System and method for controlling new energy bidirectional charging pile to realize discharging countercurrent prevention and charging demand management

Abstract

The invention discloses a system and method for controlling a new energy two-way charging pile to achieve discharging countercurrent prevention and charging demand management, the system comprises a power grid home-entry electric meter, a current transformer CT, a countercurrent prevention device, a two-way charging pile V2G and a household load, and the countercurrent prevention device is used for coordinating electric energy distribution. A power amplitude limiting function in a charging mode is realized, and the total electric power of the charging pile is prevented from exceeding the maximum capacity allowed by a power grid; an anti-reflux function in a discharge mode prevents electric energy fed back by the vehicle from reversely flowing into a power grid to cause power grid fluctuation; and the power distribution is flexibly adjusted according to the real-time load of the power grid, so that the resource utilization rate is improved. The anti-reflux device is located in a control center, collects power grid incoming line power, local load data and the operation state of the two-way charging pile in real time, generates a power adjusting instruction according to a control strategy and issues the power adjusting instruction to the charging pile, and power grid safety and efficiency management and control are achieved on the basis of being compatible with existing charging and discharging logic executed according to orders.

Description

Technical Field

[0001] This invention relates to the field of new energy charging pile technology, specifically to a management system and method for controlling bidirectional new energy charging piles to achieve discharge anti-reverse current and charging demand management. Background Technology

[0002] With the large-scale popularization of new energy vehicles and the continuous advancement of smart grid construction, bidirectional charging piles have become a core hub device in the vehicle-to-grid (V2G) ecosystem. Their core feature lies in their bidirectional energy interaction capability. On one hand, they can act as charging terminals, drawing electricity from the grid to replenish the power batteries of new energy vehicles, meeting users' daily travel range needs. On the other hand, they can feed back the energy stored in the vehicle's power battery to the grid, achieving a bidirectional energy cycle between the vehicle and the grid. The core value of this technology lies in its dual-end empowerment. On the grid side, it can leverage the distributed energy storage potential of massive numbers of new energy vehicles to smooth load fluctuations (such as peak shaving and valley filling), improving grid operation stability and renewable energy absorption efficiency. On the user side, it can obtain additional revenue through peak-valley electricity price differences, achieving economic efficiency and flexibility in energy utilization. Therefore, bidirectional charging piles are considered a key node connecting the transportation and energy sectors and an important support for building an integrated energy system encompassing "source, grid, load, and storage."

[0003] Existing technologies suffer from two major pain points and generate multiple harms: One issue is the reverse current interference during the discharge process. In V2G discharge mode, when bidirectional charging piles feed back power to the grid, they need to be precisely matched with the real-time load consumption of the local power grid (such as the distribution network of a transformer substation or residential area). However, existing technologies lack dynamic load matching and rapid regulation capabilities. When the feedback power exceeds the local instantaneous load consumption, the excess power will form a "reverse current" and be directly injected into the upstream power grid. Its harm is multi-dimensional and destructive: First, it disrupts the operating rhythm of the power grid. Reverse current can cause the grid frequency to deviate from the rated value (50Hz in my country), voltage fluctuations or distortions, exceeding the allowable deviation range of grid dispatch. Second, it damages the safety of power grid equipment. The inrush current caused by the reverse current may exceed the rated carrying capacity of equipment such as transformers and line switches. Long-term operation can easily lead to insulation aging, overheating damage, and even induce short-circuit faults. Third, it disrupts the metering and dispatching order. Reverse current can cause data distortion in the power grid metering system, affecting the accuracy of power transaction settlement. At the same time, it interferes with the load forecasting and command execution of the dispatching center, disrupting the orderly operation of the power grid.

[0004] Secondly, there are issues of load response lag and resource allocation imbalance during the charging process. Under the traditional charging model, the existing bidirectional charging pile charging management mechanism has significant rigid defects and fails to achieve dynamic coordination with grid load and user demand: First, it lacks the ability to respond to grid load in real time. During peak electricity consumption periods (such as the evening when residential electricity consumption is concentrated), a large number of vehicles charging at the same time will cause a surge in the load of the regional distribution network, which can easily exceed the line's carrying capacity limit and cause power supply failures such as voltage drops and equipment tripping; while during off-peak electricity consumption periods (such as in the early morning), the grid has a large amount of idle power generation capacity, but the charging piles still charge in a fixed mode, resulting in low energy utilization efficiency and wasted power generation capacity; Second, resource allocation lacks differentiated adaptation. Charging resources adopt a one-size-fits-all approach and do not fully consider the differentiated needs of users (such as the fast charging needs for emergency travel, the slow charging needs for daily commuting, and the time window needs for scheduled charging). Fixed charging power limitations prevent users from obtaining higher power replenishment in emergency scenarios, while the charging needs of low-priority users may occupy energy resources during off-peak hours of the power grid, creating a resource mismatch pattern of peak congestion and off-peak idleness. This not only affects user experience but also reduces the operational efficiency of the entire charging network.

[0005] To address the aforementioned issues, existing industry solutions have significant limitations and fail to fundamentally resolve the core pain points. Current backflow prevention technologies largely rely on a single current sensor (such as a current transformer connected in series on the grid side) for backflow detection, and their technical shortcomings are concentrated in two aspects: First, the response speed is slow. The total delay of sensor signal acquisition, data transmission and back-end processing usually exceeds 100ms, while the occurrence of power grid load fluctuations and reverse flow phenomena is instantaneous (millisecond-level changes), making it difficult for hysteresis detection to capture sudden changes in state in real time; Secondly, the regulation mode is passive. This type of solution is a post-event remedial mechanism, which only initiates power regulation or shutdown operations after backflow is detected. It cannot predict load changes in advance and intervene proactively, resulting in limited protection effectiveness because the backflow impact has already affected the power grid. Summary of the Invention

[0006] In view of this, it is necessary to provide a control system and method for new energy bidirectional charging piles that integrates active control of discharge anti-reverse current and dynamic optimization of charging demand.

[0007] A management system for controlling bidirectional charging piles for new energy vehicles to achieve discharge backflow prevention and charging demand management includes a grid-connected electricity meter, a current transformer (CT), a backflow preventer, a bidirectional charging pile V2G network, household loads, and a cloud platform. The household electricity meter is used to measure household electricity consumption and is connected to the public power grid. The current transformer (CT) is used to monitor the electrical parameters of voltage and current transmitted from the public power grid to the household side, and transmits the monitored data to the anti-reverse current device to provide data support for the anti-reverse current device. The household load is used for household-side electricity consumption; The bidirectional charging pile (V2G) enables energy interaction with the public power grid and the household load through the charging and discharging of electric vehicles; The anti-backflow device is connected to the household electricity meter to obtain electricity metering information; it is also connected to the current transformer (CT) and receives monitoring signals transmitted by the current transformer (CT); the anti-backflow device is communicatively connected to the bidirectional charging pile (V2G) to control the reasonable distribution of electricity between the household load and the bidirectional charging pile (V2G) to prevent electricity from flowing back into the public power grid from the household side. The cloud platform is used to connect to the power grid's electricity meter, current transformer (CT), anti-reverse current device, bidirectional charging pile (V2G), and household loads via 4G / 5G communication network. It has V2G scheduling and charging pile management functions, and can also realize remote monitoring, data uploading and storage, order management, and alarm push functions. It is the core support for remote control and data traceability of the system.

