Iot terminal management method and system

Abstract

This invention relates to the field of data management technology, and discloses an Internet of Things (IoT) terminal management method and system. By receiving the total power generated by each IoT terminal in a photovoltaic (PV) power plant, the total output power of the PV power plant is determined. When the active power value generated by the PV power plant or the actual value of the high-voltage busbar of the PV power plant's main transformer is compared with the target value issued by the dispatch center, the active power limit of the inverter is automatically adjusted to bring the current active power or voltage generated by the PV power plant closer to the target value, improving accuracy and control speed, meeting grid demand, enhancing the peak-shaving capability of the IoT system, ensuring that the operation of the new energy power plant and the grid is within a safe and controllable range, and calling upon the planned total output power of the PV power plant, thereby realizing active power control and reactive power control of the PV power plant. It tracks the active power adjustment target value and reactive power adjustment target value issued by the dispatch center, achieving the grid connection technology requirements for high-precision peak-shaving of the PV power plant.

Description

Technical Field

[0001] This invention relates to an Internet of Things (IoT) terminal management method and system, belonging to the field of data management technology. Background Technology

[0002] AGC (Automatic Generation Control) is a system that adjusts the active and reactive power of multiple generators in different power plants in response to load changes. As a core function of energy management systems, its core objective is to offset the impact of load fluctuations and the intermittent nature of renewable energy by adjusting the active power output of generation units in real time, thereby maintaining grid frequency stability and inter-regional power balance. With the large-scale grid connection of photovoltaic power generation, the application of AGC technology in photovoltaic power plants is becoming increasingly critical. However, photovoltaic output is affected by factors such as sunlight intensity, cloud movement, and ambient temperature, exhibiting significant minute-level fluctuations, posing a huge challenge to precise AGC control.

[0003] During the execution of AGC (Automatic Generation Control) in photovoltaic (PV) power plants, IoT terminals bear the core responsibilities of power generation data collection, command transmission, and equipment control. Their management level directly determines the accuracy of AGC regulation. Currently, the traditional IoT terminal systems widely deployed in PV power plants are no longer adequate for the grid regulation needs following a high proportion of PV grid connection. Specific shortcomings are reflected in the following key aspects:

[0004] Firstly, the accuracy and real-time performance of power generation data acquisition are insufficient. Photovoltaic power plants typically contain dozens to hundreds of power generation units. Traditional terminals mostly adopt a decentralized acquisition mode, with some sensors having an accuracy of less than 90%, and data transmission experiencing a 2-5 second delay. This makes it impossible to accurately capture the instantaneous fluctuations in the total power generation of each unit. This acquisition deviation results in a 5%-8% error between the statistical value and the actual value of the total power generation of the power plant, directly affecting the accuracy of subsequent output power judgment.

[0005] Secondly, the power grid dispatch center issues planned total output power to photovoltaic power plants based on load forecasts. However, some traditional systems lack the logic to establish real-time comparison between the planned and actual total output power. When sudden changes in sunlight cause the planned output power to deviate from the planned value, the system either passively waits for dispatch instructions (response delays often exceed 30 seconds, failing to meet the requirements of GB / T 38969-2020 standard) or directly implements a blanket power limiting measure, resulting in energy waste or grid frequency fluctuations. Photovoltaic power plants need to reserve frequency regulation margins to cope with sudden grid demands, but some traditional terminal systems cannot accurately calculate the regulation margin based on real-time output, nor can they scientifically divide the planned output power into remote control output and closed-loop transmission channels. In the power distribution stage, the system often uses an average distribution mode to issue instructions to inverters, ignoring the efficiency differences and operating status of each inverter. This results in some inverters having overshoots of up to 9.2% and steady-state errors exceeding 1%, seriously affecting the quality of AGC regulation.

[0006] Traditional IoT terminals in power plants struggle to achieve high-precision acquisition and utilization of output power information from frequency modulation units, easily leading to peak-shaving needs in power plants, especially photovoltaic power plants with unstable power generation. Therefore, it is necessary to propose an IoT terminal management method and system to address the weak peak-shaving capability of IoT systems in photovoltaic power plants. Summary of the Invention

[0007] This invention provides an IoT terminal management method and system that can solve the problem of weak peak-shaving capability of IoT systems in photovoltaic power plants.

[0008] This invention provides an IoT terminal management method, comprising:

[0009] Receive the total power generated by each IoT terminal in the photovoltaic power plant;

[0010] Based on the statistical value of total power generation, determine the total power to be output by the photovoltaic power plant;

[0011] Activate the planned total output power of the photovoltaic power plant;

[0012] Determine whether the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant;

[0013] If the total output power of the photovoltaic power plant does not match the planned total output power of the photovoltaic power plant, then the total output power of the photovoltaic power plant will be included in the power closed loop for power transmission.

[0014] If the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant, then calculate the power margin of the total output power of the photovoltaic power plant.

