Local control method and system for charging pile participating in real-time power factor adjustment of power grid

Abstract

The invention discloses a local control method and system for a charging pile to participate in real-time power factor adjustment of a power grid. The method comprises the following steps: acquiring current and voltage of a charging pile sampling corresponding node in a target power distribution network area, and calculating power and a power factor according to the current and voltage of the sampling corresponding node, judging whether the power factor of each node is in a target range or not; if the power factor of a certain charging pile node is not in the target range, performing power factor adjustment according to a preset power adjustment strategy model; and the adjusted power factor of the charging pile node is synchronized to other connected charging piles, and the other connected charging piles carry out power factor adjustment through a preset power adjustment strategy model until the power factor adjustment of all the charging piles in the target power distribution network area is completed. According to the invention, the power factor of the charging pile can be optimized and adjusted in real time, so that the operation efficiency and stability of the whole power distribution network are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems and smart grids, and in particular to an on-site control method and system for a charging pile to participate in real-time power factor regulation of a power grid. Background Art

[0002] In today's society, as the global climate change problem becomes increasingly serious, reducing carbon emissions has become one of the focuses of global attention. As a new type of transportation, electric vehicles are considered to be one of the important means to reduce carbon emissions. In recent years, with the popularization and promotion of electric vehicles, the supporting charging facilities have also developed rapidly. The number of charging piles continues to grow in various places, providing convenience for the use of electric vehicles.

[0003] However, despite the increasing number of charging facilities, their comprehensive utilization rate is still relatively low. This is mainly because the use of electric vehicles has a certain degree of randomness and uncertainty, which leads to the fact that charging piles cannot be fully utilized in certain time periods. In addition, with the continuous access to the power grid of distributed new energy such as solar energy and wind energy, the power fluctuations of the distribution network have become more frequent and complex. This fluctuation not only affects the stable operation of the power grid, but also leads to the continuous fluctuation of the power factor of the charging piles.

[0004] To solve this problem, the AC-DC converters equipped with charging piles can play an important role. These converters can realize bidirectional operation of reactive power, that is, they can absorb reactive power when needed and also provide reactive power. This means that charging piles can not only charge electric vehicles, but also provide reactive power support when the grid needs it, thereby achieving efficient regulation of reactive disturbances on the user side. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above existing problems, the present invention is proposed.

[0007] Therefore, the present invention provides an on-site control method and system for a charging pile to participate in real-time power factor regulation of a power grid, which can solve the problems mentioned in the background technology.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] In a first aspect, the present invention provides an on-site control method for a charging pile to participate in real-time power factor adjustment of a power grid, comprising:

[0010] Obtain the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, calculate the power and power factor according to the current and voltage of the sampling nodes, and determine whether the power factor of each node is within the target range. The charging piles in the target area are interconnected according to the spatial distance and receive the voltage and power information from other charging piles.

[0011] If the power factor of a charging pile node is not within the target range, the power factor is adjusted according to a preset power adjustment strategy model, and the objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range;

[0012] The adjusted power factor of the charging pile node is synchronized to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed.

[0013] As a preferred solution of the on-site control method for the charging pile to participate in the real-time power factor adjustment of the power grid according to the present invention, the method of obtaining the current and voltage of the charging pile sampling corresponding nodes in the target distribution network area, and calculating the power and power factor according to the current and voltage of the sampling corresponding nodes includes:

[0014] Assume that each charging pile A i Different nodes r (i=1,2,3,…,N) measure the current I of each node in real time ir and voltage V ir , N represents the total number of charging piles in the target distribution network area, and the active power P of each node is calculated based on the collected current and voltage ir and reactive power Q ir ;

[0015] Calculate the power factor cosφ of each node based on the active power and apparent power ir ;

[0016] The power factor calculation expression is as follows:

[0017]

[0018] Among them, S ir Indicates apparent power.

[0019] As a preferred solution of the on-site control method for the charging pile to participate in the real-time power factor adjustment of the power grid according to the present invention, the method of judging whether the power factor of each node is within the target range includes:

[0020] Set the power factor range to [cosφmin ,cosφ max ], compare the power factor cosφ calculated for each node ij Compare with the set power factor range to determine whether it exceeds the range.

