Transformer area power supply control method based on intelligent edge gateway and related device

Abstract

The invention discloses a transformer area power supply control method based on an intelligent edge gateway and a related device, which are applied to a transformer area power supply system comprising a distributed photovoltaic system, a distributed energy storage device, a reactive power compensation device and the intelligent edge gateway, and the control method comprises the following steps: obtaining the voltage of a transformer area grid-connected point; when the voltage of the grid-connected point of the transformer area does not exceed the upper limit of the normal operation voltage of the transformer area but exceeds the preset dead-zone voltage range, regulating the reactive power of a photovoltaic inverter in the distributed photovoltaic system to stabilize voltage fluctuation; when the voltage of the grid-connected point of the transformer area exceeds the upper limit of the normal operation voltage of the transformer area, the reactive capacity of the transformer area is determined, and the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device is determined; and adjusting and controlling the photovoltaic inverter, the distributed energy storage device and the reactive power compensation device according to the set adjustment priority based on the size relationship between the reactive power capacity of the transformer area and the sum of the reactive power capacities. The invention aims to solve the problems of low perception level, insufficient collaborative operation capability and repeated investment.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supply for power distribution areas, and in particular relates to a power supply control method for power distribution areas based on an intelligent edge gateway and related devices. Background Art

[0002] With the global attention and promotion of renewable energy, household photovoltaic power generation, as an important part of distributed energy, has shown a rapid growth in installed capacity and the number of connected low-voltage distribution networks. Although this trend has effectively promoted the use of clean energy, it has also brought about a series of power quality problems. Winter is the peak season for electricity consumption, and the residential and commercial electricity load increases significantly. However, photovoltaic power generation is affected by weather factors, and its output is significantly intermittent and uncertain. This mismatch between supply and demand leads to random fluctuations in the three-phase load in the substation, which in turn causes power quality problems such as high and low voltage and heavy load of distribution transformers. For substations that include many important users and have high requirements for power supply quality, the above problems not only affect the normal operation of user equipment, but may also cause economic losses and social impacts. Therefore, it is particularly important to carry out high-quality power supply control in the substation.

[0003] At present, power supply control schemes for low-voltage substations are mostly concentrated on a single type of power supply control device, such as static VAR generators (SVG) for regulating reactive power and voltage regulators for adjusting voltage levels. Although these traditional devices can alleviate some power quality issues to a certain extent, such schemes do not consider unified power supply control in substations, lack of perception and coordination, and may have problems of duplicate investment in implementation. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a substation power supply control method and related devices based on an intelligent edge gateway, which aims to solve the problems of low perception level, insufficient collaborative operation capability and repeated investment.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions: According to a first aspect of the present invention, a method for controlling power supply in a substation based on an intelligent edge gateway is provided, which is applied to a substation power supply system including a distributed photovoltaic system, a distributed energy storage device, a reactive power compensation device and an intelligent edge gateway, and the control method includes: Get the grid connection point voltage in the substation area; When the grid-connected point voltage of the substation does not exceed the upper limit of the normal operating voltage of the substation but exceeds the preset dead zone voltage range, the reactive power of the photovoltaic inverter in the distributed photovoltaic system is adjusted to smooth the voltage fluctuation; When the grid connection point voltage of the substation exceeds the upper limit of the normal operating voltage of the substation, the reactive capacity of the substation is determined, and the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device is determined; According to the relationship between the reactive capacity of the substation and the sum of the reactive capacity, the photovoltaic inverter, the distributed energy storage device and the reactive compensation device are regulated and controlled according to the set regulation priority.

[0006] In a possible implementation manner of the first aspect, regulating and controlling the photovoltaic inverter, the distributed energy storage device, and the reactive power compensation device according to the set regulation priority includes: When the sum of the reactive capacities is greater than the reactive capacity of the substation, the reactive compensation device is preferentially controlled to perform voltage regulation; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the grid-connected point voltage of the substation area has not recovered to the normal operating voltage of the substation area, the voltage is regulated by adjusting the reactive power of the photovoltaic inverter; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the voltage is regulated by adjusting the reactive power of the distributed energy storage device until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

[0007] In a possible implementation manner of the first aspect, regulating and controlling the photovoltaic inverter, the distributed energy storage device, and the reactive power compensation device according to the set regulation priority includes: When the sum of the reactive capacities is not greater than the reactive capacity of the substation, and the sum of the reactive capacities has been adjusted and exhausted, voltage regulation is performed by adjusting the active power of the distributed energy storage device; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the active power of the photovoltaic inverter is reduced or the distributed photovoltaic system is controlled to exit operation until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

[0008] In a possible implementation manner of the first aspect, after obtaining the grid connection point voltage of the substation area, the method further includes: When the grid-connected point voltage of the substation does not exceed the normal operating voltage upper limit of the substation and does not exceed the preset dead zone voltage range, no adjustment is performed.