[0015] Based on the power margin of photovoltaic power plants, the total output power of photovoltaic power plants is divided into remotely controlled output power and power transmitted within the power closed loop;

[0016] Based on the total amount of remotely controlled output power, calculate the target set useful power output value for each inverter.

[0017] The present invention provides an Internet of Things (IoT) terminal management system, comprising:

[0018] The host computer is used to execute the IoT terminal management method described above;

[0019] The Internet of Things (IoT) terminal communicates with the host computer.

[0020] This invention provides an IoT terminal management method and system. By receiving the total power generated by each IoT terminal in a photovoltaic (PV) power plant, the total output power of the PV power plant is determined. When the active power value generated by the PV power plant or the actual value of the high-voltage busbar of the main transformer of the PV power plant is compared with the target value issued by the dispatch center, the active power limit of the inverter is automatically adjusted to bring the current active power or voltage generated by the PV power plant closer to the target value. The total output power of the PV power plant is incorporated into the power transmission within the power closed loop and the total amount of remotely adjusted output power to calculate the target set useful power output value of each inverter, ensuring that the power generation and load of the PV power plant are balanced. The balance between power generation and reactive power is achieved by continuously optimizing the control algorithm to improve accuracy and control speed, meet grid demand, enhance the peak-shaving capability of the Internet of Things system, and ensure that the operation of new energy power plants and the grid is within a safe and controllable range. The system calls upon the planned total output power of photovoltaic power plants, selects control equipment and performs power allocation, and automatically issues the final control command to the controlled equipment (inverter), thereby realizing active power control and reactive power control of photovoltaic power plants. It tracks the active power adjustment target value and reactive power adjustment target value issued by the dispatch center, and meets the grid connection technology requirements for high-precision peak-shaving of photovoltaic power plants.

[0021] When the total output power of a photovoltaic power plant does not match the planned total output power of the photovoltaic power plant, the total output power of the photovoltaic power plant is incorporated into the power closed loop for power transmission. It can limit the rate of change of the electric field output, has the ability to set the adjustment rate in 1 minute and 10 minutes, and has constraints such as the upper limit of the inverter adjustment, the lower limit of the adjustment, the adjustment rate, and the adjustment time interval to prevent the impact of large power fluctuations on the inverter group and the grid.

[0022] When the total output power of the photovoltaic power plant matches the planned total output power, the power margin of the total output power is calculated to accurately obtain the adjustment margin, ensure the rationality of the control strategy algorithm, and guarantee minimal or no adjustments to the inverter group. Information such as the current system operation status, power increase / decrease interlock status, operating mode, and power plant production data is uploaded to the dispatch center in real time. Based on the total remotely adjusted output power, the target setpoint active power output value for each inverter is calculated. This enables automatic reception of active power control commands from the dispatch center system. Based on the calculated adjustable margin, the IoT terminal is periodically invoked to calculate the active power setpoint of the inverter and send the setpoint to the corresponding inverter. Similarly, the system automatically receives voltage control commands from the dispatch center system and, based on the calculated adjustable margin, calculates the reactive power setpoint of the inverter and the reactive power compensation device, sending the setpoint to the corresponding inverter and reactive power compensation device. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the method flow of an Internet of Things (IoT) terminal management method according to an embodiment of the present invention;

[0024] Figure 2 This is a system connection diagram of an Internet of Things (IoT) terminal management system according to an embodiment of the present invention.

[0025] Icon labels:

[0026] 100 - Host computer; 200 - Internet of Things (IoT) terminal. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, the present invention provides an IoT terminal management method, comprising:

[0029] S100 receives the total power generated by each IoT terminal in the photovoltaic power plant.

[0030] S200 determines the total output power of the photovoltaic power plant based on the statistical value of the total power generated.

[0031] S300 calls upon the planned total output power of the photovoltaic power plant.

[0032] S400 determines whether the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant.

[0033] S510 If the total output power of the photovoltaic power plant does not match the planned total output power of the photovoltaic power plant, the total output power of the photovoltaic power plant will be included in the power closed loop for power transmission.

[0034] S520: If the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant, then calculate the power margin of the total output power of the photovoltaic power plant.

[0035] S530 divides the total output power of a photovoltaic power plant into remotely controlled output power and power transmitted within the power closed loop, based on the power regulation margin of the photovoltaic power plant.

[0036] S540 calculates the target set useful power output value for each inverter based on the total amount of remotely controlled output power.

[0037] Specifically, when the total output power of a photovoltaic power plant does not match the planned total output power, the total output power of the photovoltaic power plant is incorporated into the power closed loop for power transmission. It can limit the rate of change of the electric field output, has the ability to set the adjustment rate in 1 minute and 10 minutes, and has constraints such as the upper limit of the inverter adjustment, the lower limit of the adjustment, the adjustment rate, and the adjustment time interval to prevent the impact on the inverter group and the grid when the power fluctuation is large.

