Distributed photovoltaic power control method, system and device

Abstract

The invention relates to the technical field of distributed power supplies, in particular to a distributed photovoltaic power control method, system and device. The method comprises the following steps: collecting real-time power data of each photovoltaic inverter and real-time voltage and current data of a grid-connected point bus, and processing the collected data to obtain total real-time data of a photovoltaic field station; uploading the total real-time data and the target value to a regulation and control master station; receiving an updated target value issued by the regulation and control master station in real time; according to the target value, the station model, the topological relation and the locking logic, calculating a sub-target value needing to be adjusted of each photovoltaic inverter; and adjusting the corresponding photovoltaic inverter according to the sub-target value. According to the invention, accurate regulation and control of the power of the photovoltaic inverter are realized, it is ensured that the power output of a photovoltaic field station is consistent with the regulation and control requirements, the stability and efficiency of the system are improved, and the problem that active power, reactive power and voltage are uncontrollable generally existing in distributed photovoltaic power is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of distributed power supply, and in particular to a distributed photovoltaic power control method, system and device. Background Art

[0002] With the current trend of large-scale centralized grid connection of distributed photovoltaic power stations, photovoltaic sites are facing a series of challenges. Specifically, data inconsistency, accuracy differences, and lack of power control have become urgent issues to be resolved. These issues not only affect the operating efficiency of photovoltaic power stations, but also pose a potential threat to the stability and security of the power grid. Therefore, it is urgent to formulate a set of unified and standardized data collection standards to improve the adjustability and controllability of medium and low voltage distributed photovoltaic power stations.

[0003] In view of the difficulty in effectively controlling the parameters of distributed photovoltaic sites such as active power, reactive power and voltage, it is particularly important to achieve scientific management and efficient upload of operation data. This not only helps to improve the operation and management level of photovoltaic power stations, but also provides more accurate and reliable data support for the dispatch and operation of power grids. Summary of the invention

[0004] The purpose of the present invention is to provide a distributed photovoltaic power control method, system and device in order to solve at least one of the above technical problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A distributed photovoltaic power control method is applied to a distributed photovoltaic station, the method comprising:

[0007] Collect the real-time power data of each photovoltaic inverter and the real-time voltage and current data of the grid-connected bus, and process the collected data to obtain the total real-time data of the photovoltaic station; upload the total real-time data and target value to the control master station;

[0008] Receive the updated target value issued by the control master station in real time; calculate the sub-target value that needs to be adjusted for each photovoltaic inverter according to the target value, station model, topological relationship, and locking logic;

[0009] According to the sub-target value, the corresponding photovoltaic inverter is adjusted.

[0010] Furthermore, the real-time power data includes the real-time active power, real-time reactive power, real-time active power feedback value, and real-time reactive power feedback value of the photovoltaic inverter;

[0011] The target values ​​include an active power target value, a reactive power target value, and a voltage target value.

[0012] Furthermore, the sub-target values ​​that need to be adjusted for each photovoltaic inverter are calculated, including:

[0013] The active automatic power allocation algorithm is used to calculate the active power sub-target value that needs to be adjusted for each photovoltaic inverter;

[0014] Adopting the reactive power automatic distribution algorithm, the reactive power sub-target value that needs to be adjusted for each photovoltaic inverter is calculated;

[0015] According to the range of the voltage target value, the target voltage level to be actually adjusted is determined; the distribution of the target photovoltaic inverters under the target voltage level is obtained, and the adjustment value of each target photovoltaic inverter is calculated using a power allocation algorithm.

[0016] Furthermore, the target voltage level includes a 10kv voltage level and a 380v voltage level.

[0017] Furthermore, when the updated target value sent by the control master station is not received for a preset period of time, the photovoltaic station is adjusted to an on-site state.

[0018] Furthermore, in the on-site state, the active power target value is the station rated power, the reactive power target value is 0, and the voltage target value is the real-time voltage.

[0019] Furthermore, the preset duration is 180 seconds.

[0020] Furthermore, the method further comprises:

[0021] Step 1: Switch the photovoltaic station to a remote state, and identify whether the target value includes the active power target value, the reactive power target value, or the voltage target value; if the active power target value is included, execute step 2; if the reactive power target value is included, execute step 4; if the voltage target value is included, execute step 6;

[0022] Step 2, determining whether the difference between the active power target value and the real-time active power is greater than the active power dead zone range; if greater, executing step 3; if not greater, ending active power regulation;

[0023] Step 3: Calculate the sub-target value that needs to be adjusted for each photovoltaic inverter, and adjust the active power value of the corresponding photovoltaic inverter according to the sub-target value; collect the real-time active power of the photovoltaic inverter, and repeat step 2;

[0024] Step 4, determining whether the difference between the reactive power target value and the real-time reactive power is greater than the reactive power dead zone range; if greater, executing step 5; if not greater, ending reactive power regulation;

[0025] Step 5, calculating the sub-target value that needs to be adjusted for each photovoltaic inverter, and adjusting the reactive power value of the corresponding photovoltaic inverter according to the sub-target value; collecting the real-time reactive power of the photovoltaic inverter, and repeating step 4;

[0026] Step 6: According to the range of the voltage target value, obtain the target voltage level of the actual adjustment; obtain the target photovoltaic inverter distribution under the target voltage level; determine whether the difference between the voltage target value and the real-time voltage data is greater than the voltage dead zone range; if greater, execute step 7; if not greater, end voltage regulation;

[0027] Step seven, converting the voltage target value into a reactive power target value according to the impedance of the photovoltaic station, and performing reactive power regulation; collecting the real-time voltage data, and executing step six.