[0021] As a preferred solution of the on-site control method for the charging pile to participate in the real-time power factor adjustment of the power grid described in the present invention, the power adjustment strategy model includes:

[0022] Assume that there are N charging piles in the distribution network. The reference node in a charging pile and the nodes at both ends of the reference line are marked as nref1, nref2, ..., nref r , nref1 and nref r are the nodes at both ends of the reference line. The prediction model and control logic of all charging piles are the same. The prediction model established for any charging pile j is shown as follows:

[0023]

[0024] Among them, the superscripts p, c, and m correspond to the predicted value, communication value, and set value of the variable. P(k) and Q(k) are the values ​​of the variables P and Q in the k period. ΔP(k) and ΔQ(k) are the increments of the variables P and Q in the k+1 period compared to the k period. The variables P and Q represent the active power and reactive power. represents the predicted value of the change in active power of charging pile j in time period k, represents the predicted value of the change in reactive power of charging pile j in time period k, γ represents the control parameter, They represent the set values ​​of the dq components of the line voltage v in time period k, represents the predicted value of the dq component of the line current i in the time period k, R represents the line resistance, L represents the line inductance, Represents the predicted value of the power factor of charging pile j.

[0025] As a preferred solution of the on-site control method for the charging pile to participate in the real-time power factor adjustment of the power grid according to the present invention, the power adjustment strategy model also includes:

[0026] The constraints in the power adjustment strategy model calculation mainly include charging demand constraints and charging pile capacity constraints;

[0027] If the lower and upper limits of active power set by charging pile j in period k are P j (k) The rated capacity of charging pile j is The charging demand constraint and capacity constraint of charging pile j are as follows:

[0028]

[0029] in, represents the active power of charging pile j in time period k, represents the reactive power of charging pile j in time period k.

[0030] As a preferred solution of the on-site control method for the charging pile to participate in the real-time power factor adjustment of the power grid described in the present invention, the objective function of the power adjustment strategy model includes:

[0031] The objective function is as follows:

[0032]

[0033] Where N is the number of charging piles, u j (t) is the power factor of the jth charging station at time t, cosφ target,j is the target power factor of the jth charging pile, T p is the length of the forecast period.

[0034] As a preferred solution of the on-site control method for the charging piles participating in the real-time power factor adjustment of the power grid described in the present invention, wherein: the power factor of the charging pile node after adjustment is synchronized to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed, including: each time the power factor adjustment of the charging piles in all target distribution network areas is completed, waiting for a cycle and then re-obtaining the current and voltage of the sampling corresponding nodes of the charging piles in the target distribution network area, calculating the power and power factor according to the current and voltage of the sampling corresponding nodes, and re-judging and adjusting.

[0035] In a second aspect, the present invention provides an on-site control system for a charging pile to participate in real-time power factor adjustment of a power grid, comprising:

[0036] A judgment module is used to obtain the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, calculate the power and power factor according to the current and voltage of the sampling nodes, and judge whether the power factor of each node is within the target range. The charging piles in the target area are interconnected according to the spatial distance and receive the voltage and power information from other charging piles.

[0037] A model building module is used to adjust the power factor according to a preset power adjustment strategy model if the power factor of a charging pile node is not within the target range. The objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range;

[0038] The adjustment module is used to synchronize the adjusted power factor of the charging pile node to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed.

[0039] In a third aspect, the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned method when executing the computer program.

[0040] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the method described above when executed by a processor.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes an on-site control method and system for charging piles to participate in real-time power factor adjustment of the power grid, obtains the current and voltage of the sampling corresponding nodes of the charging piles in the target distribution network area, calculates the power and power factor according to the current and voltage of the sampling corresponding nodes, and judges whether the power factor of each node is within the target range. The charging piles in the target area are interactively connected according to the spatial distance, and all receive voltage and power information from other charging piles; if the power factor of a charging pile node is not within the target range, the power factor is adjusted according to the preset power adjustment strategy model, and the objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range; the adjusted power factor of the charging pile node is synchronized to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed. The present application can optimize and adjust the power factor of the charging pile in real time, thereby improving the operating efficiency and stability of the entire distribution network. Charging pile nodes that are interactively connected through spatial distances can achieve rapid information transmission and power adjustment, ensuring that the power factor of the charging pile is always in the best state under different load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0043] Figure 1 A method flow chart of a local control method and system for a charging pile to participate in real-time power factor adjustment of a power grid provided by an embodiment of the present invention;

[0044] Figure 2 An internal structural diagram of a computer device of an on-site control method and system for real-time power factor adjustment of a charging pile participating in a power grid provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0046] Example 1

[0047] Reference Figure 1-Figure 2 , which is the first embodiment of the present invention, and provides a local control method and system for a charging pile to participate in real-time power factor adjustment of a power grid, including:

[0048] Before describing the embodiments of the present application in detail, some related concepts are first explained for the sake of clarity.