[0038] When the total output power of the photovoltaic power plant matches the planned total output power, the power margin of the total output power is calculated to accurately obtain the adjustment margin, ensure the rationality of the control strategy algorithm, and guarantee minimal or no adjustments to the inverter group. Information such as the current system operation status, power increase / decrease interlock status, operating mode, and power plant production data is uploaded to the dispatch center in real time. Based on the total remotely adjusted output power, the target setpoint active power output value for each inverter is calculated. This enables automatic reception of active power control commands from the dispatch center system. Based on the calculated adjustable margin, the IoT terminal is periodically invoked to calculate the active power setpoint of the inverter and send the setpoint to the corresponding inverter. Similarly, the system automatically receives voltage control commands from the dispatch center system and, based on the calculated adjustable margin, calculates the reactive power setpoint of the inverter and the reactive power compensation device, sending the setpoint to the corresponding inverter and reactive power compensation device.

[0039] This application relates to an IoT terminal management method. By receiving the total power generated by each IoT terminal in a photovoltaic (PV) power plant, the method determines the total output power of the PV power plant. When the active power value generated by the PV power plant or the actual value on the high-voltage bus of the main transformer is compared with the target value issued by the dispatch center, the active power limit of the inverter is automatically adjusted to bring the current active power or voltage generated by the PV power plant closer to the target value. The total output power of the PV power plant is incorporated into the power transmission within the power closed loop and the total amount of remotely adjusted output power to calculate the target set useful power output value for each inverter, ensuring a balance between power generation and load at the PV power plant. The system aims to balance power generation with the scheduled power generation plan as the target value. By continuously optimizing the control algorithm, it improves accuracy and control speed to meet grid demand, enhances the peak-shaving capability of the Internet of Things system, and ensures that the operation of new energy power plants and the grid is within a safe and controllable range. It calls upon the planned total output power of photovoltaic power plants, selects control equipment and performs power allocation, and automatically issues the final control command to the controlled equipment (inverter), thereby realizing active power control and reactive power control of photovoltaic power plants. It tracks the active power adjustment target value and reactive power adjustment target value issued by the dispatch center, and meets the grid connection technology requirements for high-precision peak-shaving of photovoltaic power plants.

[0040] In one embodiment of this application, S100 includes:

[0041] S110, select an IoT terminal.

[0042] S120 records the voltage and current data of the power generation block.

[0043] Specifically, an IoT terminal records inverter data for a power generation block.

[0044] S130, determine whether the time interval between the system time of the IoT terminal during the adoption process and the adjacent sampling time point is greater than or equal to the sampling time interval of the power generation block.

[0045] S140, if the time interval between the system time of the IoT terminal during the adoption process and the adjacent sampling time point is greater than or equal to the sampling time interval of the power generation block, then record the voltage and current data of the current power generation block.

[0046] S150, if the time interval between the system time of the IoT terminal during the adoption process and the adjacent sampling time point is less than the sampling time interval of the power generation block, then return to the judgment of whether the time interval between the system time and the adjacent sampling time point is greater than or equal to the sampling time interval of the power generation block.

[0047] S160 generates the total power generation of the power generation block based on the voltage and current data of the current power generation block recorded at each sampling time point of the selected IoT terminal.

[0048] S170, return to the step of selecting an IoT terminal, until all IoT terminals have been selected.

[0049] Specifically, the AGC sampling period refers to the period during which the AGC calculates the inverter data, feeder data, and booster station data that need to be sampled, which is generally 1-2 seconds. The control period refers to the AGC program calculation period, which is generally around 5 seconds, because the AGC period for grid-connected AGC is generally around 15 seconds, and the AGC period for photovoltaic power plants only needs to be shorter than the grid AGC period.

[0050] The IoT terminal records inverter data for a power generation block. The meanings of the bits from low to high are as follows: 0x01 Command settings to the inverter; 0x02 Do not retrieve inverter channel status and task status; 0x04 Initialize the inverter; 0x08 Save real-time inverter data to the database; 0x10 Real-time inverter fluctuations; 0x20 Set the active power at the grid connection point to 90% of the inverter's total active power and calculate the grid connection point voltage. In voltage control mode, it is initialized to the target voltage in the global parameters. In reactive power control mode, it is calculated based on the voltage level corresponding to 0 volts; 0x40 Calculate the real-time frequency.

[0051] In one embodiment of this application, S200 includes:

[0052] S210, according to the arrangement of the power generation blocks, sequentially call the total power generation of the power generation blocks.

[0053] S220 incorporates the total power generated by each power-generating block into its own real-time parameter database.

[0054] S230: Select an IoT terminal to monitor inverter data.

[0055] S240 reads the useful power conversion rate of the inverter to the total power generated by the power generation block.

[0056] S250 determines the total useful power generated by the power generation block based on the useful power conversion rate.

[0057] S260, return to the inverter monitoring data of the selected IoT terminal, until all inverter monitoring data have been selected.

[0058] S270 calculates the total useful power generated by each power generation block.

[0059] S280 obtains the total output power of the photovoltaic power plant.