[0028] A distributed photovoltaic power control system, used to implement any of the above-mentioned distributed photovoltaic power control methods, the system comprises: a front-end acquisition module, a protocol processing module, and a control strategy module;

[0029] The front acquisition module is used to collect real-time power data of the photovoltaic inverter; the front acquisition module is also used to collect real-time voltage and current data of the grid-connected point bus through the protection measurement and control device;

[0030] The protocol processing module is used to upload the data and target parameters obtained from the front-end acquisition module to the control master station; the protocol processing module is also used to receive the updated target value issued by the scheduling master station, and send the target value to the control strategy module;

[0031] The control strategy module is used to calculate the sub-target value that needs to be adjusted for each photovoltaic inverter according to the target value, the station model, the topological relationship, and the locking logic; and adjust the corresponding photovoltaic inverter according to the sub-target value.

[0032] An electronic device, characterized in that it includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, any of the above-described distributed photovoltaic power control methods is implemented.

[0033] The beneficial effects of the present invention are:

[0034] The present invention can receive the active power target value, reactive power target value and voltage target value issued by the dispatching system in real time, and through the built-in control strategy module, combined with the site model, topological relationship and locking conditions, and using advanced power allocation algorithms, accurately calculate and automatically adjust the active power sub-target value and reactive power sub-target value required by each photovoltaic inverter, ensuring that the power output of the distributed photovoltaic site closely follows the dispatching target value, thereby realizing precise control of the active and reactive power of the distributed photovoltaic site.

[0035] The present invention can automatically identify and adapt to the different voltage levels of 10kv and 380v existing in the distributed photovoltaic field, and can intelligently select and adjust the corresponding grid-connected point bus and photovoltaic inverter according to the range of the voltage target value, effectively solving the problem of unadjustable voltage.

[0036] By achieving precise power control of distributed photovoltaics, the present invention helps to improve the lean dispatching management level of the distribution network, optimize the allocation of grid resources, reduce grid operation risks, and ensure the safe and stable operation of the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A distributed photovoltaic power control method process according to an embodiment of the present invention Figure 1 ;

[0038] Figure 2 A distributed photovoltaic power control method process according to an embodiment of the present invention Figure 2 ;

[0039] Figure 3 A structural diagram of a distributed photovoltaic power control system according to an embodiment of the present invention;

[0040] Figure 4 This is an example diagram of a distributed photovoltaic power control system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The content of the present invention will now be discussed with reference to exemplary embodiments. It should be understood that the embodiments discussed are only to enable those skilled in the art to better understand and thus implement the content of the present invention, rather than implying any limitation on the scope of the present invention.

[0042] As used herein, the term “including” and variations thereof are to be interpreted as open-ended terms meaning “including, but not limited to.” The term “based on” is to be interpreted as “based, at least in part, on.” The terms “one embodiment” and “an embodiment” are to be interpreted as “at least one embodiment.”

[0043] Embodiment 1

[0044] Figure 1A distributed photovoltaic power control method process according to an embodiment of the present invention Figure 1 , Figure 2 A distributed photovoltaic power control method process according to an embodiment of the present invention Figure 2 .like Figure 1-2 As shown, according to an embodiment of the present invention, a distributed photovoltaic power control method is applied to a distributed photovoltaic station, and the method includes:

[0045] Step S102, collecting the real-time power data of each photovoltaic inverter and the real-time voltage and current data of the grid-connected bus, and processing the collected data to obtain the total real-time data of the photovoltaic station; uploading the total real-time data and the target value to the control master station;

[0046] Step S104, receiving the updated target value issued by the control master station in real time; calculating the sub-target value that needs to be adjusted for each photovoltaic inverter according to the target value, station model, topological relationship, and locking logic;

[0047] Step S106: adjusting the corresponding photovoltaic inverter according to the sub-target value.

[0048] Preferably, the real-time power data includes the real-time active power, real-time reactive power, real-time active power feedback value, and real-time reactive power feedback value of the photovoltaic inverter;

[0049] The target values ​​include active power target value, reactive power target value, and voltage target value.

