Photovoltaic power station frequency modulation method, device and system and computer program product

Abstract

The invention provides a frequency modulation method, device and system for a photovoltaic power station and a computer program product, and the method comprises the steps: constructing an instruction channel facing a power grid frequency modulation demand through introducing frequency modulation equipment and first communication management equipment on the premise of not modifying an existing system of the photovoltaic power station and not affecting the operation of the photovoltaic power station; a lengthy and low-efficiency communication link in an existing system is bypassed, a communication path and control logic of a frequency modulation function are minimized and modularized, and the transformation cost and the implementation risk are greatly reduced. The method is high in universality and suitable for old photovoltaic power stations with mixed equipment models and complex structures, and an efficient and replicable technical scheme is provided for frequency modulation transformation of a large number of existing stock photovoltaic power stations.

Description

Photovoltaic power plant frequency regulation methods, devices, systems and computer program products Technical Field

[0001] This application relates to the field of photovoltaic power generation technology, and in particular to a method, apparatus, system and computer program product for frequency regulation of a photovoltaic power station. Background Technology

[0002] Currently, the installed capacity of new energy sources, represented by photovoltaic and wind power, is growing rapidly, gradually shifting from "supplementary energy" to "primary energy." Previously, grid frequency regulation was mainly achieved by traditional energy sources such as thermal and hydropower. However, with the increasing proportion of new energy power generation, the power system is placing higher demands on the grid performance of new energy sources. This has led to requirements for photovoltaic and wind power plants to participate in grid frequency regulation.

[0003] However, many older photovoltaic power plants that were put into operation in the early stages did not fully consider frequency regulation functionality during their planning and design phases, and their initial control logic generally lacked reserved frequency regulation capabilities. These older photovoltaic power plants often also suffer from weak on-site communication infrastructure, long communication paths, inconsistent protocols, diverse equipment models, scattered manufacturers, and significant challenges in system integration and coordinated control. If a solution of completely replacing inverters or massively upgrading the communication system is adopted, it will not only affect the normal operation of the power plant, but also lead to unnecessary waste of resources due to the large-scale replacement of equipment that is still functioning normally.

[0004] Therefore, there is an urgent need for a universal and easy-to-implement frequency regulation method for photovoltaic power plants to help old photovoltaic power plants complete grid connection performance upgrades efficiently and economically. Summary of the Invention

[0005] This application provides a method, apparatus, system, and computer program product for frequency regulation in photovoltaic power plants. It introduces communication management equipment and frequency regulation equipment outside the existing system of a photovoltaic power plant, enabling old photovoltaic power plants to achieve frequency regulation functions without affecting the existing system.

[0006] To achieve the above objectives, the main technical solutions adopted in this application include: Firstly, embodiments of this application provide a photovoltaic power plant frequency regulation method, applied to frequency regulation equipment. The method includes: receiving a grid frequency regulation command issued by a grid dispatching system; determining a target inverter whose output power needs to be adjusted according to the grid frequency regulation command; and sending a power adjustment command to the target inverter through a first communication management device, so that the target inverter adjusts its output power according to the power adjustment command, thereby achieving frequency regulation of the grid.

[0007] Optionally, sending the power adjustment command to the target inverter via the first communication management device includes: sending the power adjustment command to the second communication management device, so that the second communication management device forwards the power adjustment command to the first communication management device, and then the first communication management device sends it to the target inverter. The second communication management device is deployed on the control side of the photovoltaic power station, and the first communication management device is deployed in the photovoltaic area of ​​the photovoltaic power station.

[0008] Optionally, the first communication management device, the second communication management device, and / or the frequency modulation device may use a transparent transmission communication mode for data transmission to ensure compatibility with the existing control system of the photovoltaic power station.

[0009] Optionally, the photovoltaic power station is further equipped with an energy storage system; determining the target inverter whose output power needs to be adjusted according to the grid frequency regulation command includes: decomposing the frequency regulation requirement of the grid frequency regulation command into a first adjustment amount and a second adjustment amount according to the grid frequency regulation command and a preset frequency regulation capacity allocation strategy, wherein the first adjustment amount is implemented by the energy storage system and the second adjustment amount is implemented by the target inverter; and determining the target inverter whose output power needs to be adjusted according to the second power adjustment amount.

[0010] Optionally, before receiving the grid frequency regulation command issued by the grid dispatching system, the method further includes: obtaining the overall active power regulation delay time of the photovoltaic power station and the output power regulation delay time of a single inverter in the photovoltaic power station; and determining whether the overall active power regulation delay time and the output power regulation delay time of the single inverter meet a preset first frequency regulation response time threshold.

[0011] Optionally, before receiving the grid frequency regulation command issued by the grid dispatching system, the method further includes: obtaining the transmission delay of each communication segment in the existing control system of the photovoltaic power station, wherein the existing control system includes at least a communication link consisting of multiple communication segments from the automatic generation control equipment to the target inverter; and determining whether the transmission delay of each communication segment meets a preset second frequency regulation response time threshold.