[0060] Understandably, the theoretical power is calculated using the prototype generator method, and the real-time power of the prototype generator is the theoretical power. Prototype generators generate relatively stable power, and multiple units are typically used. Abnormal real-time power from the prototype generators will affect the calculation results. Remote control is not issued to the prototype generators. The theoretical power of non-prototype generators and the adjustable upper limit of the power plant are calculated using the maximum real-time power of similar prototype generators.

[0061] The AGC (Automatic Active Power Control) system of a photovoltaic (PV) power plant calculates the adjustable active power capacity in real time. Based on the total active power control commands issued by the power grid dispatch center or locally, it sends the total active power setpoint to the PV monitoring system or distributes it to each inverter. This ensures that the total active power output of the PV power plant meets the power grid dispatch target or the local setpoint. When there is a deviation between the inverter's total active power and the active power at the grid connection point, the active power at the grid connection point needs to be adjusted to the setpoint.

[0062] AGC calculation and control are only initiated when the absolute value of the difference between the total active power setpoint and the actual active power generated by the power plant exceeds the dead zone. This dead zone is generally within 1% of the power plant capacity, typically 10% of the installed capacity.

[0063] This function can be activated when there is a significant deviation between the active power at the grid connection point and the total active power of the inverter. Activation may cause the real-time active power to fluctuate within the target active power dead zone.

[0064] In IoT terminals, 0 indicates no judgment, and 1 indicates setting upper and lower limits. When this parameter is configured to 1, both full transmission and zeroing are subject to primary frequency modulation limits, which may prevent normal full transmission and zeroing. Primary frequency modulation is performed within the dead zone range to avoid frequent initiation of primary frequency modulation. When the real-time frequency is within the range of "50Hz minus dead zone" to "50Hz plus dead zone", primary frequency modulation is not performed. The maximum frequency difference adjusted each time during primary frequency modulation is set to prevent excessive frequency fluctuations.

[0065] In one embodiment of this application, S300 includes:

[0066] S310, establishes a communication connection with the dispatch master station.

[0067] S320 receives encrypted scheduling data from the scheduling master station.

[0068] S330, parses encrypted scheduling data.

[0069] S340, obtain the planned total output power of the photovoltaic power plant.

[0070] S350, calls upon the total output power of the photovoltaic power plant.

[0071] S360 utilizes the fluctuation value of the total output power of a photovoltaic power plant with respect to time.

[0072] S370 provides adjustable useful power from photovoltaic power plants.

[0073] S380 incorporates the planned total output power of the photovoltaic power plant and the adjustable amount of useful work of the photovoltaic power plant into the real-time comparison data folder.

[0074] Understandably, the master dispatch station issues commands to the sub-tasks, receives the target value for the grid connection point, and adjusts the inverters under that grid connection point. It then adjusts the inverters under that grid connection point to ensure the voltage at that point meets requirements. Finally, it adjusts the inverters under that grid connection point to ensure the power factor at that point meets requirements. N independent sub-tasks are configured and controlled separately.

[0075] The master dispatch station issues commands to the overall task, receives the overall target value, and adjusts all inverters. Upon receiving the overall target value, it adjusts all inverters to ensure the real-time voltage at each grid-connected point meets the requirements. Upon receiving the overall target value, it adjusts all inverters to ensure the power factor at each grid-connected point meets the requirements. 1+N tasks are configured. Active and reactive power are directly adjusted by the overall task to regulate the inverters. Sub-tasks do not adjust these parameters. Voltage and power factor are adjusted by the sub-tasks to regulate the inverters. The overall task does not adjust these parameters. Within the overall task, upon receiving a remote control command, it simultaneously sends the remote control command usage message to the sub-tasks. Upon receiving a reactive power-related setting command, it sends an AVC exit message to the sub-tasks. Upon receiving voltage and power factor-related setting commands, it sends the setting command usage message to the sub-tasks and stops adjusting reactive power.

[0076] In the sub-task, messages sent from the main task are processed. Remote control and setting commands are not processed, i.e., return-to-base fails. Whether to force acceptance of target setting commands when the function is not enabled should both be configured to be enabled.

[0077] In one embodiment of this application, S400 includes:

[0078] S410, call the real-time comparison data folder.

[0079] S420, based on system time, selects one of the planned total output power of the photovoltaic power plant.

[0080] S430, which calls upon the adjustable amount of useful power from the photovoltaic power plant.

[0081] S440 determines the lower limit and upper limit of the adjustable useful power of a photovoltaic power plant.

[0082] S450 determines whether the selected planned total output power is less than or equal to the lower limit of the adjustable useful power of the photovoltaic power plant.

[0083] S460, if the selected planned total output power is less than or equal to the lower limit of the adjustable useful power of the photovoltaic power plant, then the total output power to be output by the photovoltaic power plant is determined to match the planned total output power of the photovoltaic power plant.

[0084] S470 If the selected planned total output power is greater than the lower limit of the adjustable useful power of the photovoltaic power plant, then it is further determined whether the selected planned total output power is less than or equal to the upper limit of the adjustable useful power of the photovoltaic power plant.

