Distributed photovoltaic and distribution network coordinated voltage regulating device and voltage regulating control method

Abstract

The application provides a kind of distributed photovoltaic and distribution network coordinated voltage regulating equipment and voltage regulating control method.The voltage regulating equipment includes tap changer operating device and control device;Control device includes communication module and processing module;Communication module is used to obtain the voltage data of each node in distribution network;Processing module is used to determine whether the tap changer position of transformer in distribution network needs to be adjusted based on the voltage data of each node;If yes, determine the target position to be adjusted;Determine whether the transformer is on-load voltage regulating distribution transformer;If yes, directly control tap changer operating device to adjust tap changer to target position;If not, control low-voltage switch and fuse to open, control tap changer operating device to adjust tap changer to target position, control fuse and low-voltage switch to close.The application can realize automatic voltage regulation of distribution network, reduce the safety hazard of distribution network, and improve the comfort of user electricity consumption.

Description

Technical Field

[0001] This invention relates to the field of power transmission and transformation technology, and in particular to a voltage regulation device and voltage regulation control method for the coordinated operation of distributed photovoltaic power generation and distribution network. Background Technology

[0002] In recent years, distributed photovoltaic (PV) power has experienced explosive growth. With the large-scale integration of distributed PV into the distribution network, problems such as voltage exceeding limits have emerged in some areas. According to survey and observation data, there are two main factors contributing to voltage exceeding limits: First, the base operating voltage is relatively high. Under normal operating conditions, the voltage on the user side in some distribution areas operates around 1.07 times the rated voltage. With load fluctuations, voltage exceeding the limit occurs at certain times, even at night (when there is no distributed PV output). Second, with the increasing integration of distributed PV, the number of times and the magnitude of voltage exceeding the limit on the user side are gradually increasing.

[0003] Currently, a large number of off-load tap-changing transformers exist in actual power distribution networks. Adjusting the transformer's tap position requires manual operation after a power outage, which results in prolonged outages and affects user comfort. With the integration of distributed photovoltaic systems, voltage exceeding limits is becoming increasingly frequent, and the frequent operation of off-load tap-changing transformers poses significant safety hazards. Summary of the Invention

[0004] This invention provides a voltage regulation device and voltage regulation control method for the coordinated operation of distributed photovoltaic and distribution networks, which can realize automatic voltage regulation of the distribution network, reduce safety hazards of the distribution network, and improve the user's electricity comfort.

[0005] In a first aspect, the present invention provides a voltage regulation device for distributed photovoltaic and distribution network coordination, comprising: a tap position operation device and a control device; the control device includes a communication module and a processing module; the communication module is used to acquire voltage data of each node in the distribution network, the nodes including the inverter outlet of each photovoltaic power generation user on the power generation side, the inlet of each user on the power consumption side, and the inlet of the high-voltage side distribution transformer in the distribution area; the processing module is used to determine, based on the voltage data of each node, whether it is necessary to adjust the tap position of the transformer in the distribution network; if so, determine the target tap position to be adjusted; determine whether the transformer is an on-load tap-changing distribution transformer; if so, directly control the tap position operation device to adjust the tap to the target tap position; if not, control the low-voltage switch and the fuse to open, control the tap position operation device to adjust the tap to the target tap, and control the fuse and the low-voltage switch to close.

[0006] Secondly, the present invention provides a voltage regulation control method for coordinated distributed photovoltaic and distribution network operation, applied to the voltage regulation equipment as described in the first aspect. The voltage regulation control method includes: acquiring voltage data of each node in the distribution network, wherein the nodes include the inverter outlet of each photovoltaic power generation user on the power generation side, the user inlet on the power consumption side, and the distribution transformer inlet on the high-voltage side of the distribution area; based on the voltage data of each node, determining whether it is necessary to adjust the tap position of the transformer in the distribution network; if so, determining the target tap position to be adjusted; determining whether the transformer is an on-load tap-changing distribution transformer; if so, directly controlling the tap position operation device to adjust the tap to the target tap position; if not, controlling the low-voltage switch and fuse to open, controlling the tap position operation device to adjust the tap to the target tap, and controlling the fuse and low-voltage switch to close.

[0007] In one possible implementation, determining whether the tap position of the transformer needs to be adjusted based on the voltage data of each node includes: determining the proportion of nodes in each node that experience nighttime voltage over-limit based on the voltage data of each node; if the proportion of nodes in each node that experience nighttime voltage over-limit is greater than a first set proportion, then it is determined that the tap position of the transformer needs to be adjusted.

[0008] In one possible implementation, determining the target tap position to be adjusted includes: Step 1, obtaining the current tap position and the total tap position of the transformer; Step 2, determining whether the current tap position is the highest tap position; if yes, keeping the current tap position unchanged and determining the current tap position as the target tap position; if no, proceeding to Step 3; Step 3, increasing the current tap position by one tap; Step 4, calculating the nighttime average voltage corresponding to the current tap position; Step 5, determining whether the nighttime average voltage is greater than the set voltage; if no, proceeding to Step 6; if yes, repeating Step 3, Step 4, and Step 5; Step 6, calculating the minimum voltage and the frequency of occurrence of the minimum voltage corresponding to the current tap position; Step 7, determining whether the minimum voltage and the frequency of occurrence of the minimum voltage meet the set conditions; if yes, determining the tap position after increasing it by one tap as the target tap position; if no, keeping the current tap position unchanged.

