Photovoltaic photo-thermal multi-energy complementary system automatic power generation control method based on PID control

Abstract

This invention discloses an automatic power generation control method for a photovoltaic-thermal multi-energy complementary system based on PID control. The method includes: establishing an automatic power generation control dynamic model encompassing a solar thermal power plant, a photovoltaic power plant, and a system frequency response element; constructing transfer function models for both the solar thermal and photovoltaic power plants; constructing regional control deviations based on system frequency deviations and tie-line exchange power deviations, and obtaining the total system control increment through a PID controller; and then allocating the total system control increment based on the adjustable reserve capacity, dynamic response characteristics, rated capacity, droop coefficient, and ramp constraints of each power generation unit to achieve coordinated frequency regulation control of the solar thermal and photovoltaic power plants. This invention can coordinate power generation units with different dynamic characteristics to participate in automatic power generation control, reducing system frequency fluctuations and overshoot, shortening system settling time, and improving the operational stability of the photovoltaic-thermal multi-energy complementary system and the frequency regulation utilization efficiency of the solar thermal power plant.

Description

Technical Field

[0001] This invention relates to the field of new energy power generation control and automatic power generation control technology, and in particular to an automatic power generation control method for a photovoltaic-thermal multi-energy complementary system based on PID control. Background Technology

[0002] With a high proportion of renewable energy connected to the grid, photovoltaic (PV) power generation exhibits significant randomness, volatility, and intermittency. When cloud cover, rapid changes in irradiance, or sudden changes in local load occur, the system's active power balance is easily disrupted, leading to frequency shifts and fluctuations in tie-line exchange power. Concentrated solar power (CSP) possesses a certain degree of continuous regulation capability and can serve as a supporting power source in multi-energy complementary systems, participating in automatic power generation control in conjunction with PV.

[0003] Existing automatic control schemes for photovoltaic (PV) and solar thermal (CSP) power generation mostly employ single feedback regulation or experience-based allocation methods. The main problem lies not in the ability to output control quantities, but in how to rationally allocate the generated total control quantity among power generation units with significantly different dynamic characteristics. PV power plants, connected to the grid via power electronic devices, have a fast response speed but limited continuous support capacity; CSP power plants have a relatively slower response but can provide more stable continuous power compensation. If the differences in time delay characteristics, response speed, adjustable backup capacity, and ramp-up capability between the two types of power sources are not fully considered during the control allocation phase, the following problems can easily occur: First, insufficient utilization of rapid adjustment capability in the initial stage of disturbance leads to excessive frequency drops or rises; second, mismatch between the control quantity and the actual dynamic capability of the units results in delayed response of CSP units or overshoot in PV regulation; third, during system recovery, the frequency regulation capability of CSP power plants is not fully utilized, resulting in insufficient realization of the synergistic regulation advantages of multi-energy complementary systems.

[0004] Therefore, it is necessary to propose an automatic power generation control method for photovoltaic and solar thermal multi-energy complementary systems based on traditional PID control. While maintaining a simple control structure and convenient engineering implementation, the method focuses on solving the dynamic matching and allocation problem of the total control quantity between the photovoltaic power station and the solar thermal power station, thereby improving the system frequency response process and the frequency regulation effect of multi-energy complementarity. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic power generation control method for a photovoltaic-thermal multi-energy complementary system based on PID control, so as to solve the problem that existing new energy automatic power generation control schemes are difficult to take into account the dynamic differences, backup capacity differences and operational constraints of multiple types of power generation units, resulting in large system frequency fluctuations, high overshoot, and long stabilization time.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An automatic power generation control method for a photovoltaic-thermal multi-energy complementary system based on PID control includes the following steps: S1. Obtain the system frequency deviation and tie-line switching power deviation, construct the area control deviation ACE, and input the area control deviation ACE into the PID controller to obtain the total system control increment. ΔP c ; S2. Based on the adjustable reserve capacity, dynamic response capability, rated capacity, droop coefficient, and ramp rate constraints of each power generation unit, adjust the total control increment of the system. ΔP c The control increments for solar thermal power plants and photovoltaic power plants are allocated to obtain the control increments for solar thermal power plants. S3. Input the control increment of the solar thermal power plant and the control increment of the photovoltaic power plant into the transfer function model of the corresponding power generation unit to obtain the output power increment of each power generation unit; S4. Update the system frequency deviation based on the output power increment of each power generation unit, the load disturbance change, and the system frequency response relationship, and execute closed-loop rolling control until the system frequency recovers to the preset range, thus completing the automatic power generation control of the photovoltaic-thermal multi-energy complementary system.