[0085] S480 If the selected planned total output power is less than or equal to the upper limit of the adjustable useful power of the photovoltaic power plant, then the total output power to be output by the photovoltaic power plant is determined to match the planned total output power of the photovoltaic power plant.

[0086] S490 If the selected planned total output power is greater than the upper limit of the adjustable useful power of the photovoltaic power plant, then it is determined that the total output power of the photovoltaic power plant to be output does not match the planned total output power of the photovoltaic power plant.

[0087] S490a, return to the system time-based selection of one of the planned total output power of the photovoltaic power plant, until the planned total output power for all times has been selected.

[0088] Understandably, control modes include AGC setpoint or curve modes.

[0089] The setpoint mode refers to the dispatching or local system issuing only one single-point remote control command at a time, which serves as the total active power setpoint for the station.

[0090] The curve mode refers to the dispatching center issuing power generation plans for the next few days at around 23:45 on the same day, with 96 points (one point every 15 minutes) or 288 points (one point every 5 minutes).

[0091] Output modes include AGC open-loop or closed-loop modes.

[0092] The first mode means that the AGC module only calculates the target set value of each inverter based on the total active power setting of the station, without performing remote adjustment output.

[0093] The second mode refers to the AGC module calculating the target set value of each inverter based on the total active power setting of the station and then remotely adjusting the output.

[0094] In this embodiment, the selected total planned output power is less than or equal to the lower limit of the adjustable useful power of the photovoltaic power plant, and the selected total planned output power is greater than the lower limit of the adjustable useful power of the photovoltaic power plant and less than or equal to the upper limit of the adjustable useful power of the photovoltaic power plant. In both cases, the AGC module calculates the target setting value of each inverter based on the total active power setting of the power plant and performs remote adjustment output.

[0095] When the selected total planned output power exceeds the upper limit of the adjustable useful power of the photovoltaic power plant, the AGC module calculates the target set value of each inverter based only on the total active power of the plant, without remotely adjusting the output.

[0096] In one embodiment of this application, S400 includes:

[0097] S491, based on system time, determines the matching degree between the total output power of the photovoltaic power plant and the planned total output power of the photovoltaic power plant.

[0098] S492, if the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant, then the remote control authority will be transferred to the dispatch master station.

[0099] S493, executes single-control inverter mode.

[0100] Specifically, the single-control inverter mode involves sending a command to an IoT terminal so that the IoT terminal controls one inverter.

[0101] S494 If the total output power of the photovoltaic power plant does not match the planned total output power of the photovoltaic power plant, then the plant shall exercise its local control.

[0102] S495 assigns inverter power tasks to IoT terminals, and all IoT terminals synchronously execute control over all inverters in the photovoltaic power plant.

[0103] S496 returns a value based on system time, determining the match between the total output power of the photovoltaic power plant and the planned total output power of the photovoltaic power plant, until a stop operation instruction is received.

[0104] Understandably, control permissions include remote control or local control of the host computer itself.

[0105] Local control permissions refer to the total active power setpoint of the photovoltaic power plant being derived from the total active power setpoint set by the local operator on the interface.

[0106] Remote control authority refers to the total active power setpoint of a photovoltaic power plant being issued by a remote grid dispatch automation system dispatcher, either as the total active power setpoint or as the power generation curve.

[0107] The dispatcher or local authority issues only one single-point remote control command at a time, which serves as the total active power setpoint or target voltage for the substation. Local control authority refers to the fact that the total active power setpoint or grid connection point target voltage value for the substation is derived from the total active power setpoint or target voltage set by the local operator on the interface.

[0108] Remote control authority refers to the total active power setpoint or grid connection point target voltage of the power station being issued by the dispatcher of the remote power grid dispatch automation system, which also issues the total active power setpoint or generation curve and the grid connection point target voltage or generation curve.

[0109] AGC operating parameters include local or remote setpoints, actual power generation at the site, and adjustable upper or lower limits for the site. The AGC local total active power setpoint can be modified on the interface.

[0110] In one embodiment of this application, S520 includes:

[0111] S521, select an IoT terminal.

[0112] S522 receives the inverter's theoretical power output and the inverter's actual power output collected by the IoT terminal.

[0113] S523 uses the product of the minimum power generation factor and the actual power generation to obtain the minimum power generation of the inverter.

[0114] S524 obtains the inverter's upscaling potential based on the difference between the inverter's theoretical power generation and its actual power generation.

[0115] S525 utilizes the difference between the inverter's actual power output and its minimum power output to obtain the inverter's down-adjustment range.

[0116] S526, return to the step of selecting an IoT terminal until all IoT terminals have been selected.

[0117] S527 accumulates the upward adjustment space of each inverter to obtain the upward adjustment space of power regulation margin.

[0118] S528 accumulates the down-adjustment space for each inverter to obtain the power regulation margin down-adjustment space.