[0008] Preferably, the anti-backflow device includes a data acquisition and load monitoring unit for constructing a multi-dimensional data acquisition network, and the data acquisition objects include: Grid-side data: Voltage U, current I, active power P, reactive power Q, and load change rate dP / dt of the regional distribution network are collected in real time through voltage sensors, current sensors, and power analyzers. The sampling frequency is not less than 1Hz to ensure the capture of dynamic fluctuations in grid load. User-side data: The cloud platform is used to obtain the user's set electricity demand limit, charging reservation information, and historical charging load curves. Equipment-side data: Collect parameters such as the current charging power, electric vehicle battery charging status, battery temperature, and charging interface status of each bidirectional charging pile V2G to ensure that the power adjustment is adapted to the safety requirements of the electric vehicle battery.

[0009] Preferably, the bidirectional charging pile V2G includes a multi-dimensional sensing unit, a collaborative control unit, a bidirectional power execution unit, a user interaction unit, and a safety protection unit, wherein... The multi-dimensional sensing unit is used to achieve comprehensive perception of power grid status and load demand by combining multiple types of sensors and fusing real-time data. The collaborative control unit is used to implement the discharge anti-reverse current active control logic and the charging demand dynamic optimization logic; The bidirectional power execution unit is used to control the input and output power of the electric vehicle battery in charging and discharging modes. In discharging mode, according to the maximum output power Pmax command of the battery discharge issued by the cooperative control unit, the power fed back to the public grid is precisely adjusted through pulse width modulation (PWM) control to ensure that it does not exceed the locked upper limit. In charging mode, the output current is adaptively adjusted according to the dynamically optimized charging power command, while being compatible with the charging protocols of different vehicle models. The safety protection unit is used to ensure the reliability and ease of use of the system; it includes an overcurrent protection relay, an overvoltage protection module, a temperature sensor, and a leakage protection module; when reverse current, overcurrent, overvoltage, or equipment overheating is detected, the main circuit is immediately cut off, a fault signal is sent to the collaborative control unit, and an alarm is triggered through the user interaction unit. The user interaction unit is used to ensure the ease of use of the system; it is used to display the current charging or discharging power of the electric vehicle battery, the grid load status, and the battery charging status (SOC); all real-time operating data is synchronously uploaded to the cloud platform to realize centralized data monitoring and traceability. Once an alarm is triggered, the system will notify the user through the background and can also link 4G and the cloud platform to push alarm information to maintenance personnel to ensure that abnormal situations are detected and handled in a timely manner.

[0010] Preferably, the multi-dimensional sensing unit includes a power grid parameter sensing subunit, a vehicle status sensing subunit, and a user demand sensing subunit, wherein, The power grid parameter sensing subunit is used to collect parameters of current, voltage, and power factor on the public power grid side in real time, calculate the total power consumption P_load of the local load of the current public power grid, and provide basic data for anti-reverse flow control. The vehicle status perception subunit is a data acquisition module connected to the battery management system (BMS) of the new energy vehicle via the CAN bus. It is used to support reading parameters such as battery charging status (SOC), allowable charging and discharging power (P_veh_max / P_veh_min), and battery temperature, to obtain the real-time status of the vehicle battery and avoid power regulation failure caused by the battery's own limitations. The user demand perception subunit is used to transform user demand into quantified priority parameters, providing a basis for decision-making regarding charging demand allocation.

[0011] Preferably, the discharge anti-reverse current active control logic, based on the total local load consumption power P_load of the current public power grid collected by the power grid parameter sensing subunit, combined with historical load fluctuation data, uses the ARIMA prediction model to predict the minimum local load consumption power value P_load_min within a predetermined time period in the future, and sets the upper limit of discharge feedback power Pmax to be less than the minimum local load consumption power value P_load_min; if a predetermined decrease in P_load_min is detected within the predetermined time period, Pmax is adjusted down in real time.

[0012] Preferably, the dynamic optimization logic for charging demand adopts a target weighted optimization algorithm, with the objective function being the grid load balance and the satisfaction of user demand. Based on the load rate data collected by the grid parameter sensing subunit, the grid state is divided into multiple levels, and the grid load state and user demand are updated every predetermined time interval. The charging power of each charging pile is dynamically adjusted according to the grid load state and user demand to avoid local overload or energy waste.

[0013] Furthermore, a method for controlling bidirectional charging piles for new energy vehicles to achieve discharge reverse current prevention and charging demand management, used to solve the problems of easy discharge reverse current and inefficient charging demand management of existing bidirectional charging piles by controlling bidirectional charging piles for discharge reverse current prevention and charging demand management as described above, specifically including the following steps: Step 1: The anti-backflow device collects data, including voltage U, current I, active power P, reactive power Q, and load change rate dP / dt. Step 2, power limiting control in charging mode; by monitoring the regional power grid load, user demand electricity fee threshold and charging pile operation status in real time, the charging power of one or more charging piles is dynamically adjusted to avoid the total charging power exceeding the upper limit of the power grid's safe carrying capacity or the user's set demand electricity fee threshold, and ultimately achieve the dual goals of power grid load peak shaving and charging cost optimization. Step 3, Anti-reverse current control in discharge mode; During V2G discharge, the electric vehicle battery feeds power to the public power grid. By monitoring the power flow and grid acceptance capacity in real time, the discharge power is dynamically adjusted or the discharge circuit is cut off to ensure that the power fed does not exceed the real-time available capacity of the grid, avoid the reverse flow of power into the upstream grid, and ensure the stability of grid frequency and voltage and the safety of power distribution equipment. Step 4, Dynamic Capacity Increase Control: Based on the dynamic changes in grid load, the utilization rate of charging pile capacity, and the charging and discharging needs of electric vehicle batteries, without modifying the grid hardware, the capacity allocation is optimized through software algorithms, transforming the fixed capacity of charging piles into dynamically adjustable capacity. During periods of low load, the available capacity of charging piles is increased, and during periods of high load, the basic capacity is restored, ultimately improving the utilization rate of charging piles and the flexibility of grid capacity configuration.

[0014] Preferably, step two, the specific steps of power limiting control in charging mode, include: Step 2.1: Set a hysteresis loop of a predetermined width and a control target, wherein the control target is to stabilize the total power input to the grid at a predetermined proportion of the total power consumption limit in order to reduce frequent power switching; Step 2.2: Monitor the regional power grid load, user demand electricity fee threshold, and charging pile operation status in real time; Step 2.3: When the total power input to the power grid exceeds the preset total power consumption limit, the charging power of the charging pile must be immediately reduced to prevent power grid overload. The reduction trigger condition is: total power input to the power grid > total power consumption limit; when the total power input to the power grid is less than the charging target power, the charging power of the charging pile must be immediately increased. The increase trigger condition is: total power input to the power grid < a predetermined percentage value of the total power consumption limit. Step 2.4, Local load power P load After being summed with the target charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of k. cmd Execution delay Za -1 After the delay, the charging power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 The delayed feedback is sent to the summer to form a closed-loop control.