[0009] In a possible implementation of the first aspect, the determination of the reactive capacity of the substation area is specifically as follows: The reactive capacity of the substation is determined according to the voltage deviation degree between the grid connection point voltage of the substation and the normal operating voltage of the substation and the voltage sensitivity.

[0010] In a possible implementation manner of the first aspect, adjusting the reactive power of the photovoltaic inverter specifically includes: The constant power factor-reactive power droop control strategy is used to regulate the reactive power of the photovoltaic inverter.

[0011] In a possible implementation of the first aspect, the dead zone voltage range is pre-set based on historical data of the transformer area voltage, power grid operation specifications and safety standards.

[0012] According to a second aspect of the present invention, a power supply control device for a substation based on an intelligent edge gateway is provided, which is applied to a substation power supply system including a distributed photovoltaic system, a distributed energy storage device, a reactive power compensation device and an intelligent edge gateway, and the control device includes: An acquisition module is used to obtain the voltage of the grid connection point in the substation area; A first regulating module is used to adjust the reactive power of the photovoltaic inverter in the distributed photovoltaic system to smooth the voltage fluctuation when the voltage of the grid-connected point in the substation area does not exceed the upper limit of the normal operating voltage of the substation area but exceeds the preset dead zone voltage range; A determination module, used to determine the reactive capacity of the substation when the grid connection point voltage of the substation exceeds the upper limit of the normal operating voltage of the substation, and determine the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device; The second regulating module is used to regulate and control the photovoltaic inverter, the distributed energy storage device and the reactive compensation device according to the set regulation priority according to the size relationship between the reactive capacity of the substation and the sum of the reactive capacity.

[0013] According to a third aspect of the present invention, there is provided a device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of a method for controlling power supply of a substation based on an intelligent edge gateway when executing the computer program.

[0014] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of a method for controlling power supply of a substation based on an intelligent edge gateway.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: The present invention provides a power supply control method for a substation based on an intelligent edge gateway. By integrating a distributed photovoltaic system, a distributed energy storage device, a reactive compensation device and an intelligent edge gateway, when the voltage at the substation grid connection point does not exceed the upper limit of the normal operating voltage of the substation but exceeds the preset dead zone voltage range, the reactive power of the photovoltaic inverter in the distributed photovoltaic system is adjusted to smooth the voltage fluctuation; when the voltage at the substation grid connection point exceeds the upper limit of the normal operating voltage of the substation, the reactive capacity of the substation is determined, and the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device is determined; according to the size relationship between the reactive capacity of the substation and the sum of the reactive capacity, the photovoltaic inverter, the distributed energy storage device and the reactive compensation device are adjusted and controlled according to the set adjustment priority. Compared with the traditional single type of power supply control, the present invention can more comprehensively and accurately perceive the power status of the substation, and perform coordinated control, thereby improving the overall regulation capability and response speed of the substation power supply system. In the traditional scheme, various types of power supply control devices may lead to repeated investment due to the lack of unified coordination. The present invention realizes centralized monitoring and coordinated control of various devices through the intelligent edge gateway, avoiding redundancy and waste between devices, thereby optimizing the investment cost. At the same time, since it can more accurately match the actual needs of the substation for regulation, the utilization rate and economic benefits of the equipment are improved.

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the specific implementation modes of the present invention, the drawings required for use in the description of the specific implementation modes will be briefly introduced below. Obviously, the drawings described below are some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a flow chart of a method for controlling power supply in a substation based on an intelligent edge gateway according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the principle of a bidirectional energy storage DC-DC Buck mode in an embodiment of the present invention; Figure 3 Schematic diagram of the principle of the bidirectional energy storage DC-DC Boost mode in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Combination Figure 1 As shown, an embodiment of the present invention provides a power supply control method for a substation based on an intelligent edge gateway, which aims to achieve comprehensive optimization and coordinated control of a substation power supply system including a distributed photovoltaic system, a distributed energy storage device, a reactive compensation device and an intelligent edge gateway through integrated and intelligent means. Exemplarily, the method is applied to a typical low-voltage distribution substation, which includes several residential and commercial users, as well as a distributed photovoltaic system, a distributed energy storage device (such as a battery energy storage system), a reactive compensation device (such as a static VAR compensator SVG) and an intelligent edge gateway.

