A Multi-Area Interconnected Power Grid Load Frequency Control Method and System

Abstract

The present invention relates to the field of power system load frequency control, and in particular to a load frequency control method and system for a multi-area interconnected power grid. An estimator corresponding to each area receives the load frequency error at time k sent by the power plant in the current area and the control instruction sent by the compensator, updates the pseudo partial derivative, and sends it to the trigger corresponding to the current area. The trigger determines whether the event trigger condition is satisfied. If it is satisfied, the updated pseudo partial derivative and the load frequency error at time k are sent to the controller corresponding to the current area. The controller sends the updated controller control instruction to the compensator corresponding to the current area through the power network. The compensator compensates the updated controller control instruction through the power network delay compensation strategy and sends it to the power plant corresponding to the current area. The present invention can achieve the control of the power system load frequency without a power system model, and solves the problems of limited power network communication resources and power network delay.

Description

Technical Field

[0001] The present invention relates to the field of load frequency control in power systems, and particularly to a load frequency control method and system for a multi-area interconnected power grid. Background Art

[0002] In a power system, maintaining frequency stability is an important factor for the safe operation of the system. Unstable power systems not only affect user electricity consumption and damage system equipment, but may even lead to power grid collapse, causing large-scale power outages and huge losses to society. Load Frequency Control (LFC) is a key technology in power systems, which is used to maintain system frequency stability and ensure that power exchanges between regions proceed as planned. In a multi-area interconnected power system, the goal of load frequency control is to ensure that the power generation in each area matches the power consumption and maintain the system frequency within an acceptable range. With the continuous expansion of the scale of power systems and the large-scale access of renewable energy sources such as wind and solar energy, load frequency control faces new challenges.

[0003] A power system is a complex power network composed of many different types of generators, loads, and transmission lines. The structure of the power system is complex and affected by various factors, making it difficult to establish an accurate mathematical model. In a multi-area interconnected power system, information needs to be transmitted between different control centers through a communication power network, which can cause signal transmission delays. In addition, the bandwidth and energy in the actual communication power network are limited, and frequent data transmission will increase communication costs and energy consumption. Therefore, when controlling the load frequency of a multi-area interconnected power system, the finiteness of communication resources should be considered and the number of communication times and energy consumption should be reduced. Therefore, developing a load frequency control method for a multi-area interconnected power system that does not require a power system model and considers power network delays and limited communication resources has become an important research direction. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the technical problems in the prior art that it is difficult to obtain an accurate model of the power system in reality, and there are power network delays and limited communication resources, resulting in very difficult load frequency control in each area.

[0005] To solve the above technical problems, the present invention provides a load frequency control method for a multi-area interconnected power grid, including the following steps:

[0006] Step S1: The estimator corresponding to each area receives the load frequency error sent by the power plant in the current area at the current moment and the control instruction sent by the compensator. The estimator updates the pseudo partial derivative and compares the updated pseudo partial derivative with the The moment load frequency error is sent to the corresponding trigger in the current area through the power grid;

[0007] Step S2: At the moment when the trigger receives the updated pseudo partial derivative and the moment load frequency error, based on the moment load frequency error and the dynamic event trigger function, determine whether the event trigger condition is satisfied. If it is satisfied, send the updated pseudo partial derivative and the moment load frequency error to the corresponding controller in the current area. Among them, is the delay duration for the estimator to send the updated pseudo partial derivative and the moment load frequency error to the corresponding trigger in the current area through the power grid; is the delay duration for the estimator to send the updated pseudo partial derivative and the moment load frequency error to the corresponding trigger in the current area through the power grid;

[0008] Step S3: After the controller receives the updated pseudo partial derivative and the moment load frequency error, send the updated controller control instruction to the corresponding compensator in the current area through the power grid;

[0009] Step S4: At the moment when the compensator receives the updated controller control instruction, compensate the updated controller control instruction through the power grid delay compensation strategy, and send the compensated control instruction to the corresponding power plant in the current area. Among them, is the delay duration for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power grid; is the delay duration for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power grid; is the delay duration for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power grid;

[0010] Through steps S1 - S4, control the load frequency error in each area of the multi - area interconnected power system to be within a preset range centered on 0.