[0009] In one possible implementation, the voltage regulation control method further includes: determining whether voltage regulation of each node is required based on the daytime voltage data of each node; if so, determining the regulation object that needs to be regulated based on the daytime voltage data of each node; and adjusting the power factor and active power of the regulation object to achieve voltage regulation control of the regulation object.

[0010] In one possible implementation, the target of voltage regulation is determined based on the daytime voltage data of each node, including: calculating the daily average voltage of each photovoltaic inverter on the power generation side; calculating the proportion of nodes in each photovoltaic inverter whose daily average voltage exceeds the normal range; if the proportion of such nodes is greater than a second set proportion, then the nodes in each photovoltaic inverter on the power generation side that exceed the normal range are identified as the target of voltage regulation.

[0011] In one possible implementation, adjusting the power factor and active power of the regulated object to achieve voltage regulation control of the regulated object includes: for any regulated object, if the voltage of the regulated object is greater than the upper voltage limit, then determining whether the current power factor has reached the upper power factor limit; if yes, then reducing the active power of the photovoltaic power generation of the regulated object; if no, then reducing the power factor of the photovoltaic inverter of the regulated object; if the voltage of the regulated object is less than the lower voltage limit, then determining whether the current power factor has reached the lower power factor limit; if yes, then increasing the active power of the photovoltaic power generation of the regulated object; if no, then increasing the power factor of the photovoltaic inverter of the regulated object.

[0012] Thirdly, embodiments of the present invention provide a control device, comprising: a communication module for acquiring voltage data of each node in the distribution network, wherein the nodes include inverter outlets of each photovoltaic power generation user on the power generation side, inlets of each user on the power consumption side, and inlets of the high-voltage distribution transformer on the distribution area; and a processing module for determining, based on the voltage data of each node, whether it is necessary to adjust the tap position of the transformer in the distribution network; if so, determining the target tap position to be adjusted; determining whether the transformer is an on-load tap-changing transformer; if so, directly controlling the tap position operation device to adjust the tap to the target tap position; if not, controlling the low-voltage switch and the fuse to open, controlling the tap position operation device to adjust the tap to the target tap, and controlling the fuse and the low-voltage switch to close.

[0013] In one possible implementation, the processing module is specifically used to determine the proportion of nodes in each node that experience nighttime voltage overruns based on the voltage data of each node; if the proportion of nodes in each node that experience nighttime voltage overruns is greater than a first set proportion, then it is determined that the tap position of the transformer needs to be adjusted.

[0014] In one possible implementation, the processing module is specifically used to perform the following steps: Step 1, obtain the current tap position and the total tap position of the transformer; Step 2, determine whether the current tap position is the highest tap position; if yes, keep the current tap position unchanged and determine the current tap position as the target tap position; if no, proceed to Step 3; Step 3, increase the current tap position by one tap; Step 4, calculate the nighttime average voltage corresponding to the current tap position; Step 5, determine whether the nighttime average voltage is greater than the set voltage; if no, proceed to Step 6; if yes, repeat Step 3, Step 4, and Step 5; Step 6, calculate the minimum voltage and the frequency of occurrence of the minimum voltage corresponding to the current tap position; Step 7, determine whether the minimum voltage and the frequency of occurrence of the minimum voltage meet the set conditions; if yes, determine the tap position after increasing the tap position by one tap as the target tap position; if no, keep the current tap position unchanged.

[0015] In one possible implementation, the processing module is further configured to determine whether voltage regulation of each node is required based on the daytime voltage data of each node; if so, to determine the regulation object that needs voltage regulation based on the daytime voltage data of each node; and to adjust the power factor and active power of the regulation object to achieve voltage regulation control of the regulation object.

[0016] In one possible implementation, the processing module is specifically used to calculate the daily average voltage of each photovoltaic inverter on the power generation side; calculate the proportion of nodes in each photovoltaic inverter whose daily average voltage exceeds the normal range; if the proportion of such nodes is greater than a second set proportion, then the nodes in each photovoltaic inverter on the power generation side that exceed the normal range are identified as voltage regulation targets.

[0017] In one possible implementation, the processing module is specifically configured to, for any regulated object, determine whether the current power factor has reached the upper limit if the voltage of the regulated object is greater than the upper limit; if yes, reduce the active power of the photovoltaic power generation of the regulated object; if no, reduce the power factor of the photovoltaic inverter of the regulated object; if the voltage of the regulated object is less than the lower limit, determine whether the current power factor has reached the lower limit; if yes, increase the active power of the photovoltaic power generation of the regulated object; if no, increase the power factor of the photovoltaic inverter of the regulated object.

[0018] Fourthly, embodiments of the present invention provide an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, the processor being configured to call and run the computer program stored in the memory to perform the steps of the method as described in the second aspect and any possible implementation thereof.