[0021] It should be understood that the distributed photovoltaic system is equipped with a photovoltaic array and a photovoltaic inverter. The photovoltaic inverter must have reactive power regulation capability and be able to adjust reactive power output according to control instructions. The distributed energy storage device has bidirectional charging and discharging capabilities and supports reactive power regulation. The reactive power compensation device is used to quickly respond to the reactive power demand of the system and provide continuously adjustable reactive power compensation.

[0022] The power supply control method based on the intelligent edge gateway specifically includes the following steps: S1. Obtain the grid connection point voltage in the substation area.

[0023] Specifically, the voltage value of the substation grid connection point is monitored in real time through the voltage sensor, and it is determined whether it is within the normal operating voltage range of the substation and the preset dead zone voltage range.

[0024] S2. When the grid-connected point voltage of the substation does not exceed the upper limit of the normal operating voltage of the substation but exceeds the preset dead zone voltage range, the reactive power of the photovoltaic inverter in the distributed photovoltaic system is adjusted to smooth the voltage fluctuation.

[0025] Specifically, when the voltage at the grid-connected point in the substation does not exceed the upper limit of the normal operating voltage of the substation but exceeds the preset dead zone voltage range, the intelligent edge gateway first calculates the amount of reactive power that needs to be adjusted, and then sends instructions to the photovoltaic inverter of the distributed photovoltaic system to adjust its reactive output to smooth out voltage fluctuations. At this stage, the rapid response capability of the photovoltaic inverter is mainly used to achieve voltage regulation.

[0026] S3. When the grid-connected point voltage of the substation exceeds the upper limit of the normal operating voltage of the substation, the reactive capacity of the substation is determined, and the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device is determined.

[0027] Specifically, when the grid-connected point voltage exceeds the upper limit of the normal operating voltage of the substation, the intelligent edge gateway first calculates the reactive capacity currently required by the substation. Then, it evaluates the reactive capacity currently available for each of the photovoltaic inverter, distributed energy storage device, and reactive compensation device, and calculates the sum of the three.

[0028] S4. According to the relationship between the reactive capacity of the substation and the sum of the reactive capacity, the photovoltaic inverter, the distributed energy storage device and the reactive compensation device are regulated and controlled according to the set regulation priority.

[0029] Specifically, based on the evaluation results, the intelligent edge gateway sends adjustment instructions to each device in turn according to the preset adjustment priority. Through comprehensive regulation, it ensures that the voltage in the substation area quickly returns to the normal range, while optimizing the operating efficiency of each device and avoiding unnecessary energy waste.

[0030] Through continuous data collection and analysis, the intelligent edge gateway continuously optimizes the adjustment strategy to ensure the optimal coordinated operation between various devices. Through the intelligent edge gateway, comprehensive monitoring and intelligent control of the power supply system in the substation area is realized, which effectively improves the power supply quality in the substation area and solves the problems of low perception level, insufficient coordinated operation capability and repeated investment in traditional control solutions.

[0031] In one achievable manner, regarding regulating and controlling the photovoltaic inverter, the distributed energy storage device, and the reactive power compensation device according to the set regulation priority, the implementation method includes the following: When the sum of the reactive capacities is greater than the reactive capacity of the substation, the reactive compensation device is preferentially controlled to perform voltage regulation; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the grid-connected point voltage of the substation area has not recovered to the normal operating voltage of the substation area, the voltage is regulated by adjusting the reactive power of the photovoltaic inverter; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the voltage is regulated by adjusting the reactive power of the distributed energy storage device until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

[0032] That is to say, when the intelligent edge gateway detects that the voltage at the grid connection point in the substation exceeds the upper limit of the normal operating voltage of the substation, and has determined the sum of the reactive capacity required by the substation and the reactive capacity that can be provided by each device at present, the regulation control strategy will be executed in the following priority order: Step a: Prioritize control of reactive power compensation devices If the calculated reactive capacity is greater than the reactive capacity required by the substation, it indicates that there are sufficient reactive resources in the current system for regulation. In this case, first try to quickly respond and reduce the voltage at the substation grid connection point by adjusting the reactive compensation device (such as SVG).

[0033] The intelligent edge gateway sends adjustment instructions to the reactive power compensation device, gradually adjusting its reactive power output until it detects that the voltage at the grid connection point begins to drop.

[0034] If the voltage at the grid-connected point of the substation recovers to within the normal operating voltage range of the substation during the adjustment process, the adjustment of the reactive power compensation device will be stopped immediately and the current status monitoring will be maintained.