[0049] Nonlinear Model Predictive Control: Nonlinear model predictive control is an advanced control strategy that uses a mathematical model of the system to predict the future response of the system and calculate the optimal control sequence based on this. This control method is particularly suitable for processes with complex dynamic characteristics, especially those with nonlinear characteristics and multiple constraints. The basic steps of NMPC are as follows: Model building: Build a nonlinear mathematical model of the system. State prediction: Use the model to predict the state of the system for a period of time in the future. Optimization: Based on the predicted results, find the optimal control input sequence while satisfying all constraints. Implementation: Apply the first element of the optimal control sequence to the actual system. Iteration: Repeat the above process, update the state prediction and recalculate the optimal control sequence at each sampling time.

[0050] Power factor: The power factor refers to the ratio of the actual active power consumed in an AC circuit to the apparent power. It is a dimensionless value, usually expressed in Indicates that It is the phase difference angle between voltage and current. Active power (P): It is the power that is actually converted into useful work. Reactive power (Q): Energy stored and released in inductive and capacitive loads that is not converted into useful work. Apparent power (S): The product of the total voltage and current in the circuit. When the power factor is close to 1, it means that most of the energy is effectively converted into useful work, and when the power factor is low, it means that more energy is wasted in the storage and release process, which will increase the loss of power transmission.

[0051] In the related technology, there are some problems, such as the power factor adjustment of charging piles usually relies on the central control system, which may lead to slow response speed, poor system stability and excessive dependence on the central control system. In addition, the existing power factor adjustment methods often do not fully consider the spatial distance and real-time information interaction, resulting in insufficient coordination of the power factor adjustment between charging piles, affecting the efficiency and stability of the entire distribution network.

[0052] The present application provides an effective solution to the above-mentioned problems. Next, a method for implementing the on-site control of the charging pile to participate in the real-time adjustment of the power factor of the power grid will be described in detail in combination with multiple embodiments.

[0053] Figure 1 A method flow chart of a local control method and system for a charging pile to participate in real-time power factor adjustment of a power grid is shown, including:

[0054] S101, obtaining the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, calculating the power and power factor according to the current and voltage of the sampling nodes, and judging whether the power factor of each node is within the target range. The charging piles in the target area are interconnected according to the spatial distance, and receive the voltage and power information from other charging piles.

[0055] In the embodiment of the present application, obtaining the current and voltage of the sampling corresponding nodes of the charging piles in the target distribution network area, and calculating the power and power factor according to the current and voltage of the sampling corresponding nodes includes:

[0056] Assume that each charging pile A i Different nodes r (i=1,2,3,…,N) measure the current I of each node in real time ir and voltage V ir , N represents the total number of charging piles in the target distribution network area, and the active power P of each node is calculated based on the collected current and voltage ir and reactive power Q ir ;

[0057] Calculate the power factor cosφ of each node based on the active power and apparent power ir ;

[0058] The power factor calculation expression is as follows:

[0059]

[0060] Among them, S ir Indicates apparent power.

[0061] Judging whether the power factor of each node is within the target range includes:

[0062] Set the power factor range to [cosφ min ,cosφ max ], compare the power factor cosφ calculated for each node ij Compare with the set power factor range to determine whether it exceeds the range.

[0063] It should be noted that "node" refers to a specific location in the distribution network. These locations can be the location where the charging pile itself is connected or the grid node related to the charging pile. The "node" mentioned here mainly refers to the electrical connection point in the distribution network, which can be:

[0064] The secondary side of the distribution transformer where the charging pile is located: This is where the charging pile is directly connected to the power grid, and it is also an important location for monitoring the power factor of the charging pile.

[0065] The output end of the charging pile: that is, the connection point between the charging pile and the electric vehicle charging plug. The current and voltage here reflect the quality of the electric energy directly provided by the charging pile.

