooperative control theory, guide vane opening and power angle of multiple units are selected to form guide vane control macrovariables and power angle control macrovariables, respectively. The selected macrovariables and their derivatives are substituted into the cooperative control convergence manifold, from which the guide vane and power angle control objects, i.e., the additional negative feedback terms, are derived. This approach establishes the connection between the state variables of multiple units, realizes information change feedback and control, and effectively reduces the output oscillation of the hydropower units and the hydraulic coupling in the shared pipeline. Attached Figure Description

[0056] Figure 1 This is a flowchart of the dual-loop coordinated feedback control method for guide vanes and power angle of the present invention;

[0057] Figure 2 This is a schematic diagram of the dual-loop collaborative feedback control model for the guide vane and power angle of the present invention;

[0058] Figure 3 This is a diagram showing the active power output of unit 1 under power regulation according to the present invention;

[0059] Figure 4 This is a diagram showing the active power output of unit 2 under power regulation according to the present invention;

[0060] Figure 5 This is a diagram showing the terminal voltage output of unit 1 under power regulation according to the present invention;

[0061] Figure 6 This is a diagram showing the terminal voltage output of unit 2 under power regulation according to the present invention;

[0062] Figure 7This is a comparison diagram of the output of the hydraulic coupling term under the two control modes of the present invention;

[0063] Figure 8 This is a comparison diagram of active power output under two control modes in the case of a three-phase short-circuit fault according to the present invention;

[0064] Figure 9 This is a comparison diagram of the terminal voltage output under two control methods in the case of a three-phase short-circuit fault according to the present invention. Detailed Implementation

[0065] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention.

[0066] A dual-loop coordinated feedback control method for guide vanes and power angle in a multi-machine hydropower system, such as... Figure 1 As shown, it includes the following steps:

[0067] S1. Construct a nonlinear model of elastic water hammer under a single pipe and multiple machines, and select the guide vane opening of the hydraulic part and the power angle of the generator part as the dual-loop control objects in the nonlinear model, and define the dual-loop control objects.

[0068] S2. Introduce a dual-loop control object as an additional negative feedback term into the original guide vane and power angle control model to obtain a dual-loop cooperative feedback control model.

[0069] S3. Introduce the theory of coordinated control, select the guide vane opening and power angle of multiple units to form the guide vane control macro variable and the power angle control macro variable respectively, and obtain the derivatives of the guide vane control macro variable and the power angle control macro variable respectively.

[0070] S4. Substitute the guide vane control macrovariate and its derivative, the power angle control macrovariate and its derivative into the collaborative control convergent manifold to obtain the guide vane and power angle control laws. Then, add the guide vane and power angle control laws into the dual-loop collaborative feedback control model and use the dual-loop collaborative feedback control model to control the multi-machine hydropower system.

[0071] This invention is a dual-loop coordinated feedback control method for guide vane-power angle in a multi-machine hydropower system. Its application in the control field of hydropower units has important engineering significance and can effectively reduce the output oscillation of the system.

[0072] The specific steps are as follows:

[0073] S1. The specific steps for constructing a nonlinear model of a single-pipe, multi-machine elastic water hammer, selecting a dual-loop object, and defining the functional form of the control object are as follows:

[0074] The state equations for a single-pipe, multi-unit hydro-turbine generator set under elastic water hammer conditions are shown below:

[0075] ;

[0076] in,

[0077] , ,

[0078] In the formula, and State variables for transient hydraulic calculations of branch pipes; This is the normalized value of the hydraulic impact resistance of the branch pipe; The elastic time constant of the branch pipe; This represents the relative value of the static head of the hydropower station. This is a shared head loss coefficient; This represents the relative flow rate of the public pipeline. The head loss coefficient of the branch pipe; The flow rate of the branch pipe; The time constant of the unit's main servo motor; For the unit speed governor control signal; This is the initial value of the guide vane opening; For guide vane opening; This is the guide vane opening at rated load; This is a multi-machine coupling term; The generator's power angle; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; The inertial time constant of the generator set; The mechanical power of the generator; This refers to the generator's output active power. This is the damping factor of the generator; For generator Axial transient electromotive force; This refers to the output excitation voltage of the excitation system. for Shaft synchronous reactance; for Shaft transient reactance; This refers to the terminal voltage. The excitation time constant of the generator; subscript Indicates the first Each branch pipe and its corresponding unit.