[0035] Step b: Regulate the reactive power of the PV inverter If the voltage at the grid connection point in the substation area has not recovered to the normal operating voltage after the reactive power compensation device is adjusted in step a, the next step of adjustment will be entered. At this time, the intelligent edge gateway will turn its target to the photovoltaic inverter and use its reactive power adjustment capability for auxiliary adjustment.

[0036] The intelligent edge gateway sends regulation instructions to the photovoltaic inverter to adjust its working mode and increase or decrease reactive power output to further balance the reactive power demand in the substation area and promote voltage recovery.

[0037] Likewise, if the grid-connected point voltage in the substation returns to the normal operating voltage during this process, the regulation of the PV inverter is stopped.

[0038] Step c: Regulate the reactive power of distributed energy storage devices If the first two steps fail to restore the voltage at the grid connection point to the normal range, the intelligent edge gateway will activate the reactive power regulation capability of the distributed energy storage device. At this time, the distributed energy storage device not only acts as an energy buffer, but also helps stabilize the grid voltage by regulating reactive power.

[0039] The intelligent edge gateway sends specific reactive power regulation instructions to the distributed energy storage device, and uses the reactive power regulation function in its bidirectional charging and discharging characteristics to gradually adjust its reactive power output until the voltage at the grid connection point in the substation reaches the normal range.

[0040] During the entire regulation process, the intelligent edge gateway will continuously monitor the voltage at the substation and grid connection point to ensure that all regulation actions are stopped immediately once the voltage returns to the normal operating range to avoid overregulation or unnecessary energy consumption.

[0041] Through the above-mentioned specific implementation methods, the present invention realizes the refined and intelligent control of the power supply system in the substation, effectively improves the power supply quality and stability in the substation, and reduces the economic losses caused by power quality problems.

[0042] In an achievable manner, regarding regulating and controlling the photovoltaic inverter, the distributed energy storage device, and the reactive power compensation device according to the set regulation priority, the implementation method further includes: When the sum of the reactive capacities is not greater than the reactive capacity of the substation, and the sum of the reactive capacities has been adjusted and exhausted, voltage regulation is performed by adjusting the active power of the distributed energy storage device; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the active power of the photovoltaic inverter is reduced or the distributed photovoltaic system is controlled to exit operation until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

[0043] Specifically, when the intelligent edge gateway detects that the reactive capacity required by the substation is greater than or equal to the sum of the reactive capacities that can be provided by the current photovoltaic inverter, reactive compensation device, and distributed energy storage device, and the reactive regulation capabilities of these devices have been exhausted, the system is facing a situation of insufficient reactive resources. But at the same time, if the voltage at the substation grid connection point still deviates from the normal operating range, the intelligent edge gateway will consider adjusting the voltage by adjusting the active power of the distributed energy storage device. The intelligent edge gateway will evaluate the current state of charge (SOC), charging and discharging capacity of the distributed energy storage device, and its impact on system stability. On the premise of ensuring the safe operation of the energy storage device, by adjusting its active power output (i.e., increasing or decreasing its power supply to the grid or absorbing the power from the grid), the power balance state of the substation grid is changed, thereby achieving the regulation of the voltage at the substation grid connection point. During the regulation process, the intelligent edge gateway continuously monitors the voltage at the substation grid connection point. Once the voltage returns to the normal operating voltage range, it immediately stops regulating the active power of the distributed energy storage device and maintains the current state for continuous monitoring.

[0044] If the voltage at the grid connection point in the substation area has not recovered to the normal operating voltage after adjusting the active power of the distributed energy storage device, it means that more radical measures need to be taken to balance the power of the grid. The intelligent edge gateway will turn to adjust the active power output of the photovoltaic inverter. The intelligent edge gateway sends an adjustment instruction to the photovoltaic inverter, requiring it to gradually reduce the active power output. This process is gradual to avoid excessive impact on the grid. If the voltage has not recovered after reducing the active power of the photovoltaic inverter, as a last resort, the intelligent edge gateway can control the distributed photovoltaic system to exit operation in whole or in part to completely eliminate the impact of its active power output on the grid voltage. In the process of reducing the active power of the photovoltaic inverter or controlling the distributed photovoltaic system to exit operation, the intelligent edge gateway continuously monitors the voltage at the grid connection point in the substation area. Once the voltage returns to the normal operating voltage range, stop further adjustment measures immediately, evaluate the system status, and prepare to restore the normal operation of the photovoltaic inverter or reconnect to the distributed photovoltaic system when necessary.