[0011] Preferably, the estimator corresponding to the current area receives the moment load frequency error sent by the power plant in the current area and the control instruction sent by the compensator. The estimator updates the pseudo partial derivative, including:

[0012] Based on the moment load frequency error, the estimator updates the pseudo partial derivative;

[0013] When the updated pseudo partial derivative satisfies the reset mechanism condition, make the updated pseudo partial derivative equal to the initial value of the pseudo partial derivative set in the current area;

[0014] When the updated pseudo partial derivative does not satisfy the reset mechanism condition, the updated pseudo partial derivative remains unchanged.

[0015] Preferably, the The moment load frequency error, the estimator updates the pseudo partial derivative, and the calculation formula is:

[0016] ;

[0017] Wherein, is the updated pseudo partial derivative corresponding to the th area at the moment, is the updated pseudo partial derivative corresponding to the th area at the moment, is the first set constant greater than 0 and less than or equal to 1 for the th area, is the second set constant greater than 0 for the th area, represents the moment, is the increment of the load frequency error of the th area at the moment, , is the load frequency error of the th area at the moment, is the load frequency error of the th area at the moment, , is the increment of the control command sent by the compensator of the th area at the moment, is the control command sent by the compensator of the th area at the moment, is the control command sent by the compensator of the th area at the moment, , represents the total number of areas.

[0018] Preferably, the reset mechanism condition is:

[0019] ;

[0020] Wherein, is the updated pseudo partial derivative corresponding to the th area at the moment, represents the moment, is the third set constant greater than 0, , is the increment of the control command sent by the compensator of the th area at the moment For the th area control instruction sent by the time compensator, For the th area time control instruction, , indicating the total number of areas.

[0021] Preferably, based on the time load frequency error and the dynamic event trigger function, it is judged whether the event trigger condition is satisfied. If not, the updated pseudo partial derivative and the time load frequency error are not sent to the corresponding controller of the current area.

[0022] Preferably, the dynamic event trigger function includes:

[0023] Define the time set when the th area satisfies the event trigger condition as , indicating the number of times the event trigger condition is satisfied at the time, indicating the number of times the event trigger condition is satisfied;

[0024] For the th area the calculation formula of the dynamic event trigger function at the

[0025] ;

[0026] For the th area the dynamic variable at the time is calculated as:

[0027] ;

[0028] For the th area the calculation formula of the event trigger error at the

[0029] , ;

[0030] Among them, is the dynamic event trigger function at the th area , is the dynamic variable at the th area , is the th area The dynamic variable at a moment is the th region event trigger error at a moment is the th region event trigger error at a moment , is the difference between the set value of the target area control error of the th region and the load frequency error at a moment is the difference between the set value of the target area control error of the th region and the load frequency error at a moment represents the set value of the target area control error is the th region load frequency error at a moment represents the th region at the corresponding moment when the th event trigger condition is satisfied is the third set constant greater than 0 for the th region is the fourth set constant greater than 0 for the th region, and .

[0031] Preferably, the event trigger condition is:

[0032] ;

[0033] wherein, represents the th region at the corresponding moment when the th event trigger condition is satisfied is the th region dynamic event trigger function at a moment

[0034] Preferably, after the controller receives the updated pseudo partial derivative and the load frequency error at a moment, the updated controller control instruction is sent to the corresponding compensator in the current region through the power network, and the calculation formula of the updated controller control instruction is:

[0035] ;

[0036] wherein, is the a region the updated controller control instruction corresponding to the moment, for the a region the updated controller control instruction corresponding to the moment, , for the a region the updated pseudo partial derivative corresponding to the moment, represents the target region control error set value, for the a region the moment load frequency error, for the the sixth set constant of the a region greater than 0 and less than or equal to 1, for the the seventh set constant of the a region greater than 0, and .

[0037] Preferably, the compensator receives the updated controller control instruction at the moment, and compensates the updated controller control instruction through the power network delay compensation strategy. The compensation formula is:

[0038] ;

[0039] wherein, for the a region the compensated control instruction corresponding to the moment, for the a region the compensated control instruction corresponding to the moment, , for the a region the difference between the updated controller control instruction corresponding to the moment and the updated controller control instruction corresponding to the moment, , for the a region the updated controller control instruction corresponding to the moment, for the a region the updated controller control instruction corresponding to the moment, , is a set constant, and , and are respectively and the upper bounds of, is the pseudo partial derivative, , is the total delay duration, represents the moment.

