System frequency stability control method and system taking into consideration new-energy frequency modulation energy constraint

Abstract

Disclosed in the present invention are a system frequency stability control method and system taking into consideration a new-energy frequency modulation energy constraint. The method comprises: calculating a lowest-frequency-point arrival time of a system under active disturbance; determining whether the lowest-frequency-point arrival time meets a frequency stability energy balance criterion, and acquiring a determination result; when the lowest-frequency-point arrival time does not meet the frequency stability energy balance criterion, determining available frequency modulation energy of each new-energy station; and in the previous time period of the lowest-frequency-point arrival time, sequentially adding the available frequency modulation energy of the new-energy stations to a frequency modulation sequence in ascending order of the magnitude of the available frequency modulation energy until a frequency modulation stability requirement is met, so as to complete system frequency stability control. In the present invention, from the perspective of energy, frequency stability is equivalent to the problem of whether disturbance energy and frequency modulation energy can be balanced, and the contribution of new-energy frequency modulation to the frequency is then equivalent to energy square blocks, such that the frequency stability is guaranteed by means of superimposed discrimination of the energy square blocks, and the requirement for new-energy frequency modulation energy is minimized.

Description

System frequency stability control method and system considering new energy frequency modulation energy constraints

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present invention is based on and claims the priority of Chinese patent application with application number 202310706307.2 and application date June 15, 2023. The entire content of the Chinese patent application is hereby introduced into the present invention as a reference. Technical Field

[0003] The present invention relates to the technical field of power system analysis and operation control, and more specifically, to a system frequency stability control method and system considering energy constraints of new energy frequency regulation. Background Art

[0004] Currently, the most widely used frequency regulation control strategies for renewable energy sources include droop control, virtual inertia control, and their combined control. Among these, additional inertia control simulates the inertial response of synchronous generators by introducing the grid frequency change rate; additional primary frequency regulation control responds to changes in grid frequency by introducing the difference between the grid frequency and the rated value. However, whether the frequency regulation characteristics of synchronous generators must be simulated and their optimal support for system frequency response require further study. Furthermore, current research on the active frequency support provided by renewable energy frequency regulation control for the grid fails to consider the constraints of renewable energy frequency regulation energy, which is inconsistent with the limited frequency regulation energy actually provided by renewable energy sources. Excessive use of renewable energy frequency regulation energy could cause secondary frequency drops and threaten the safety of the units themselves.

[0005] Therefore, frequency regulation coordination between renewable energy sources and synchronous generators needs to be considered. Specifically, the coordination of their control principles with the frequency response characteristics of synchronous generators is crucial. Synchronous generators remain a crucial frequency regulation resource in the system and do not incur a frequency regulation energy penalty. The frequency support characteristics of renewable energy sources and synchronous generators are completely different. The rotor kinetic energy or frequency regulation energy that renewable energy sources can release to achieve frequency support is limited (not considering energy storage), but they offer fast response speeds and flexible power control. Synchronous generators possess ample frequency regulation energy, but due to the mechanical delay of a primary frequency regulation response, their frequency regulation is slow and inflexible. Therefore, frequency regulation coordination between synchronous generators and renewable energy sources is necessary. If synchronous generators and renewable energy sources coordinate well in frequency support, the system frequency response characteristics will also be better. However, current frequency droop control and virtual inertia control methods for renewable energy sources struggle to achieve good coordination with synchronous generators, and the coordination mechanism and its impact on the stabilization of the system frequency response remain unclear. What control principles can effectively release renewable energy frequency regulation energy and effectively coordinate it with the synchronous generator frequency regulation energy, thereby improving system frequency stability?

[0006] Among these, the question of when to introduce renewable energy into frequency regulation arises. The current consensus is that the earlier renewable energy is introduced, the stronger the frequency regulation control, and the more pronounced the improvement in the system's frequency characteristics. However, while this improvement in frequency characteristics occurs, it also suppresses the synchronous generator's primary frequency regulation response, making it difficult to fully utilize the synchronous generator's cost-free primary frequency regulation backup energy output. Excessive and premature use of renewable energy in frequency regulation can also lead to problems with power recovery later on. Therefore, further research is needed to determine when renewable energy should be introduced into frequency regulation to maximize its advantages of fast and controllable frequency regulation, while circumventing its disadvantages of limited frequency regulation energy and high cost, thereby maximizing system frequency stability.