[0066] Key nodes in the power grid: such as substations, switch stations, etc. These nodes are crucial for monitoring the operating status of the entire distribution network.

[0067] Specific locations on distribution lines: For example, branch points, intersections, or connection points with other equipment (such as energy storage devices, distributed generation, etc.) on distribution lines. Current and voltage data at these locations can help better understand the operating status of the power grid.

[0068] Connection points between adjacent chargers: If multiple chargers are located in the same area, they may be connected to each other in some way (for example, through a local network) so that they can share data and work better together.

[0069] Access points for specific users: For some residential or commercial areas, there may be multiple charging piles serving multiple users. At this time, the power quality of the entire area can be managed by monitoring the current and voltage of these user access points.

[0070] In actual applications, the current and voltage of these nodes are collected and used to calculate active power, reactive power and power factor. By analyzing this data, it is possible to determine which charging piles need to adjust their power factor to reach the expected target range, and take corresponding measures to adjust them. These adjustment measures usually involve changing the reactive compensation capacity of the charging pile, such as improving the power factor of the power grid through built-in capacitor banks or other reactive compensation devices.

[0071] It should be noted that the benefit of the above steps is that the power factor of the charging pile can be monitored and adjusted in real time to ensure that it operates within the optimal range, thereby improving the efficiency and stability of the entire distribution network.

[0072] S102, if the power factor of a charging pile node is not within the target range, the power factor is adjusted according to a preset power adjustment strategy model, and the objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range;

[0073] In the embodiment of the present application, the power adjustment strategy model includes:

[0074] Assume that there are N charging piles in the distribution network. The reference node in a charging pile and the nodes at both ends of the reference line are marked as nref1, nref2, ..., nref r , nref1 and nref r are the nodes at both ends of the reference line. The prediction model and control logic of all charging piles are the same. The prediction model established for any charging pile j is shown as follows:

[0075]

[0076]

[0077] Among them, the superscripts p, c, and m correspond to the predicted value, communication value, and set value of the variable. P(k) and Q(k) are the values ​​of the variables P and Q in the k period. ΔP(k) and ΔQ(k) are the increments of the variables P and Q in the k+1 period compared to the k period. The variables P and Q represent the active power and reactive power. represents the predicted value of the change in active power of charging pile j in time period k, represents the predicted value of the change in reactive power of charging pile j in time period k, γ represents the control parameter, They represent the set values ​​of the dq components of the line voltage v in time period k, represents the predicted value of the dq component of the line current i in the time period k, R represents the line resistance, L represents the line inductance, Represents the predicted value of the power factor of charging pile j.

[0078] In the embodiment of the present application, the power adjustment strategy model also includes:

[0079] The constraints in the power adjustment strategy model calculation mainly include charging demand constraints and charging pile capacity constraints;

[0080] If the lower and upper limits of active power set by charging pile j in period k are P j (k) The rated capacity of charging pile j is The charging demand constraint and capacity constraint of charging pile j are as follows:

[0081]

[0082] in, represents the active power of charging pile j in time period k, represents the reactive power of charging pile j in time period k.

[0083] In the embodiment of the present application, the objective function of the power adjustment strategy model includes:

[0084] The objective function is as follows:

[0085]

[0086] Where N is the number of charging piles, u j (t) is the power factor of the jth charging station at time t, cosφ target,j is the target power factor of the jth charging pile, T p is the length of the forecast period.

[0087] It should be noted that the benefit of the above step S102 is that it can systematically and prospectively optimize the power factor of the charging pile, ensuring that within the future target time range, each node in the entire distribution network can reach or maintain within the preset power factor target range. The realization of this goal not only relies on an accurate prediction model to estimate the power change of the charging pile in the future cycle, but also guides the generation and execution of the power adjustment strategy by constructing a reasonable objective function and constraint conditions.

[0088] Specifically, the prediction model in the power adjustment strategy model accurately predicts the power changes of the charging pile in the future time period by comprehensively considering the historical operation data of the charging pile (such as the periodic changes of active power and reactive power), grid parameters (such as line resistance and inductance), and control parameters. This prediction capability enables the system to identify potential power factor deviation risks in advance and formulate corresponding adjustment plans accordingly.