[0040] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0041] For a multi - area interconnected power grid load frequency control method and system according to the present invention, the estimator corresponding to each area receives the load frequency error at the moment and the control instruction sent by the compensator from the power plant in the current area, updates the pseudo - partial derivative, and sends it to the trigger corresponding to the current area. Based on the load frequency error at the moment and the dynamic event - triggering function, the trigger determines whether the event - triggering condition is met. If it is met, the updated pseudo - partial derivative and the load frequency error at the moment are sent to the controller corresponding to the current area. The controller sends the updated controller control instruction to the compensator corresponding to the current area through the power network. The compensator compensates the updated controller control instruction through the power network delay compensation strategy and sends it to the power plant corresponding to the current area. The present invention can achieve the control of the load frequency of the power system without knowing the internal model information of the power system. By designing the dynamic event - triggering function and the power network delay compensation strategy, the problems of limited communication resources in the power network and power network delay are solved respectively, the frequency fluctuations between regions are reduced, and the stability and reliability of the power system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to the specific embodiments of the present invention and in combination with the drawings, where:

[0043] Figure 1 is the structural diagram of a multi - area interconnected power grid load frequency control method and system of the present invention.

[0044] Figure 2 is the step - flow diagram of a multi - area interconnected power grid load frequency control method of the present invention.

[0045] Figure 3 is the schematic diagram of an interconnected power system composed of three areas in a multi - area interconnected power grid load frequency control method and system of the present invention.

[0046] Figure 4 is the schematic diagram of the power network time delay in an interconnected power system composed of three areas in a multi - area interconnected power grid load frequency control method and system of the present invention.

[0047] Figure 5It is a schematic diagram of the event trigger interval under static load in a multi - area interconnected power grid load frequency control method and system of the present invention.

[0048] Figure 6 It is a load increment curve graph under static load in a multi - area interconnected power grid load frequency control method and system of the present invention.

[0049] Figure 7 It is a schematic diagram of the event trigger interval under dynamic load in a multi - area interconnected power grid load frequency control method and system of the present invention.

[0050] Figure 8 It is a load increment curve graph under dynamic load in a multi - area interconnected power grid load frequency control method and system of the present invention. Detailed implementation manners

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments cited are not intended to limit the present invention.

[0052] Refer to Figure 1 、 2 As shown, Embodiment 1 of the present invention provides a multi - area interconnected power grid load frequency control method, including the following steps:

[0053] Step S1: Each area - corresponding estimator receives the load frequency error sent by the power plant in the current area at the moment and the control instruction sent by the compensator. The estimator updates the pseudo - partial derivative and sends the updated pseudo - partial derivative and the load frequency error at the moment to the trigger corresponding to the current area through the power network;

[0054] Among them, the load frequency error of the power plant in the current area at the moment is the difference between the actual load frequency and the target load frequency at the moment.

[0055] In this embodiment, preferably, each area - corresponding estimator receives the load frequency error sent by the power plant in the current area at the moment and the control instruction sent by the compensator. The estimator updates the pseudo - partial derivative, including:

[0056] Based on the load frequency error at the moment, the estimator updates the pseudo - partial derivative;

[0057] When the updated pseudo - partial derivative meets the reset mechanism condition, make the updated pseudo - partial derivative equal to the initial value of the pseudo - partial derivative set for the current area;

[0058] When the updated pseudo partial derivative does not meet the reset mechanism condition, the updated pseudo partial derivative remains unchanged.

[0059] Based on the instantaneous load frequency error sent by the power plant in the current area, the estimator updates the pseudo partial derivative, and the calculation formula is:

[0060] ;

[0061] where is the updated pseudo partial derivative corresponding to the th area at the moment, is the updated pseudo partial derivative corresponding to the th area at the moment, is the first set constant greater than 0 and less than or equal to 1 for the th area, is the second set constant greater than 0 for the th area, represents the moment, is the th area instantaneous increment of the load frequency error at the moment, , is the load frequency error of the th area at the moment, is the load frequency error of the th area at the moment, , is the th area instantaneous increment of the control command sent by the compensator at the moment, is the control command sent by the compensator of the th area at the moment, is the control command sent by the compensator of the th area at the moment, , represents the total number of areas.

[0062] The reset mechanism condition is:

[0063] ;

[0064] where is the updated pseudo partial derivative corresponding to the th area at the moment, represents the moment, is a third set constant greater than 0, , is the increment of the control command sent by the time compensator for the th region, is the control command sent by the time compensator for the th region, is the control command for the th region at the time, , represents the total number of regions.