[0007] Therefore, a system frequency stability control method considering the energy constraints of renewable energy frequency regulation is needed.

[0008] Summary of the Invention

[0009] The present invention proposes a system frequency stability control method and system considering the energy constraint of new energy frequency modulation, so as to solve the problem of how to efficiently achieve frequency stability control of new energy system.

[0010] In order to solve the above problem, according to one aspect of the present invention, a system frequency stability control method considering the energy constraint of new energy frequency modulation is provided, the method comprising:

[0011] Calculate the arrival time of the system's lowest frequency point under active power disturbance;

[0012] Determine whether the frequency minimum point arrival time satisfies a frequency stability energy balance criterion, and obtain a determination result;

[0013] When the judgment result indicates that the frequency stability energy balance criterion is not met, determining the available frequency modulation energy of each new energy station;

[0014] The available frequency modulation energy of the new energy station is added to the frequency modulation sequence in sequence in the order of the available frequency modulation energy from small to large in the period before the arrival time of the lowest frequency point, and stops when the frequency modulation stability requirement is met, thereby completing the system frequency stability control.

[0015] Preferably, the calculation of the arrival time of the lowest frequency point of the system under active power disturbance includes:

[0016] Discretize time t into n+1 periods, and the time interval of each period is Δt, t∈[t1,t2,...,T g ], gradually increase the time period of t, and determine the arrival time of the lowest frequency point based on the following formula, including:

[0017] Among them, t nis the arrival time of the lowest frequency point; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; ΔP L is the disturbance power; D is the damping coefficient; Δf max The maximum frequency deviation allowed under disturbance.

[0018] Preferably, the frequency stability energy balance criterion includes:

[0019] Where ΔP L is the disturbance power; t n is the time when the frequency reaches the lowest point; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0020] Preferably, the step of determining the available frequency modulation energy of each new energy station comprises: ΔE i =ΔP Ni *Δt,

[0021] Where ΔE i is the available frequency modulation energy of the i-th new energy station; ΔP Ni is the output power of the new energy station under a certain control strategy; Δt is the time interval.

[0022] Preferably, the frequency modulation stabilization requirement includes:

[0023] Where ΔP L is the disturbance power; t n is the arrival time of the lowest frequency point; I is the number of new energy stations added to the frequency modulation sequence; ΔE i is the available frequency modulation energy of the i-th new energy station; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0024] According to another aspect of the present invention, a system frequency stability control system considering energy constraints of new energy frequency modulation is provided, the system comprising:

[0025] The frequency minimum point arrival time determining part is configured to calculate the frequency minimum point arrival time of the system under active power disturbance;

[0026] A judging part is configured to judge whether the frequency minimum point arrival time satisfies a frequency stability energy balance criterion, and obtain a judgment result;

[0027] The available frequency modulation energy determining part is configured to determine the available frequency modulation energy of each new energy station when the judgment result indicates that the frequency stability energy balance criterion is not satisfied;

[0028] The frequency stabilization control part is configured to add the available frequency modulation energy of the new energy station to the frequency modulation sequence in the order of the available frequency modulation energy from small to large in the previous period of the arrival time of the lowest frequency point, and stop when the frequency modulation stability requirements are met to complete the system frequency stabilization control.

[0029] Preferably, the frequency minimum point arrival time determining part is further configured to:

[0030] Discretize time t into n+1 periods, and the time interval of each period is Δt, t∈[t1,t2,...,T g ], gradually increase the time period of t, and determine the arrival time of the lowest frequency point based on the following formula, including:

[0031] Among them, t n is the arrival time of the lowest frequency point; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; ΔP L is the disturbance power; D is the damping coefficient; Δf max The maximum frequency deviation allowed under disturbance.

[0032] Preferably, the frequency stability energy balance criterion includes:

[0033] Where ΔP L is the disturbance power; t n is the time when the frequency reaches the lowest point; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0034] Preferably, the step of determining the available frequency modulation energy of each new energy station comprises: ΔE i =ΔP Ni *Δt,

[0035] Where ΔE i is the available frequency modulation energy of the i-th new energy station; ΔP Ni is the output power of the new energy station under a certain control strategy; Δt is the time interval.