[0089] The constraints in the power adjustment strategy model ensure the feasibility and effectiveness of the adjustment strategy in actual implementation. The charging demand constraint ensures that the charging pile is adjusted on the premise of meeting the user's charging demand, avoiding user dissatisfaction or service interruption caused by excessive adjustment; the charging pile capacity constraint limits the maximum output power of the charging pile, preventing equipment damage or safety hazards caused by overload operation.

[0090] Finally, by minimizing the sum of squares of power factor deviations in the objective function, the power adjustment strategy model can find an optimal adjustment plan so that the power factor of all charging piles in the future forecast period is as close to its target value as possible. The implementation of this optimization strategy not only helps to improve the power quality and operating efficiency of the entire distribution network, but also effectively reduces the power loss and operating costs of the power grid, achieving a win-win situation in economic and social benefits.

[0091] S103, synchronizing the adjusted power factor of the charging pile node to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through a preset power adjustment strategy model until the power factor adjustment of all charging piles in the target distribution network area is completed.

[0092] It should be noted that the adjusted power factor of the charging pile node is synchronized to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through a preset power adjustment strategy model until the power factor adjustment of all charging piles in the target distribution network area is completed, including: each time the power factor adjustment of all charging piles in the target distribution network area is completed, wait for a cycle and then re-acquire the current and voltage of the corresponding nodes of the charging piles in the target distribution network area, calculate the power and power factor based on the current and voltage of the corresponding nodes, and re-judge and adjust them.

[0093] It should be noted that a cycle can be understood as a fixed time interval of grid operation, such as a day, an hour or a shorter period of time, depending on the specific needs of grid management and the sophistication of system design. At the end of this cycle, the system will re-evaluate the power factor status of the charging piles in the entire target distribution network area to ensure that they remain in the optimal or near-optimal operating state.

[0094] When retrieving the current and voltage data of the charging piles in the target distribution network area, the system uses high-precision measurement equipment to sample the current and voltage of each node in real time. These data are then fed into the preset power adjustment strategy model to calculate the power and power factor in the current cycle. By comparing the current power factor with the target power factor, the system can determine whether the power factor of the charging pile needs to be further adjusted.

[0095] If the power factor of a charging pile is found to deviate from the target value, the system will generate a new adjustment plan based on the optimization algorithm and constraints in the power adjustment strategy model. This adjustment plan may include adjusting the active power output, reactive power compensation or other related power electronic control strategies of the charging pile. Subsequently, the adjustment command will be sent to the corresponding charging pile to execute the new power factor adjustment plan.

[0096] This periodic re-evaluation and adjustment process ensures that the charging piles in the target distribution network area can continuously and stably operate at the optimal or near-optimal power factor state. This not only helps to improve the power quality and operating efficiency of the power grid, but also effectively reduces the power loss and operating costs of the power grid. At the same time, through real-time monitoring and adjustment, the system can also respond to emergencies and changes in the power grid in a timely manner to ensure the safe and reliable operation of the power grid.

[0097] In summary, the present invention proposes an on-site control method for charging piles to participate in real-time power factor adjustment of power grids, obtain the current and voltage of the sampling corresponding nodes of the charging piles in the target distribution network area, calculate the power and power factor according to the current and voltage of the sampling corresponding nodes, and judge whether the power factor of each node is within the target range, the charging piles in the target area are interactively connected according to the spatial distance, and all receive voltage and power information from other charging piles; if there is a power factor of a charging pile node that is not within the target range, the power factor is adjusted according to the preset power adjustment strategy model, and the objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range; the adjusted power factor of the charging pile node is synchronized to the remaining connected charging piles, and the remaining connected charging piles are adjusted by the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed. The present application can optimize and adjust the power factor of the charging pile in real time, thereby improving the operating efficiency and stability of the entire distribution network. Charging pile nodes that are interactively connected through spatial distances can achieve rapid information transmission and power adjustment, ensuring that the power factor of the charging pile is always in the best state under different load conditions.

[0098] This embodiment also provides an on-site control system for a charging pile to participate in real-time power factor adjustment of a power grid, including:

[0099] The judgment module is used to obtain the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, calculate the power and power factor according to the current and voltage of the sampling nodes, and judge whether the power factor of each node is within the target range. The charging piles in the target area are interactively connected according to the spatial distance, and all receive voltage and power information from other charging piles;

[0100] A model building module is used to adjust the power factor according to a preset power adjustment strategy model if the power factor of a charging pile node is not within the target range. The objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range;

[0101] The adjustment module is used to synchronize the adjusted power factor of the charging pile node to the other connected charging piles. The other connected charging piles adjust the power factor through a preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed.