[0019] Fifthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program, characterized in that, when executed by a processor, the computer program implements the steps of the method as described in the second aspect and any possible implementation thereof.

[0020] This invention provides a voltage regulation device and control method for coordinated distribution photovoltaic and distribution network operation. By setting up the voltage regulation device, based on voltage data from each node, it determines whether the transformer tap position needs adjustment. When voltage regulation is required, if it is an on-load tap-changing transformer, the tap is directly adjusted to the target position; if it is an off-load tap-changing transformer, the low-voltage switch and fuse are opened, the tap position operating device is controlled to adjust the tap to the target position, and the fuse and low-voltage switch are closed. This enables automatic voltage regulation of the distribution network transformer, eliminating the need for manual operation, reducing safety hazards in the distribution network, shortening adjustment time, and improving user comfort. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a power distribution network architecture provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a voltage regulating device provided in an embodiment of the present invention; Figure 3 This is a schematic flowchart of a voltage regulation control method provided in an embodiment of the present invention; Figure 4 This is a schematic flowchart of another voltage regulation control method provided in an embodiment of the present invention; Figure 5 This is a schematic flowchart of another voltage regulation control method provided in an embodiment of the present invention; Figure 6 This is a schematic flowchart of another voltage regulation control method provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a control device provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0023] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0024] In the description of this invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" and "more than one" refer to two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0025] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0026] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the steps or modules listed, but may optionally include other steps or modules not listed, or may optionally include other steps or modules inherent to such process, method, product, or device.

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0028] Figure 1 This is a schematic diagram of a power distribution network architecture provided in an embodiment of the present invention. The power distribution network includes distributed photovoltaic power, electrical loads, transformers in each distribution area, and a main transformer.

[0029] In some embodiments, the voltage regulation equipment of distributed photovoltaic and distribution networks is deployed locally and communicates with the distribution automation system and grid dispatching system through a local intelligent fusion terminal, responding to the control requirements of the intelligent fusion terminal. Based on the collected information from the distribution transformer and user side, a voltage regulation strategy is determined and executed. For example, adjusting the tap position of the distribution transformer or adjusting the power factor of the photovoltaic inverter, thereby ensuring that the voltage of users in the distribution area meets the requirements.

[0030] Figure 2 This is a schematic diagram of a voltage regulation device for coordinated operation of distributed photovoltaic power generation and distribution network, provided as an embodiment of the present invention. The voltage regulation device includes a tap position operation device and a control device.

[0031] For example, the tap position operation device includes three parts: a communication module, a status acquisition module, and a mechanical handle. The communication module is responsible for communicating with the control device, sending information such as the total tap position and the current tap position to the control device. The status acquisition module acquires the total tap position and the current tap position of the distribution transformer via video or images. The mechanical handle is responsible for changing the tap position based on control commands.

[0032] For example, the control device is responsible for communicating with fuse operating devices, tap position operating devices, low-voltage switch operating devices, photovoltaic inverters, etc. The control device collects information from each device and sends control commands to each device. The control device can use communication methods such as RS-485, power line carrier, and LoRa.

[0033] In some embodiments, the control device can directly collect information such as voltage and current at each node of the distribution network. Alternatively, the control device can also communicate with devices such as a smart grid integration terminal to receive information such as voltage and current at each node in the distribution area, user-side voltage and current, and photovoltaic inverter voltage and current.

[0034] In some embodiments, the control device can also compile ledger information such as transformer area type (on-load tap changer, off-load tap changer), transformer area tap, user account number, load level, electricity consumption type, photovoltaic installation capacity of each user, and photovoltaic meter account number. In some embodiments, the control device is further equipped with an encryption device, including a forward and reverse isolation device or a security encryption chip to meet information transmission security requirements. The control module embeds a control strategy, which integrates information such as the type of distribution area, tap position, and user voltage, and issues tap adjustment commands and photovoltaic inverter power factor adjustment commands to ensure the normal and coordinated operation of distributed photovoltaic and distribution area voltage.

[0035] In some embodiments, the voltage regulating device further includes a low-voltage switch operating device and a fuse operating device.

[0036] For example, the fuse operating device includes two parts: a communication module and a mechanical handle. The communication module is responsible for communicating with the control device and receiving control commands issued by the control device. The mechanical handle is responsible for opening or closing the fuse according to the control commands. The fuse can be a drop-out fuse.

[0037] For example, the low-voltage switch operating device includes a communication module and a control module. The communication module is responsible for communicating with the control device and receiving control commands issued by the control device. The control module is responsible for issuing control commands to the secondary devices of the low-voltage switch to control the opening and closing of each low-voltage switch.

[0038] Thus, the voltage regulating device provided in this application includes a high-pressure side device and a low-pressure side device. For example, the low-pressure side device may include a tap changer operating device.

[0039] like Figure 3 As shown, this embodiment of the invention provides a voltage regulation control method for coordinated distribution of photovoltaic power and distribution network, applicable to, for example... Figure 2 The pressure regulating device shown includes a tap position operating device and a control device. The pressure regulating control method includes steps S101-S106.