[0036] Preferably, the frequency modulation stabilization requirement includes:

[0037] Where ΔP L is the disturbance power; t n is the arrival time of the lowest frequency point; I is the number of new energy stations added to the frequency modulation sequence; ΔE i is the available frequency modulation energy of the i-th new energy station; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0038] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any step of a system frequency stability control method considering new energy frequency modulation energy constraints.

[0039] According to another aspect of the present invention, the present invention provides an electronic device, including:

[0040] The computer-readable storage medium described above; and

[0041] One or more processors are configured to execute the program in the computer-readable storage medium.

[0042] The present invention provides a system frequency stability control method and system that considers energy constraints of frequency modulation of renewable energy sources. The method comprises: calculating the arrival time of the system's frequency minimum point under active power disturbance; judging whether the arrival time of the frequency minimum point satisfies a frequency stability energy balance criterion, and obtaining a judgment result; when the judgment result indicates that the frequency stability energy balance criterion is not satisfied, determining the available frequency modulation energy of each renewable energy station; sequentially adding the available frequency modulation energy of the renewable energy station to the frequency modulation sequence in the period preceding the arrival time of the frequency minimum point in ascending order of available frequency modulation energy, until the frequency modulation stability requirement is met, thereby completing system frequency stability control. From an energy perspective, the present invention equates frequency stability to the question of whether disturbance energy and frequency modulation energy can be balanced, then equates the contribution of renewable energy frequency modulation to frequency to energy blocks, and through the superposition and judgment of the energy blocks, ensures frequency stability while minimizing the demand for renewable energy frequency modulation energy. This invention can provide a reference and reference for the judgment of regional and provincial system frequency stability and the timing of renewable energy station participation in frequency modulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0044] FIG1 is a flow chart of a system frequency stabilization control method 100 considering energy constraints of new energy frequency modulation according to an embodiment of the present invention;

[0045] FIG2 is a schematic structural diagram of a system frequency stabilization control system 200 considering energy constraints of new energy frequency modulation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments shown in the accompanying drawings is not intended to limit the present invention. In the accompanying drawings, identical elements are denoted by the same reference numerals.

[0047] Unless otherwise specified, the terms used herein (including technical terms) have the meanings commonly understood by those skilled in the art. In addition, it is understood that terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0048] FIG1 is a flow chart of a system frequency stability control method 100 considering energy constraints of frequency modulation of new energy sources according to an embodiment of the present invention. As shown in FIG1 , the system frequency stability control method considering energy constraints of frequency modulation of new energy sources provided by an embodiment of the present invention, from the perspective of energy, equates frequency stability to the problem of whether disturbance energy and frequency modulation energy can be balanced, and then equates the contribution of frequency modulation of new energy sources to frequency to energy blocks. By superimposing and judging the energy blocks, frequency stability is ensured, while minimizing the demand for frequency modulation energy of new energy sources. This can provide a reference and reference for the judgment of frequency stability of regional and provincial systems and the timing of new energy stations participating in frequency modulation. The system frequency stability control method 100 considering energy constraints of frequency modulation of new energy sources provided by an embodiment of the present invention starts from step 101:

[0049] In step 101, the arrival time of the lowest frequency point of the system under active power disturbance is calculated.

[0050] Preferably, the calculation of the arrival time of the lowest frequency point of the system under active power disturbance includes:

[0051] Discretize time t into n+1 periods, and the time interval of each period is Δt, t∈[t1,t2,...,T g ], gradually increase the time period of t, and determine the arrival time of the lowest frequency point based on the following formula, including:

[0052] Among them, t n is the arrival time of the lowest frequency point; R is the maximum power of one frequency modulation; T gis the frequency modulation response time; ΔP L is the disturbance power; D is the damping coefficient; Δf max The maximum frequency deviation allowed under disturbance.

[0053] In the present invention, the synchronous machine frequency modulation output is linearized and the time t of the system reaching the lowest frequency point under a certain active disturbance is calculated by using the piecewise approximation method. n .

[0054] Among them, the linear representation of synchronous machine output is:

[0055] Among them, R is the maximum power of a frequency modulation, T g The frequency regulation response time is 10s, which is close to the arrival time of the lowest frequency point under the maximum disturbance in the traditional power system dominated by synchronous machines.