[0050] In this embodiment, the distributed photovoltaic power control method applied to the distributed photovoltaic station realizes the precise control of the photovoltaic inverter power through a series of fine steps. First, the real-time power data of each photovoltaic inverter (including real-time active power, real-time reactive power, real-time active power feedback value, real-time reactive power feedback value) is collected, and the real-time data such as voltage and current of the grid-connected bus (including real-time voltage data, real-time current data, etc.) are collected from the protection and measurement and control device; these data are processed to obtain the total real-time data of the photovoltaic station. Subsequently, these total real-time data and the preset target values ​​are uploaded to the control master station. The control master station calculates the target values ​​of the active power, reactive power, and voltage of the grid-connected bus of the photovoltaic station, as well as the real-time values ​​of the total active power, total reactive power, and voltage of the regulating bus of the photovoltaic station, and sends the updated target value to the target photovoltaic station; when the distributed photovoltaic station is connected to the dispatching master station, the distributed photovoltaic station is in a remote state. After receiving the updated target value sent by the control master station in real time, the photovoltaic station will conduct an in-depth analysis of these target values ​​based on the station model, topological relationship, and locking logic, and calculate the specific sub-target value that each photovoltaic inverter needs to adjust. Among them, the target value includes the active power target value, reactive power target value, and voltage target value. Finally, the system will adjust the corresponding photovoltaic inverter according to these sub-target values ​​to ensure that the power output of the photovoltaic station meets the requirements of the control master station.

[0051] The present invention collects power, voltage and current data of photovoltaic inverters and grid-connected point buses in real time, uploads them to the control master station and receives updated target values, accurately calculates the sub-target values ​​that need to be adjusted for each photovoltaic inverter based on the site model, topological relationship and locking logic, thereby achieving precise control of photovoltaic inverter power, ensuring that the power output of the photovoltaic site is consistent with the control requirements, improving the stability and efficiency of the system, and solving the common problems of uncontrollable active power, reactive power and voltage in distributed photovoltaics.

[0052] According to one embodiment of the present invention, step S104 includes:

[0053] The active automatic power allocation algorithm is used to calculate the active power sub-target value that needs to be adjusted for each photovoltaic inverter;

[0054] Adopting the reactive power automatic distribution algorithm, the reactive power sub-target value that needs to be adjusted for each photovoltaic inverter is calculated;

[0055] According to the range of the voltage target value, the target voltage level to be actually adjusted is determined; the distribution of the target photovoltaic inverters under the target voltage level is obtained, and the adjustment value of each target photovoltaic inverter is calculated using a power allocation algorithm.

[0056] Preferably, the target voltage level includes a 10kv voltage level and a 380v voltage level.

[0057] In this implementation, in view of the common coexistence of different voltage levels of 10kv and 380v in distributed photovoltaic sites, the bus voltage level is automatically distinguished and adjusted according to the voltage target value range, and the data acquisition or inverter under the bus with the adjusted voltage level is obtained according to the actual model and topological relationship of the site, and the data acquisition or inverter mounted under the bus is adjusted in a targeted manner to adjust the real-time voltage of the bus, solve the problem of coexistence of different voltage levels and unadjustable voltage in distributed photovoltaic sites, and realize the orderly grid connection of distributed photovoltaic power stations. Specifically,

[0058] Receive the active power target value instructions issued by the dispatcher in real time, and use the active automatic power distribution algorithm according to the station model, topological relationship, and locking logic to calculate the active power sub-target value that needs to be adjusted for each inverter, distribute it to the inverter that needs to be adjusted, and adjust the real-time active power of the station to follow the dispatch active power target value.

[0059] Receive the reactive power target value instructions issued by the dispatcher in real time, and use the reactive power automatic power distribution algorithm according to the station model, topological relationship, and locking logic to calculate the reactive power sub-target value that needs to be adjusted for each inverter, distribute it to the inverter that needs to be adjusted, and adjust the real-time reactive power of the station to follow the dispatched reactive power target value.

[0060] Receive the voltage target value instruction issued by the dispatch in real time. In view of the common problem of 10kv and 380v different voltage levels in distributed photovoltaic sites, the voltage cannot be adjusted automatically. According to the voltage target value range, automatically determine whether the adjusted voltage level is 10kv or 380v. According to the actual model, topological relationship, and locking logic conditions of the site, calculate the target photovoltaic inverter distribution under the actual adjusted target voltage level. According to the power allocation algorithm, the voltage target value instruction is allocated to the data acquisition or inverter mounted under the bus of the voltage level, and the real-time voltage of the grid-connected point bus is adjusted to follow the dispatch voltage target value. When the target photovoltaic inverter distribution is obtained, the corresponding data acquisition can be accurately called to collect the real-time power data of the target inverter, and the power of the target photovoltaic inverter can be accurately found and adjusted, thereby realizing efficient photovoltaic site output power regulation.

[0061] The algorithms used in this implementation (including the active automatic power allocation algorithm, the reactive automatic power allocation algorithm and the power allocation algorithm) all adopt general algorithms in the prior art and will not be further described here.