[0102] The above-mentioned unit modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above-mentioned modules.

[0103] This embodiment also provides a computer device, which may be a terminal, and its internal structure diagram may be as follows: Figure 2 As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a local control method for a charging pile to participate in real-time power factor adjustment of the power grid is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a button, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse.

[0104] This embodiment further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0105] Obtain the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, calculate the power and power factor based on the current and voltage of the sampling nodes, and determine whether the power factor of each node is within the target range. The charging piles in the target area are interconnected according to the spatial distance and receive voltage and power information from other charging piles.

[0106] If the power factor of a charging pile node is not within the target range, the power factor is adjusted according to the preset power adjustment strategy model. The objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range.

[0107] The adjusted power factor of the charging pile node is synchronized to the other connected charging piles, and the other connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed.

[0108] Example 2

[0109] Reference Figure 1-Figure 2 , which is an embodiment of the present invention, provides an on-site control method and system for a charging pile to participate in real-time adjustment of the power factor of a power grid. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0110] The experimental simulation is as follows: In a medium-sized city, assume that there is a commercial area equipped with 50 charging piles, which are located in different locations but belong to the same distribution network area. The charging piles can communicate with each other through wireless communication technology and share their voltage and power information. The goal is to keep the power factor of these charging piles in an ideal range, such as between 0.95 and 1.00.

[0111] The implementation steps are as follows:

[0112] Step 1: Initial state: All charging piles are operating normally, but no power factor adjustment measures are implemented.

[0113] Step 2: Data collection: Collect the current and voltage data of all charging piles every 15 minutes, and calculate the power and power factor of each charging pile.

[0114] Step 3: Power factor assessment: Check whether the power factor of each charging station falls within the target range of 0.95 to 1.00.

[0115] Step 4: Adjustment strategy: If the power factor of a charging pile is not within the target range, the preset power adjustment strategy model is applied for adjustment.

[0116] Step 5: Synchronous adjustment: Synchronize the adjusted power factor information to other charging piles so that they can also make adjustments according to the strategy model.

[0117] Step 6: Periodic reassessment: Repeat steps 2 to 5 every hour to ensure that the power factor of all charging stations remains within the target range.

[0118] It should be noted that nonlinear model predictive control (NMPC) is used as the basis of the power adjustment strategy model. The power adjustment strategy model takes into account the charging demand constraints and capacity constraints of the charging piles. The objective function of the power adjustment strategy model is that the power factors of all charging piles are kept within the target range in the next 24 hours.

[0119] The experimental results are as follows, experimental group and control group:

[0120] Experimental group: Apply the above-mentioned on-site control method to adjust the power factor of the charging pile.

[0121] Control group: The charging piles were adjusted for power factor using the traditional centralized control method, i.e., they were uniformly dispatched by a central controller.

[0122] Data collection and analysis method settings:

[0123] Data collection: record key indicators such as power factor, grid loss, and operating cost of charging piles in both groups.

[0124] Analytical methods: Statistical methods were used to compare the two sets of data to evaluate the effectiveness of implementing the on-site control method.

[0125] The comparative experimental data is shown in Table 1:

[0126] Table 1: Comparative experimental data table (part).

[0127]

[0128] From the above table, we can see that the average power factor of the experimental group is significantly better than that of the control group, and the grid loss and operating cost are also reduced. This means that the application of local control methods can more effectively improve the operating efficiency and economy of the grid.

[0129] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0130] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0131] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0132] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0134] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0135] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A local control method for a charging pile to participate in real-time power factor adjustment of a power grid, characterized in that: include: Obtain the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, calculate the power and power factor according to the current and voltage of the sampling nodes, and determine whether the power factor of each node is within the target range. The charging piles in the target area are interconnected according to the spatial distance and receive the voltage and power information from other charging piles. If the power factor of a charging pile node is not within the target range, the power factor is adjusted according to a preset power adjustment strategy model, and the objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range; The adjusted power factor of the charging pile node is synchronized to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed.