[0056] Discretize time t, let t∈[t1,t2,...,T g ], the time interval of each period is Δt, there are n+1 periods in total, and the period of t is gradually increased. When the period of t satisfies the following formula, t n This is the arrival time of the lowest frequency point:

[0057] Where ΔP L is the disturbance power, D is the damping coefficient, including the load damping and electrical damping in the system, Δf max is the maximum frequency deviation allowed under disturbance, t n is the arrival time of the lowest frequency point.

[0058] In step 102, it is determined whether the frequency minimum point arrival time satisfies the frequency stability energy balance criterion, and a determination result is obtained.

[0059] Preferably, the frequency stability energy balance criterion includes:

[0060] Where ΔP L is the disturbance power; t n is the time when the frequency reaches the lowest point; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0061] In step 103, when the judgment result indicates that the frequency stability energy balance criterion is not satisfied, the available frequency regulation energy of each new energy station is determined.

[0062] Preferably, determining the available frequency modulation energy of each new energy station includes: ΔEi =ΔP Ni *Δt,

[0063] Where ΔE i is the available frequency modulation energy of the i-th new energy station; ΔP Ni is the output power of the new energy station under a certain control strategy; Δt is the time interval.

[0064] In step 104, the available frequency modulation energy of the new energy station is added to the frequency modulation sequence in the previous period of the arrival time of the lowest frequency point in the order of the available frequency modulation energy from small to large, and the process stops when the frequency modulation stability requirement is met, thereby completing the system frequency stability control.

[0065] Preferably, the frequency modulation stabilization requirement includes:

[0066] Where ΔP L is the disturbance power; t n is the arrival time of the lowest frequency point; I is the number of new energy stations added to the frequency modulation sequence; ΔE i is the available frequency modulation energy of the i-th new energy station; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0067] In the present invention, the frequency stability energy balance criterion is used to determine whether the arrival time of the lowest frequency point under large disturbance meets the requirement Δf<Δf max Among them, the frequency stability energy balance criterion is:

[0068] Where ΔP L is the disturbance power; t n is the time when the frequency reaches the lowest point; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0069] If the frequency does not meet the requirements, calculate the available frequency modulation energy ΔE of each new energy station i i , each new energy station meets the frequency regulation energy constraint ΔE i =ΔP Ni *Δt; where ΔP Ni It is the output power of the new energy station under a certain control strategy.

[0070] Then sort the available frequency modulation energy from small to large, and then place the I new energy frequency modulation station in the previous period t before the arrival time of the lowest frequency point in order. n-1 The time periods are added to the frequency modulation sequence in sequence until the formula is satisfied:

[0071] Ensure that the frequency stability requirements are met and complete frequency stability control.

[0072] The method of the present invention is based on the frequency stabilization framework of energy balance, can realize online evaluation and preventive control of frequency stability, has high engineering applicability, can effectively support the grid company's operation mode formulation and unit arrangement, and ensure the frequency safety of the grid; the present invention optimizes the time when new energy participates in frequency regulation, maximizes the frequency regulation capacity of synchronous units, and minimizes the new energy frequency regulation standby energy participating in frequency regulation, so as to cope with the problem of traditional frequency regulation energy shortage after a high proportion of new energy is connected, and reduce the risk of system frequency instability. At the same time, the present invention proposes the frequency regulation technology requirements for new energy from a system perspective, which can be evaluated as the new energy frequency regulation resources (energy) required to meet the system frequency stability.

[0073] Figure 2 is a schematic diagram of the structure of a system frequency stability control system 200 that considers renewable energy frequency modulation energy constraints according to an embodiment of the present invention. As shown in Figure 2, the system frequency stability control system 200 that considers renewable energy frequency modulation energy constraints, provided in an embodiment of the present invention, includes: a frequency minimum point arrival time determination section 201, a determination section 202, an available frequency modulation energy determination section 203, and a frequency stability control section 204.

[0074] Preferably, the frequency minimum point arrival time determining part 201 is configured to calculate the frequency minimum point arrival time of the system under active power disturbance.

[0075] Preferably, the frequency minimum point arrival time determining part 201 is further configured to:

[0076] Discretize time t into n+1 periods, and the time interval of each period is Δt, t∈[t1,t2,...,T g ], gradually increase the time period of t, and determine the arrival time of the lowest frequency point based on the following formula, including:

[0077] Among them, t n is the arrival time of the lowest frequency point; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; ΔP L is the disturbance power; D is the damping coefficient; Δf max The maximum frequency deviation allowed under disturbance.