[0079] For the model configuration, the guide vane opening of the hydraulic section and the power angle of the generator section are selected as the dual-loop control objects, namely:

[0080] ;

[0081] ;

[0082] in, For guide vane opening; For time; The time constant of the unit's main servo motor; For the unit speed governor control signal; This is the initial value of the guide vane opening; The generator's power angle; This refers to the synchronous angular velocity of the generator. This represents the generator's angular velocity.

[0083] Define the control objects for each loop:

[0084] ;

[0085] ;

[0086] in, and These are the controlled objects of the guide vane control loop and the power angle control loop, respectively. and These are the functions satisfied by the controlled objects in the guide vane control loop and the power angle control loop, respectively. For guide vane opening; For the unit speed governor control signal; The generator's angular velocity; This refers to the generator's power angle.

[0087] S2. By introducing the corresponding controlled object as an additional negative feedback term into the original guide vane and power angle control differential equations, the original model was improved. The specific steps are as follows:

[0088] definition and The additional feedback terms for the guide vane opening and power angle of the multi-machine system are respectively introduced into the original guide vane and power angle control differential equations, resulting in the new model:

[0089] ;

[0090] ;

[0091] in, For guide vane opening; For time; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; This is the initial value of the guide vane opening; The generator's power angle; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; It is the controlled object of the power angle control loop.

[0092] It can be seen from the above formula that and The original model was improved by introducing negative feedback.

[0093] S3. Introducing the theory of coordinated control, the guide vane opening and power angle of multiple units were selected to form the guide vane control macrovariable and the power angle control macrovariable respectively:

[0094] The macro variables for the multi-machine guide vane opening and power angle are as follows:

[0095] ;

[0096] ;

[0097] in, and These are the macro variables selected for the guide vane and power angle control loops, respectively. For the first Reference value for guide vane opening of the tactical unit; For the first Reference value for the power angle of the generator set; and The first The coordination coefficient between the guide vane opening change and the power angle change of the generator unit; The number of generating units; For the first Guide vane opening of the generator set; For the first The generator power angle of the unit; For the first The difference between the guide vane opening of the generator set and the reference value; For the first The difference between the power angle of the generator set and the reference value.

[0098] Taking the derivative of the above macro variables, we get:

[0099] ;

[0100] ;

[0101] in, The derivative of the guide vane control macro variable; For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; For guide vane opening; This is the initial value of the guide vane opening; The derivative of the macro variable controlling the power angle; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; It is the controlled object of the power angle control loop.

[0102] S4. Substitute the selected macro variables and their derivatives into the convergent manifold of the cooperative control system to derive the guide vane and power angle control laws, i.e., add negative feedback terms to achieve system control, as detailed below:

[0103] Substituting the macro variables and their derivatives into the convergent manifold of the cooperative control In, that is:

[0104] ;

[0105] ;

[0106] in, For macro variables; The derivative of the macro variable; Design parameters for coordination time; and These are the coordinated time design parameters for the guide vane control loop and the power angle control loop, respectively. For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; For guide vane opening; This is the initial value of the guide vane opening; For the first Reference value for guide vane opening of the tactical unit; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; The controlled object of the power angle control loop; For the first The generator power angle of the unit; For the first Reference value for the power angle of the generator set.

[0107] The output equations for the cooperative additional feedback terms of the guide vane opening and the power angle are as follows:

[0108] ;

[0109] ;

[0110]

[0111]

[0112] in, and These are the controlled objects of the guide vane control loop and the power angle control loop, respectively. These are the coefficient terms for each parameter; For constant terms; Custom items; For guide vane opening; For the unit speed governor control signal; The generator's power angle; The generator's angular velocity; For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; This is the initial value of the guide vane opening; For the first Reference value for guide vane opening of the tactical unit; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. For the first Reference value for the power angle of the generator set; and These are the coordinated time design parameters for the guide vane control loop and the power angle control loop, respectively.

[0113] As can be seen from the above equation, the output equation of the guide vane control loop includes the guide vane opening, the governor output signal, and a constant term, while the output equation of the power angle control loop includes the power angle, frequency, and a constant term, which is consistent with the above-defined function.