[0045] Preferably, after obtaining the grid connection point voltage of the substation, it also includes: when the grid connection point voltage of the substation does not exceed the upper limit of the normal operating voltage of the substation and does not exceed the preset dead zone voltage range, no adjustment is performed. That is to say, after obtaining the voltage value, the intelligent edge gateway will immediately compare it with the upper limit of the normal operating voltage of the substation and the preset dead zone voltage range. The preset dead zone voltage range is usually determined based on the characteristics of the substation power grid, the safe operating range of the equipment, and the historical operating data, aiming to balance the accuracy of the adjustment. If the grid connection point voltage of the substation does not exceed the upper limit of the normal operating voltage of the substation, and is within the preset dead zone voltage range at the same time, the intelligent edge gateway will judge that the current voltage state is normal and no adjustment is required. At this time, the system will maintain the current operating state and continue to monitor the voltage.

[0046] In one achievable manner, the reactive capacity of the substation is determined by: determining the reactive capacity of the substation according to the voltage deviation degree between the grid connection point voltage of the substation and the normal operating voltage of the substation and the voltage sensitivity.

[0047] Specifically, the intelligent edge gateway first obtains the voltage value of the grid connection point in the substation in real time, compares it with the preset normal operating voltage range of the substation, and calculates the current voltage deviation value. The voltage deviation value can be in the form of an absolute value, indicating the difference between the actual voltage and the center value of the normal operating voltage; it can also be in the form of a relative value, such as a percentage, indicating the deviation ratio. Voltage sensitivity refers to the sensitivity of the substation power grid to voltage changes, which is affected by many factors, such as load characteristics, grid structure, equipment performance, etc. The intelligent edge gateway can evaluate the voltage sensitivity of the current power grid based on historical data or expert experience. For substations with high voltage sensitivity, even a small voltage deviation may have a greater impact on the operation of the power grid, so faster response and more accurate reactive compensation are required. According to the degree of voltage deviation and voltage sensitivity, the intelligent edge gateway uses fuzzy logic or table lookup to calculate and determine the reactive capacity required for the current substation.

[0048] Through the above implementation methods, the intelligent edge gateway can dynamically determine the reactive capacity required by the substation according to actual conditions, and realize precise control of the reactive compensation device, thereby improving the voltage quality and power supply reliability of the substation power grid.

[0049] In one achievable method, in order to optimize the reactive power balance of the power grid in the substation area and improve the voltage stability of the power grid, this embodiment proposes to use a constant power factor-reactive droop control strategy to adjust the reactive power output of the photovoltaic inverter. This control strategy combines the advantages of constant power factor control and reactive droop control. Constant power factor control can ensure that the photovoltaic inverter operates at a specific power factor, thereby controlling the ratio of its active and reactive power. Reactive droop control is a method of automatically adjusting reactive power output according to changes in grid voltage, aiming to maintain the stability of grid voltage. The intelligent edge gateway can effectively adjust the reactive power output of the photovoltaic inverter using the constant power factor-reactive droop control strategy, thereby optimizing the reactive power balance and voltage stability of the power grid.

[0050] Preferably, the dead zone voltage range is pre-set according to the historical data of the station voltage, the grid operation specifications and safety standards. The dead zone voltage range is set to avoid the intelligent edge gateway from adjusting the station voltage too frequently, reduce unnecessary operations, and improve the stability and efficiency of the system. By analyzing the long-term monitoring data of the station voltage, the fluctuation range, distribution law and extreme value of the voltage can be understood. The intelligent edge gateway can automatically collect, process and analyze these data, identify the normal fluctuation range and abnormal fluctuation of the voltage, and thus set a dead zone voltage range that can reflect the actual voltage situation and has a certain margin. The grid operation specifications usually include the allowable deviation range, adjustment requirements and safety restrictions of the grid voltage. When setting the dead zone voltage range, the intelligent edge gateway needs to ensure that the range meets the requirements of the grid operation specifications to avoid conflicts with the grid operation rules. Safety standards are an important basis for ensuring the safe operation of the power grid. When setting the dead zone voltage range, the safe operation requirements and voltage stability requirements of the power grid equipment must be fully considered. By setting a reasonable dead zone voltage range, voltage fluctuations can be avoided from causing damage to the power grid equipment or causing the occurrence of grid instability.