[0078] Preferably, the judging part 202 is configured to judge whether the frequency minimum point arrival time satisfies a frequency stability energy balance criterion, and obtain a judgment result.

[0079] Preferably, the frequency stability energy balance criterion includes:

[0080] Where ΔP L is the disturbance power; t n is the time when the frequency reaches the lowest point; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0081] Preferably, the available frequency modulation energy determining part 203 is configured to determine the available frequency modulation energy of each new energy station when the judgment result indicates that the frequency stability energy balance criterion is not met.

[0082] Preferably, determining the available frequency modulation energy of each new energy station includes: ΔE i =ΔP Ni *Δt,

[0083] Where ΔE i is the available frequency modulation energy of the i-th new energy station; ΔP Ni is the output power of the new energy station under a certain control strategy; Δt is the time interval.

[0084] Preferably, the frequency stabilization control part 204 is configured to add the available frequency modulation energy of the new energy station into the frequency modulation sequence in sequence in the order of available frequency modulation energy from small to large in the previous period of the arrival time of the lowest frequency point, and stop when the frequency modulation stability requirement is met, thereby completing the system frequency stabilization control.

[0085] Preferably, the frequency modulation stabilization requirement includes:

[0086] Where ΔP L is the disturbance power; t n is the arrival time of the lowest frequency point; I is the number of new energy stations added to the frequency modulation sequence; ΔE i is the available frequency modulation energy of the i-th new energy station; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of one frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

[0087] The system frequency stability control system 200 considering energy constraints of frequency modulation by renewable energy in an embodiment of the present invention corresponds to the system frequency stability control method 100 considering energy constraints of frequency modulation by renewable energy in another embodiment of the present invention, and will not be described in detail here.

[0088] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any step of a system frequency stability control method considering new energy frequency modulation energy constraints.

[0089] According to another aspect of the present invention, the present invention provides an electronic device, including:

[0090] The computer-readable storage medium described above; and

[0091] One or more processors are configured to execute the program in the computer-readable storage medium.

[0092] The present invention has been described with reference to a few embodiments. However, it is apparent to those skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the present invention.

[0093] Generally, all terms used in this disclosure are to be interpreted according to their ordinary meaning in the art, unless explicitly defined otherwise herein. All references to "a / the / the [device, component, etc.]" are to be interpreted openly as referring to at least one instance of the device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily need to be performed in the exact order disclosed, unless explicitly stated otherwise.

[0094] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0095] The present application is described with reference to the flow chart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each flow process and / or box in the flow chart and / or block diagram and the combination of the flow process and / or box in the flow chart and / or block diagram can be realized by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processing machine or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one flow chart flow or multiple flows and / or one box or multiple boxes of the block diagram.

[0096] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the present invention. Industrial Applicability

[0099] The embodiment of the present application discloses a system frequency stability control method and system considering the energy constraint of new energy frequency modulation, including: calculating the arrival time of the frequency lowest point of the system under active disturbance; judging whether the arrival time of the frequency lowest point satisfies the frequency stability energy balance criterion, and obtaining the judgment result; when the judgment result indicates that the frequency stability energy balance criterion is not satisfied, determining the available frequency modulation energy of each new energy station; adding the available frequency modulation energy of the new energy station to the frequency modulation sequence in the previous period of the arrival time of the frequency lowest point in order from small to large according to the available frequency modulation energy, stopping when the frequency modulation stability requirement is met, and completing the system frequency stability control. From the perspective of energy, the present invention equates frequency stability to the problem of whether the disturbance energy and the frequency modulation energy can be balanced, and then equates the contribution of the new energy frequency modulation to the frequency to the energy block, and judges by the superposition of the energy blocks to ensure frequency stability while minimizing the demand for the new energy frequency modulation energy. It can provide reference and reference for the judgment of regional and provincial system frequency stability and the timing of new energy station participation in frequency modulation.