[0062] The present invention achieves precise regulation of the power of distributed photovoltaic inverters by distinguishing different voltage levels (such as 10kv and 380v), adopting active and reactive automatic power allocation algorithms, and power allocation algorithms for specific voltage levels, thereby solving the problem of unadjustable voltage caused by the coexistence of different voltage levels on site, ensuring the orderly grid connection of distributed photovoltaic power stations, and meeting the lean scheduling management requirements of active distribution networks.

[0063] According to an implementation mode of the present invention, when the updated target value sent by the control master station is not received for a preset period of time, the photovoltaic station is adjusted to the local state.

[0064] Preferably, in the on-site state, the active power target value is the station rated power, the reactive power target value is 0, and the voltage target value is the real-time voltage.

[0065] Preferably, the preset duration is 180 seconds.

[0066] In this implementation, considering that there may be a gap in the issuance of the active power target value, an on-site waiting time is set. The time can be set according to actual needs. In this implementation, it is set to 180 seconds. If the photovoltaic station fails to receive the dispatched active power target value instruction within the time limit, it will automatically switch to the on-site state. In the on-site state, in order to maximize the power generation efficiency of the station, the active power target value takes the rated power of the station to maximize the power generation efficiency of the station. Considering that there is also a gap in the issuance of the reactive power target value, a reactive on-site waiting time is set. The time can be set. Here, it is the same as the active on-site waiting time, and is set to 180 seconds. If the dispatched reactive power target value instruction is not received within the time limit, it will automatically switch to the on-site state. In the on-site state, the system reactive power target value takes 0 to maximize the power generation efficiency of the station. Taking into account that there is also a gap in the scheduling and issuance of voltage target values, the system sets a voltage on-site waiting time. The time can be set, and it is set to 180 seconds here. If the system times out and does not receive the scheduling voltage target value instruction, it will automatically switch to the on-site state. In the on-site state, the voltage target value takes the real-time voltage and the voltage is not adjusted.

[0067] The present invention sets a preset time (such as 180 seconds). When the target value updated by the control master station is not received within the time, the photovoltaic station automatically adjusts to the on-site state. At this time, the active power target value takes the rated power of the station to maximize the power generation efficiency, the reactive power target value is set to 0 to improve the power generation efficiency, and the voltage target value takes the real-time voltage without adjustment, thereby ensuring the stability and efficiency of the station operation and avoiding operation problems caused by delays in target value updates.

[0068] According to one embodiment of the present invention, the method further comprises:

[0069] Step 1: Switch the photovoltaic station to the remote state, and identify whether the target value includes an active power target value, a reactive power target value, or a voltage target value; if it includes an active power target value, execute step 2; if it includes a reactive power target value, execute step 4; if it includes a voltage target value, execute step 6;

[0070] Step 2: determine whether the difference between the active power target value and the real-time active power is greater than the active power dead zone range; if greater, execute step 3; if not, end the active power regulation;

[0071] Step 3: Calculate the sub-target value that needs to be adjusted for each photovoltaic inverter, and adjust the active power value of the corresponding photovoltaic inverter according to the sub-target value; collect the real-time active power of the photovoltaic inverter, and repeat step 2;

[0072] Step 4: determine whether the difference between the reactive power target value and the real-time reactive power is greater than the reactive power dead zone range; if greater, execute step 5; if not, end reactive power regulation;

[0073] Step 5: Calculate the sub-target value that needs to be adjusted for each photovoltaic inverter, and adjust the reactive power value of the corresponding photovoltaic inverter according to the sub-target value; collect the real-time reactive power of the photovoltaic inverter, and repeat step 4;

[0074] Step 6: According to the voltage target value range, obtain the target voltage level of the actual adjustment; obtain the target photovoltaic inverter distribution under the target voltage level; determine whether the difference between the voltage target value and the real-time voltage data is greater than the voltage dead zone range; if greater, execute step 7; if not greater, end the voltage adjustment;

[0075] Step seven: convert the voltage target value into a reactive power target value according to the impedance of the photovoltaic station, and perform reactive power regulation; collect real-time voltage data and execute step six.

[0076] In this implementation, when receiving the updated target value sent by the control master station, it is identified whether the target value includes an active power target value, a reactive power target value or a voltage target value; when the corresponding target value is included, the corresponding adjustment process is executed; specifically,

[0077] If active power regulation is included, calculate the difference between the active power target value and the real-time active power to see if it is greater than the active power dead zone range; the dead zone range is the accuracy range of the regulation result, which is set according to actual needs; if the difference between the active power target value and the real-time active power is less than the active power dead zone range, the regulation is determined to be successful and the regulation process ends; otherwise, the power regulation is not over and needs to be continued, and the active power target value of each regulating unit is calculated, and the active power sub-target value is allocated to the corresponding inverter, so that the real-time active power of the station follows Along with the active power target value, the real-time active power of each unit is collected in real time through digital acquisition, and the difference between the active power target value and the real-time active power is calculated to see whether it is less than the active power dead zone range, and whether the unit active power is adjusted in place, until the difference between the active power target value and the real-time active power is less than the active power dead zone range, the reactive power and voltage dead zone ranges are similar; if the dispatched active power target value is not received within the time limit, it will automatically switch to the active power on-site state, and the active power target value will take the rated power of the station to maximize the station's power generation power.