[0119] Understandably, let the theoretical power output of a single inverter be Pref. Let the actual power output of a single inverter be Preal. Let the minimum power output of a single inverter be Pmin = 20% multiplied by Preal. Then, the upward adjustment space of a single inverter is upcapi = Pref minus Preal. Then, the downward adjustment space of a single inverter is downcapi = Preal minus Pmin. The upward and downward adjustment spaces of each inverter are summed separately to obtain the total upward adjustment space upcapsub and downward adjustment space downcapsub for the entire plant.

[0120] This provides room for both upward and downward adjustments to power regulation margin.

[0121]

[0122] In one embodiment of this application, S530 includes:

[0123] The S531 receives real-time data on the actual power generation of the inverter from each IoT terminal.

[0124] S532 sums the actual power generation of each inverter to obtain the actual power of the photovoltaic power plant.

[0125] S533 receives the planned total output power of the photovoltaic power plant.

[0126] S534 determines whether the planned total output power of a photovoltaic power plant is equal to the actual power output of the photovoltaic power plant.

[0127] S535 If the planned total output power of the photovoltaic power plant is equal to the actual power of the photovoltaic power plant, then the remote control output power and the power transmission within the power closed loop shall be executed according to the power plant plan.

[0128] S536 If the planned total output power of the photovoltaic power plant is greater than the actual power of the photovoltaic power plant, the power adjustment margin will be used to adjust the output power remotely and transmit power within the power closed loop.

[0129] S537 If the planned total output power of the photovoltaic power plant is less than the actual power of the photovoltaic power plant, the power adjustment margin will be used to adjust the output power remotely and transmit power within the power closed loop.

[0130] Specifically, let the actual power of the entire plant be... The target value issued by the scheduler is .

[0131] Then when Greater than At that time, utilizing the power regulation margin to increase the adjustment space, the power deficit of the entire plant is:

[0132]

[0133] The remote adjustment value of the output power for each inverter is then:

[0134]

[0135] Then when Less than When the power regulation margin is reduced, the power surplus deficit for the entire plant is:

[0136]

[0137] The remote adjustment value of the output power for each inverter is then:

[0138]

[0139] In one embodiment of this application, S540 includes:

[0140] S541, select an IoT terminal.

[0141] S542 receives the real-time frequency of the inverter from the IoT terminal.

[0142] S543 determines whether the real-time frequency of the inverter is greater than the operating frequency of the target set useful power output value.

[0143] S544, if the inverter's real-time frequency is less than or equal to the operating frequency of the target set useful power output value, then return to the step of selecting an IoT terminal until all IoT terminals have been selected.

[0144] S545 If the real-time frequency of the inverter is greater than the operating frequency of the target set useful power output value, then reduce the real-time frequency of the inverter to reduce the target set useful power output value.

[0145] S546, return to the step of selecting an IoT terminal until all IoT terminals have been selected.

[0146] Specifically, the total active power of the grid is forwarded from the outside. Since there may be a discrepancy between the total active power of the inverter and the total active power of the grid connection point, it is adjusted in two steps.

[0147] The first step is the fast adjustment phase. After receiving the grid connection point setpoint, the system enters the fast adjustment phase to adjust the inverter's total active power to the grid connection point target value or coefficient. When the inverter's total active power is adjusted to the dead zone range, the system enters the second fine-tuning phase. Alternatively, if the grid connection point active power is within the setpoint dead zone range, the system directly enters the second fine-tuning phase. The second step is the fine-tuning phase. Based on the difference between the grid connection point active power and the setpoint, the system calculates the actual total setpoint value sent to the inverter, ensuring that the grid connection point active power matches the setpoint within the dead zone range. The grid connection point active power is the inverter's total active power. After receiving the setpoint, the inverter's total active power is adjusted to the target value. When the inverter's total active power is outside the dead zone range, the setpoint values ​​for each inverter are redistributed. By setting the telemetry coefficient, the inverter's real-time reactive power is inverted. By setting the reactive power transmission coefficient in the inverter's table, the inverter's reactive power transmission setpoint is inverted. If the collected real-time reactive power from the grid connection point is used, the real-time reactive power of the grid connection point also needs to be inverted by setting the telemetry coefficient. When the output increase is blocked, the real-time power of the plant is less than the plant setpoint; when the output decrease is blocked, the real-time power of the plant is greater than the plant setpoint. The AGC is not invoked to calculate the new setpoint for the inverters, and no commands are issued to any inverters.

[0148] like Figure 2 As shown, the present invention provides an Internet of Things (IoT) terminal management system, comprising:

[0149] The host computer 100 is used to execute IoT terminal management methods.

[0150] The Internet of Things terminal 200 is communicatively connected to the host computer 100.