[0012] Optionally, the method further includes: when the communication of the existing control system and / or the frequency regulation system used to implement power grid frequency regulation is abnormal, acquiring the multiplexing status of each communication segment in the communication link between the frequency regulation system and the existing control system, wherein the multiplexing status is used to indicate whether the corresponding communication segment is used by the frequency regulation system and the existing control system simultaneously; if the existing control system and the frequency regulation system both experience communication abnormalities at the same time, it is determined that the fault occurs in the communication segment shared by the frequency regulation system and the existing control system; if only the frequency regulation system experiences a communication abnormality and the existing control system communicates normally at the same time, it is determined that the fault occurs in the communication segment used independently by the frequency regulation system; if only the existing control system experiences a communication abnormality and the frequency regulation system communicates normally at the same time, it is determined that the fault occurs in the communication segment used independently by the existing control system.

[0013] Secondly, embodiments of this application provide a frequency regulation device for a photovoltaic power plant. The device includes: a receiving unit for receiving a grid frequency regulation command issued by a grid dispatching system; an analysis unit for determining a target inverter whose output power needs to be adjusted based on the grid frequency regulation command; and a sending unit for sending a power adjustment command to the target inverter through a first communication management device, so that the target inverter adjusts its output power according to the power adjustment command, thereby achieving frequency regulation of the power grid.

[0014] Thirdly, embodiments of this application provide a photovoltaic power plant frequency regulation system, including: a target inverter, a first communication management device, and a frequency regulation device; the frequency regulation device is used to receive a grid frequency regulation command issued by a grid dispatching system; determine the target inverter whose output power needs to be adjusted according to the grid frequency regulation command; send a power adjustment command to the target inverter through the first communication management device; the first communication management device is communicatively connected to both the frequency regulation device and the target inverter, and is used to receive the power adjustment command sent by the frequency regulation device and forward the power adjustment command to the corresponding target inverter; the target inverter is electrically connected to the photovoltaic module and is used to adjust its output power according to the received power adjustment command to achieve frequency regulation of the grid.

[0015] Fourthly, embodiments of this application provide a computer program product, including computer instructions, which are used to cause a computer to execute the photovoltaic power plant frequency regulation method described in the first aspect.

[0016] The frequency regulation method for photovoltaic power plants proposed in this application, without modifying the existing photovoltaic power plant system or affecting its operation, constructs a command channel oriented towards grid frequency regulation needs by introducing frequency regulation equipment and a first communication management device. This bypasses the lengthy and inefficient communication links in the existing system, minimizing and modularizing the communication path and control logic of the frequency regulation function, significantly reducing the transformation cost and implementation risk. This method is highly versatile and applicable to old photovoltaic power plants with mixed equipment models and complex structures, providing an efficient and replicable technical solution for the frequency regulation transformation of a large number of existing photovoltaic power plants. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 is a flowchart illustrating the steps of a photovoltaic power station frequency regulation method provided in an embodiment of this application.

[0019] Figure 2 is a schematic diagram of the structure of an existing control system for a photovoltaic power station provided in an embodiment of this application.

[0020] Figure 3 is a structural diagram of a photovoltaic power station frequency regulation device provided in an embodiment of this application.

[0021] Figure 4 is a structural diagram of a photovoltaic power station frequency regulation system provided in an embodiment of this application.

[0022] Figure 5 is a structural schematic diagram of an example of a computer device provided in an embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] The installed capacity of new energy sources, represented by photovoltaic and wind power, continues to grow rapidly, and their positioning has gradually shifted from "supplementary energy" to "primary energy." With the significant increase in the penetration rate of new energy in the power system, the grid's requirements for frequency stability are becoming increasingly stringent. The traditional mode of relying on conventional power sources such as thermal power and hydropower for frequency regulation is no longer suitable for the system operation needs under a high proportion of new energy grid integration. Therefore, the power system has successively put forward new performance requirements for new energy power plants, requiring photovoltaic power plants to have the ability to participate in grid frequency regulation and other ancillary services.

[0025] However, many old photovoltaic power plants that were put into operation early on did not fully consider frequency regulation function during the planning and design stage, and generally have the following problems: 1. The inverter control logic is simple, most of them do not have fast power regulation, and frequency regulation capability is not reserved in the existing control system.

[0026] 2. The existing control architecture in the field is weak, the communication paths within the system are long and the protocols are not uniform, resulting in high delays and poor reliability in the transmission of control commands.

[0027] 3. The diverse range of equipment models and the dispersed manufacturers make system integration and coordinated control extremely difficult.