[0051] In a specific embodiment, an exemplary power supply control method for a substation based on an intelligent edge gateway adopts a "cloud-edge-end" IoT architecture design, and is specifically implemented as follows: Deploy a distributed resource coordination control APP on the cloud. The APP is responsible for real-time monitoring of the voltage at the photovoltaic grid-connected point, receiving data from the edge intelligent gateway, and generating control instructions according to the preset governance strategy, which are sent to the edge intelligent gateway through the cloud server. Deploy an edge intelligent gateway at the edge of the substation area. The gateway establishes a communication link with the distributed photovoltaic inverter, distributed energy storage device and refined reactive power compensation device through LoRa wireless networking. The gateway has built-in AGC / AVC / PCS and other control strategy algorithms for real-time analysis of grid-connected point voltage data and execution of corresponding voltage regulation strategies according to the control instructions sent from the cloud. The distributed photovoltaic control system is integrated into the edge intelligent gateway and is responsible for monitoring and controlling the photovoltaic inverter and energy storage device to ensure that each device works in coordination according to the established strategy. Deploy distributed measurement and control terminals on the photovoltaic inverter, distributed energy storage device and refined reactive power compensation device. By extending the communication interface and configuring the LoRa wireless acquisition terminal, the four remote (telemetry, remote signaling, remote control and remote adjustment) communication with the edge intelligent gateway is realized. The terminal is responsible for collecting equipment status data and uploading it to the edge intelligent gateway, while receiving and executing control instructions from the gateway. The edge intelligent gateway obtains the voltage data of the substation grid connection point in real time through the distributed measurement and control terminal, and uploads it to the cloud-based distributed resource coordination control APP.

[0052] When the grid-connected point voltage does not exceed the upper limit of the normal operating voltage of the substation but exceeds the preset dead zone voltage range, the edge intelligent gateway first attempts to smooth the voltage fluctuation by adjusting the reactive power of the photovoltaic inverter. Specifically, it adopts a constant power factor-reactive power droop or voltage-reactive power droop (variable droop) control strategy to automatically adjust the reactive power output of the inverter according to the voltage deviation.

[0053] If the grid-connected point voltage in the substation area continues to exceed the upper limit of the normal operating voltage in the substation area, the edge smart gateway performs the following steps: Determine the reactive capacity of the substation area, which is calculated based on the voltage deviation degree and voltage sensitivity. Calculate the sum of the reactive capacities of the photovoltaic inverter, distributed energy storage device and refined reactive compensation device.

[0054] According to the comparison result of the sum of reactive capacity and the reactive capacity of the substation, the voltage is regulated according to the set regulation priority: if the sum of reactive capacity is greater than the reactive capacity of the substation, the refined reactive compensation device is controlled first to regulate the voltage; if the voltage has not recovered, the reactive power of the photovoltaic inverter and the distributed energy storage device is adjusted in turn until the voltage is restored. If the sum of reactive capacity is not greater than the reactive capacity of the substation and has been exhausted, the voltage is regulated by adjusting the active power of the distributed energy storage device; if the voltage still cannot be restored, the active power of the photovoltaic inverter is reduced or the distributed photovoltaic system is controlled to exit operation.

[0055] Specifically, regarding the regulation of distributed energy storage devices, Figure 2 As shown in the figure, by controlling the bidirectional energy storage DC / DC converter, different control strategies can be used when the energy storage battery is charged / discharged to achieve a stable inverter DC side voltage. u dc The function of the energy storage battery is to charge when the voltage at the photovoltaic grid point is too high and the reactive power cannot be adjusted. At this time, the bidirectional energy storage DC / DC converter is in Buck mode, and the DC voltage is given. u dcpre and u dc The compared difference is passed through the PI controller to obtain the input signal of the PWM generator.

[0056] like Figure 3 As shown in the figure, when the photovoltaic output power is not enough to support the voltage and the grid voltage is low, the energy storage battery discharges. At this time, the bidirectional energy storage DC / DC converter is in Boost mode. Pref With output power P After making a difference, the PI controller is used to obtain the given value of the inductor current of the bidirectional energy storage DC / DC converter. I lref And with the inductor current of the bidirectional energy storage DC / DC converter Il The result is passed through the PI controller as the input signal of the PWM generator.

[0057] Through the control structure of the voltage outer loop and the current inner loop, better dynamic performance can be obtained compared to single-loop control, so that the energy storage system can promptly smooth out fluctuations when the voltage exceeds the limit, thereby ensuring the stability of the substation voltage.

[0058] During any regulation process, once the voltage at the grid connection point in the substation returns to the normal operating range, the edge intelligent gateway immediately stops all regulation operations to maintain system stability.