[0151] This embodiment relates to an Internet of Things (IoT) terminal management system. The host computer 100 receives the total power output from each IoT terminal 200 of the photovoltaic power plant to determine the total output power of the photovoltaic power plant. When the active power value generated by the photovoltaic power plant or the actual value of the high-voltage bus of the main transformer of the photovoltaic power plant is compared with the target value issued by the dispatch center, the active power limit of the inverter will be automatically adjusted to bring the current active power or voltage generated by the photovoltaic power plant closer to the target value. The total output power of the photovoltaic power plant is incorporated into the power transmission within the power closed loop and the total amount of remotely adjusted output power to calculate the target set useful power output value of each inverter, ensuring the balance between power generation and load of the photovoltaic power plant. With the scheduled power generation plan as the target value, the host computer 100 continuously optimizes the control algorithm to improve accuracy and control speed, meet the grid demand, enhance the peak-shaving capability of the Internet of Things system, and ensure that the operation of new energy power plants and the grid is within a safe and controllable range. It calls upon the planned total output power of the photovoltaic power plant, selects control equipment and performs power allocation, and finally automatically issues control commands to the controlled equipment, i.e., the inverter, through the Internet of Things terminal 200. This enables the active power control and reactive power control of the photovoltaic power plant, tracks the active power adjustment target value and reactive power adjustment target value issued by the dispatch center, and meets the grid connection technology requirements for high-precision peak-shaving of the photovoltaic power plant.

[0152] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An Internet of Things terminal management method characterized by comprising: include: Receive the total power generated by each IoT terminal in the photovoltaic power plant; Based on the statistical value of total power generation, determine the total power to be output by the photovoltaic power plant; Activate the planned total output power of the photovoltaic power plant; Determine whether the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant; If the total output power of the photovoltaic power plant does not match the planned total output power of the photovoltaic power plant, then the total output power of the photovoltaic power plant will be included in the power closed loop for power transmission. If the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant, then calculate the power margin of the total output power of the photovoltaic power plant. Based on the power margin of photovoltaic power plants, the total output power of photovoltaic power plants is divided into remotely controlled output power and power transmitted within the power closed loop; Based on the total amount of remotely controlled output power, calculate the target set useful power output value for each inverter; If there is a deviation between the total active power of the inverter and the total active power at the grid connection point, it is adjusted in two steps. The first step is the fast adjustment stage. After receiving the target value at the grid connection point, the fast adjustment stage is entered to adjust the total active power of the inverter to the target value or coefficient value at the grid connection point. When the inverter's total active power is adjusted to the dead zone range, it enters the second fine-tuning stage. The second step is the fine-tuning stage, which calculates the total target value actually sent to the inverter based on the difference between the active power at the grid connection point and the target value, so that the active power at the grid connection point is consistent with the target value.

2. The IoT terminal management method of claim 1, wherein The total power generated by each IoT terminal of the photovoltaic power plant is received, including: Select an IoT terminal; Record voltage and current data for the power generation block; one IoT terminal records inverter data for one power generation block; Determine whether the time interval between the system time of the IoT terminal during the adoption process and the adjacent sampling time point is greater than or equal to the sampling time interval of the power generation block; If the time interval between the system time of the IoT terminal during the adoption process and the adjacent sampling time point is greater than or equal to the sampling time interval of the power generation block, then the voltage and current data of the current power generation block are recorded. If the time interval between the system time of the IoT terminal during the adoption process and the adjacent sampling time point is less than the sampling time interval of the power generation block, then return to the judgment of whether the time interval between the system time and the adjacent sampling time point is greater than or equal to the sampling time interval of the power generation block. Based on the voltage and current data of the current power generation block recorded at each sampling time point of the selected IoT terminal, the total power generation of the power generation block is generated. Return to the previous step and select an IoT terminal until all IoT terminals have been selected.

3. The IoT terminal management method according to claim 2, characterized in that, The determination of the total output power of the photovoltaic power plant based on the statistical value of the total generated power includes: Based on the arrangement of the power generation blocks, the total power generation of the power generation blocks is called sequentially; The total power generated by each power generation block is incorporated into its own real-time parameter database; Select an inverter from an IoT terminal to monitor data; Read the useful power conversion rate of the inverter to the total power generated by the power generation block; Based on the useful power conversion rate, determine the total useful power generated by the power generation block; Return to the selected IoT terminal inverter monitoring data until all inverter monitoring data have been selected; The total useful power generation of each power generation block is statistically analyzed; Obtain the total output power of the photovoltaic power plant.

4. The IoT terminal management method according to claim 3, characterized in that, The method of calling upon the planned total output power of the photovoltaic power plant includes: Establish a communication connection with the dispatch master station; Receive encrypted scheduling data from the scheduling master station; Parse encrypted scheduling data; Obtain the planned total output power of the photovoltaic power plant; Calling upon the total output power of the photovoltaic power plant; Utilizing the fluctuation value of the total output power of the photovoltaic power plant with respect to time; To obtain the adjustable amount of useful work from photovoltaic power plants; The planned total output power of the photovoltaic power plant and the adjustable amount of useful work of the photovoltaic power plant are included in the real-time comparison data folder.