[0040] S101. Obtain the voltage data of each node in the distribution network.

[0041] In this embodiment of the application, the nodes include the inverter outlets of each photovoltaic power generation user on the power generation side, the user inlets on the power consumption side, and the distribution transformer inlets on the high-voltage side of the distribution area.

[0042] As one possible implementation, the control device can acquire voltage data for each node within a set time period. The set time period can be a week, a month, or several days, and is not limited thereto.

[0043] S102. Based on the voltage data of each node, determine whether it is necessary to adjust the tap position of the transformer.

[0044] As one possible implementation, the control device can determine whether it is necessary to adjust the tap position of the transformer based on steps S1021-S1022.

[0045] S1021. Based on the voltage data of each node, determine the proportion of nodes in each node that experience nighttime voltage over-limit. In some embodiments, voltage exceeding a limit may include exceeding the upper voltage limit or the lower voltage limit.

[0046] For example, for a single-phase user, when At that time, the control device can determine if the voltage exceeds the upper limit. For three-phase users, when At that time, the control device can determine if the voltage exceeds the upper limit.

[0047] For example, if the voltage for a single-phase user exceeds 235.4V, it is determined that the voltage has exceeded the upper limit. If the voltage for a three-phase user exceeds 406.6V, it is determined that the voltage has exceeded the upper limit.

[0048] S1022. If the proportion of nodes experiencing nighttime voltage over-limit is greater than the first set proportion, then it is determined that the tap position of the transformer needs to be adjusted.

[0049] It should be noted that if the proportion of nodes experiencing voltage exceeding the upper limit is greater than the set proportion, it indicates that the voltage in the distribution network is too high and needs to be lowered. Conversely, if the proportion of nodes experiencing voltage exceeding the lower limit is greater than the set proportion, it indicates that the voltage in the distribution network is too low and needs to be raised.

[0050] It should be noted that when the average operating voltage of most users is at or above the upper voltage limit (≥1.07Un), the user-side base voltage is considered to be high, with a large adjustment range. In this case, the user type in the distribution area can be disregarded, and the tap changer operation can be performed directly. When the voltage is between (Un~1.07Un), it is considered to have some adjustment range, and the user type needs to be considered for judgment.

[0051] Optionally, step S1022 can be specifically implemented as A1-A2.

[0052] A1. If the proportion of nodes experiencing nighttime voltage exceedances is greater than a set proportion, then determine the proportion of various types of users in the distribution network.

[0053] It should be noted that the proportion of nodes experiencing nighttime voltage exceedances is greater than the set proportion. The control device can determine whether the transformer tap position needs to be adjusted based on the proportions of various users.

[0054] A2. If the proportion of industrial users in the distribution network is less than the set proportion of industrial users, then the tap position of the transformer needs to be adjusted.

[0055] It should be noted that if the proportion of industrial users in the distribution network is less than the set proportion of industrial users, it indicates that the proportion of residential and commercial users is relatively high, and it is appropriate to adjust the tap position.

[0056] S103. If so, determine the target gear to be adjusted.

[0057] As one possible implementation, such as Figure 4 As shown, the control device can determine the target gear to be adjusted based on the following steps.

[0058] Step 1: Obtain the current tap position and the total tap position of the transformer.

[0059] Step two: Determine if the current tap position is the highest. If yes, keep the current position unchanged and set it as the target position; otherwise, proceed to step three.

[0060] Step 3: Adjust the current tap position one level higher.

[0061] Step 4: Calculate the average nighttime voltage corresponding to the current gear level.

[0062] In some embodiments, for any gear position to be adjusted, the control device can calculate the average value and standard deviation of the nighttime voltage of each node to determine the nighttime average voltage.

[0063] For example, the control device can correct the nighttime average voltage by removing outlier data that is more than three times the standard deviation and the average value.

[0064] For example, the control device can determine the nighttime average voltage of the gear to be adjusted based on the following formula.

[0065] ; in, This indicates the voltage difference on the user side corresponding to the current tap position and the tap to be adjusted. This indicates the current high-voltage side voltage of the transformer. Indicates the current tap position. Indicates the gear to be adjusted. This indicates the average voltage corresponding to the current tap position. This represents the average voltage corresponding to the gear position to be adjusted. This indicates the number of days within a specified time period. Indicates the number of users. Indicates the number of nodes. This represents the voltage value of the i-th user at time t on day d.

[0066] It should be noted that for a 5-slot transformer, For a 3-speed transformer, .

[0067] Step 5: Determine if the average nighttime voltage is greater than the set voltage. If not, proceed to step 6; if yes, repeat steps 3, 4, and 5.

[0068] Step 6: Calculate the minimum voltage and the frequency of occurrence of the minimum voltage corresponding to the current gear.

[0069] In some embodiments, the control device can calculate the difference between the daily minimum voltage and the nighttime average voltage of each node, and based on the difference, calculate the average voltage deviation of each node within a set time period, thereby determining the minimum voltage and frequency of occurrence corresponding to the gear to be adjusted.

[0070] For example, the control device may determine the minimum voltage based on the following formula.