[0007] As a preferred embodiment of the present invention, the transfer function model of the solar thermal power plant is represented by a low-order linear dynamic model to characterize the dynamic process of the solar thermal power plant from the input of AGC control commands to the output of unit power; the low-order linear dynamic model includes, in sequence, an AGC time delay element, a governor element, a reheat turbine element, and a generator element.

[0008] As a preferred embodiment of the present invention, the transfer function model of the solar thermal power plant consists of an AGC time delay component, a governor component, a reheat turbine component, and a generator-power system component, the expressions of which are as follows:

[0009]

[0010]

[0011]

[0012]

[0013] In the formula, Control commands issued by the controller; The control command is the result of the delay module; For the AGC time delay factor of the solar thermal unit; This refers to the amount of adjustment change in the position of the governor valve; This refers to the static proportional coefficient of the speed controller; The time constant of the speed controller; This is the adjustment coefficient; This refers to the system frequency deviation. This is expressed as the gain coefficient of the steam turbine; Expressed as the time constant of the steam turbine; This is the coefficient for reheat gain; This is a constant representing the reheat time; It is the inertial time constant of the generator; This is the unit regulating power coefficient of the load in the system.

[0014] As a preferred embodiment of the present invention, the photovoltaic power station is represented by a transfer function model that includes an AGC delay element and a power response element, in order to characterize the dynamic response characteristics of the photovoltaic power station when participating in automatic power generation control.

[0015] As a preferred embodiment of the present invention, the transfer function model of the photovoltaic power station is as follows:

[0016] In the formula, ; This represents the increase in output power of the photovoltaic power station. For the control increment of photovoltaic power plants; The AGC delay factor for photovoltaic power plants; This represents the power response time constant of a photovoltaic power plant.

[0017] As a preferred embodiment of the present invention, in step S1, the regional control deviation ACE is determined by the system frequency deviation. Δf Power deviation of the tie line ΔP tie The PID controller, based on the regional control deviation ACE, outputs the total control increment of the system through proportional, integral, and derivative operations. ΔP c .

[0018] As a preferred embodiment of the present invention, in step S2, the total control increment of the system is... ΔP c When allocating power, the generating units with high dynamic response capabilities are assigned a higher proportion of control increments during the initial stage of frequency regulation.

[0019] As a preferred embodiment of the present invention, when the output of the photovoltaic power station fluctuates, the reserve capacity of the solar thermal power station and the photovoltaic power station jointly participate in frequency regulation control to reduce the amplitude of system frequency fluctuations.

[0020] As a preferred embodiment of the present invention, in step S4, the closed-loop rolling control continuously corrects the total system control increment and the control increment of each power generation unit by re-inputting the updated system frequency deviation into the PID controller.

[0021] Beneficial effects: Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Under the traditional PID control framework, this invention does not assign frequency regulation tasks to a single power source in a fixed manner. Instead, it coordinates and allocates the total control quantity of the system by combining the dynamic response capability, reserve capacity, and ramping constraints of photovoltaic power plants and solar thermal power plants, thereby improving the matching degree between the control quantity and the actual regulation capability of the unit.

[0022] 2. This invention utilizes the complementary characteristics of fast photovoltaic response and strong continuous solar thermal support to make the frequency regulation task allocation more reasonable in the initial and recovery phases of disturbance, and to give fuller play to the frequency regulation utilization efficiency of solar thermal power plants.

[0023] 3. Without changing the main structure of traditional PID control, this invention realizes coordinated frequency modulation of photovoltaic and solar thermal power, which has the characteristics of simple implementation, small engineering modification, and easy implementation. Attached Figure Description

[0024] To more clearly illustrate the implementation of the present invention or the existing technical solutions, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0025] Figure 1 A model diagram of a solar thermal power plant system provided in an embodiment of the present invention; Figure 2 A photovoltaic power plant system model diagram provided for an embodiment of the present invention; Figure 3 A model diagram of a photovoltaic-thermal multi-energy complementary system provided in an embodiment of the present invention; Figure 4 A comparison of system frequency changes provided in embodiments of the present invention; Figure 5 A comparison chart of output changes of a solar thermal power plant provided in an embodiment of the present invention. Detailed Implementation

[0026] To make the technical solution, objective, and beneficial effects of the present invention clearer, the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0027] Reference Figures 1 to 3 This embodiment provides an automatic power generation control method for a photovoltaic-thermal multi-energy complementary system based on traditional PID control, in order to solve the problem that existing new energy automatic power generation control schemes are unable to take into account the dynamic differences, backup capacity differences and operational constraints of multiple types of power generation units, resulting in large system frequency fluctuations, high overshoot, and long stabilization time.