[0028] For these aging photovoltaic power plants, adopting a solution of completely replacing inverters or massively upgrading the communication system would not only result in a long renovation cycle, impacting the normal operation of the power plant during that period, but also lead to unnecessary waste of resources by replacing equipment that is still functioning normally. Against this backdrop, how to enable aging photovoltaic power plants to have fast and reliable frequency regulation capabilities while minimizing modifications to the existing system architecture and reducing renovation resource consumption has become a critical technical problem that urgently needs to be solved in the field of new energy grid connection and operation control.

[0029] The first embodiment of this application provides a frequency regulation method for a photovoltaic power plant to solve the above-mentioned problems. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here. The method provided in this embodiment is applied to a frequency regulation device. As shown in Figure 1, the method may include the following steps: Step 110, receiving a grid frequency regulation command issued by the grid dispatching system.

[0030] The method in this embodiment is applied to a frequency regulation device. When the method is executed, the frequency regulation device receives the power grid frequency regulation command issued by the power grid dispatching system through a local power dispatching data network or a remote communication device.

[0031] Grid frequency regulation commands can include information such as frequency deviation, frequency regulation direction (upward / downward), and response time limit. They can also include information such as the amount of power to be regulated or the percentage of power to be regulated. Grid frequency regulation commands instruct photovoltaic power plants to adjust their active power at the grid connection point within the time required by the frequency regulation function in order to participate in grid frequency support.

[0032] In this embodiment, the method of receiving power grid frequency regulation commands can be set to active continuous monitoring or active periodic monitoring of power grid frequency regulation commands. It can also be set to activate the corresponding frequency regulation command receiving mechanism only when a power grid frequency over-limit event is detected.

[0033] Step 120: Based on the grid frequency regulation command, determine the target inverter whose output power needs to be adjusted.

[0034] Upon receiving the frequency regulation command, the frequency regulation equipment, based on the current operating status information of the photovoltaic power station, such as the real-time output power, communication status, available capacity, health status, and whether the inverters in the station are operating under quota, and in conjunction with the preset power allocation strategy, determines at least one inverter participating in this frequency regulation response as the target inverter.

[0035] Power allocation strategies can include average allocation, allocation based on preset priorities, allocation by capacity ratio, priority selection of high-efficiency inverters, polling equalization, neural network prediction, or fully random selection. Regardless of the selection strategy, inverters with faults or communication abnormalities should be excluded from selection as target inverters by default to ensure the reliability and safety of frequency regulation.

[0036] Step 130: Send a power adjustment command to the target inverter through the first communication management device, so that the target inverter adjusts its output power according to the power adjustment command, thereby realizing frequency regulation of the power grid.

[0037] Currently, power grid frequency regulation is mainly achieved through power generation balance control. The frequency of the power system is determined by the real-time balance between power generation and load power. When load power increases, the system frequency tends to decrease. At this time, it is necessary to rapidly increase the active power output on the generation side to compensate for the power deficit and thus stabilize the frequency at the rated value. Conversely, when load power decreases, the generation side needs to reduce power output to avoid frequency rise. In traditional frequency regulation schemes, thermal power and hydropower units convert mechanical energy into electrical energy through rotor rotation, and their speed is strongly coupled with the grid frequency. Therefore, it is easy to think of designing a speed regulation system to adjust the mechanical power input to the generator unit and thus change the output power of the generator unit, ultimately bringing the grid frequency back to the target value. However, the principle of photovoltaic power generation is to convert the energy of photons in sunlight into electrical energy. This is not suitable for traditional frequency regulation schemes that involve setting up speed regulation systems in generator units.

[0038] In a photovoltaic (PV) power plant, the inverter is electrically connected to the PV modules and serves as the interface between the PV power generation system and the power grid. The core function of the inverter is to perform AC-DC conversion and control the electrical parameters at the grid connection point. Modern inverters employ power electronic conversion technology, enabling them to adjust their output active power through the switching states of internal electronic devices and control logic. Therefore, when the grid frequency changes, the inverter is primarily used to adjust the PV power output, achieving grid frequency regulation and providing support for the grid frequency.

[0039] In this embodiment, the frequency modulation device sends power adjustment commands to at least one target inverter via a first communication management device. The first communication management device is a single device or a group of functionally identical devices deployed in the photovoltaic power plant. The power adjustment command instructs at least one target inverter to adjust its output power according to the command. The power adjustment command can be generated directly by the frequency modulation device, or, to conserve the computing resources of the frequency modulation device, it can be generated using existing photovoltaic power plant system calculations or by setting up dedicated computing equipment, and then the generated power adjustment command is sent to the frequency modulation device.

[0040] The first communication management device is a dedicated communication node for frequency regulation control, bypassing the existing control system of the photovoltaic power station to establish a direct communication connection with the target inverter. Upon receiving the command, the target inverter quickly adjusts its output power to complete the response, thereby effectively supporting the grid frequency.