[0059] Disconnection equipment with obvious disconnection points and reliable grounding functions is installed at the grid connection point of distributed energy storage devices to ensure safe operation. Both the edge intelligent gateway and distributed measurement and control terminal have lightning protection and surge protection functions to improve the system's safety protection capabilities. The edge intelligent gateway provides a variety of IoT interfaces and IO interfaces to achieve access to massive terminal devices, and provides open standard interfaces to connect to industry application systems of different partners to build a wide range of industry practicality. Through the remote and cloud operation and maintenance platform, remote maintenance, upgrades and management of on-site equipment can be achieved to improve system reliability and maintenance efficiency. Due to the lack of unified specifications and different forms of communication interfaces for photovoltaic inverters, the communication interfaces adopted by different manufacturers include RS-485, USB, Ethernet, RS-232, etc., so they need to be converted to a unified RS-485 port output through an interface converter. In addition, the RS-485 bus interface of some photovoltaic inverters has been occupied, and an interface converter is needed to expand the original one-way communication to two-way communication, so as to achieve two-way data collection and issue control instructions while ensuring that the manufacturer's cloud platform communication is not affected. The photovoltaic inverter is connected to the communication interface converter to realize communication protocol conversion, and then connected to the intelligent gateway module to form a set of distributed measurement and control terminal products.

[0060] This embodiment is based on the modular and compact R&D design of the edge intelligent gateway, which can be promoted and applied to various scenarios such as distributed photovoltaics for the entire county, photovoltaic power stations in industrial parks, and flexibly select and configure different functional modules according to needs. Based on the edge intelligent gateway, real-time and efficient data processing, calculation, and analysis are provided nearby, and multiple protocols are supported. The computing system is more efficient and intelligent, and diversified control strategies can be flexibly configured. In the design process of the integrated solution, convenient debugging and maintenance in the later stage have been taken into consideration, remote configuration and debugging are supported, and it has a power failure alarm function and efficient maintenance. Integrated solutions based on distributed energy storage devices, reactive power compensation devices, etc. can effectively solve the problem of high voltage exceeding the limit caused by distributed photovoltaic access.

[0061] In another embodiment of the present invention, a power supply control device for a substation based on an intelligent edge gateway is provided, which is applied to a substation power supply system including a distributed photovoltaic system, a distributed energy storage device, a reactive power compensation device and an intelligent edge gateway, and the control device includes: The acquisition module is used to obtain the voltage of the grid connection point in the substation area.

[0062] The first regulating module is used to regulate the reactive power of the photovoltaic inverter in the distributed photovoltaic system to smooth voltage fluctuations when the grid-connected point voltage in the substation does not exceed the upper limit of the normal operating voltage in the substation but exceeds a preset dead zone voltage range.

[0063] The determination module is used to determine the reactive capacity of the substation when the grid-connected point voltage of the substation exceeds the upper limit of the normal operating voltage of the substation, and to determine the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device.

[0064] The second regulating module is used to regulate and control the photovoltaic inverter, the distributed energy storage device and the reactive compensation device according to the set regulation priority according to the size relationship between the reactive capacity of the substation and the sum of the reactive capacity.

[0065] Exemplarily, the regulating and controlling the photovoltaic inverter, the distributed energy storage device, and the reactive power compensation device according to the set regulation priority includes: When the sum of the reactive capacities is greater than the reactive capacity of the substation, the reactive compensation device is preferentially controlled to perform voltage regulation; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the grid-connected point voltage of the substation area has not recovered to the normal operating voltage of the substation area, the voltage is regulated by adjusting the reactive power of the photovoltaic inverter; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the voltage is regulated by adjusting the reactive power of the distributed energy storage device until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

[0066] Exemplarily, the regulating and controlling the photovoltaic inverter, the distributed energy storage device, and the reactive power compensation device according to the set regulation priority includes: When the sum of the reactive capacities is not greater than the reactive capacity of the substation, and the sum of the reactive capacities has been adjusted and exhausted, voltage regulation is performed by adjusting the active power of the distributed energy storage device; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the active power of the photovoltaic inverter is reduced or the distributed photovoltaic system is controlled to exit operation until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

[0067] All relevant contents of each step involved in the aforementioned embodiment of a substation power supply control method based on an intelligent edge gateway can be referred to the functional description of the functional module corresponding to a substation power supply control device based on an intelligent edge gateway in an embodiment of the present invention, and will not be repeated here. The division of modules in the embodiment of the present invention is schematic, which is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present invention can be integrated into a processor, or it can exist physically separately, or two or more modules can be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0068] In another embodiment of the present invention, a computer device is provided, the computer device including a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of a power supply control method for a station area based on an intelligent edge gateway.

[0069] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of a power supply control method for a station area based on an intelligent edge gateway in the above embodiment.