[0028] Before detailing the specific steps of the control method, it is first necessary to construct a mathematical model of the photovoltaic-thermal multi-energy complementary system. The system model constructed in this embodiment mainly includes a solar thermal power plant, a photovoltaic power plant, a system frequency response element, and a controller element. To quantitatively describe the dynamic characteristics of each element, the transfer function models of each part are defined in detail below. These models constitute the theoretical foundation for the subsequent implementation of the control strategy.

[0029] Establish a control object model for a photovoltaic-thermal multi-energy complementary system.

[0030] A multi-energy complementary system model is established, including solar thermal power plants and photovoltaic power plants, in which both solar thermal power plants and photovoltaic power plants are used as control objects for automatic power generation control.

[0031] The solar thermal power plant model adopts a modeling approach similar to that of the thermal power unit load frequency control model, including a time delay model, a governor model, a turbine model, and a generator model; the photovoltaic power plant uses a transfer function to characterize its system dynamic characteristics and a simplified transfer function model for dynamic simulation.

[0032] Dynamic Model of a Concentrated Solar Power Plant: The dynamic processes of a concentrated solar power plant are quite complex, involving the conversion between thermal and mechanical forces. For example... Figure 1 As shown, this embodiment uses a low-order linear transfer function model to characterize the dynamic process from AGC command input to power output.

[0033] In the power system AGC process, in order to more accurately simulate the dynamic response changes of the solar thermal power unit after receiving the control command issued by the controller, the AGC delay of the solar thermal power unit is increased. The formula is as follows: (1) (2) In the formula, Control commands issued by the controller; The control command is the result of the delay module; This is the AGC time delay factor for the solar thermal unit.

[0034] In a solar thermal power generator set, the speed governor's main function is to regulate the prime mover of the turbine. It mainly consists of components such as a speed measurement unit, an amplifier, and an actuator. In practical engineering applications, speed governors of different types of units generally share the same mathematical model, roughly as shown in the following formula: (3) The turbine transfer function is as follows: (4) In current AGC (Automatic Generation Control) processes, my country typically employs reheat turbines to improve steam utilization efficiency. Reheat turbines are also used as generator units in solar thermal power plants. The principle is that after performing work, the steam re-enters the reheater for a second heat exchange, and then returns to the turbine to perform work again. Therefore, this reheating and recirculation of steam leads to a significant time lag, resulting in the transfer function of the reheat turbine as shown in the following equation: (5) In the formula, This is the coefficient for reheat gain; This is a constant representing the reheat time.

[0035] In a power system, load disturbances ultimately result in fluctuations in the system frequency. Generators are the primary devices that convert mechanical energy into electrical energy. When a generator is operating normally, its rotational speed is constant. From the energy conservation equation for generator operation, we can deduce: (6) In the formula, The change in mechanical power obtained by the generator; It is the change in the emitted electromagnetic power; It is the inertial time constant of the generator; It is the change in angular velocity in the generator, and its trend is proportional to the change in frequency.

[0036] The above equation can be transformed using a Laplace transform: (7) Furthermore, since the generator's output electromagnetic power is related to changes in the load on the power grid, it can be concluded that: (8) In the formula, These are the variables of the system in its initial state; The frequency regulation variable is automatically adjusted by the load itself; This is the unit regulating power coefficient of the load in the system.

[0037] Combining the above equations, we can obtain the transfer function for this part: (9) In the formula, It is the inertial time constant of the generator; This is the unit regulating power coefficient of the load in the system.

[0038] Dynamic model of a photovoltaic power plant: Unlike solar thermal power, photovoltaic power plants are connected to the grid via power electronic devices, resulting in extremely fast response times. For example... Figure 2As shown, its model mainly includes AGC delay and power dynamic response components: (10) In the formula, ; This represents the increase in output power of the photovoltaic power station. For the control increment of photovoltaic power plants; The AGC delay factor for photovoltaic power plants; This represents the power response time constant of a photovoltaic power plant.

[0039] Construct a multi-source AGC collaborative control system model.