[0114] Next, we will test the data of a certain hydro-generator unit, taking a one-pipe two-generator system as an example. The specific process is as follows: Its characteristic parameters are: , Other parameters: , , , , , , , , , , , , .

[0115] A dual-loop supplementary cooperative controller was designed based on the dual-loop cooperative feedback control model of this invention, such as... Figure 2 As shown, the active power and voltage output diagrams of the two generating units under the power regulation of Unit 1 are obtained (e.g., Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown), a comparison of the outputs of the hydraulic coupling term under the two control modes (as shown). Figure 7 As shown), a comparison diagram of the outputs of the two control modes under a three-phase short-circuit fault (as shown). Figure 8 , Figure 9 (As shown).

[0116] As can be seen from the diagram, the initial power of both units is 0.8. Step condition setting: When At that time, the active power of unit 1 was adjusted from 0.8 to 0.5, while the active power of unit 2 remained unchanged. At that time, the active power of unit 1 was adjusted from 0.5 to 0.8, and the power of unit 2 was adjusted from 0.8 to 0.9. Three-phase short-circuit fault setting: Units 1 and 2 changed in the same way. At that time, a three-phase short circuit fault occurred on the output side of the unit, which lasted for 0.1 seconds, and then returned to normal.

[0117] When the unit performs power regulation, the introduction of a dual-loop auxiliary cooperative controller significantly reduces the output overshoot of the system's active power and terminal voltage, shortens the time for the system to reach equilibrium, and significantly suppresses hydraulic coupling in the shared pipeline. Under three-phase short-circuit faults, although the instantaneous changes in the unit are not significantly reduced, the time for active power and voltage to return to normal is shortened from 8 seconds to within 0.5 seconds, effectively improving system stability. The dual-loop cooperative feedback control method for guide vane-power angle in a multi-unit hydropower system using a single pipe, as described in this invention, has certain control advantages.

[0118] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalents or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A dual-loop coordinated feedback control method for guide vanes and power angle in a multi-machine hydropower system, characterized in that, Includes the following steps: S1. Construct a nonlinear model of elastic water hammer under a single pipe and multiple machines, and select the guide vane opening of the hydraulic part and the power angle of the generator part as the dual-loop control objects in the nonlinear model, and define the dual-loop control objects. S2. Introduce a dual-loop control object as an additional negative feedback term into the original guide vane and power angle control model to obtain a dual-loop cooperative feedback control model. S3. Introduce the theory of coordinated control, select the guide vane opening and power angle of multiple units to form the guide vane control macro variable and the power angle control macro variable respectively, and obtain the derivatives of the guide vane control macro variable and the power angle control macro variable respectively. S4. Substitute the guide vane control macro variables and their derivatives, and the power angle control macro variables and their derivatives into the collaborative control convergent manifold to obtain the guide vane and power angle control laws. Then, add the guide vane and power angle control laws into the dual-loop collaborative feedback control model and use the dual-loop collaborative feedback control model to control the multi-machine hydropower system. In step S1, selecting the guide vane opening of the hydraulic component and the power angle of the generator component as the dual-loop control objects in the nonlinear model includes: ； ； in, For guide vane opening; For time; The time constant of the unit's main servo motor; For the unit speed governor control signal; This is the initial value of the guide vane opening; The generator's power angle; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; In step S1, defining the dual-loop control object includes: ； ； in, and These are the controlled objects of the guide vane control loop and the power angle control loop, respectively. and These are the functions satisfied by the controlled objects in the guide vane control loop and the power angle control loop, respectively. For guide vane opening; For the unit speed governor control signal; The generator's angular velocity; The generator's power angle; Step S2 includes: taking the control objects of the guide vane control loop and the power angle control loop in the dual-loop control objects as the cooperative additional feedback terms of the multi-machine guide vane opening and power angle of the multi-machine system, respectively, and introducing them into the original guide vane and power angle control differential equations to obtain the dual-loop cooperative feedback control model. In step S2, the dual-loop cooperative feedback control model includes: ； ； in, For guide vane opening; For time; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; This is the initial value of the guide vane opening; The generator's power angle; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; It is the controlled object of the power angle control loop.