[0078] If reactive power regulation is included, the difference between the reactive power target value and the real-time reactive power is calculated. If it is less than the reactive power dead zone range, the regulation process is exited; if it is greater than the reactive power dead zone range, the reactive power target value of each regulating unit is calculated according to the target value, and the reactive power sub-target value is allocated to each corresponding inverter, so that the real-time reactive power of the station follows the dispatched reactive power target value, and the real-time reactive power of the unit is collected in real time through digital acquisition, and the difference between the reactive power target value and the real-time reactive power is calculated to determine whether the reactive power regulation of the unit is successful. If the difference is greater than the reactive power dead zone range, continue to calculate and allocate the reactive power target value adjustment until the difference between the reactive power target value and the real-time reactive power is less than the reactive power dead zone range, then the reactive power regulation is successful and the loop is exited; if the reactive power target value is not received within the timeout, it is automatically converted to the reactive power on-site state, and the reactive power target value is 0.

[0079] If the voltage target value is included, it will automatically switch to the remote state. According to the received voltage target value, it will determine whether the regulated voltage level is 10kv or 380v. Then, according to the station model and topology, the busbar of the grid-connected point and the digital acquisition or inverter mounted under the busbar are obtained. The difference between the voltage target value and the real-time voltage is calculated. If it is greater than the voltage dead zone range, the voltage target value is converted into a reactive power target value according to parameters such as the station impedance, and the reactive power sub-target value of the regulated unit is calculated and allocated to the corresponding inverter. The real-time voltage of the regulated busbar is collected and regulated in real time through the corresponding digital acquisition. The difference between the voltage target value and the real-time voltage is calculated. If the difference is greater than the voltage dead zone range, the voltage target value is continued to be calculated and allocated until the difference between the voltage target value and the real-time voltage is less than the voltage dead zone range. In this case, the voltage regulation is successful and the loop is exited. If the voltage target instruction is not received within the time limit, it will automatically switch to the voltage local state. The voltage target value takes the real-time voltage of the current regulated busbar, and the voltage is not regulated.

[0080] The present invention recognizes, decomposes and regulates the target values ​​issued by the master station, and accurately adjusts the power output of the photovoltaic inverter according to the comparison result of the difference between the active power, reactive power and voltage and the respective dead zone ranges, thereby realizing the refined management of the power of distributed photovoltaic sites and effectively improving the operating efficiency and stability of the sites. At the same time, by automatically switching the state and setting a reasonable dead zone range, the economy and response speed of the system are ensured.

[0081] Embodiment 2

[0082] like Figure 1-2 As shown, according to one embodiment of the present invention, a distributed photovoltaic power control method includes the following steps:

[0083] Step s1, active control aims to adjust the active power of the station, receives the active power target value in real time, and automatically calculates the active power target value and active power sub-target value of each unit and inverter according to the station model, topological relationship, units not involved in the adjustment, and constraints through the power allocation algorithm, issues active power sub-target value control instructions, and collects and adjusts the active power of the unit in real time for comparison with the active power target value to determine whether the adjustment is successful or not, forming a closed-loop control. The detailed control process is as follows:

[0084] 1. Decompose the active power target value according to the site model and topological relationship;

[0085] 2. Calculate the units that participate in and do not participate in active power regulation based on the switch position, function activation and deactivation, communication status, etc., and obtain the active power value that needs to be adjusted;

[0086] 3. Consider the active power change rate limit, including 1-minute active power change, 10-minute active power change, and the change range can be set;

[0087] 4. Calculate the active power sub-target value of each unit according to the power allocation strategy, locking and constraint conditions;

[0088] 5. Send the active power sub-target value to the unit that needs to be adjusted;

[0089] 6. Collect and adjust the real-time values ​​of the active power of the unit, the total active power of the entire station, etc., and compare them with the active power target value to form a closed-loop control of active power regulation.

[0090] Step s2, reactive power control aims at regulating the reactive power of the station, receives the dispatched reactive power target value in real time, and automatically calculates the reactive power sub-target value of each unit that needs to be adjusted through the reactive power allocation algorithm according to the station model, comprehensively considers the topological relationship, the units not involved in the adjustment, and the constraints, and issues the reactive power sub-target value control instruction, and collects the reactive power of the adjusted unit in real time for comparison with the reactive power target value to form a closed-loop control. The detailed control process is as follows:

[0091] 1. Decompose the reactive power target value according to the site model and topological relationship;

[0092] 2. Calculate the units that participate in and do not participate in reactive power regulation based on the switch position, function activation and deactivation, communication status, etc., and obtain the reactive power value that needs to be adjusted;

[0093] 3. Consider the reactive power change rate limit, including 1-minute reactive power change and 10-minute reactive power change, and the change range can be set;

[0094] 4. Calculate the reactive power sub-target value of each unit based on the power allocation strategy, blocking and constraint conditions;

[0095] 5. Distribute the reactive power sub-target value to the units that need to be adjusted;

[0096] 6. Collect and adjust the real-time values ​​of reactive power of the unit, total reactive power of the whole station, etc., compare the real-time reactive power with the reactive power target value, and form a closed-loop control.