[0040] Based on the established transfer function models of solar thermal power plants and photovoltaic power plants, a multi-source AGC collaborative control system model is constructed.

[0041] In the aforementioned coordinated control system, the solar thermal power plant and the photovoltaic power plant respectively receive control increments allocated by the controller, and after passing through their respective time delay and dynamic response stages, output power changes to participate in system frequency regulation. The coordinated control system includes parameters or variables such as the solar thermal power plant's AGC time delay constant, the photovoltaic power plant's AGC time delay constant, the governor's time constant, the turbine's reheat coefficient, the reheat time constant, the generator's time constant, the load damping coefficient, the unit's moment of inertia, the system droop coefficient, the unit's droop coefficient, the tie-line exchange power increment, the controller's total control increment, the output power increment of each power generation unit, the control increment allocated to each power generation unit, load disturbance changes, and frequency deviations.

[0042] In this embodiment, the multi-source AGC collaborative control system model can be written as the following state equation: (11) Further written in state-space form: (12) The parameters can be expressed as follows: (13) in, This refers to the system frequency deviation. This represents the increase in output power of a solar thermal power plant. This represents the increase in output power of the photovoltaic power station. This refers to the change in load disturbance. This refers to the power deviation of the tie line. This is the load damping coefficient; The moment of inertia of the unit; The time constant of the solar thermal generator; The power response time constant of the photovoltaic power plant; For the governor position increment, This is the time-delayed increment for photothermal control; This is the time-delayed photovoltaic control increment; and These are the control increments allocated to solar thermal power plants and photovoltaic power plants, respectively.

[0043] Based on the established precise mathematical model, the automatic power generation control method proposed in this embodiment aims to coordinate the output of solar thermal and photovoltaic power through closed-loop control. The core of this method lies in the rational allocation of control commands according to the model characteristics. The specific execution steps are as follows: Step S1: Construct the system frequency deviation and tie-line switching power deviation into a regional control deviation ACE, and input the regional control deviation ACE into the PID controller to obtain the total system control increment. ΔP c .

[0044] This step marks the beginning of control. The system monitors the actual frequency f of the power grid and the switching power of the tie lines in real time. P tie The system frequency deviation Δf and tie-line switching power deviation are obtained by comparing them with their set values. ΔP tie Then, according to the formula ( Calculate the area control deviation (ACE), where B a This represents the system frequency deviation coefficient. The ACE signal comprehensively reflects the power deficit in this control region.

[0045] The calculated ACE signal is input into a PID controller with preset parameters. The PID controller outputs the total power regulation demand of the system, i.e., the total control increment of the system, based on the proportional, integral, and derivative operation laws. The control law of the PID controller is as follows: (14) In this invention, let When the target value of the regional control deviation is zero, that is... Then there is The total system control increment output by the controller is denoted as... .

[0046] in, For proportional gain, The integral coefficient is... These are the differential coefficients. To control the deviation, This represents the total control increment of the system.

[0047] Step S2: Based on the adjustable reserve capacity, dynamic response capability, rated capacity, droop coefficient, and ramp rate constraints of each power generation unit, adjust the total control increment of the system. △P c The control increments for solar thermal power plants and photovoltaic power plants are allocated to obtain the control increments for solar thermal power plants and photovoltaic power plants.

[0048] This step is the core of achieving coordinated frequency modulation of solar thermal and photovoltaic power. The control and distribution module receives data from step S1. Based on the real-time status and physical limitations of the solar thermal power plant and the photovoltaic power plant, it dynamically decomposes them into two sub-instructions.

[0049] The allocation should follow these principles: Adjustable reserve capacity constraint: The increment allocated to any power plant shall not exceed its current adjustable / lower reserve capacity.

[0050] Rated capacity and ramp rate constraints: The output variation of each power station must be within its rated capacity range, and the variation per unit time must not exceed its maximum ramp rate.

[0051] Dynamic response characteristics: To optimize overall regulation performance, power generation units with high dynamic response capabilities (such as photovoltaic power plants) should bear a higher proportion of control increments in the initial stage of frequency regulation to quickly curb frequency changes; while solar thermal power plants with continuous regulation capabilities should provide stable power support.