[0015] Preferably, step three, the specific steps of the anti-reverse current control in the discharge mode, includes: Step 3.1: Set the target discharge power and control error; Step 3.2: Monitor the total power input to the power grid and the operating status of the charging pile in real time; when the total power input to the power grid is negative, it indicates that the power is flowing into the public power grid in reverse, and a reverse flow occurs. The discharge power needs to be reduced to suppress the reverse flow. Step 3.3, Local load power P load After being summed with the discharge target power by a summer, the power is then adjusted and controlled by a gain adjustment and control command P with a gain coefficient of -k. cmd Execution delay Za -1 After the delay, the discharge power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Z via the feedback loop b -1 After the delay and -1 negative feedback loop, the feedback signal P will be... V2G The data is fed back to the summation point in reverse, forming a closed-loop control.

[0016] Step 3.4: When the total power input to the grid is positive but close to the reverse current threshold, and the system detects a small error, the system performs fine-tuning: slightly reducing the discharge power to increase the safety margin and avoid entering the reverse current state; when the actual grid input power exceeds the reverse current threshold, the system enters the reverse current state, and the control error becomes negative, the system significantly reduces the discharge power to quickly suppress the reverse current and restore to a safe state.

[0017] Preferably, step four, the specific steps of dynamic capacity expansion control, include: Step 4.1: Set the hysteresis width, target power, and control error, where the target power is a predetermined proportion of the total power consumption limit, and the control error is the target power minus the actual total power input to the power grid. Step 4.2: Monitor the regional power grid load, user demand electricity fee threshold, and charging pile operation status in real time; when the total power input to the power grid is positive and the available capacity is positive, increase the charging power to make full use of power grid resources; Step 4.3, negative local load power P load After being summed with the target charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of k. cmd Execution delay Za -1 After the delay, the charging power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 The delayed feedback is sent to the summer to form a closed-loop control. Step 4.4, set the upper limit charging power to: 0.1P max - P thrshld When the total power input to the grid is negative, but the absolute value is much smaller than the reverse current threshold, the discharge power is increased to improve the discharge efficiency of the bidirectional charging pile. Step 4.5, negative local load power P load After being summed with the upper limit charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of -k. cmd Execution delay Za -1 After the delay, the discharge power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Z via the feedback loop b -1 After the delay and -1 negative feedback loop, the feedback signal P will be... V2G The data is fed back to the summation point in reverse, forming a closed-loop control.

[0018] In the aforementioned control method for bidirectional charging piles of new energy vehicles to achieve discharge anti-reverse current and charging demand management system, the core function of the anti-reverse current device is to generate V2G power commands to meet the three major functional requirements of the system: power limiting function in charging mode to prevent the total power consumption of the charging pile from exceeding the maximum capacity allowed by the power grid; anti-reverse current function in discharge mode to prevent the reverse flow of power fed back by the vehicle into the power grid, causing grid fluctuations; and advanced functions such as dynamic capacity expansion to flexibly adjust power allocation according to the real-time load of the power grid and improve resource utilization. The anti-reverse current device is located at the control center, collecting real-time power input from the power grid, local load data, and the operating status of the charging pile, such as charging and discharging mode, power value, and vehicle battery status, and generating power adjustment commands according to the control strategy and sending them to the charging pile. While being compatible with the existing order-based charging and discharging logic, it achieves power grid safety and efficiency management. The method of this invention is simple, easy to implement, low in cost, and easy to promote. Attached Figure Description

[0019] Figure 1 This is a structural block diagram of the control system for bidirectional charging piles for new energy vehicles to prevent backflow during discharge and manage charging demand, according to an embodiment of the present invention.

[0020] Figure 2 This is a flowchart illustrating the process of controlling a new energy bidirectional charging pile to achieve discharge anti-reverse current and online activation of the charging demand management system, according to an embodiment of the present invention.

[0021] Figure 3 This is a control block diagram of the charging mode power limiting method for controlling bidirectional charging piles of new energy vehicles to achieve discharge anti-reverse current and charging demand management according to an embodiment of the present invention.

[0022] Figure 4 This is a control block diagram of the charging scheduling method for controlling bidirectional charging piles of new energy vehicles to achieve discharge anti-reverse current and charging demand management according to an embodiment of the present invention.

[0023] Figure 5 This is a control block diagram of the discharge reverse current method for controlling the discharge anti-reverse current and charging demand management method of the new energy bidirectional charging pile in an embodiment of the present invention.

[0024] Figure 6 This is a control block diagram of the power surplus in the charging mode of the method for controlling the discharge anti-reverse current and charging demand management of the new energy bidirectional charging pile according to an embodiment of the present invention.

[0025] Figure 7 This is a control block diagram of the method for controlling bidirectional charging piles for new energy vehicles to achieve discharge anti-reverse current and charging demand management when the discharge power has a margin, according to an embodiment of the present invention. Detailed Implementation

[0026] This embodiment takes a new energy bidirectional charging pile as an example to realize the discharge anti-reverse current and charging demand management system and method. The invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0027] Please see Figure 1 This invention illustrates a management system for controlling bidirectional charging piles for new energy vehicles to achieve discharge backflow prevention and charging demand management, including a grid-connected electricity meter, a current transformer (CT), a backflow preventer, a bidirectional charging pile V2G, household loads, and a cloud platform. The household electricity meter is used to measure household electricity consumption and is connected to the public power grid. The current transformer (CT) is used to monitor the electrical parameters of voltage and current transmitted from the public power grid to the household side, and transmits the monitored data to the anti-reverse current device to provide data support for the anti-reverse current device. The household load is used for household-side electricity consumption; The bidirectional charging pile (V2G) enables energy interaction with the public power grid and the household load through the charging and discharging of electric vehicles; The anti-backflow device is connected to the household electricity meter to obtain electricity metering information; it is also connected to the current transformer (CT) and receives monitoring signals transmitted by the current transformer (CT); the anti-backflow device is communicatively connected to the bidirectional charging pile (V2G) to control the reasonable distribution of electricity between the household load and the bidirectional charging pile (V2G) to prevent electricity from flowing back into the public power grid from the household side. The cloud platform is used to connect to the power grid's electricity meter, current transformer (CT), anti-reverse current device, bidirectional charging pile (V2G), and household loads via 4G / 5G communication network. It has V2G scheduling and charging pile management functions, and can also realize remote monitoring, data uploading and storage, order management, and alarm push functions. It is the core support for remote control and data traceability of the system.