[0041] As shown in Figure 2, the existing communication structures of photovoltaic power plant control systems are often complex and lengthy, and multiple communication methods are often used interchangeably. For example, the existing control system shown in Figure 2 uses fiber optic cables, network cables, and RS485 for information transmission simultaneously. The photovoltaic power plant frequency regulation method provided in this embodiment, compared to a complete overhaul, makes full use of existing equipment resources, minimizing and modularizing only the communication path and control logic, significantly reducing renovation costs and implementation risks. Simultaneously, by accurately identifying and directly issuing power adjustment commands to the target inverter, it bypasses the original lengthy and inefficient communication links of the existing photovoltaic power plant control system, significantly improving the response speed and timeliness of frequency regulation commands. This enables older photovoltaic power plants that previously lacked grid-connected frequency regulation capabilities to meet the grid's performance requirements for new energy participation in grid frequency regulation. This method is highly versatile and applicable to complex site environments with multiple manufacturers and models of inverters, providing an efficient, economical, and replicable technical path for the intelligent and compliant transformation of large-scale existing photovoltaic power plants.

[0042] The second embodiment of this application further specifies the photovoltaic power plant frequency regulation method in the first embodiment in a more detailed and specific way. Some or all of the technical features in the second embodiment can be combined with or replaced by the first embodiment, either individually or in combination, to obtain more feasible photovoltaic power plant frequency regulation methods.

[0043] The frequency regulation method of the photovoltaic power station in the second embodiment of this application is described in detail below: Optionally, a power adjustment command is sent to the target inverter through the first communication management device, including: sending the power adjustment command to the second communication management device so that the second communication management device forwards the power adjustment command to the first communication management device, and then the first communication management device sends it to the target inverter. The second communication management device is deployed on the control side of the photovoltaic power station, and the first communication management device is deployed in the photovoltaic area of ​​the photovoltaic power station.

[0044] This embodiment further proposes a specific implementation method for deploying a second communication management device in a photovoltaic power plant to optimize the command transmission path.

[0045] Specifically, the frequency modulation equipment sends power adjustment commands to the second communication management equipment. The second communication management equipment is deployed on the control side of the photovoltaic power station. Specifically, the second communication management equipment should be installed near the frequency modulation equipment, such as inside the control cabinet where the frequency modulation equipment is installed, near the booster station, or near the main control room.

[0046] In the actual operating environment of photovoltaic power plants, communication conditions are typically quite complex. Due to the differences in adaptability of wired and wireless communication to factors such as ambient temperature, humidity, and electromagnetic interference, even if the existing control system of the photovoltaic power plant is bypassed and the communication link structure is optimized, the communication process from the frequency modulation equipment to the inverter may still involve multiple transmission methods and require data conversion between various communication protocols. In this embodiment, the second communication management device is a collective term for one device or a group of devices with the same function deployed in the photovoltaic power plant. As a command aggregation and forwarding node on the control side, the second communication management device, after receiving commands from the frequency modulation equipment, standardizes and encapsulates the data according to a pre-set communication protocol to ensure that the commands can be reliably and efficiently transmitted to the next stage.

[0047] In this embodiment, the first communication management device is deployed in the photovoltaic area, specifically near the inverter cluster, and communicates with the second communication management device. The second communication management device sends instructions to the first communication management device, which then encapsulates the data according to the protocol and distributes the power adjustment instructions conforming to the inverter interface communication protocol to the corresponding target inverter.

[0048] The number and deployment location of the first and second communication management devices can be set according to actual needs, such as being close to the inverter or the frequency modulation equipment to reduce communication latency. This embodiment does not impose specific limitations.

[0049] This embodiment constructs a frequency modulation communication link consisting of "frequency modulation equipment → second communication management equipment → first communication management equipment → target inverter". This communication link is independent of the existing control system of the photovoltaic power station, and the number of communication links is significantly reduced, thereby greatly shortening the transmission delay.

[0050] In one embodiment, the 104 communication protocol and Modbus TCP communication protocol, which have higher transmission efficiency, are used for information transmission. Specifically, in one example, the frequency modulation device uses the 104 communication protocol to communicate with the outside world, while the second communication device uses the Modbus TCP communication protocol to communicate with the inverter.

[0051] This embodiment is particularly suitable for older photovoltaic power plants with complex communication architectures, high loads on existing control systems, or large communication delays. It can introduce a second communication management device to provide a dedicated command path for frequency modulation control that is low-latency, highly reliable, and easy to maintain, without affecting the data acquisition and monitoring functions of the existing system.

[0052] Optionally, the first communication management device, the second communication management device, and / or the frequency modulation device may use a transparent communication mode for data transmission to ensure compatibility with the existing control system of the photovoltaic power station.

[0053] Transparent transmission communication mode refers to the communication device performing only physical layer or link layer signal forwarding during data transmission, without parsing, modifying or encapsulating the content, format or communication protocol of the application layer data.