2. The guide vane and power angle dual-loop coordinated feedback control method for a single-pipe multi-machine hydropower system as described in claim 1, characterized in that, In step S1, the nonlinear model is the state equation under elastic water hammer of a multi-unit hydro-turbine generator set, including: ； in, ， ， In the formula, and State variables for transient hydraulic calculations of branch pipes; This is the normalized value of the hydraulic impact resistance of the branch pipe; The elastic time constant of the branch pipe; This represents the relative value of the static head of the hydropower station. This is a shared head loss coefficient; This represents the relative flow rate of the public pipeline. The head loss coefficient of the branch pipe; The flow rate of the branch pipe; The time constant of the unit's main servo motor; For the unit speed governor control signal; This is the initial value of the guide vane opening; For guide vane opening; This is the guide vane opening at rated load; This is a multi-machine coupling term; The generator's power angle; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; The inertial time constant of the generator set; The mechanical power of the generator; This refers to the generator's output active power. This is the damping factor of the generator; For generator Axial transient electromotive force; This refers to the output excitation voltage of the excitation system. for Shaft synchronous reactance; for Shaft transient reactance; This refers to the terminal voltage. The excitation time constant of the generator; subscript Indicates the first Each branch pipe and its corresponding unit.

3. The dual-loop coordinated feedback control method for guide vanes and power angle in a single-pipe multi-machine hydropower system as described in claim 1, characterized in that, In step S3, the guide vane control macrovariable and the power angle control macrovariable are respectively: ； ； in, and These are the macro variables selected for the guide vane and power angle control loops, respectively. For the first Reference value for guide vane opening of the tactical unit; For the first Reference value for the power angle of the generator set; and The first The coordination coefficient between the guide vane opening change and the power angle change of the generator unit; The number of generating units; For the first Guide vane opening of the generator set; For the first The generator power angle of the unit; For the first The difference between the guide vane opening of the generator set and the reference value; For the first The difference between the power angle of the generator set and the reference value.

4. The guide vane and power angle dual-loop coordinated feedback control method for a single-pipe multi-machine hydroelectric system as described in claim 1, characterized in that, In step S3, the derivatives of the guide vane control macrovariable and the power angle control macrovariable are respectively: ； ； in, The derivative of the guide vane control macro variable; For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; For guide vane opening; This is the initial value of the guide vane opening; The derivative of the macro variable controlling the power angle; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; It is the controlled object of the power angle control loop.

5. The guide vane and power angle dual-loop coordinated feedback control method for a single-pipe multi-machine hydroelectric system as described in claim 1, characterized in that, In step S4, substituting the guide vane control macrovariable and its derivative, and the power angle control macrovariable and its derivative into the collaborative control convergent manifold, respectively, includes: substituting each macrovariable and its derivative into the collaborative control convergent manifold. In other words: ； ； in, For macro variables; The derivative of the macro variable; Design parameters for coordination time; and These are the coordinated time design parameters for the guide vane control loop and the power angle control loop, respectively. For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; For the unit speed governor control signal; The controlled object of the guide vane control loop; For guide vane opening; This is the initial value of the guide vane opening; For the first Reference value for guide vane opening of the tactical unit; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. The generator's angular velocity; The controlled object of the power angle control loop; For the first The generator power angle of the unit; For the first Reference value for the power angle of the generator set.

6. The guide vane and power angle dual-loop coordinated feedback control method for a single-pipe multi-machine hydroelectric system as described in claim 1, characterized in that, In step S4, the process of obtaining the guide vane and power angle control law, which is the output equation for obtaining the cooperative additional feedback term of the guide vane opening and power angle, includes: ； ； in, and These are the controlled objects of the guide vane control loop and the power angle control loop, respectively. These are the coefficient terms for each parameter; For constant terms; Custom items; For guide vane opening; For the unit speed governor control signal; The generator's power angle; The generator's angular velocity; For the first The coordination coefficient of the guide vane opening change value of the tandem generator unit; The time constant of the unit's main servo motor; This is the initial value of the guide vane opening; For the first Reference value for guide vane opening of the tactical unit; For the first The coordination coefficient of the power angle variation value of the generator set; This refers to the synchronous angular velocity of the generator. For the first Reference value for the power angle of the generator set; and These are the coordinated time design parameters for the guide vane control loop and the power angle control loop, respectively.

Images