[0071] ; in, This represents the minimum average nighttime voltage for the i-th user corresponding to the current tap position. This represents the minimum nighttime average voltage for the i-th user corresponding to the gear position to be adjusted. This represents the voltage value of the i-th user corresponding to the current tap position at time t on day d. This represents the voltage value of the i-th user corresponding to the gear position to be adjusted at time t on day d. This indicates the voltage difference on the user side corresponding to the current tap position and the tap to be adjusted.

[0072] It should be noted that, ,in, This represents the minimum allowed voltage for the i-th user recorded by the system. For example, a typical residential user. The standard is to ensure that it does not affect the normal start-up and use of electrical equipment. For example, the operating voltage range of computers and televisions is 110-250V, and the operating voltage of refrigerators and ordinary fixed-speed air conditioners is between 187-242V. 180V is acceptable.

[0073] For example, the control device can determine the frequency of occurrence of the minimum voltage based on the following formula.

[0074] ; in, Indicates satisfaction The number of nodes, Indicates satisfaction The number of nodes, where d represents the frequency of the lowest voltage occurrence.

[0075] Step 7: Determine whether the minimum voltage and the frequency of minimum voltage occurrence meet the set conditions. If yes, then set the tap position one level higher as the target position; if not, keep the current position unchanged and set the current tap position as the target position.

[0076] It should be noted that the minimum voltage setting condition is if >198V is normal; if ≥180V will not affect production or daily life; if If the voltage is less than 180V, it is not recommended to adjust it, or the voltage should be increased.

[0077] It should be noted that the setting condition for the frequency of occurrence of the lowest voltage is if More than 95% of the number of nodes at night; If the number of nodes exceeds 80% of the number of nodes at night, it means that the adjustment position will not affect the user's normal power consumption.

[0078] In this way, when it is necessary to increase the voltage of the power distribution network, the present invention can automatically adjust the tap position by calculating the appropriate tap position to meet the voltage regulation requirements.

[0079] S104. Determine whether the transformer is an on-load tap-changing transformer.

[0080] As one possible implementation, the control device can communicate with the intelligent integrated terminal of the distribution area to obtain the voltage regulation type of the distribution area, thereby determining whether the transformer is an on-load voltage regulating transformer or an off-load voltage regulating transformer.

[0081] S105. If so, directly control the tap position operating device to adjust the tap to the target position.

[0082] As one possible implementation, the control device can send a control command to the tap position operating device to control the tap position operating device to adjust the tap to the target position.

[0083] S106. If not, control the low-voltage switch and fuse to open, control the tap position operating device to adjust the tap to the target position, and control the fuse and low-voltage switch to close.

[0084] This invention provides a voltage regulation device and control method for coordinated distribution photovoltaic and distribution network operation. By setting up the voltage regulation device, based on voltage data from each node, it determines whether the transformer tap position needs adjustment. When voltage regulation is required, if it is an on-load tap-changing transformer, the tap is directly adjusted to the target position; if it is an off-load tap-changing transformer, the low-voltage switch and fuse are opened, the tap position operating device is controlled to adjust the tap to the target position, and the fuse and low-voltage switch are closed. This enables automatic voltage regulation of the distribution network transformer, eliminating the need for manual operation, reducing safety hazards in the distribution network, shortening adjustment time, and improving user comfort.

[0085] Optional, such as Figure 5 As shown, the voltage regulation control method provided in this embodiment of the invention further includes steps S201-S203.

[0086] S201. Based on the daytime voltage data of each node, determine whether voltage regulation is required at each node.

[0087] S202. If so, then based on the daytime voltage data of each node, determine the regulation target that needs voltage regulation.

[0088] As one possible implementation, the control device can calculate the daily average voltage of each photovoltaic inverter on the power generation side; calculate the proportion of nodes in each photovoltaic inverter whose daily average voltage exceeds the normal range; if the proportion of such nodes is greater than a second set proportion, then the nodes in each photovoltaic inverter on the power generation side that exceed the normal range are identified as voltage regulation targets.

[0089] For example, the control device can calculate the voltage of each photovoltaic inverter. If 95% of the measurement points are outside the normal operating range (≥1.07Un, which is more than 235.4V for 220V grid-connected users and more than 406.6V for 380V grid-connected users), then the nodes that are outside the normal range will be marked as adjustable objects.

[0090] S203. Adjust the power factor and active power of the object being regulated to achieve voltage regulation control of the object being regulated.

[0091] As one possible implementation, such as Figure 6 As shown, for any regulated object, if the voltage of the regulated object is greater than the upper voltage limit, it is determined whether the current power factor has reached the upper power factor limit; if yes, the active power of the photovoltaic power generation of the regulated object is reduced; if no, the power factor of the photovoltaic inverter of the regulated object is reduced. As one possible implementation, such as Figure 6 As shown, for any regulated object, if the voltage of the regulated object is less than the lower voltage limit, it is determined whether the current power factor has reached the lower power factor limit. If so, the active power of the photovoltaic power generation of the regulated object is increased; otherwise, the power factor of the photovoltaic inverter of the regulated object is increased.