[0054] In the aforementioned embodiments, the frequency regulation system composed of the first communication management device, the second communication management device, the frequency regulation device, and the inverter differs from the existing control system in both logical and physical structure. Since the transparent transmission mode does not change the original communication protocol, there is no need to upgrade or replace the original equipment according to the protocol, nor is it necessary to implement complex protocol conversion logic in the frequency regulation system. Therefore, it can directly be compatible with the communication protocol used by the existing control system of the photovoltaic power station.

[0055] With the adoption of transparent transmission mode, the communication link of the frequency modulation system can operate in parallel with the existing control system without interference. In other words, the frequency modulation system and the existing control system can be logically isolated but physically shared. For example, the communication link between the second communication management device and the first communication management device can reuse the existing network cable resources of the photovoltaic power station. Only the two newly added communication management devices need to be configured in transparent transmission mode to be integrated into the existing network topology, which greatly reduces the amount of modification work and deployment costs.

[0056] In addition, the pass-through mode avoids the processing delay and parsing overhead of data at intermediate nodes, improves the transmission speed of instructions, and helps to meet the high requirements of response time for primary frequency modulation.

[0057] Optionally, the photovoltaic power station is also equipped with an energy storage system; according to the grid frequency regulation command, the target inverter that needs to adjust its output power is determined, including: according to the grid frequency regulation command and the preset frequency regulation capacity allocation strategy, decomposing the frequency regulation requirement of the grid frequency regulation command into a first adjustment amount and a second adjustment amount, the first adjustment amount is realized by the energy storage system response, and the second adjustment amount is realized by the target inverter response; the target inverter that needs to adjust its output power is determined according to the second power adjustment amount.

[0058] This embodiment proposes a method for optimizing the allocation of frequency regulation capacity through coordinated frequency regulation of photovoltaic and energy storage systems, specifically for scenarios where a photovoltaic power station is equipped with an energy storage system.

[0059] Specifically, based on the received grid frequency regulation command, the total power regulation amount to be responded to is determined. Then, based on a preset frequency regulation capacity allocation strategy, the total power regulation amount is decomposed into two parts: a first adjustment amount and a second adjustment amount.

[0060] In one embodiment, the frequency regulation capacity allocation strategy can be dynamically optimized by comprehensively considering factors such as the real-time available capacity of the energy storage system, the current adjustability margin of the photovoltaic power station, the frequency regulation response speed requirements, and economic efficiency. For example, the energy storage system can be prioritized to handle rapid and small-amplitude frequency fluctuation regulation, while the photovoltaic inverter can handle relatively slow or larger-amplitude regulation.

[0061] After the allocation is completed, the first adjustment is executed by the energy storage system. Based on the power allocation strategy, one or more target inverters are selected for the second adjustment, and a corresponding power adjustment is allocated to each target inverter.

[0062] The method provided in this embodiment is applicable to old photovoltaic power plants that have been configured or can be equipped with energy storage systems. By upgrading the software strategy and modifying a small number of control links, photovoltaic-storage coordinated frequency regulation can be achieved without large-scale hardware replacement of the original photovoltaic power generation units, which has high feasibility and economy.

[0063] Optionally, before receiving the grid frequency regulation command issued by the grid dispatching system, the method further includes: obtaining the active power regulation delay time of the entire photovoltaic power plant and the output power regulation delay time of a single inverter in the photovoltaic power plant; and determining whether the active power regulation delay time of the entire photovoltaic power plant and the output power regulation delay time of a single inverter meet a preset first frequency regulation response time threshold.

[0064] This embodiment proposes a pre-inspection method for photovoltaic power plants, which can be used to assess the regulation delay of photovoltaic power plants during the retrofitting of those without frequency regulation functions.

[0065] Specifically, this embodiment proposes to obtain two key parameters: the overall active power regulation delay time of a photovoltaic power plant and the output power regulation delay time of a single inverter in the photovoltaic power plant. These parameters can be obtained through historical operating data statistics or on-site testing.

[0066] The first frequency regulation response time threshold includes the overall active power regulation delay time threshold and the individual inverter output power regulation delay time threshold. After obtaining the actual parameters, it is determined whether the obtained parameters meet the corresponding thresholds in the preset first frequency regulation response time threshold.

[0067] The pre-inspection method proposed in this embodiment is mainly used for the following two purposes: 1. Reusing the functions of the existing control system to assist in the maintenance of the existing control system and determine whether there is a fault.

[0068] 2. Determine whether the current performance of the existing control system meets the frequency modulation requirements. If it does, consider implementing the structure described in the previous embodiment where the frequency modulation system and the existing control system are logically isolated but physically shared. Only the relevant communication management equipment needs to be added, without laying additional communication lines. If it does not meet the requirements, it is necessary to determine whether the existing control system can be optimized, or whether it is necessary to build a separate physical communication line for the frequency modulation system.

[0069] Optionally, before receiving the grid frequency regulation command issued by the grid dispatching system, the method further includes: obtaining the transmission delay of each communication segment in the existing control system of the photovoltaic power station, wherein the existing control system includes at least a communication link consisting of multiple communication segments from the automatic generation control equipment to the target inverter; and determining whether the transmission delay of each communication segment meets the preset second frequency regulation response time threshold.