[0097] Step s3, voltage control takes the bus voltage of the station grid-connected point as the adjustment target, receives the voltage target value instruction in real time, and automatically identifies whether the adjustment voltage level is 10kv or 380v according to the voltage target value range. According to the station model, the grid-connected point bus and inverter that need to be adjusted are judged, and the voltage target value is converted into a reactive power target value according to system impedance, voltage, current and other parameters, and sent to the adjusted unit. The adjustment steps are the same as reactive power adjustment, refer to the reactive power adjustment process.

[0098] In order to solve the problems of inconsistent distributed photovoltaic field data, inconsistent accuracy and uncontrollable power, the present invention provides a distributed photovoltaic power control method including active, reactive and voltage control, which can automatically identify and adjust different voltage levels of 10kv and 380v, realize accurate control of active, reactive power and voltage, meet the needs of lean dispatching management of distribution network, and ensure the safe and stable operation of power grid.

[0099] Embodiment 3

[0100] According to an embodiment of the present invention, a distributed photovoltaic power control method further improves the method of embodiment 2, and the method includes the following steps:

[0101] Step 1: The protocol processing module receives the dispatch target value, automatically switches to the remote state, and identifies whether it is active power dispatch, reactive power dispatch or voltage dispatch; if it is active power dispatch, execute step 2; if it is reactive power dispatch, execute step 3; if it is voltage dispatch, execute step 4;

[0102] Step 2: adjusting the active power according to the dispatch target value, specifically including:

[0103] Step 2-1, calculate whether the difference between the active power target value and the real-time active power is greater than the active power dead zone range; if so, it is necessary to continue to adjust, and execute step 2-2 until the difference between the active power target value and the real-time active power is less than the active power dead zone range; otherwise, it is determined that the adjustment is successful and the adjustment process ends;

[0104] The dead zone range is the accuracy range of the adjustment result; if the difference between the active power target value and the real-time active power is less than the active power dead zone range, the adjustment is considered successful and the adjustment process ends; otherwise, the power adjustment is not completed and the adjustment needs to be continued until the difference between the active power target value and the real-time active power is less than the active power dead zone range. The active power dead zone range can be set. If the difference in the active power dead zone range is less than the active power dead zone range, the adjustment is exited;

[0105] Step 2-2: If it is greater than the dead zone range, execute step s1 of the second embodiment to collect the active power of each unit in real time and execute step 2-1;

[0106] According to step s1 of the second embodiment, the active power sub-target value of each regulating unit is calculated and allocated to each data acquisition or inverter, so that the real-time value of the active power of the station follows the active power target value, and the active power of each unit is collected in real time through the data acquisition;

[0107] In step 2, the active power of the unit is adjusted by repeatedly executing step 2-1 and step 2-2. By calculating whether the difference between the active power target value and the real-time active power is less than the active power dead zone range, it is judged whether the active power of the unit is adjusted in place. If the difference is greater than the active power dead zone range, continue to return to step s1 of embodiment 2, continue to calculate and allocate the active power target value, until the difference between the active power target value of the unit and the real-time active power is less than the active power dead zone range, the active power of the unit is successfully adjusted, and the adjustment process is exited;

[0108] If the dispatched active power target value is not received within the time limit, it will automatically switch to the active power local state. The active power target value will take the rated power of the station to maximize the station's power generation capacity.

[0109] The reactive power and voltage dead zone ranges are similar.

[0110] Step 3, adjusting the reactive power according to the reactive power target value, specifically includes:

[0111] Step 3-1, calculate the difference between the reactive power target value and the current real-time reactive power, whether it is greater than the reactive power dead zone range; if so, it is necessary to continue to adjust, and execute step 3-2 until the difference between the reactive power target value and the real-time value is less than the reactive power dead zone range; otherwise, it is determined that the adjustment is successful and the adjustment process ends;

[0112] For reactive power regulation, the protocol processing module receives the reactive power target value, automatically switches to the remote state, calculates the difference between the reactive power target value and the current real-time reactive power, and exits the regulation process if it is less than the reactive power dead zone range; if it is greater than the reactive power dead zone range, it needs to continue to regulate and execute step 3-2 until the difference between the reactive power target value and the real-time reactive power is less than the reactive power dead zone range;

[0113] Step 3-2: If it is greater than the reactive power dead zone range, execute step s2 in the second embodiment to collect the reactive power of each unit in real time and execute step 3-1;

[0114] According to step s2 in the second embodiment, the reactive power sub-target value of each regulating unit is calculated and allocated to each data acquisition or inverter, so that the station reactive power follows the dispatch reactive power target value in real time, and the reactive power of the unit is collected in real time through data acquisition;

[0115] In step 3, the difference between the reactive power distribution target value and the real-time value is calculated to determine whether the reactive power regulation of the unit is successful. If the difference is greater than the reactive power dead zone range, return to s2 in embodiment 2 and continue to calculate the reactive power target value until the difference between the reactive power target value and the real-time reactive power is less than the reactive power dead zone range. In this case, the reactive power regulation is successful and the loop is exited.