[0065] Step S2: The trigger receives the updated pseudo partial derivative and the load frequency error at time . Based on the load frequency error and the dynamic event triggering function at time , it determines whether the event triggering condition is satisfied. If it is satisfied, it sends the updated pseudo partial derivative and the load frequency error at time to the corresponding controller of the current region, where , is the delay duration for the estimator to send the updated pseudo partial derivative and the load frequency error at time to the corresponding trigger of the current region through the power grid;

[0066] In this embodiment, preferably, based on the load frequency error and the dynamic event triggering function at time , it determines whether the event triggering condition is satisfied. If it is not satisfied, it does not send the updated pseudo partial derivative and the load frequency error at time to the corresponding controller of the current region.

[0067] In this embodiment, preferably, the dynamic event triggering function includes:

[0068] Define the set of times when the th region satisfies the event triggering condition as , represents the number of times the event triggering condition is satisfied at time, , represents the number of times the event triggering condition is satisfied;

[0069] For the th region, the calculation formula of the dynamic event triggering function at time is:

[0070] ;

[0071] For the th region, Dynamic variable at a moment The calculation formula is:

[0072] ;

[0073] The th region The calculation formula for the event trigger error at a moment is:

[0074] , ;

[0075] Among them, is the dynamic event trigger function at the moment of the th region, is the dynamic variable at the moment of the th region, is the dynamic variable at the moment of the th region, is the dynamic variable at the moment of the th region, is the event trigger error at the moment of the th region, is the event trigger error at the moment of the th region, is the difference between the target area control error setting value of the th region and the load frequency error at the moment of is the difference between the target area control error setting value of the th region and the load frequency error at the moment of represents the target area control error setting value, is the load frequency error at the moment of the th region, represents the corresponding moment when the th region satisfies the event trigger condition for the th time, is the third set constant greater than 0 for the th region, is the fourth set constant greater than 0 for the th region, represents the th region, and at the moment of the th time when the event trigger condition is satisfied, is the fifth set constant greater than 0 for the th region, and is the th region, and is the th region, and .

[0076] The event trigger condition is:

[0077] ;

[0078] Among them, represents the corresponding moment when the th region satisfies the event triggering condition for the th time, is the dynamic event triggering function of the th region at the moment.

[0079] By setting the event triggering condition, the event triggering mechanism allows the system to perform data transmission under specific conditions, enabling the controller not to update the control instructions in real time, thereby reducing the transmission of redundant data. Frequent real-time communication and data transmission consume a large amount of power. Through the event triggering mechanism, the controller updates the instructions only when necessary, thus reducing the number of communications and energy consumption, and improving the overall efficiency of load frequency control.

[0080] Step S3: After the controller receives the updated pseudo partial derivative and the load frequency error at the moment, it sends the updated controller control instruction to the corresponding compensator in the current region through the power network;

[0081] The calculation formula for the updated controller control instruction is:

[0082] ;

[0083] Among them, is the updated controller control instruction corresponding to the th region at the moment, is the updated controller control instruction corresponding to the th region at the moment, , is the updated pseudo partial derivative corresponding to the th region at the moment, represents the target region control error set value, is the th region load frequency error at the moment, is the sixth set constant greater than 0 and less than or equal to 1 for the th region, is the seventh set constant greater than 0 for the th region, and .

[0084] Step S4: The compensator is at Receive the updated controller control instruction at all times, compensate the updated controller control instruction through the power network delay compensation strategy, and send the compensated control instruction to the corresponding power plant in the current area, where , is the delay duration for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power network;

[0085] The compensator Receives the updated controller control instruction at all times, compensates the updated controller control instruction through the power network delay compensation strategy, and the compensation formula is:

[0086] ;

[0087] where is the th area is the th area , is the th area is the difference between the updated controller control instruction corresponding to and is the th area is the th area , is a set constant, and , and are respectively and upper bounds, is the pseudo partial derivative, , is the total delay duration, represents the time.

[0088] Through steps S1 - S4, control the load frequency error in each area of the multi - area interconnected power system to be within a preset range centered on 0.

[0089] Considering the impact of power network delay, a power network delay compensation strategy is designed to compensate the control instructions sent by the updated compensator. Power network delay causes a time difference between the control instructions and the actual situation. Through delay compensation, the control instructions can be adjusted to make up for this time difference, thereby improving the control accuracy of the system for the target state.