[0092] It should be noted that if the node voltage is high, for distributed photovoltaic users with high grid connection point voltage, a leading-phase operation command (generating active power and absorbing reactive power) is sent to the inverters of each distributed photovoltaic user at a step size of 0.01 and a time interval of 30 seconds to reduce the user-side voltage. When the user-side voltage returns to normal after 15 minutes (taking HPLC meter data as an example; if real-time measurement data is available, this period can be further shortened), the same command is continuously sent. If the voltage still exceeds the upper limit, the power factor is further reduced; if the voltage is below the lower limit, the power factor is increased. When the power factor reaches -0.95 and the voltage of each user side still exceeds the upper limit, a command to reduce active power is issued; the active power is reduced at a frequency of 5% until the user-side voltage meets the requirements.

[0093] In this way, embodiments of the present invention can regulate the voltage of the distribution network by adjusting the power factor and active power of the photovoltaic inverter.

[0094] It should be noted that after large-scale distributed photovoltaic (PV) grid integration, some distribution areas have experienced voltage exceedance issues. Adjusting the tap position of the distribution transformer can alleviate the voltage exceedance problem to some extent, but most distribution transformers use no-load voltage regulation, which requires manual operation after a power outage. This results in long outage times, frequent operations, significant safety hazards, and impacts user comfort. Furthermore, most distributed PV inverters use maximum power point tracking (MPPT) and lack constant power factor control methods, making it difficult to respond promptly to grid active power and voltage regulation control requirements. Once a voltage exceedance occurs, the entire system must be disconnected, resulting in substantial losses for users.

[0095] To address the aforementioned technical problems, this invention proposes targeted voltage regulation solutions based on the causes of voltage anomalies after distributed photovoltaic grid connection. For the issue of high base voltage in the distribution area, a tap adjustment strategy is developed based on the nighttime voltage of each user in the area. For the issue of high voltage caused by distributed photovoltaic grid connection, methods for adjusting the power factor and adjusting the active power of the photovoltaic system are used.

[0096] This invention presents a collaborative tap changer device that automatically adjusts tap positions, avoiding the high investment and cost associated with replacing numerous off-load tap changers with on-load tap changers. It also solves the problems of long adjustment times and frequent, potentially dangerous manual tap adjustments. Furthermore, the device can adjust in real-time based on load characteristics and user-side voltage changes, making it more versatile.

[0097] Based on a large amount of historical data from actual monitoring of various users, this invention uses statistical methods to filter out abnormal points, determine overvoltage, and initiate tap changer adjustments, thereby reducing frequent operations and making the device more practical for engineering applications.

[0098] This invention employs a coordinated control voltage regulation strategy that, while ensuring the safety of grid equipment, fully considers user-side benefits. For photovoltaic systems exceeding grid connection limits, the power factor is adjusted first, followed by active power adjustment. Regulation commands are issued to distributed photovoltaic systems via a coordinated device, enabling flexible power control on the user side. This avoids the problem of shutting down the entire system due to voltage exceeding limits, thus improving user benefits.

[0099] It should be understood that the sequence number of each step in the above embodiments does not imply 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.

[0100] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0101] Figure 7A schematic diagram of a control device for a power distribution network provided in an embodiment of the present invention is shown. The control device 300 includes a communication module 301 and a processing module 302.

[0102] The communication module 301 is used to acquire voltage data of each node in the distribution network. The nodes include the inverter outputs of each photovoltaic power generation user on the power generation side, the user inputs on the power consumption side, and the inputs of the high-voltage distribution transformers in the distribution area. The processing module 302 is used to determine whether the tap position of the transformer in the distribution network needs to be adjusted based on the voltage data of each node. If so, the target tap position to be adjusted is determined. The module also determines whether the transformer is an on-load tap-changing transformer. If so, the module directly controls the tap position operation device to adjust the tap to the target tap position. If not, the module controls the low-voltage switch and the fuse to open, controls the tap position operation device to adjust the tap to the target tap position, and controls the fuse and the low-voltage switch to close.

[0103] In one possible implementation, the processing module 302 is specifically used to determine the proportion of nodes in each node that experience nighttime voltage over-limit based on the voltage data of each node; if the proportion of nodes in each node that experience nighttime voltage over-limit is greater than a first set proportion, then it is determined that the tap position of the transformer needs to be adjusted.

[0104] In one possible implementation, the processing module 302 is specifically used to perform the following steps: Step 1, obtain the current tap position and the total tap position of the transformer; Step 2, determine whether the current tap position is the highest tap position; if yes, keep the current tap position unchanged and determine the current tap position as the target tap position; if no, proceed to Step 3; Step 3, increase the current tap position by one tap; Step 4, calculate the nighttime average voltage corresponding to the current tap position; Step 5, determine whether the nighttime average voltage is greater than the set voltage; if no, proceed to Step 6; if yes, repeat Step 3, Step 4, and Step 5; Step 6, calculate the minimum voltage and the frequency of occurrence of the minimum voltage corresponding to the current tap position; Step 7, determine whether the minimum voltage and the frequency of occurrence of the minimum voltage meet the set conditions; if yes, determine the tap position after increasing the tap position by one tap as the target tap position; if no, keep the current tap position unchanged.