[0070] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0071] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, 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 generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0072] These computer program instructions may also be stored in a computer-readable memory capable of directing 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 an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0073] 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, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0074] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0075] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A power supply control method for a substation based on an intelligent edge gateway. It is characterized in that Applied to a power supply system for a substation including a distributed photovoltaic system, a distributed energy storage device, a reactive power compensation device, and an intelligent edge gateway, the control method includes: Get the grid connection point voltage in the substation area; When the grid-connected point voltage of the substation does not exceed the upper limit of the normal operating voltage of the substation but exceeds the preset dead zone voltage range, the reactive power of the photovoltaic inverter in the distributed photovoltaic system is adjusted to smooth the voltage fluctuation; When the grid connection point voltage of the substation exceeds the upper limit of the normal operating voltage of the substation, the reactive capacity of the substation is determined, and the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device is determined; According to the relationship between the reactive capacity of the substation and the sum of the reactive capacity, the photovoltaic inverter, the distributed energy storage device and the reactive compensation device are regulated and controlled according to the set regulation priority.

2. According to the method for controlling power supply of a substation based on an intelligent edge gateway according to claim 1, It is characterized in that The step of regulating and controlling the photovoltaic inverter, the distributed energy storage device and the reactive power compensation device according to the set regulation priority includes: When the sum of the reactive capacities is greater than the reactive capacity of the substation, the reactive compensation device is preferentially controlled to perform voltage regulation; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the grid-connected point voltage of the substation area has not recovered to the normal operating voltage of the substation area, the voltage is regulated by adjusting the reactive power of the photovoltaic inverter; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the voltage is regulated by adjusting the reactive power of the distributed energy storage device until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

3. According to the method for controlling power supply of a substation based on an intelligent edge gateway according to claim 1, It is characterized in that The step of regulating and controlling the photovoltaic inverter, the distributed energy storage device and the reactive power compensation device according to the set regulation priority includes: When the sum of the reactive capacities is not greater than the reactive capacity of the substation, and the sum of the reactive capacities has been adjusted and exhausted, voltage regulation is performed by adjusting the active power of the distributed energy storage device; If the grid connection point voltage of the substation area is restored to the normal operating voltage of the substation area, the regulation is stopped; If the voltage at the grid-connected point in the substation has not recovered to the normal operating voltage of the substation, the active power of the photovoltaic inverter is reduced or the distributed photovoltaic system is controlled to exit operation until the voltage at the grid-connected point in the substation recovers to the normal operating voltage of the substation.

4. According to the method for controlling power supply of a substation based on an intelligent edge gateway according to claim 1, It is characterized in that After obtaining the grid connection point voltage of the substation area, the method further includes: When the grid-connected point voltage of the substation does not exceed the normal operating voltage upper limit of the substation and does not exceed the preset dead zone voltage range, no adjustment is performed.

5. According to the method for controlling power supply of a substation based on an intelligent edge gateway according to claim 1, It is characterized in that The determination of the reactive capacity of the substation area is specifically as follows: The reactive capacity of the substation is determined according to the voltage deviation degree between the grid connection point voltage of the substation and the normal operating voltage of the substation and the voltage sensitivity.

6. According to claim 1, a power supply control method based on an intelligent edge gateway for a substation area, It is characterized in that The step of regulating the reactive power of the photovoltaic inverter specifically includes: The constant power factor-reactive power droop control strategy is used to regulate the reactive power of the photovoltaic inverter.

7. According to claim 1, a power supply control method for a substation based on an intelligent edge gateway, It is characterized in that The dead zone voltage range is preset based on historical data of the substation voltage, grid operation specifications and safety standards.

8. A power supply control device for a substation based on an intelligent edge gateway, It is characterized in that Applied to the power supply system of the substation including distributed photovoltaic system, distributed energy storage device, reactive power compensation device and intelligent edge gateway, the control device includes: An acquisition module is used to obtain the voltage of the grid connection point in the substation area; A first regulating module is used to adjust the reactive power of the photovoltaic inverter in the distributed photovoltaic system to smooth the voltage fluctuation when the voltage of the grid-connected point in the substation area does not exceed the upper limit of the normal operating voltage of the substation area but exceeds the preset dead zone voltage range; A determination module, used to determine the reactive capacity of the substation when the grid connection point voltage of the substation exceeds the upper limit of the normal operating voltage of the substation, and determine the sum of the reactive capacities of the photovoltaic inverter, the distributed energy storage device and the reactive compensation device; The second regulating module is used to regulate and control the photovoltaic inverter, the distributed energy storage device and the reactive compensation device according to the set regulation priority according to the size relationship between the reactive capacity of the substation and the sum of the reactive capacity.

9. A device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, It is characterized in that When the processor executes the computer program, the steps of a power supply control method for an area based on an intelligent edge gateway as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program. It is characterized in that When the computer program is executed by the processor, the steps of a power supply control method for an area based on an intelligent edge gateway as described in any one of claims 1 to 7 are implemented.

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