[0090] As Figure 3 、 4 shown, Figure 3 it is a schematic diagram of an interconnected power system composed of three regions, Figure 4 and it is a schematic diagram of power network time delay in the interconnected power system composed of three regions.

[0091] In the second embodiment of the present invention, an interconnected power system composed of three regions is built, and the load frequency control of static load and dynamic load is carried out respectively by a multi-region interconnected power grid load frequency control method of the present invention.

[0092] For the interconnected power system composed of three regions, the power system model is:

[0093] ,

[0094] The main parameters of the power system model are designed as: , , , , , , , , , , , , , , , , , , , .

[0095] Among them, is the synchronous torque coefficient between region and region , is the generator unit damping coefficient, is the generator inertia, is the generator speed reduction coefficient, is the governor time constant, is the turbine time constant, is the frequency offset factor.

[0096] The main parameters of the controller are set as: , , , , , , , , , , .

[0097] Set the target area control error to , and apply of static load to each area after 10 s. As Figure 5 shown, Figure 5 is a schematic diagram of the event trigger interval under static load, showing the moment of event trigger and the corresponding trigger interval, where the height of each point represents the time difference between the current trigger moment and the previous trigger moment. Among 12,000 times, 1,320 times, 979 times, and 1,270 times were triggered in each area respectively, saving 89.00%, 91.84%, and 89.41% of energy. As Figure 6 shown, Figure 6 is a load increment curve graph under static load. According to Figure 6 , it can be known that the system load frequency increment curve converges at .

[0098] Set the target area control error to . Apply of dynamic load after 5 s. A load frequency control method for a multi-area interconnected power grid proposed by the present invention is still effective for dynamic load. As Figure 7 shown, Figure 7 is a schematic diagram of the event trigger interval under dynamic load, showing the moment of event trigger and the corresponding trigger interval, where the height of each point represents the time difference between the current trigger moment and the previous trigger moment. Among 12,000 times, 4,214 times, 3,036 times, and 4,413 times were triggered in each area respectively, saving 64.88%, 74.70%, and 63.23% of energy. As Figure 8 shown, Figure 8 is a load increment curve graph under dynamic load, showing the load frequency increment fluctuation curve.

[0099] It can be seen from the above load frequency control of static load and dynamic load that the load frequency control method of the multi-area interconnected power system provided by the present invention is effective for both static load and dynamic load, and can reduce a large amount of energy consumption.

[0100] Embodiment 3 of the present invention also provides a multi - area interconnected power grid load frequency control system, including: estimators, triggers, controllers, and compensators corresponding to each regional power plant in the multi - area interconnected power system;

[0101] The estimator receives the load frequency error at the current moment sent by the regional power plant and the control instruction sent by the compensator, updates the pseudo - partial derivative, and sends the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding trigger in the current area through the power network; The trigger, when receiving the updated pseudo - partial derivative and the load frequency error at the current moment at the current moment, based on the load frequency error at the current moment and the dynamic event trigger function, determines whether the event trigger condition is met. If it is met, it sends the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding controller in the current area, where, The trigger, when receiving the updated pseudo - partial derivative and the load frequency error at the current moment at the current moment, based on the load frequency error at the current moment and the dynamic event trigger function, determines whether the event trigger condition is met. If it is met, it sends the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding controller in the current area, where,

[0102] The trigger, at the current moment, when receiving the updated pseudo - partial derivative and the load frequency error at the current moment, based on the load frequency error at the current moment and the dynamic event trigger function, determines whether the event trigger condition is met. If it is met, it sends the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding controller in the current area, where, when receiving the updated pseudo - partial derivative and the load frequency error at the current moment at the current moment, based on the load frequency error at the current moment and the dynamic event trigger function, determines whether the event trigger condition is met. If it is met, it sends the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding controller in the current area, where, when receiving the updated pseudo - partial derivative and the load frequency error at the current moment at the current moment, based on the load frequency error at the current moment and the dynamic event trigger function, determines whether the event trigger condition is met. If it is met, it sends the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding controller in the current area, where, when receiving the updated pseudo - partial derivative and the load frequency error at the current moment at the current moment, based on the load frequency error at the current moment and the dynamic event trigger function, determines whether the event trigger condition is met. If it is met, it sends the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding controller in the current area, where, is the delay duration for the estimator to send the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding trigger in the current area through the power network; is the delay duration for the estimator to send the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding trigger in the current area through the power network; is the delay duration for the estimator to send the updated pseudo - partial derivative and the load frequency error at the current moment to the corresponding trigger in the current area through the power network;