[0105] In one possible implementation, the processing module 302 is further configured to determine whether voltage regulation of each node is required based on the daytime voltage data of each node; if so, to determine the regulation object that needs voltage regulation based on the daytime voltage data of each node; and to adjust the power factor and active power of the regulation object to achieve voltage regulation control of the regulation object.

[0106] In one possible implementation, the processing module 302 is specifically used to calculate the daily average voltage of each photovoltaic inverter on the power generation side; calculate the proportion of nodes in each photovoltaic inverter whose daily average voltage exceeds the normal range; if the proportion of such nodes is greater than a second set proportion, then the nodes in each photovoltaic inverter on the power generation side that exceed the normal range are identified as voltage regulation targets.

[0107] In one possible implementation, the processing module 302 is specifically configured to, for any regulated object, if the voltage of the regulated object is greater than the upper voltage limit, determine whether the current power factor has reached the upper power factor limit; if yes, reduce the active power of the photovoltaic power generation of the regulated object; if no, reduce the power factor of the photovoltaic inverter of the regulated object; if the voltage of the regulated object is less than the lower voltage limit, determine whether the current power factor has reached the lower power factor limit; if yes, increase the active power of the photovoltaic power generation of the regulated object; if no, increase the power factor of the photovoltaic inverter of the regulated object.

[0108] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. For example... Figure 8 As shown, the electronic device 400 of this embodiment includes: a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, it implements the steps in the above-described method embodiments, for example... Figure 3 Steps 101 to 106 are shown. Alternatively, when the processor 401 executes the computer program 403, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 7 The functions of the communication module 301 and the processing module 302 shown are illustrated.

[0109] For example, the computer program 403 can be divided into one or more modules / units, which are stored in the memory 402 and executed by the processor 401 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 403 in the electronic device 400. For example, the computer program 403 can be divided into... Figure 7 The communication module 301 and the processing module 302 are shown.

[0110] The processor 401 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0111] The memory 402 can be an internal storage unit of the electronic device 400, such as a hard disk or memory of the electronic device 400. The memory 402 can also be an external storage device of the electronic device 400, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD) card, flash card, etc., equipped on the electronic device 400. Furthermore, the memory 402 can include both internal and external storage units of the electronic device 400. The memory 402 is used to store the computer program and other programs and data required by the terminal. The memory 402 can also be used to temporarily store data that has been output or will be output.

[0112] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0113] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0114] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0115] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0116] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0117] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0118] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0119] The above-described 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A voltage regulation device for coordinated operation of distributed photovoltaic power generation and distribution network, characterized in that, include: The device includes a tap position operating device, a control device, a low-voltage switch operating device, and a fuse operating device; the control device includes a communication module and a processing module. The communication module is used to acquire voltage data of each node in the distribution network. The nodes include the inverter output of each photovoltaic power generation user on the power generation side, the user input on the power consumption side, and the high-voltage side transformer input of the distribution area. The processing module is used to determine whether the tap position of the transformer in the distribution network needs to be adjusted based on the voltage data of each node; if so, the target tap position to be adjusted is determined; it is determined whether the transformer is an on-load tap-changing transformer; if so, the tap position operation device is directly controlled to adjust the tap to the target tap position; if not, the low-voltage switch is controlled to open through the low-voltage switch operation device, the fuse is controlled to open through the fuse operation device, the tap position operation device is controlled to adjust the tap to the target tap position, and the fuse and low-voltage switch are controlled to close. The processing module is also used to determine whether voltage regulation of each node is required based on the daytime voltage data of each node; if so, it determines the regulation target that needs to be regulated based on the daytime voltage data of each node. Adjusting the power factor and active power of the object being regulated in order to achieve voltage regulation control of the object being regulated; The process of determining the target tap position includes: Step 1, obtaining the current tap position and the total tap position of the transformer; Step 2, determining whether the current tap position is the highest tap position; if yes, keeping the current tap position unchanged and determining the current tap position as the target tap position; if no, proceeding to Step 3; Step 3, increasing the current tap position by one tap; Step 4, calculating the nighttime average voltage corresponding to the current tap position; Step 5, determining whether the nighttime average voltage is greater than the set voltage; if no, proceeding to Step 6; if yes, repeating Step 3, Step 4, and Step 5; Step 6, calculating the minimum voltage and the frequency of occurrence of the minimum voltage corresponding to the current tap position; Step 7, determining whether the minimum voltage and the frequency of occurrence of the minimum voltage meet the set conditions; if yes, determining the tap position after increasing it by one tap as the target tap position; if no, keeping the current tap position unchanged and determining the current tap position as the target tap position.