[0028] Specifically, the anti-backflow device coordinates power distribution to ensure orderly power use in households and prevents reverse power flow into the grid. By integrating the grid-connected electricity meter, current transformer (CT), and other monitoring and control units, and utilizing various communication methods, the anti-backflow device manages the electricity consumption of household loads and the energy interaction of the V2G bidirectional charging pile, preventing reverse flow of electricity into the public grid and ensuring grid stability and orderly power consumption.

[0029] Preferably, the anti-backflow device includes a data acquisition and load monitoring unit for constructing a multi-dimensional data acquisition network, with the core data acquisition objects including: Grid-side data: Voltage U, current I, active power P, reactive power Q, and load change rate dP / dt of the regional distribution network are collected in real time through voltage sensors, current sensors, and power analyzers. The sampling frequency is not less than 1Hz to ensure the capture of dynamic fluctuations in grid load. User-side data: The cloud platform is used to obtain the user's set electricity demand limit, charging reservation information, and historical charging load curves. Equipment-side data: Collect parameters such as the current charging power, electric vehicle battery charging status, battery temperature, and charging interface status of each bidirectional charging pile V2G to ensure that the power adjustment is adapted to the safety requirements of the electric vehicle battery.

[0030] Specifically, the anti-reverse current device also includes a V2G scheduling unit, which works with the cloud platform to complete the V2G scheduling function, realize intelligent control of bidirectional energy interaction between electric vehicles and the power grid, and use the dispersed electric vehicle battery clusters as distributed energy storage resources to participate in grid load regulation through algorithm-driven charging and discharging strategies.

[0031] Preferably, the bidirectional charging pile V2G includes a multi-dimensional sensing unit, a collaborative control unit, a bidirectional power execution unit, a user interaction unit, and a safety protection unit, wherein... The multi-dimensional sensing unit is used to achieve comprehensive perception of power grid status and load demand by combining multiple types of sensors and fusing real-time data. The collaborative control unit is used to implement the discharge anti-reverse current active control logic and the charging demand dynamic optimization logic; The bidirectional power execution unit is used to control the input and output power of the electric vehicle battery in charging and discharging modes. In discharging mode, according to the maximum output power Pmax command of the battery discharge issued by the cooperative control unit, the power fed back to the public grid is precisely adjusted through pulse width modulation (PWM) control to ensure that it does not exceed the locked upper limit. In charging mode, the output current is adaptively adjusted according to the dynamically optimized charging power command, while being compatible with the charging protocols of different vehicle models. The safety protection unit is used to ensure the reliability and ease of use of the system; it includes an overcurrent protection relay, an overvoltage protection module, a temperature sensor, and a leakage protection module; when reverse current, overcurrent, overvoltage, or equipment overheating is detected, the main circuit is immediately cut off, a fault signal is sent to the collaborative control unit, and an alarm is triggered through the user interaction unit. The user interaction unit is used to ensure the ease of use of the system; it is used to display the current charging or discharging power of the electric vehicle battery, the grid load status, and the battery charging status (SOC); all real-time operating data is synchronously uploaded to the cloud platform to realize centralized data monitoring and traceability. Once an alarm is triggered, the system will notify the user through the background and can also link 4G and the cloud platform to push alarm information to maintenance personnel to ensure that abnormal situations are detected and handled in a timely manner.

[0032] Preferably, the multi-dimensional sensing unit includes a power grid parameter sensing subunit, a vehicle status sensing subunit, and a user demand sensing subunit, wherein, The power grid parameter sensing subunit is used to collect parameters of current, voltage, and power factor on the public power grid side in real time, calculate the total power consumption P_load of the local load of the current public power grid, and provide basic data for anti-reverse flow control. The vehicle status perception subunit is a data acquisition module connected to the battery management system (BMS) of the new energy vehicle via the CAN bus. It is used to support reading parameters such as battery charging status (SOC), allowable charging and discharging power (P_veh_max / P_veh_min), and battery temperature, to obtain the real-time status of the vehicle battery and avoid power regulation failure caused by the battery's own limitations. The user demand perception subunit is used to transform user demand into quantified priority parameters, providing a basis for decision-making regarding charging demand allocation.

[0033] Preferably, the discharge anti-reverse current active control logic, based on the total local load consumption power P_load of the current public power grid collected by the power grid parameter sensing subunit, combined with historical load fluctuation data, uses the ARIMA prediction model to predict the minimum local load consumption power value P_load_min within a predetermined time period in the future, and sets the upper limit of discharge feedback power Pmax to be less than the minimum local load consumption power value P_load_min; if a predetermined decrease in P_load_min is detected within the predetermined time period, Pmax is adjusted down in real time.

[0034] Specifically, the ARIMA (Autoregressive Integral Moving Average) forecasting model is a classic time series forecasting method used to model and predict future values ​​of historical data with trending, seasonal, or non-stationary characteristics.

[0035] Specifically, in this embodiment, the minimum power consumption value P_load_min of the local load is reserved with a 5% redundancy to avoid reverse current caused by sudden load changes. The upper limit of the discharge feedback power Pmax is set to 95% of the minimum power consumption value P_load_min; if P_load_min drops by more than 2kW within 3 seconds, Pmax is adjusted down in real time, and the adjustment response time ranges from 20ms to 1000ms, preferably ≤50ms.

[0036] Specifically, when a decrease in P_load_min is predicted, Pmax is adjusted down in real time with an adjustment response time of ≤50ms, which is much faster than the 100ms+ lag adjustment of existing technologies. This shifts from post-event remediation to pre-event prediction, completely avoiding the occurrence of backflow phenomenon, rather than only correcting after backflow.

[0037] Preferably, the dynamic optimization logic for charging demand adopts a target weighted optimization algorithm, with the objective function being the grid load balance and the satisfaction of user demand. Based on the load rate data collected by the grid parameter sensing subunit, the grid state is divided into multiple levels, and the grid load state and user demand are updated every predetermined time interval. The charging power of each charging pile is dynamically adjusted according to the grid load state and user demand to avoid local overload or energy waste.

[0038] Specifically, in this embodiment, the load rate Pgrid is the ratio (percentage) of the current actual load power of the regional distribution network to the rated load power of the distribution network. Based on the load rate collected by the power grid parameter sensing subunit, the power grid status is divided into three levels: peak: Pgrid ≥ 80% of rated load, flat period: 40% ≤ Pgrid < 80%, and valley: Pgrid < 40%. The power grid load status and user demand are updated every 10 seconds, and the charging power of each charging pile is dynamically adjusted according to the power grid load status and user demand to avoid local overload or energy waste.

[0039] Please see Figure 2 This illustrates the entire process from plugging in the charging gun to whether the device ultimately starts discharging, within the control system for the bidirectional charging pile of the new energy vehicle to achieve discharge anti-reverse current and charging demand management.

[0040] In this embodiment, the control system for the bidirectional charging pile, which controls the discharge anti-reverse current and charging demand management, is connected to a remote cloud platform via a wireless communication network to enable remote order control or operation via an app. The control system can be activated when the scheduled time for the order arrives or via remote operation through the app.