[0070] This embodiment proposes another pre-inspection method for photovoltaic power plants, which is mainly applied to the diagnosis and analysis of communication delays in various communication segments of the existing control system of photovoltaic power plants, in order to determine physically reusable communication link segments.

[0071] Specifically, the existing control system of a photovoltaic power station includes an Automatic Generation Control (AGC) device or a central control device, and a communication link formed by several communication devices (such as switches, communication management units, protocol converters, etc.) connected in series from the AGC or central control device to each inverter. A communication segment refers to the physical or logical connection between two adjacent communication nodes in the link. As shown in Figure 2, in the existing control system, the automatic generation control device to the inverter uses network cables, optical fibers, and RS485 as transmission carriers, passing through multiple layers of switches and vertical encryption devices. In the example shown in Figure 2, two adjacent communication nodes constitute a communication segment.

[0072] Methods for obtaining transmission delay may include: active measurement based on network packet timestamps; round-trip delay testing using probes deployed at key nodes; parsing communication status monitoring data built into the device, etc., and this embodiment does not impose specific limitations.

[0073] The second frequency modulation response time threshold is a communication performance indicator set according to the frequency modulation requirements. Its value can be decomposed based on the total frequency modulation response time requirements and adjusted according to factors such as communication protocol, line length, data length, and communication network load.

[0074] In this embodiment, if the delay of all communication segments meets the threshold, it indicates that the existing control system's communication link can support the real-time and reliable transmission of frequency modulation commands. Only the relevant communication management equipment needs to be added, and the existing system's physical communication lines can be reused to implement the frequency modulation function. If there are communication segments with delays exceeding the threshold, these unqualified communication segments can be recorded for future optimization or to provide a basis for decision-making in the subsequent design of the frequency modulation system's physical communication line architecture. The final communication architecture of the frequency modulation system should avoid using these communication segments with excessively high delays and reuse, as far as possible, continuous communication segments that meet the threshold requirements to reduce modification costs.

[0075] The method provided in this embodiment can accurately identify key communication segments affecting frequency regulation response speed, thereby precisely determining communication delay optimization targets or designing the physical communication architecture of a frequency regulation system. It is particularly suitable for older photovoltaic power plants with complex communication architectures and numerous equipment layers. Through non-intrusive delay monitoring, it enables visualized evaluation and early warning of communication performance without affecting the normal operation of the power plant, providing a reference for the design of the frequency regulation system.

[0076] Optionally, the method further includes: when the communication of the existing control system and / or the frequency regulation system used to implement power grid frequency regulation is abnormal, acquiring the multiplexing status of each communication segment in the communication link between the frequency regulation system and the existing control system, the multiplexing status being used to indicate whether the corresponding communication segment is used by both the frequency regulation system and the existing control system simultaneously; if both the existing control system and the frequency regulation system experience communication abnormalities at the same time, the fault is determined to occur in the communication segment shared by the frequency regulation system and the existing control system; if only the frequency regulation system experiences communication abnormalities and the existing control system communicates normally at the same time, the fault is determined to occur in the communication segment used independently by the frequency regulation system; if only the existing control system experiences communication abnormalities and the frequency regulation system communicates normally at the same time, the fault is determined to occur in the communication segment used independently by the existing control system.

[0077] This embodiment further defines the delay detection method provided in the foregoing embodiments, and provides a fault diagnosis method based on the multiplexing status of communication links.

[0078] Specifically, when it is determined that a communication anomaly has been detected in the existing control system and / or frequency modulation system, the multiplexing status of each communication segment is obtained. The multiplexing status indicates whether a communication segment is shared by the existing control system and the frequency modulation system. For example, if a fiber optic cable or the same switch may simultaneously carry data traffic from two systems, then the communication segment is marked as "multiplexed"; if a communication device or link serves only one system, it should be marked as "independent use".

[0079] The design of the physical communication architecture of the frequency modulation system references the delay detection results provided by the methods in the aforementioned embodiments, and reuses the communication delay components in the existing control system that meet the requirements. Based on the above, this embodiment proposes the following fault judgment logic: Case 1: If both the existing control system and the frequency modulation system experience communication anomalies at the same time, the fault is determined to occur in the shared communication segment between the two. For example, a shared communication optical cable interruption or a shared communication equipment failure, such a fault will simultaneously affect the communication functions of both systems.

[0080] Scenario 2: If only the frequency modulation system communication is abnormal, while the existing control system communication is normal at the same time, the fault is determined to occur in the communication segment used independently by the frequency modulation system, that is, a newly established physical communication line outside the existing communication system communication line. For example, the communication cable or communication equipment on the communication segment from the frequency modulation equipment to the second communication management equipment is abnormal, or the communication cable or communication equipment between the first communication management equipment and the inverter is abnormal, etc.