[0116] If the reactive power target value is not received within the time limit, it will automatically switch to the reactive power local state and the reactive power target value will be 0.

[0117] Step 4, adjusting the voltage according to the voltage target value, specifically includes:

[0118] Step 4-1, according to the received voltage target value, determine the regulated voltage level, obtain the regulated grid connection point bus and the data acquisition or inverter mounted under the bus according to the site model and topology structure, and execute step 4-2;

[0119] Step 4-2, calculate the difference between the voltage target value and the current real-time voltage, whether it is greater than the voltage dead zone range; if so, it is necessary to continue to adjust, and execute step 4-3 until the difference between the voltage target value and the real-time voltage is less than the voltage dead zone range; otherwise, it is determined that the adjustment is successful and the adjustment process ends;

[0120] Step 4-3: If the voltage is greater than the voltage dead zone range, the voltage target value is converted into a reactive power target value according to parameters such as the station impedance, and the voltage of the bus is collected and adjusted in real time according to step s3 of the second embodiment, and step 4-2 is executed;

[0121] In step 4, for voltage regulation, the voltage target value is received and automatically switched to the remote state. According to the received voltage target value, it is determined whether the regulated voltage level is 10kv or 380v. Then, according to the station model and topology structure, the grid-connected point bus and the digital acquisition or inverter mounted under the bus that need to be regulated are obtained; the difference between the voltage target value and the real-time voltage is calculated. If it is greater than the voltage dead zone range, the voltage target value is converted into a reactive power target value according to parameters such as the station impedance. According to step S3 of embodiment 2, the reactive power sub-target value of the regulating unit is calculated and allocated to the digital acquisition or inverter, and the voltage of the bus is regulated by real-time acquisition through digital acquisition. The difference between the voltage target value and the real-time voltage is calculated. If the difference is greater than the voltage dead zone range, it returns to step S3 of embodiment 2 and continues to calculate the voltage target value until the difference between the voltage target value and the real-time voltage is less than the voltage dead zone range. The voltage regulation is successful and the loop is exited. If the voltage target value is not received within the timeout, it is automatically switched to the voltage local state. The voltage target value currently regulates the real-time voltage of the bus, and the voltage is not regulated.

[0122] The present invention optimizes the power control method of distributed photovoltaics, realizes accurate closed-loop regulation of active power, reactive power and voltage, and solves problems such as the coexistence of different voltage levels and delayed target value updates, thereby ensuring the maximization of site power generation efficiency and the safe and stable operation of the power grid, and improving the lean dispatching management level of the distribution network.

[0123] Embodiment 4

[0124] Figure 3 A structural diagram of a distributed photovoltaic power control system according to an embodiment of the present invention; Figure 4 This is an example diagram of a distributed photovoltaic power control system according to an embodiment of the present invention. Figure 3-4 As shown, according to an embodiment of the present invention, a distributed photovoltaic power control system is used to implement any distributed photovoltaic power control method of the present invention, and the system includes: a front-end acquisition module, a protocol processing module, and a control strategy module;

[0125] The front acquisition module is used to collect real-time power data of the photovoltaic inverter; the front acquisition module is also used to collect real-time voltage and current data of the grid-connected point bus through the protection measurement and control device;

[0126] The protocol processing module is used to upload the data and target parameters obtained from the front-end acquisition module to the control master station; the protocol processing module is also used to receive the updated target value issued by the dispatch master station, and send the target value to the control strategy module;

[0127] The control strategy module is used to calculate the sub-target value that needs to be adjusted for each photovoltaic inverter based on the target value, station model, topological relationship, and locking logic; and adjust the corresponding photovoltaic inverter based on the sub-target value.

[0128] In this embodiment, the power control system of distributed photovoltaics includes a front-end acquisition module, a protocol processing module and a control strategy module. Front-end acquisition: collects real-time information such as active power, reactive power, active power feedback value, reactive power feedback value of the photovoltaic inverter, and collects real-time information such as voltage and current of the grid-connected bus from the protection and measurement and control device. Protocol processing: receives the dispatching active power, reactive power, and voltage target value instructions and sends them to the control strategy module, and sends the active power, reactive power, voltage regulation target value and real-time value required for dispatching, the total active power, total reactive power, and voltage regulation of the photovoltaic station to the dispatching master station system through the protocol forwarding program. Control strategy module: The control strategy supports two modes: remote and local. For the specific working mode, please refer to the description of embodiments one to three.

[0129] According to one embodiment of the present invention, an electronic device includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, any distributed photovoltaic power control method of the present invention is implemented.