2. The on-site control method for real-time power factor adjustment of a charging pile participating in a power grid as claimed in claim 1 is characterized in that: The obtaining of the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, and calculating the power and power factor according to the current and voltage of the sampling nodes corresponding to the charging piles includes: Assume that each charging pile A i Different nodes r (i=1,2,3,…,N) measure the current I of each node in real time ir and voltage V ir , N represents the total number of charging piles in the target distribution network area, and the active power P of each node is calculated based on the collected current and voltage ir and reactive power Q ir ; Calculate the power factor cosφ of each node based on the active power and apparent power ir ; The power factor calculation expression is as follows: Among them, S ir Indicates apparent power.

3. The on-site control method for real-time power factor adjustment of a charging pile participating in a power grid as claimed in claim 2, characterized in that: The step of determining whether the power factor of each node is within a target range includes: Set the power factor range to [cosφ min ,cosφ max ], compare the calculated power factor cosφ of each node ij Compare with the set power factor range to determine whether it exceeds the range.

4. The on-site control method for real-time power factor adjustment of a charging pile participating in a power grid as claimed in claim 3 is characterized in that: The power adjustment strategy model includes: Assume that there are N charging piles in the distribution network. The reference node in a charging pile and the nodes at both ends of the reference line are marked as nref1, nref2, ..., nref r , nref1 and nref r are the nodes at both ends of the reference line. The prediction model and control logic of all charging piles are the same. The prediction model established for any charging pile j is shown as follows: Among them, the superscripts p, c, and m correspond to the predicted value, communication value, and set value of the variable. P(k) and Q(k) are the values ​​of the variables P and Q in the k period. ΔP(k) and ΔQ(k) are the increments of the variables P and Q in the k+1 period compared to the k period. The variables P and Q represent the active power and reactive power. represents the predicted value of the change in active power of charging pile j in time period k, represents the predicted value of the change in reactive power of charging pile j in time period k, γ represents the control parameter, They represent the set values ​​of the dq components of the line voltage v in time period k, represents the predicted value of the dq component of the line current i in the time period k, R represents the line resistance, L represents the line inductance, Represents the predicted value of the power factor of charging pile j.

5. The on-site control method for real-time power factor adjustment of a charging pile participating in a power grid as claimed in claim 4 is characterized in that: The power adjustment strategy model also includes: The constraints in the power adjustment strategy model calculation mainly include charging demand constraints and charging pile capacity constraints; If the lower and upper limits of active power set by charging pile j in period k are P j (k) The rated capacity of charging pile j is The charging demand constraint and capacity constraint of charging pile j are as follows: in, represents the active power of charging pile j in time period k, represents the reactive power of charging pile j in time period k.

6. The on-site control method for real-time power factor adjustment of a charging pile participating in a power grid as claimed in claim 5, characterized in that: The objective function of the power adjustment strategy model includes: The objective function is as follows: Where N is the number of charging piles, u j (t) is the power factor of the jth charging station at time t, cosφ target,j is the target power factor of the jth charging pile, T p is the length of the forecast period.

7. The on-site control method for real-time power factor adjustment of a charging pile participating in a power grid as claimed in claim 6 is characterized in that: The adjusted power factor of the charging pile node is synchronized to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of all charging piles in the target distribution network area is completed, including: waiting for a period after each completion of the power factor adjustment of all charging piles in the target distribution network area, and then re-obtaining the current and voltage of the sampling corresponding nodes of the charging piles in the target distribution network area, calculating the power and power factor according to the current and voltage of the sampling corresponding nodes, and re-judging and adjusting.

8. An on-site control system for a charging pile to participate in real-time power factor adjustment of a power grid, characterized in that: include: A judgment module is used to obtain the current and voltage of the sampling nodes corresponding to the charging piles in the target distribution network area, calculate the power and power factor according to the current and voltage of the sampling nodes, and judge whether the power factor of each node is within the target range. The charging piles in the target area are interconnected according to the spatial distance and receive the voltage and power information from other charging piles. A model building module is used to adjust the power factor according to a preset power adjustment strategy model if the power factor of a charging pile node is not within the target range. The objective function of the power adjustment strategy model is that the power factors of all nodes within the future target time range are within the target range; The adjustment module is used to synchronize the adjusted power factor of the charging pile node to the remaining connected charging piles, and the remaining connected charging piles adjust the power factor through the preset power adjustment strategy model until the power factor adjustment of the charging piles in all target distribution network areas is completed.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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