[0081] Scenario 3: If only the existing control system experiences a communication anomaly, while the frequency modulation system communicates normally at the same time, the fault is determined to occur in a communication segment used independently by the existing control system but not by the frequency modulation system. For example, the communication cable leading from the switch to the central control room in the existing control system may be interrupted.

[0082] Based on the above judgment logic, after the frequency regulation system is deployed, the scope of communication faults in photovoltaic power plants can be automatically determined, so as to support operation and maintenance personnel to quickly and accurately locate the specific communication segment where the fault occurred, avoid blind troubleshooting, and improve the efficiency and reliability of system operation and maintenance.

[0083] The third embodiment of this application also proposes a photovoltaic power station frequency regulation device, as shown in Figure 3. The device includes: a receiving unit 310 for receiving a grid frequency regulation command issued by the grid dispatching system; an analysis unit 320 for determining the target inverter whose output power needs to be adjusted according to the grid frequency regulation command; and a sending unit 330 for sending a power adjustment command to the target inverter through a first communication management device, so that the target inverter adjusts its output power according to the power adjustment command, thereby realizing frequency regulation of the grid.

[0084] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0085] In this embodiment, the photovoltaic power station frequency regulation device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0086] The fourth embodiment of this application also proposes a photovoltaic power plant frequency regulation system, including: a target inverter, a first communication management device, and a frequency regulation device; the frequency regulation device is used to receive a grid frequency regulation command issued by the grid dispatching system; determine the target inverter whose output power needs to be adjusted according to the grid frequency regulation command; send a power adjustment command to the target inverter through the first communication management device; the first communication management device is communicatively connected to both the frequency regulation device and the target inverter, and is used to receive the power adjustment command sent by the frequency regulation device and forward the power adjustment command to the corresponding target inverter; the target inverter is electrically connected to the photovoltaic module and is used to adjust its output power according to the received power adjustment command to achieve frequency regulation of the grid.

[0087] Figure 4 shows an example of a frequency regulation system structure for a photovoltaic power plant provided in this embodiment. The example in Figure 4 can be understood as a frequency regulation system built on the existing photovoltaic power plant system shown in Figure 2.

[0088] In the example shown in Figure 4, the FM workstation acts as an operating terminal, communicating with the FM equipment to provide relevant personnel with information related to the FM function. The FM equipment uses the 104 communication protocol to communicate with the FM workstation and the remote control device.

[0089] Optionally, in the example shown in Figure 4, a second communication device is provided between the first communication management device and the frequency modulation device. The second communication management device is used to forward power adjustment commands to the first communication management device, which then sends them to the target inverter. The second communication management device is deployed on the control side of the photovoltaic power station, and the first communication management device is deployed in the photovoltaic area of ​​the photovoltaic power station.

[0090] Optionally, the first communication management device, the second communication management device, and / or the frequency modulation device may use a transparent communication mode for data transmission to ensure compatibility with the existing control system of the photovoltaic power station.

[0091] Please refer to Figure 5, which is a schematic diagram of the structure of a computer device provided in an embodiment of this application. The computer device provided in this embodiment can be a frequency modulation device or a computer device containing a frequency modulation device. As shown in Figure 5, the computer device includes: one or more processors 510, a memory 520, and interfaces for connecting the various components, including high-speed interfaces and low-speed interfaces. The various components communicate with each other using different buses and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on an external input / output device (such as a display device coupled to the interface). In some alternative embodiments, multiple processors and / or multiple buses can be used with multiple memories and multiple memory units, if needed. Similarly, multiple computer devices can be connected, each device providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 5 uses a single processor 510 as an example.

[0092] Processor 510 may be a central processing unit, a network processor, or a combination thereof. Processor 510 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0093] The memory 520 stores instructions executable by at least one processor 510 to cause the at least one processor 510 to perform the method shown in the above embodiments.

[0094] The memory 520 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 520 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 520 may optionally include memory remotely located relative to the processor 510, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0095] The memory 520 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 520 may also include a combination of the above types of memory.

[0096] The computer device also includes a communication interface 530 for communicating with other devices or communication networks.

[0097] This application also provides a computer-readable storage medium. The methods described in this application can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code downloaded over a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the methods shown in the above embodiments are implemented.

[0098] This application provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method of any embodiment of this application.

[0099] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

[0100] It is understood that the data involved in this technical solution (including but not limited to the data itself, the acquisition or use of the data) shall comply with the requirements of relevant laws, regulations and related provisions.

[0101] It is understood that in the specific implementation of this application, data such as user information, location information, and navigation data are involved. When the above embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0102] The methods, apparatus, systems, computer devices, computer-readable storage media, and computer program products described in the above embodiments can be implemented by computer chips or entities, or by products having a certain function. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0103] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0104] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, systems, computer devices, computer-readable storage media, and computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-readable program code.