[0130] According to one embodiment of the present invention, a computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any distributed photovoltaic power control method of the present invention is implemented.

[0131] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, devices and media can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0132] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

[0133] It should be understood that the size of the serial numbers of each step in the content of the invention and the embodiments of the present invention does not absolutely mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Claims

1. A distributed photovoltaic power control method, applied to a distributed photovoltaic station, characterized in that: The method comprises: Collect the real-time power data of each photovoltaic inverter and the real-time voltage and current data of the grid-connected bus, and process the collected data to obtain the total real-time data of the photovoltaic station; upload the total real-time data and target value to the control master station; Receive the updated target value issued by the control master station in real time; calculate the sub-target value that needs to be adjusted for each photovoltaic inverter according to the target value, station model, topological relationship, and locking logic; According to the sub-target value, the corresponding photovoltaic inverter is adjusted.

2. The distributed photovoltaic power control method according to claim 1, characterized in that: The real-time power data includes the real-time active power, real-time reactive power, real-time active power feedback value, and real-time reactive power feedback value of the photovoltaic inverter; The target values ​​include an active power target value, a reactive power target value, and a voltage target value.

3. The distributed photovoltaic power control method according to claim 2, characterized in that: Calculate the sub-target values ​​that need to be adjusted for each photovoltaic inverter, including: The active automatic power allocation algorithm is used to calculate the active power sub-target value that needs to be adjusted for each photovoltaic inverter; Adopting the reactive power automatic power allocation algorithm, calculate the reactive power sub-target value that needs to be adjusted for each photovoltaic inverter; According to the range of the voltage target value, the target voltage level to be actually adjusted is determined; the distribution of the target photovoltaic inverters under the target voltage level is obtained, and the adjustment value of each target photovoltaic inverter is calculated using a power allocation algorithm.

4. The distributed photovoltaic power control method according to claim 3, characterized in that: The target voltage levels include a 10kv voltage level and a 380v voltage level.

5. The distributed photovoltaic power control method according to claim 3, characterized in that: When the updated target value sent by the control master station is not received for a preset period of time, the photovoltaic station is adjusted to the on-site state.

6. The distributed photovoltaic power control method according to claim 5, characterized in that: In the on-site state, the active power target value is the rated power of the station, the reactive power target value is 0, and the voltage target value is the real-time voltage.

7. The distributed photovoltaic power control method according to claim 5, characterized in that: The preset duration is 180 seconds.

8. The distributed photovoltaic power control method according to claim 2, characterized in that: The method further comprises: Step 1: Switch the photovoltaic station to a remote state, and identify whether the target value includes the active power target value, the reactive power target value, or the voltage target value; if the active power target value is included, execute step 2; if the reactive power target value is included, execute step 4; if the voltage target value is included, execute step 6; Step 2, determining whether the difference between the active power target value and the real-time active power is greater than the active power dead zone range; if greater, executing step 3; if not greater, ending active power regulation; Step 3: Calculate the sub-target value that needs to be adjusted for each photovoltaic inverter, and adjust the active power value of the corresponding photovoltaic inverter according to the sub-target value; collect the real-time active power of the photovoltaic inverter, and repeat step 2; Step 4, determining whether the difference between the reactive power target value and the real-time reactive power is greater than the reactive power dead zone range; if greater, executing step 5; if not greater, ending reactive power regulation; Step 5, calculating the sub-target value that needs to be adjusted for each photovoltaic inverter, and adjusting the reactive power value of the corresponding photovoltaic inverter according to the sub-target value; collecting the real-time reactive power of the photovoltaic inverter, and repeating step 4; Step 6: According to the range of the voltage target value, obtain the target voltage level of the actual adjustment; obtain the target photovoltaic inverter distribution under the target voltage level; determine whether the difference between the voltage target value and the real-time voltage data is greater than the voltage dead zone range; if greater, execute step 7; if not greater, end voltage regulation; Step seven, converting the voltage target value into a reactive power target value according to the impedance of the photovoltaic station, and performing reactive power regulation; collecting the real-time voltage data, and executing step six.

9. A distributed photovoltaic power control system, used to implement the distributed photovoltaic power control method as claimed in any one of claims 1 to 8, characterized in that: The system includes: a front-end acquisition module, a protocol processing module, and a control strategy module; The front acquisition module is used to collect real-time power data of the photovoltaic inverter; the front acquisition module is also used to collect real-time voltage and current data of the grid-connected point bus through the protection measurement and control device; The protocol processing module is used to upload the data and target parameters obtained from the front-end acquisition module to the control master station; the protocol processing module is also used to receive the updated target value issued by the scheduling master station, and send the target value to the control strategy module; The control strategy module is used to calculate the sub-target value that needs to be adjusted for each photovoltaic inverter according to the target value, the station model, the topological relationship, and the locking logic; and adjust the corresponding photovoltaic inverter according to the sub-target value.

10. An electronic device, characterized in that: The invention comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the distributed photovoltaic power control method as described in any one of claims 1 to 8 is implemented.

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