[0041] In the control system for bidirectional charging piles for new energy vehicles to prevent backflow during discharge and manage charging demand, the anti-backflow device controls the operation of the entire system.

[0042] Furthermore, a method for controlling bidirectional charging piles for new energy vehicles to achieve discharge reverse current prevention and charging demand management, used to solve the problems of easy discharge reverse current and inefficient charging demand management of existing bidirectional charging piles by controlling bidirectional charging piles for discharge reverse current prevention and charging demand management as described above, specifically including the following steps: Step 1: The anti-backflow device collects data, including voltage U, current I, active power P, reactive power Q, and load change rate dP / dt.

[0043] Specifically, voltage (U) implementation: A 0.2-level three-phase voltage sensor is installed at the front end of the household electricity meter in the incoming cabinet of the regional distribution network. The A / B / C three-phase line voltage is sampled at 1Hz. The instantaneous fluctuation noise is eliminated by the moving average filter of 5 sampling points. At 12:00 a.m. every day, it is calibrated with the standard metering device of the power grid through the RS485 interface (allowable error ±0.5%). After being processed by the anti-reverse current device, it is synchronized to the V2G dispatch unit through LoRa communication to provide support for power calculation and voltage stability judgment.

[0044] Current (I) implementation: The incoming line cabinet is equipped with a series current transformer (CT) to collect the total three-phase current. A small CT with a different ratio is installed in the single-pile branch circuit to collect the branch current. Harmonic interference is filtered by hardware decoupling circuit. At the software level, the effective value of the current per second is extracted by peak detection algorithm. The standard current is simulated and calibrated weekly using a load box (error ≤ ±1%). The total current is used for the calculation of the total power input to the power grid, and the branch current assists in the calibration of the single-pile power distribution.

[0045] Active power (P) implementation: A 0.1-level precision power analyzer is used to directly collect the total three-phase active power, combined with P= The UIcosφ formula undergoes double verification, and transient load anomalies are eliminated through trend smoothing. The power factor is corrected monthly with the power grid's metering terminal (error ≤ ±0.8%). As the core data source, it directly triggers control logic such as power limiting and anti-reverse flow.

[0046] Reactive power (Q) implementation: The total three-phase reactive power is synchronously collected using a power analyzer, and Q= The UIsinφ formula is used for auxiliary calculation, filtering out fluctuations caused by the switching of reactive power compensation devices and retaining the average reactive power per second. It is calibrated synchronously with the active power (error ≤ ±1%) to determine the nature of the grid load and assist in adjusting the reactive power compensation strategy of charging piles to ensure the stability of total power.

[0047] Load change rate (dP / dt) implementation: Based on two sets of active power data at time t and time t+1, the load change rate is calculated according to the formula dP / dt=(P2-P1) / 1s. A threshold of ±50kW / s is set to mark the value exceeding the threshold as a sudden load disturbance signal. When the fluctuation intensity is ≥30kW / s, the control algorithm gain coefficient is automatically increased to speed up the response speed and adapt to the load fluctuation of the power grid.

[0048] Step 2, power limiting control in charging mode; by monitoring the regional power grid load, user demand electricity fee threshold and charging pile operation status in real time, the charging power of one or more charging piles is dynamically adjusted to avoid the total charging power exceeding the upper limit of the power grid's safe carrying capacity or the user's set demand electricity fee threshold, and ultimately achieve the dual goals of power grid load peak shaving and charging cost optimization. The specific steps include: Step 2.1: Set a hysteresis loop of a predetermined width and a control target, wherein the control target is to stabilize the total power input to the grid at a predetermined proportion of the total power consumption limit in order to reduce frequent power switching.

[0049] Specifically, in this embodiment, the hysteresis width is 10% of the total power consumption limit, the control objective is to stabilize the total power input from the grid at 90% of the total power consumption limit, the charging target power = total power consumption limit × 90%, and 10% of the total power consumption limit is reserved as a buffer zone.

[0050] Specifically, the control error (the difference between the target charging power and the actual total power input to the grid) is: target charging power minus the actual total power input to the grid, i.e., total power consumption limit × 90% minus the actual total power input to the grid; combined with the power balance relationship, it can also be expressed as total power consumption limit × 90% minus (local load power + charging pile charging power).

[0051] Step 2.2: Monitor the regional power grid load, user demand electricity fee threshold, and charging pile operation status in real time.

[0052] Step 2.3: When the total power input to the grid exceeds the preset total power consumption limit, the charging power of the charging pile must be immediately reduced to prevent grid overload. The reduction trigger condition is: total power input to the grid > total power consumption limit. When the total power input to the grid is less than the charging target power, the charging power of the charging pile must be immediately increased. The increase trigger condition is: total power input to the grid < a predetermined percentage of the total power consumption limit.

[0053] Specifically, in this embodiment, the trigger condition for the upward adjustment is: the total power input to the power grid is less than the total power consumption limit × 90%.

[0054] For step 2.4, please refer to [link / reference]. Figure 3 Local load power P loadAfter being summed with the target charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of k. cmd Execution delay Za -1 After the delay, the charging power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 The delayed feedback is sent to the summer to form a closed-loop control.

[0055] Specifically, since the local load power is uncontrollable and unmeasured, it can be considered as a system disturbance. Ignoring the delay, the system state coefficient is 1, indicating a critical stable state. To ensure stability, a gain coefficient less than 1 needs to be introduced, with the value ranging from 0 to 1. This improvement reduces the response sensitivity and suppresses oscillations.

[0056] Specifically, in other embodiments, please refer to Figure 4 To simplify the control structure, a dead-time element can be used to replace the hysteresis loop mentioned above. A dead-time module DT is added after the summer. The inputs of the summer are the total power consumption limit and the local load power P. load The dead zone is set from 90% of the total power consumption limit to the total power consumption limit. When the total power input from the grid is within the dead zone, the system does not perform regulation; when it exceeds the dead zone, the dead zone component outputs a control error, triggering a unified small-signal control algorithm.

[0057] Step 3, Anti-reverse current control in discharge mode; During V2G discharge, the electric vehicle battery feeds power to the public power grid. By monitoring the power flow and grid acceptance capacity in real time, the discharge power is dynamically adjusted or the discharge circuit is cut off to ensure that the power fed does not exceed the real-time available capacity of the grid, avoid the reverse flow of power into the upstream grid, and ensure the stability of grid frequency and voltage and the safety of power distribution equipment. The specific steps include: Step 3.1: Set the target discharge power and control error.

[0058] Specifically, in this embodiment, the target discharge power is: total power consumption limit × 10% + reverse current threshold; the control error is: absolute value of total grid input power + total power consumption limit × 10% + reverse current threshold.

[0059] Specifically, the reverse current threshold is the maximum permissible negative power input to the grid. Since the total grid input power is negative, its absolute value is equal to the opposite of this value. Therefore, the control error is: negative total grid input power + total power consumption limit × 10% + reverse current threshold.