[0105] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus, systems, computer devices, computer-readable storage media, and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0108] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0109] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, systems, computer devices, computer-readable storage media, and computer program products are basically similar to the method embodiments, so the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments.

[0110] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0111] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A frequency regulation method for a photovoltaic power station, characterized in that, The method, applied to frequency regulation equipment, includes: receiving a power grid frequency regulation command issued by a power grid dispatching system; determining a target inverter whose output power needs to be adjusted according to the power grid frequency regulation command; and sending a power adjustment command to the target inverter through a first communication management device, so that the target inverter adjusts its output power according to the power adjustment command, thereby achieving frequency regulation of the power grid.

2. The method according to claim 1, characterized in that, Sending a power adjustment command to the target inverter via the first communication management device includes: sending the power adjustment command to a second communication management device, so that the second communication management device forwards the power adjustment command to the first communication management device, and then the first communication management device sends it to the target inverter. The second communication management device is deployed on the control side of the photovoltaic power station, and the first communication management device is deployed in the photovoltaic area of ​​the photovoltaic power station.

3. The method according to claim 2, characterized in that, The first communication management device, the second communication management device, and / or the frequency modulation device use a transparent transmission communication mode for data transmission to ensure compatibility with the existing control system of the photovoltaic power station.

4. The method according to claim 1, characterized in that, The photovoltaic power station is also equipped with an energy storage system; the step of determining the target inverter whose output power needs to be adjusted according to the grid frequency regulation command includes: decomposing the frequency regulation requirement of the grid frequency regulation command into a first adjustment amount and a second adjustment amount according to the grid frequency regulation command and a preset frequency regulation capacity allocation strategy, wherein the first adjustment amount is implemented by the energy storage system and the second adjustment amount is implemented by the target inverter; and determining the target inverter whose output power needs to be adjusted according to the second power adjustment amount.

5. The method according to claim 1, characterized in that, Before receiving the grid frequency regulation command issued by the grid dispatching system, the method further includes: obtaining the active power regulation delay time of the entire photovoltaic power station and the output power regulation delay time of a single inverter in the photovoltaic power station; and determining whether the active power regulation delay time of the entire photovoltaic power station and the output power regulation delay time of the single inverter meet a preset first frequency regulation response time threshold.

6. The method according to claim 1, characterized in that, Before receiving the grid frequency regulation command issued by the grid dispatch system, the method further includes: obtaining the transmission delay of each communication segment in the existing control system of the photovoltaic power station, wherein the existing control system includes at least a communication link consisting of multiple communication segments from the automatic generation control equipment to the target inverter; and determining whether the transmission delay of each communication segment meets the preset second frequency regulation response time threshold.

7. The method according to claim 5 or 6, characterized in that, The method further includes: when the communication between the existing control system and / or the frequency regulation system used to implement power grid frequency regulation is abnormal, acquiring the multiplexing status of each communication segment in the communication link between the frequency regulation system and the existing control system, wherein the multiplexing status is used to indicate whether the corresponding communication segment is used by the frequency regulation system and the existing control system simultaneously; if the existing control system and the frequency regulation system both experience communication abnormalities at the same time, it is determined that the fault occurs in the communication segment shared by the frequency regulation system and the existing control system; if only the frequency regulation system experiences a communication abnormality and the existing control system communicates normally at the same time, it is determined that the fault occurs in the communication segment used independently by the frequency regulation system; if only the existing control system experiences a communication abnormality and the frequency regulation system communicates normally at the same time, it is determined that the fault occurs in the communication segment used independently by the existing control system.

8. A frequency regulation device for a photovoltaic power station, characterized in that, The device includes: a receiving unit for receiving a grid frequency regulation command issued by a grid dispatching system; an analysis unit for determining a target inverter whose output power needs to be adjusted based on the grid frequency regulation command; and a sending unit for sending a power adjustment command to the target inverter through a first communication management device, so that the target inverter adjusts its output power according to the power adjustment command, thereby achieving frequency regulation of the grid.

9. A frequency regulation system for a photovoltaic power station, characterized in that, include: The target inverter, the first communication management equipment, and the frequency modulation equipment; The frequency regulation equipment is used to receive power grid frequency regulation commands issued by the power grid dispatching system; Based on the grid frequency regulation command, determine the target inverter whose output power needs to be adjusted; The first communication management device sends a power adjustment command to the target inverter; the first communication management device is communicatively connected to both the frequency modulation device and the target inverter, and is used to receive the power adjustment command sent by the frequency modulation device and forward the power adjustment command to the corresponding target inverter. The target inverter is electrically connected to the photovoltaic module and is used to adjust its output power according to the received power adjustment command in order to achieve frequency regulation of the power grid.

10. A computer program product, characterized in that, It includes computer instructions for causing a computer to execute the frequency regulation method for a photovoltaic power plant as described in any one of claims 1 to 7.

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