2. A voltage regulation control method for coordinated operation of distributed photovoltaic power generation and distribution network, characterized in that, The voltage regulation control method, applied to the voltage regulating device as described in claim 1, comprises: Obtain voltage data for each node in the distribution network, wherein the nodes include the inverter outputs of each photovoltaic power generation user on the power generation side, the user inputs on the power consumption side, and the high-voltage side transformer inputs of the distribution area; Based on the voltage data of each node, determine whether it is necessary to adjust the tap position of the transformer in the distribution network; if so, determine the target tap position to be adjusted, including: Step 1, obtain the current tap position and the total tap position of the transformer; Step 2, determine whether the current tap position is the highest tap position; if so, keep the current tap position unchanged and determine the current tap position as the target tap position; if not, proceed to Step 3; Step 3, increase the current tap position by one tap; Step 4, calculate the nighttime average voltage corresponding to the current tap position; Step 5, determine whether the nighttime average voltage is greater than the set voltage; if not, proceed to Step 6; if so, repeat Step 3, Step 4, and Step 5; Step 6, calculate the minimum voltage and the frequency of occurrence of the minimum voltage corresponding to the current tap position; Step 7, determine whether the minimum voltage and the frequency of occurrence of the minimum voltage meet the set conditions; if so, determine the tap position after increasing the tap position by one tap as the target tap position; if not, keep the current tap position unchanged and determine the current tap position as the target tap position. Determine whether the transformer is an on-load tap-changing transformer; If so, directly control the tap position control device to adjust the tap to the target position; If not, the low-voltage switch and fuse will be opened, the tap position operating device will be adjusted to the target position, and the fuse and low-voltage switch will be closed. The voltage regulation control method further includes: determining whether voltage regulation of each node is required based on the daytime voltage data of each node; if so, determining the regulation object that needs voltage regulation based on the daytime voltage data of each node; and adjusting the power factor and active power of the regulation object to achieve voltage regulation control of the regulation object.

3. The voltage regulation control method according to claim 2, characterized in that, The determination of whether the transformer tap position needs to be adjusted based on the voltage data of each node includes: Based on the voltage data of each node, determine the proportion of nodes in each node that experience nighttime voltage over-limit. If the proportion of nodes experiencing nighttime voltage exceedances is greater than the first set proportion, then it is determined that the tap position of the transformer needs to be adjusted.

4. The voltage regulation control method according to claim 2, characterized in that, The determination of the regulation targets requiring voltage adjustment based on the daytime voltage data of each node includes: Calculate the daily average voltage of each photovoltaic inverter on the power generation side; Calculate the proportion of nodes in each photovoltaic inverter whose daily average voltage exceeds the normal range; If the node ratio is greater than the second set ratio, then the nodes in each photovoltaic inverter on the power generation side that exceed the normal range will be identified as voltage regulation targets.

5. The voltage regulation control method according to claim 2, characterized in that, The power factor and active power of the object being regulated are adjusted to achieve voltage regulation control of the object, including: For any regulated object, if the voltage of the regulated object is greater than the upper voltage limit, it is determined whether the current power factor has reached the upper power factor limit; if yes, the active power of the photovoltaic power generation of the regulated object is reduced; if no, the power factor of the photovoltaic inverter of the regulated object is reduced. If the voltage of the regulated object is less than the lower voltage limit, it is determined whether the current power factor has reached the lower power factor limit. If so, the active power of the photovoltaic power generation of the regulated object is increased; otherwise, the power factor of the photovoltaic inverter of the regulated object is increased.

6. A control device, characterized in that, include: The communication module is used to acquire voltage data of each node in the distribution network. The nodes include the inverter output of each photovoltaic power generation user on the power generation side, the user input on the power consumption side, and the high-voltage side transformer input of the distribution area. The processing module is used to determine whether the tap position of the transformer in the distribution network needs to be adjusted based on the voltage data of each node; if so, the target tap position to be adjusted is determined; it is determined whether the transformer is an on-load tap-changing transformer; if so, the tap position operation device is directly controlled to adjust the tap to the target tap position; if not, the low-voltage switch and fuse are opened, the tap position operation device is controlled to adjust the tap to the target tap position, and the fuse and low-voltage switch are closed. The processing module is also used to determine whether voltage regulation of each node is required based on the daytime voltage data of each node; if so, it determines the regulation target that needs to be regulated based on the daytime voltage data of each node. Adjusting the power factor and active power of the object being regulated in order to achieve voltage regulation control of the object being regulated; The process of determining the target tap position includes: Step 1, obtaining the current tap position and the total tap position of the transformer; Step 2, determining whether the current tap position is the highest tap position; if yes, keeping the current tap position unchanged and determining the current tap position as the target tap position; if no, proceeding to Step 3; Step 3, increasing the current tap position by one tap; Step 4, calculating the nighttime average voltage corresponding to the current tap position; Step 5, determining whether the nighttime average voltage is greater than the set voltage; if no, proceeding to Step 6; if yes, repeating Step 3, Step 4, and Step 5; Step 6, calculating the minimum voltage and the frequency of occurrence of the minimum voltage corresponding to the current tap position; Step 7, determining whether the minimum voltage and the frequency of occurrence of the minimum voltage meet the set conditions; if yes, determining the tap position after increasing it by one tap as the target tap position; if no, keeping the current tap position unchanged and determining the current tap position as the target tap position.

7. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor being used to invoke and run the computer program stored in the memory to perform the method as described in any one of claims 2 to 5.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 2 to 5 above.

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