[0060] Step 3.2: Monitor the total power input to the power grid and the operating status of the charging pile in real time. When the total power input to the power grid is negative, it indicates that the power is flowing into the public power grid in reverse, and a reverse flow occurs. The discharge power needs to be reduced to suppress the reverse flow.

[0061] For step 3.3, please refer to [link / reference]. Figure 5 Local load power P load After being summed with the discharge target power by a summer, the power is then adjusted and controlled by a gain adjustment and control command P with a gain coefficient of -k. cmd Execution delay Za -1 After the delay, the discharge power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Z via the feedback loop b -1 After the delay and -1 negative feedback loop, the feedback signal P will be... V2G The data is fed back to the summation point in reverse, forming a closed-loop control.

[0062] Step 3.4: When the total power input to the grid is positive but close to the reverse current threshold, and the system detects a small error, the system performs fine-tuning: slightly reducing the discharge power to increase the safety margin and avoid entering the reverse current state; when the actual grid input power exceeds the reverse current threshold, the system enters the reverse current state, and the control error becomes negative, the system significantly reduces the discharge power to quickly suppress the reverse current and restore to a safe state.

[0063] Specifically, the small-signal control block diagram includes execution delay and feedback delay. Ignoring these delays, the system is critically stable. A gain coefficient of 0 < 1 needs to be introduced to ensure system stability and quickly suppress reverse current. The incoming power is slightly less than the reverse current threshold. When the total grid input power is positive but close to the reverse current threshold, although there is no reverse current, the margin is insufficient. Therefore, the discharge power needs to be fine-tuned, slightly reduced to increase the margin.

[0064] The target discharge power remains the total power consumption limit × 10% + reverse current threshold. The control error is the target power minus the actual total grid input power, i.e., the control error is: total power consumption limit × 10% + reverse current threshold - current total grid input power. The small-signal control block diagram is the same as that for reverse current, and the adjustment range is distinguished by the magnitude of the error.

[0065] Step 4, Dynamic Capacity Increase Control: Based on the dynamic changes in grid load, the utilization rate of charging pile capacity, and the charging and discharging needs of electric vehicle batteries, without modifying the grid hardware, the capacity allocation is optimized through software algorithms, transforming the fixed capacity of charging piles into dynamically adjustable capacity. During periods of low load, the available capacity of charging piles is increased, and during periods of high load, the basic capacity is restored, ultimately improving the utilization rate of charging piles and the flexibility of grid capacity configuration.

[0066] The specific steps include: Step 4.1: Set the hysteresis width, target power, and control error, where the target power is a predetermined proportion of the total power consumption limit, and the control error is the target power minus the actual total power input to the power grid.

[0067] Specifically, in this embodiment, the hysteresis width is set to 10% of the total power consumption limit, the target power is set to 90% of the total power consumption limit, and the control error is the target power minus the actual total grid input power. That is, target power = total power consumption limit × 90%, and control error is: total power consumption limit × 90% - current total grid input power.

[0068] Step 4.2: Monitor the regional power grid load, user demand electricity fee threshold, and charging pile operation status in real time; when the total power input to the power grid is positive and the available capacity is positive, increase the charging power to make full use of power grid resources.

[0069] For step 4.3, please refer to [link / reference]. Figure 6 negative local load power P load After being summed with the target charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of k. cmd Execution delay Za -1 After the delay, the charging power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 The delayed feedback is sent to the summer to form a closed-loop control.

[0070] Specifically, the available capacity is: 0.9 P max - P load This positive value indicates that additional power can be provided, which is then adjusted through gain. k Amplify and generate instructions P cmd After a delay, the output P is given. V2G At the same time, feedback is provided to stabilize the system.

[0071] Step 4.4, set the upper limit charging power to: 0.1P max - P thrshld When the total power input to the grid is negative, but the absolute value is much smaller than the reverse current threshold, the discharge power is increased to improve the discharge efficiency of the bidirectional charging pile.

[0072] For step 4.5, please refer to... Figure 7 negative local load power P load After being summed with the upper limit charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of -k. cmd Execution delay Za-1 After the delay, the discharge power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Z via the feedback loop b -1 After the delay and -1 negative feedback loop, the feedback signal P will be... V2G The data is fed back to the summation point in reverse, forming a closed-loop control.

[0073] Specifically, the maximum allowed charging power is 0.1Pmax. Pthrshld dynamically adjusts the charging power based on the current load, using feedback to ensure stable system operation. When grid power is too high (P... grid >P target When the load P is at its maximum, the electric vehicle charging is activated to absorb excess electrical energy. load When the value is small, the error is large, and the controller generates a large P. cmd Since the gain is negative and the feedback is positive, the system will automatically adjust the charging power to stabilize the power grid.

[0074] Specifically, in this technical solution, high-frequency data acquisition increases the data sampling frequency on the power grid side, and the load change rate dP / dt is calculated in real time (once per second) to ensure the capture of millisecond-level load fluctuations; closed-loop feedback optimization ensures that after the charging and discharging power is adjusted, the feedback data can be verified in one sampling cycle (1 second) to avoid repeated adjustments; the above technical means improve the system's response speed.

[0075] The active adjustment logic of this technical solution includes pre-setting and real-time tracking. First, the upper limit of the discharge feedback power Pmax = P_load_min × 95% (with a 5% redundancy) is set in advance to prevent the discharge power from exceeding the load capacity from the source. Then, the decrease of P_load_min within a predetermined time period is tracked in real time. If the load change rate dP / dt is predicted to decrease by more than 2KW for 3 seconds, the anti-reverse current device will reduce the discharge power.

[0076] The table below compares the response speed and effectiveness of this technical solution with existing technologies:

[0077] The following specific embodiments illustrate the power limiting control in charging mode, the anti-reverse current control in discharging mode, and the dynamic capacity expansion control in the method for controlling bidirectional charging piles for new energy vehicles to achieve discharge anti-reverse current and charging demand management.

[0078] Example 1: Power limiting control in charging mode. Initially, the grid-side active power = 400kW (corresponding to U=380V, I=606A, dP / dt=10kW / s), the grid load power = 200kW, and the total charging power of the charging piles = 200kW (4 piles operating, 50kW per pile). Since the grid-side active power = 400kW < P_max × 90% = 450kW (P_max is 500kW), the upward adjustment condition is met. After calculating a control error of 50kW, the V2G dispatch unit instructs to add 2 more charging piles (25kW each), resulting in a final total charging power of 250kW and a grid-side active power of 450kW. Subsequently, the start-up of production equipment increases the grid load power to 300kW, and the grid-side active power = 550kW > P_max = 500kW. The V2G dispatch unit then instructs to reduce the total power of the 6 charging piles by 100kW (approximately 25kW per pile), resulting in a final total charging power of 150kW and a grid-side active power of = 450kW. refer to Figure 3 and Figure 4 In charging mode, the positive direction of power is defined as "inflow into the charging pile (charging) is positive" and outflow is negative. At this time, the system power balance relationship is: the total power input to the grid is equal to the sum of the local load power and the charging power of the charging pile (i.e., the total power input to the grid = local load power + charging power of the charging pile).