Claims

1. A system frequency stability control method considering energy constraints of new energy frequency modulation, the method comprising: Calculate the arrival time of the lowest frequency point of the system under active disturbance; Determine whether the frequency minimum point arrival time satisfies the frequency stability energy balance criterion, and obtain a determination result; When the judgment result indicates that the frequency stability energy balance criterion is not met, determining the available frequency modulation energy of each new energy station; The available frequency modulation energy of the new energy station is added to the frequency modulation sequence in the previous period of the arrival time of the lowest frequency point in the order of available frequency modulation energy from small to large, and stops when the frequency modulation stability requirement is met, thereby completing the system frequency stability control.

2. The method according to claim 1, wherein: The calculation system frequency minimum point arrival time under active power disturbance includes: Discretize time t into n+1 time periods, and the time interval of each period is Δt, t∈[t1,t2,...,T g ], gradually increase the time period of t, and determine the arrival time of the lowest frequency point based on the following formula, including: Among them, t n is the arrival time of the lowest frequency point; R is the maximum power of a frequency modulation; T g is the frequency modulation response time; ΔP L is the disturbance power; D is the damping coefficient; Δf max is the maximum frequency deviation allowed under disturbance.

3. The method according to claim 1, wherein: The frequency stability energy balance criterion includes: Among them, ΔP L is the disturbance power; t n is the time when the frequency reaches the lowest point; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of a frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

4. The method according to claim 1, wherein: The determination of the available frequency modulation energy of each new energy station includes: ΔE i =ΔP Ni *Δt, Among them, ΔE i is the available frequency modulation energy of the i-th new energy station; ΔP Ni is the output power of the new energy station under a certain control strategy; Δt is the time interval.

5. The method according to claim 1, wherein: The frequency modulation stability requirements include: Among them, ΔP L is the disturbance power; t n is the arrival time of the lowest frequency point; I is the number of new energy stations added to the frequency modulation sequence; ΔE i is the available frequency modulation energy of the i-th new energy station; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of a frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

6. A system frequency stability control system considering energy constraints of new energy frequency modulation, the system comprising: The frequency minimum point arrival time determination part is configured to calculate the frequency minimum point arrival time of the system under active power disturbance; A judging part, configured to judge whether the frequency minimum point arrival time satisfies a frequency stability energy balance criterion, and obtain a judging result; The available frequency modulation energy determination part is configured to determine the available frequency modulation energy of each new energy station when the judgment result indicates that the frequency stability energy balance criterion is not met; The frequency stability control part is configured to add the available frequency modulation energy of the new energy station to the frequency modulation sequence in the previous period of the arrival time of the lowest frequency point in the order of the available frequency modulation energy from small to large, and stop when the frequency modulation stability demand is met to complete the system frequency stability control.

7. The system according to claim 6, wherein: The frequency minimum point arrival time determination part is further configured to discretize the time t into n+1 time periods, and the time interval of each time period is Δt, t∈[t1,t2,...,T g ], gradually increase the time period of t, and determine the arrival time of the lowest frequency point based on the following formula, including: Among them, t n is the arrival time of the lowest frequency point; R is the maximum power of a frequency modulation; T g is the frequency modulation response time; ΔP L is the disturbance power; D is the damping coefficient; Δf max is the maximum frequency deviation allowed under disturbance.

8. The system according to claim 6, wherein: The frequency stability energy balance criterion includes: Among them, ΔP L is the disturbance power; t n is the time when the frequency reaches the lowest point; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of a frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

9. The system according to claim 6, wherein: The determination of the available frequency modulation energy of each new energy station includes: ΔE i =ΔP Ni *Δt, Among them, ΔE i is the available frequency modulation energy of the i-th new energy station; ΔP Ni is the output power of the new energy station under a certain control strategy; Δt is the time interval.

10. The system according to claim 6, wherein: The frequency modulation stability requirements include: Among them, ΔP L is the disturbance power; t n is the arrival time of the lowest frequency point; I is the number of new energy stations added to the frequency modulation sequence; ΔE i is the available frequency modulation energy of the i-th new energy station; M is the inertia of the synchronous machine started in the system; Δf max is the maximum frequency deviation allowed under disturbance; R is the maximum power of a frequency modulation; T g is the frequency modulation response time; D is the damping coefficient.

11. A computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

12. An electronic device comprising: The computer readable storage medium as claimed in claim 11; as well as One or more processors are configured to execute the program in the computer-readable storage medium.

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