[0103] The controller receives the updated pseudo - partial derivative and the load frequency error at the current moment, and sends the updated controller control instruction to the corresponding compensator in the current area through the power network; The controller receives the updated pseudo - partial derivative and the load frequency error at the current moment, and sends the updated controller control instruction to the corresponding compensator in the current area through the power network;

[0104] The compensator, at the current moment, when receiving the updated controller control instruction, compensates the updated controller control instruction through the power network delay compensation strategy, and sends the compensated control instruction to the corresponding power plant in the current area, where, is the delay duration for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power network; is the delay duration for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power network;

[0105] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer - usable storage media (including but not limited to disk storage, CD - ROM, optical storage, etc.) containing computer - usable program code.

[0106] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce a means for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0107] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction means that implements the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0108] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0109] Obviously, the above embodiments are merely examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for controlling load frequency of a multi-region interconnected power grid, characterized in that: The following steps are involved: Step S1: Each region corresponding estimator receives the power plant in the current region The load frequency error at the moment is consistent with the control instruction sent by the compensator. The estimator updates the pseudo partial derivative and compares the updated pseudo partial derivative with The moment load frequency error is sent to the corresponding trigger in the current area through the power network; Step S2: The trigger is The updated pseudo partial derivatives and The load frequency error at the moment is based on The load frequency error at the moment and the dynamic event trigger function are used to determine whether the event trigger condition is met. If so, the updated pseudo partial derivative is combined with The load frequency error at the moment is sent to the corresponding controller of the current area, where: , The estimator combines the updated pseudo partial derivatives with The delay time for the load frequency error at the moment to be sent to the corresponding trigger of the current area through the power network; Step S3: The controller receives the updated pseudo partial derivative and After the load frequency error is determined, the updated controller control command is sent to the corresponding compensator in the current area through the power network; Step S4: The compensator The updated controller control instructions are received at all times, and the updated controller control instructions are compensated through the power network delay compensation strategy. The compensation formula is: , and sends the compensated control instructions to the corresponding power plant in the current area, where: , It is the delay time for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power network. For the Regions The time corresponds to the compensated control instruction. For the Regions The time corresponds to the compensated control instruction. , For the Regions The updated controller control instructions correspond to the The difference of the controller control instructions corresponding to the updated time, , For the Regions Always correspond to the updated controller control instructions, For the Regions Always correspond to the updated controller control instructions, , is a set constant, and , and They are and The upper bound of is the pseudo partial derivative, , is the total delay time, Indicates the moment; Through steps S1-S4, the load frequency error of each region in the multi-region interconnected power system is controlled to be within a preset range centered on 0.

2. A method for controlling load frequency of a multi-regional interconnected power grid according to claim 1, characterized in that: The current region corresponding estimator receives the current region power plant sent The load frequency error at the moment and the control command sent by the compensator, the estimator updates the pseudo partial derivative, including: based on The load frequency error at the moment, the estimator updates the pseudo partial derivative; When the updated pseudo partial derivative meets the reset mechanism condition, the updated pseudo partial derivative is set equal to the initial value of the pseudo partial derivative of the current region; When the updated pseudo partial derivative does not satisfy the reset mechanism condition, the updated pseudo partial derivative remains unchanged.

3. A method for controlling load frequency of a multi-regional interconnected power grid according to claim 2, characterized in that: The current regional power plants send The load frequency error at the moment, the estimator updates the pseudo partial derivative, and the calculation formula is: ; in, For the Regions The moment corresponds to the updated pseudo partial derivative, For the Regions The moment corresponds to the updated pseudo partial derivative, For the The first set constant of the region is greater than 0 and less than or equal to 1, For the The second setting constant is greater than 0 in the area. Indicates the time, For the Regions The increment of load frequency error at time, , For the Regions The load frequency error at the moment, For the Regions The load frequency error at the moment, , For the Regions The increment of the control command sent by the moment compensator, For the Regions The control instructions sent by the time compensator, For the Regions The control instructions sent by the time compensator, , Indicates the total number of regions.