[0079] 1) When the total power input to the power grid exceeds the preset total power consumption limit, the charging power of the charging pile must be reduced immediately to prevent the power grid from overloading; 2) To reduce frequent power switching, a hysteresis loop (buffer zone) with a width of 10% of the total power consumption limit is set. The control objective is to stabilize the total power input to the grid at 90% of the total power consumption limit (i.e., target power = total power consumption limit × 90%).

[0080] At this point, the control error (the difference between the target power and the actual total power input to the grid) is: target power minus the actual total power input to the grid, i.e., total power consumption limit × 90% minus the actual total power input to the grid; combined with the power balance relationship, it can also be expressed as total power consumption limit × 90% minus (local load power + charging pile charging power).

[0081] Since the local load power is uncontrollable and unmeasured (considered a system disturbance), adjustment needs to be achieved through a small-signal control block diagram. This block diagram contains two delay components: execution delay (the time difference between the control command and the power adjustment) and feedback delay (the time difference between the power measurement value and the V2G scheduling unit). Ignoring the delay, the system state coefficient is 1, indicating a critical stable state. To ensure stability, a gain coefficient less than 1 (0 < gain coefficient < 1) is introduced to reduce response sensitivity and suppress oscillations. A unified control method is used in charging modes. In charging mode, regardless of whether the power is increased or decreased, the core of the small-signal control algorithm remains the same, only the triggering conditions differ: the triggering condition for increasing power is that the total grid input power < 90% of the total power consumption limit; the triggering condition for decreasing power is that the total grid input power > the total power consumption limit.

[0082] To simplify the control structure, a dead-zone element can replace the aforementioned hysteresis loop: the dead-zone range is set from 90% of the total power consumption limit to the total power consumption limit. When the total power input from the grid is within the dead-zone, the system does not perform regulation; when it exceeds the dead-zone, the dead-zone element outputs a control error, triggering a unified small-signal control algorithm. This design allows upward and downward adjustments to share the same algorithm, distinguishing the regulation demand only by the direction of the error, thus reducing complexity.

[0083] Example 2: Backflow Prevention Control in Discharge Mode. Initially, the total discharge power of 5 electric vehicles = 100kW, grid load power = 80kW, and grid-side active power = -20kW (corresponding to U = 385V, I = -303A, dP / dt = -15kW / s). Because the grid-side active power = -20kW > the backflow threshold P_thrshld = -50kW (insufficient margin), fine-tuning is triggered. After calculating the target power of 0kW and the control error of 20kW, the V2G dispatch unit instructs the discharge power to be reduced by 20kW to 80kW. After adjustment, the grid-side active power = 0kW. Subsequently, the shutdown of some production equipment reduces the grid load power to 30kW, and the grid-side active power = -50kW (reaching the backflow threshold). The V2G dispatch unit then instructs the discharge power to be further reduced by 30kW to 50kW. After adjustment, the grid-side active power = -20kW, thus avoiding the backflow risk. (Reference) Figure 5 When the total power input to the power grid is negative, it indicates that electrical energy is flowing into the power grid in the opposite direction (reverse flow occurs), and the discharge power needs to be reduced to suppress the reverse flow.

[0084] The target power is set as "total power consumption limit × 10% + reverse current threshold" (where the reverse current threshold is the maximum allowable negative grid input power). The control error is: absolute value of total grid input power + total power consumption limit × 10% + reverse current threshold, i.e., negative total grid input power + total power consumption limit × 10% + reverse current threshold (since the total grid input power is negative, its absolute value is equal to the opposite of this value). The small-signal control block diagram includes execution delay and feedback delay. When the delay is ignored, the system is critically stable; 0 < gain coefficient < 1 needs to be introduced to ensure system stability and quickly suppress reverse current. The incoming power is slightly less than the reverse current threshold. When the total grid input power is positive but close to the reverse current threshold, although there is no reverse current, the margin is insufficient, and the discharge power needs to be fine-tuned (slightly reduced) to increase the margin.

[0085] The target power remains "total power consumption limit × 10% + reverse current threshold", and the control error is: target power minus the actual total grid input power (i.e., total power consumption limit × 10% + reverse current threshold - current total grid input power). The small-signal control block diagram is the same as that for reverse current, and the adjustment range (fine-tuning characteristic) is distinguished by the magnitude of the error.

[0086] Example 3: Dynamic Capacity Expansion. Initially, the total discharge power of 5 electric vehicles = 100kW, grid load power = 80kW, and grid-side active power = -20kW (corresponding to U = 385V, I = -303A, dP / dt = -15kW / s). Because the grid-side active power = -20kW > the reverse current threshold P_thrshld = -50kW (insufficient margin), fine-tuning is triggered. After calculating the target power of 0kW and the control error of 20kW, the V2G dispatch unit instructs the discharge power to be reduced by 20kW to 80kW. After adjustment, the grid-side active power = 0kW. Subsequently, the shutdown of some production equipment reduces the grid load power to 30kW, and the grid-side active power = -50kW (reaching the reverse current threshold). The V2G dispatch unit then instructs the discharge power to be further reduced by 30kW to 50kW. After adjustment, the grid-side active power = -20kW, thus avoiding the reverse current risk. (Reference) Figure 6 and Figure 7 When the total power input to the grid is lower than the hysteresis lower limit (i.e., lower than 90% of the total power consumption limit), it indicates that the grid capacity is sufficient. When there is a higher demand for charging, the charging power can be increased to make full use of grid resources.

[0087] At this point, the target power remains 90% of the total power consumption limit, and the control error is the target power minus the actual total grid input power (i.e., 90% of the total power consumption limit minus the current total grid input power). The small-signal block diagram of the control principle is the same as that for power limiting, and the effects of local load disturbances and delays must also be considered.

[0088] The system's small-signal model shows that the state transition coefficient needs to be adjusted (by introducing a gain coefficient less than 1). After the improvement, stable control can be achieved, ensuring a smooth power increase process while balancing efficiency and safety.

[0089] When the total power input to the grid is negative but its absolute value is much smaller than the reverse current threshold (sufficient margin), the discharge power can be appropriately increased to improve V2G efficiency.

[0090] The target power is set as "total power consumption limit × 10% - reverse current threshold". Compared with the target power of the scenario, a small hysteresis loop with a width of 2 × reverse current threshold is formed to avoid frequent switching. The control error is: target power minus the actual total grid input power (i.e., total power consumption limit × 10% - reverse current threshold - current total grid input power).

[0091] The small signal control block diagram is consistent with other scenarios in the discharge mode, and stable adjustment is achieved through a unified algorithm framework and dynamic parameter matching.