5. The IoT terminal management method according to claim 4, characterized in that, The determination of whether the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant includes: Access the real-time comparison data folder; Based on system time, select one of the planned total output power of the photovoltaic power plant; Utilize the adjustable amount of useful power from photovoltaic power plants; Determine the lower limit and upper limit of the adjustable useful power of a photovoltaic power plant; Determine whether the selected planned total output power is less than or equal to the lower limit of the adjustable useful power of the photovoltaic power plant; If the selected planned total output power is less than or equal to the lower limit of the adjustable useful power of the photovoltaic power plant, then the total output power to be output by the photovoltaic power plant is determined to be matched with the planned total output power of the photovoltaic power plant. If the selected total planned output power is greater than the lower limit of the adjustable useful power of the photovoltaic power plant, then it is further determined whether the selected total planned output power is less than or equal to the upper limit of the adjustable useful power of the photovoltaic power plant. If the selected planned total output power is less than or equal to the upper limit of the adjustable useful power of the photovoltaic power plant, then the total output power to be output by the photovoltaic power plant is determined to be matched with the planned total output power of the photovoltaic power plant. If the selected planned total output power is greater than the upper limit of the adjustable useful power of the photovoltaic power plant, then it is determined that the total output power of the photovoltaic power plant to be output is mismatched with the planned total output power of the photovoltaic power plant. Returning to the system time-based selection, choose one of the planned total output power of the photovoltaic power plant, until the planned total output power for all times has been selected.

6. The IoT terminal management method according to claim 5, characterized in that, After determining whether the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant, the following steps are included: Based on system time, determine the degree of matching between the total output power of the photovoltaic power plant and the planned total output power of the photovoltaic power plant; If the total output power of the photovoltaic power plant matches the total planned output power of the photovoltaic power plant, then the remote control authority will be transferred to the dispatch master station. Execute single-control inverter mode; the single-control inverter mode is to send a command to an Internet of Things (IoT) terminal so that the IoT terminal controls one inverter; If the total output power of the photovoltaic power plant does not match the planned total output power of the photovoltaic power plant, then it shall utilize its local control. The inverter power task is assigned to the Internet of Things (IoT) terminals, and all IoT terminals synchronously execute control of all inverters in the photovoltaic power plant. The system returns a value based on system time, determining the match between the total output power of the photovoltaic power plant and its planned total output power, until a stop operation instruction is received.

7. The IoT terminal management method according to claim 6, characterized in that, If the total output power of the photovoltaic power plant matches the planned total output power of the photovoltaic power plant, then the power margin of the total output power of the photovoltaic power plant is calculated, including: Select an IoT terminal; Receive the inverter's theoretical power generation and the inverter's actual power generation collected by the IoT terminal; The minimum power output of the inverter is obtained by multiplying the minimum power generation factor by the actual power generation. The upscaling potential of the inverter is obtained based on the difference between the inverter's theoretical power generation and its actual power generation. The down-adjustment range of the inverter can be obtained by using the difference between the actual power output of the inverter and the minimum power output of the inverter. Return to the previous step of selecting an IoT terminal, until all IoT terminals have been selected; The upward adjustment space of each inverter is accumulated to obtain the upward adjustment space of the power regulation margin. The downward adjustment space of each inverter is accumulated to obtain the downward adjustment space of the power regulation margin.

8. The IoT terminal management method according to claim 7, characterized in that, The method, based on the power regulation margin of the photovoltaic power plant, divides the total output power of the photovoltaic power plant into remotely regulated output power and power transmitted within the power closed loop, including: Receive the real-time actual power generation of the inverter from each IoT terminal; The actual power output of the photovoltaic power plant is obtained by summing the actual power output of each inverter. Receive the planned total output power of the photovoltaic power plant; Determine whether the planned total output power of a photovoltaic power plant is equal to the actual power output of the photovoltaic power plant; If the planned total output power of the photovoltaic power plant is equal to the actual power of the photovoltaic power plant, then the remote control output power and the power transmission within the power closed loop will be executed according to the power plant plan. If the planned total output power of the photovoltaic power plant is greater than the actual output power of the photovoltaic power plant, the power adjustment margin will be used to adjust the output power remotely and transmit power within the power closed loop. If the planned total output power of the photovoltaic power plant is less than the actual output power of the photovoltaic power plant, the power adjustment margin will be used to adjust the output power remotely and transmit power within the power closed loop.

9. The IoT terminal management method according to claim 8, characterized in that, Based on the total amount of remotely controlled output power, calculate the target set useful power output value for each inverter, including: Select an IoT terminal; Receive the real-time frequency of the inverter collected by the IoT terminal; Determine whether the real-time frequency of the inverter is greater than the operating frequency of the target set useful power output value; If the inverter's real-time frequency is less than or equal to the operating frequency of the target set useful power output value, then return to the step of selecting an IoT terminal until all IoT terminals have been selected. If the inverter's real-time frequency is greater than the operating frequency of the target set useful power output value, then reduce the inverter's real-time frequency to lower the target set useful power output value. Return to the previous step and select an IoT terminal until all IoT terminals have been selected.

10. An Internet of Things (IoT) terminal management system, characterized in that, include: The host computer is used to execute the IoT terminal management method as described in any one of claims 1 to 9; The Internet of Things (IoT) terminal communicates with the host computer.

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