4. A method for controlling load frequency of a multi-regional interconnected power grid according to claim 2, characterized in that: The reset mechanism conditions are: ； in, For the Regions The moment corresponds to the updated pseudo partial derivative, Indicates the time, is a third set constant greater than 0, , For the Regions The increment of the control command sent by the moment compensator, For the Regions The control instructions sent by the time compensator, For the Regions The control instructions sent by the time compensator, , Indicates the total number of regions.

5. The method for controlling load frequency of a multi-regional interconnected power grid according to claim 1, characterized in that: The basis The load frequency error at the moment and the dynamic event trigger function are used to determine whether the event trigger condition is met. If not, the updated pseudo partial derivative and The load frequency error at each moment is adjusted to the controller corresponding to the current area.

6. A method for controlling load frequency of a multi-region interconnected power grid according to claim 1, characterized in that: The dynamic event triggering function includes: Definition The set of times when the region meets the event triggering conditions is , express The number of times the event triggering conditions are met at a moment. , Indicates the number of times the event triggering condition is met; No. Regions The calculation formula of the dynamic event trigger function at the moment is: ； No. Regions Dynamic variables at the moment The calculation formula is: ； No. Regions The calculation formula of the event trigger error at time is: ， ； in, For the Regions Dynamic event trigger function at the moment, For the Regions Dynamic variables at any time, For the Regions Dynamic variables at any time, For the Regions Time event trigger error, For the Regions Time event trigger error, , For the The target area control error setting value and The difference of load frequency error at each moment, For the The target area control error setting value and The difference of load frequency error at each moment, Indicates the target area control error setting value, For the Regions The load frequency error at the moment, Indicates The area in The corresponding time when the event triggering condition is met, For the The third setting constant is greater than 0 in the region, For the The fourth setting constant is greater than 0 in the area, For the The fifth setting constant of the area is greater than 0, and .

7. A method for controlling load frequency of a multi-regional interconnected power grid according to claim 6, characterized in that: The event triggering conditions are: ； in, Indicates The area in The corresponding time when the event triggering condition is met, For the Regions Dynamic events trigger functions at certain moments.

8. A method for controlling load frequency of a multi-region interconnected power grid according to claim 1, characterized in that: The controller receives the updated pseudo partial derivative and After the load frequency error is calculated, the updated controller control command is sent to the corresponding compensator in the current area through the power network. The calculation formula of the updated controller control command is: ； in, For the Regions Always correspond to the updated controller control instructions, For the Regions Always correspond to the updated controller control instructions, , For the Regions The moment corresponds to the updated pseudo partial derivative, Indicates the target area control error setting value, For the Regions The load frequency error at the moment, For the The sixth setting constant of the region is greater than 0 and less than or equal to 1, For the The seventh setting constant of the area is greater than 0, and .

9. A multi-region interconnected power grid load frequency control system, characterized in that: include: Estimators, triggers, controllers and compensators corresponding to each regional power plant in a multi-regional interconnected power system; The estimator receives the current regional power plants' The load frequency error at the moment is compared with the control instruction sent by the compensator to update the pseudo partial derivative, and the updated pseudo partial derivative is compared with The moment load frequency error is sent to the corresponding trigger in the current area through the power network; Trigger, in The updated pseudo partial derivatives and The load frequency error at the moment is based on The load frequency error at the moment and the dynamic event trigger function are used to determine whether the event trigger condition is met. If so, the updated pseudo partial derivative is combined with The load frequency error at the moment is sent to the corresponding controller of the current area, where: , The estimator combines the updated pseudo partial derivatives with The delay time for the load frequency error at the moment to be sent to the corresponding trigger of the current area through the power network; The controller receives the updated pseudo-partial derivatives and The load frequency error at the moment, the updated controller control command is sent to the corresponding compensator in the current area through the power network; Compensator, in The updated controller control instructions are received at all times, and the updated controller control instructions are compensated through the power network delay compensation strategy. The compensation formula is: , and sends the compensated control instructions to the corresponding power plant in the current area, where: , It is the delay time for the controller to send the updated controller control instruction to the corresponding compensator in the current area through the power network. For the Regions The time corresponds to the compensated control instruction. For the Regions The time corresponds to the compensated control instruction. , For the Regions The updated controller control instructions correspond to the The difference of the controller control instructions corresponding to the updated time, , For the Regions Always correspond to the updated controller control instructions, For the Regions Always correspond to the updated controller control instructions, , is a set constant, and , and They are and The upper bound of is the pseudo partial derivative, , is the total delay time, Indicates time.

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