[0052] Furthermore, to address fluctuations in photovoltaic (PV) power output, when a PV power plant experiences a sudden decrease or increase in its output due to changes in solar irradiance, the aforementioned allocation mechanism will be immediately activated. This mechanism coordinates the use of their respective reserve capacities by both solar thermal (CSP) and PV power plants to participate in frequency regulation. For example, when PV output drops sharply, control commands will instruct the PV power plant to instantly increase its output (if reserves are sufficient) by fully utilizing its rapid response capabilities, while simultaneously instructing the CSP power plant to steadily increase its output. The two power plants work together to quickly compensate for the power deficit, thereby effectively reducing the amplitude of system frequency fluctuations.

[0053] One feasible allocation strategy in this embodiment is to first set initial allocation weights based on the dynamic response speed of each power plant (determined by the time constant of its transfer function model), and then perform rolling optimization calculations in each control cycle, taking into account the above constraints, to finally determine the control increment of the solar thermal power plant. And photovoltaic power plant control increment And satisfy + = .

[0054] Step S3: Input the control increment of the solar thermal power plant and the control increment of the photovoltaic power plant into the transfer function model of the corresponding power generation unit to obtain the output power increment of each power generation unit.

[0055] This step describes how control commands are executed by each power generation unit and translated into actual power output changes.

[0056] The result obtained in step S2 and These are respectively used as inputs to the previously established transfer function models for solar thermal power plants and photovoltaic power plants. Through model calculations (or, in a real system, as the response of the power plant control system according to its inherent dynamic characteristics), the actual output power increment of each power plant can be obtained. and .Right now: (15) (16) Step S4: Update the system frequency deviation based on the output power increment of each power generation unit, the load disturbance change, and the system frequency response relationship, and execute closed-loop rolling control until the system frequency recovers to the preset range.

[0057] This step completes the control loop. The actual power output of the solar thermal and photovoltaic power plants, along with current load disturbances, interact with the power system, creating a new net power imbalance. The system's frequency response model generates a new system frequency deviation, which is then fed back to the input of step S1 as the starting point for calculating the ACE in the next control cycle. Steps S1 to S4 are executed cyclically with a fixed control cycle (e.g., 2-4 seconds), forming a closed-loop rolling control system. This process continues, constantly revising the control commands until the system frequency deviation is adjusted and stabilized within an allowable range (e.g., ±0.05 Hz).

[0058] To illustrate the effectiveness of the method of this invention, a comparison is made below with a set of simulation parameters and working conditions.

[0059] Under a specific operating condition, the relevant parameters of the solar thermal power plant are set as follows: rated capacity 100 MW, ramp rate 5% / min, AGC time delay constant 20 s, governor time constant 0.1 s, reheat coefficient 2.5, reheat time constant 10 s, generator time constant 0.2 s, load damping coefficient 2, unit moment of inertia 10 s, unit time constant 10 s, and unit droop coefficient 0.1.

[0060] When the solar thermal power plant is affected by a 5 MW step disturbance load, the controller issues a control command to rapidly increase the output of the solar thermal power plant without exceeding the ramp rate, and reaches stability after experiencing one overshoot and slight fluctuation within 15 minutes.

[0061] In another specific operating condition, when the solar thermal power plant receives a frequency regulation command from the power grid, the controller issues a control command to cause the output of the solar thermal power plant to rise rapidly and reach a stable state after an overshoot within 15 minutes.

[0062] The photovoltaic power plant parameters are set as follows: rated capacity 50 MW, unit time constant 2 s, AGC delay constant 1 s, inverter time constant 0.01 s, and unit droop coefficient 0.02; the parameters of the solar thermal power plant are the same as in step S4.

[0063] When the photovoltaic power plant experiences a sudden 5 MW output drop due to resource fluctuations, the controller issues control commands to coordinate all power generation units to utilize reserve capacity to increase output, jointly compensating for the power deficit and suppressing system frequency deviation. The multi-energy complementary system stabilizes within 8 minutes after one overshoot and minor fluctuation. Simultaneously, the controller issues output-boosting commands to the concentrated solar power (CSP) plant, and adjusts the control commands as the photovoltaic power plant's output gradually recovers, returning the CSP plant to its original output state. Under a total output fluctuation of 10 MW, the system can complete the frequency regulation control process within 15 minutes, with a frequency change not exceeding 0.1 Hz.

[0064] Furthermore, the following comparison conditions are set: Operating condition 1 is that the solar thermal power plant receives a 10 MW frequency regulation command independently; Operating condition two involves a sudden drop of 10 MW in the total output of the multi-energy complementary system, in which the solar thermal power plant and the photovoltaic power plant work together to participate in frequency regulation. Reference Figure 4 and Figure 5 In operating condition one, the control duration is 24 minutes, the frequency change is 0.12 Hz, the maximum frequency overshoot is 0.118 Hz, and the maximum power overshoot of the solar thermal power plant is 7.083 MW. In operating condition two, the control duration is 13 minutes, the frequency change is 0.044 Hz, the maximum frequency overshoot is 0.039 Hz, and the maximum power overshoot of the solar thermal power plant is 1.792 MW.

[0065] Therefore, the automatic power generation control method described in this invention can reduce system frequency fluctuations and overshoot, shorten system stabilization time, and improve the frequency regulation utilization efficiency of solar thermal power plants in multi-energy complementary systems.

Claims

1. A PID control-based photovoltaic photo-thermal multi-energy complementary system automatic power generation control method, characterized in that, Includes the following steps: S1, acquire system frequency deviation and tie-line exchange power deviation, construct regional control deviation ACE, and input the regional control deviation ACE into a PID controller to obtain a system total control increment ΔP c ; S2, according to the adjustable reserve capacity, dynamic response ability, rated capacity, regulation difference coefficient and climbing rate constraint of each power generation unit, the system total control increment is allocated to each power generation unit ΔP c The allocation is performed to obtain a photo-thermal power station control increment and a photovoltaic power station control increment. S3. Input the control increment of the solar thermal power plant and the control increment of the photovoltaic power plant into the transfer function model of the corresponding power generation unit to obtain the output power increment of each power generation unit; S4. Update the system frequency deviation based on the output power increment of each power generation unit, the load disturbance change, and the system frequency response relationship, and execute closed-loop rolling control until the system frequency recovers to the preset range, thus completing the automatic power generation control of the photovoltaic-thermal multi-energy complementary system.

2. The method according to claim 1, characterized in that: The transfer function model of the solar thermal power plant is represented by a low-order linear dynamic model to characterize the dynamic process of the solar thermal power plant from the input of AGC control commands to the output of unit power; the low-order linear dynamic model includes, in sequence, the AGC time delay stage, the governor stage, the reheat turbine stage, and the generator stage.

3. The method of claim 2, wherein: The transfer function model of the solar thermal power plant consists of an AGC time delay component, a governor component, a reheat turbine component, and a generator-power system component, and their expressions are as follows: ; ； ； ； ； In the formula, Control commands issued by the controller; The control command is the result of the delay module; For the AGC time delay factor of the solar thermal unit; This refers to the amount of adjustment change in the position of the governor valve; This refers to the static proportional coefficient of the speed controller; The time constant of the speed controller; This is the adjustment coefficient; This refers to the system frequency deviation. This is expressed as the gain coefficient of the steam turbine; Expressed as the time constant of the steam turbine; This is the coefficient for reheat gain; This is a constant representing the reheat time; It is the inertial time constant of the generator; This is the unit regulating power coefficient of the load in the system.

4. The method according to claim 1, characterized in that: The photovoltaic power station is represented by a transfer function model that includes an AGC delay element and a power response element, in order to characterize the dynamic response characteristics of the photovoltaic power station when participating in automatic power generation control.

5. The method according to claim 4, characterized in that: The transfer function model of the photovoltaic power station is as follows: ； In the formula, ; This represents the increase in output power of the photovoltaic power station. For the control increment of photovoltaic power plants; The AGC delay factor for photovoltaic power plants; This represents the power response time constant of a photovoltaic power plant.

6. The method according to claim 1, characterized in that: In step S1, the regional control deviation ACE is determined by the system frequency deviation. Δf Power deviation of the tie line Δ P tie The PID controller, based on the regional control deviation ACE, outputs the total control increment of the system through proportional, integral, and derivative operations. ΔP c .

7. The method according to claim 1, characterized in that: In step S2, the total control increment of the system is... ΔP c When allocating power, the generating units with high dynamic response capabilities are assigned a higher proportion of control increments during the initial stage of frequency regulation.

8. The method according to claim 1, characterized in that: When the output of a photovoltaic power plant fluctuates, the reserve capacity of both the solar thermal power plant and the photovoltaic power plant participates in frequency regulation control to reduce the amplitude of system frequency fluctuations.

9. The automatic power generation control method according to claim 1, characterized in that: In step S4, the closed-loop rolling control continuously corrects the total system control increment and the control increment of each power generation unit by re-inputting the updated system frequency deviation into the PID controller.

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