[0092] In the aforementioned control method for bidirectional charging piles of new energy vehicles to achieve discharge anti-reverse current and charging demand management system, the core function of the anti-reverse current device is to generate V2G power commands to meet the three major functional requirements of the system: power limiting function in charging mode to prevent the total power consumption of the charging pile from exceeding the maximum capacity allowed by the power grid; anti-reverse current function in discharge mode to prevent the reverse flow of power fed back by the vehicle into the power grid, causing grid fluctuations; and advanced functions such as dynamic capacity expansion to flexibly adjust power allocation according to the real-time load of the power grid and improve resource utilization. The anti-reverse current device is located at the control center, collecting real-time power input from the power grid, local load data, and the operating status of the charging pile, such as charging and discharging mode, power value, and vehicle battery status, and generating power adjustment commands according to the control strategy and sending them to the charging pile. While being compatible with the existing order-based charging and discharging logic, it achieves power grid safety and efficiency management. The method of this invention is simple, easy to implement, low in cost, and easy to promote.

[0093] It should be noted that the present invention is not limited to the above-described embodiments. Based on the inventive spirit of the present invention, those skilled in the art can make other changes, and these changes made in accordance with the inventive spirit of the present invention should be included within the scope of protection claimed by the present invention.

Claims

1. A management system for controlling bidirectional charging piles for new energy vehicles to achieve discharge anti-reverse current and charging demand, characterized in that, This includes the grid-connected electricity meter, current transformer (CT), backflow preventer, V2G bidirectional charging station, household loads, and cloud platform. The household electricity meter is used to measure household electricity consumption and is connected to the public power grid. The current transformer (CT) is used to monitor the electrical parameters of voltage and current transmitted from the public power grid to the household side, and transmits the monitored data to the anti-reverse current device to provide data support for the anti-reverse current device. The household load is used for household-side electricity consumption; The bidirectional charging pile (V2G) enables energy interaction with the public power grid and the household load through the charging and discharging of electric vehicles; The anti-backflow device is connected to the household electricity meter to obtain electricity metering information; it is also connected to the current transformer (CT) and receives monitoring signals transmitted by the current transformer (CT); the anti-backflow device is communicatively connected to the bidirectional charging pile (V2G) to control the reasonable distribution of electricity between the household load and the bidirectional charging pile (V2G) to prevent electricity from flowing back into the public power grid from the household side. The cloud platform is used to connect to the power grid's electricity meter, current transformer (CT), anti-reverse current device, bidirectional charging pile (V2G), and household loads via 4G / 5G communication network. It has V2G scheduling and charging pile management functions, and can also realize remote monitoring, data uploading and storage, order management, and alarm push functions. It is the core support for remote control and data traceability of the system.

2. The system for controlling bidirectional charging piles for new energy vehicles to achieve discharge anti-reverse current and charging demand management as described in claim 1, characterized in that, The backflow prevention device includes a data acquisition and load monitoring unit, used to construct a multi-dimensional data acquisition network. The data acquisition objects include: Grid-side data: Voltage U, current I, active power P, reactive power Q, and load change rate dP / dt of the regional distribution network are collected in real time through voltage sensors, current sensors, and power analyzers. The sampling frequency is not less than 1Hz to ensure the capture of dynamic fluctuations in grid load. User-side data: The cloud platform is used to obtain the user's set electricity demand limit, charging reservation information, and historical charging load curves. Equipment-side data: Collect parameters such as the current charging power, electric vehicle battery charging status, battery temperature, and charging interface status of each bidirectional charging pile V2G to ensure that the power adjustment is adapted to the safety requirements of the electric vehicle battery.

3. The control system for bidirectional charging piles for new energy vehicles to achieve discharge anti-reverse current and charging demand management as described in claim 1, characterized in that, The bidirectional charging pile V2G includes a multi-dimensional sensing unit, a collaborative control unit, a bidirectional power execution unit, a user interaction unit, and a safety protection unit. The multi-dimensional sensing unit is used to achieve comprehensive perception of power grid status and load demand by combining multiple types of sensors and fusing real-time data. The collaborative control unit is used to implement the discharge anti-reverse current active control logic and the charging demand dynamic optimization logic; The bidirectional power execution unit is used to control the input and output power of the electric vehicle battery in charging and discharging modes. In discharging mode, according to the maximum output power Pmax command of the battery discharge issued by the cooperative control unit, the power fed back to the public grid is precisely adjusted through pulse width modulation (PWM) control to ensure that it does not exceed the locked upper limit. In charging mode, the output current is adaptively adjusted according to the dynamically optimized charging power command, while being compatible with the charging protocols of different vehicle models. The safety protection unit is used to ensure the reliability and ease of use of the system; it includes an overcurrent protection relay, an overvoltage protection module, a temperature sensor, and a leakage protection module; when reverse current, overcurrent, overvoltage, or equipment overheating is detected, the main circuit is immediately cut off, a fault signal is sent to the collaborative control unit, and an alarm is triggered through the user interaction unit. The user interaction unit is used to ensure the ease of use of the system; it is used to display the current charging or discharging power of the electric vehicle battery, the grid load status, and the battery charging status (SOC); all real-time operating data is synchronously uploaded to the cloud platform to realize centralized data monitoring and traceability. Once an alarm is triggered, the system will notify the user through the background and can also link 4G and the cloud platform to push alarm information to maintenance personnel to ensure that abnormal situations are detected and handled in a timely manner.

4. The system for controlling bidirectional charging piles for new energy vehicles to achieve discharge anti-reverse current and charging demand management as described in claim 3, characterized in that, The multi-dimensional sensing unit includes a power grid parameter sensing subunit, a vehicle status sensing subunit, and a user demand sensing subunit, wherein... The power grid parameter sensing subunit is used to collect parameters of current, voltage, and power factor on the public power grid side in real time, calculate the total power consumption P_load of the local load of the current public power grid, and provide basic data for anti-reverse flow control. The vehicle status perception subunit is a data acquisition module connected to the battery management system (BMS) of the new energy vehicle via the CAN bus. It is used to support reading parameters such as battery charging status (SOC), allowable charging and discharging power (P_veh_max / P_veh_min), and battery temperature, to obtain the real-time status of the vehicle battery and avoid power regulation failure caused by the battery's own limitations. The user demand perception subunit is used to transform user demand into quantified priority parameters, providing a basis for decision-making regarding charging demand allocation.

5. The control system for preventing reverse current during discharge and managing charging demand of bidirectional charging piles as described in claim 4, characterized in that, The discharge anti-reverse current active control logic, based on the total local load consumption power P_load of the current public power grid collected by the power grid parameter sensing subunit, combined with historical load fluctuation data, uses the ARIMA prediction model to predict the minimum local load consumption power value P_load_min within a predetermined time period in the future, and sets the upper limit of discharge feedback power Pmax to be less than the minimum local load consumption power value P_load_min; if a predetermined decrease in P_load_min is detected within the predetermined time period, Pmax is adjusted down in real time.

6. The control system for preventing reverse current during discharge and managing charging demand of bidirectional charging piles as described in claim 4, characterized in that, The dynamic optimization logic for charging demand adopts a target weighted optimization algorithm, with the objective function being the grid load balance and the satisfaction of user demand. Based on the load rate data collected by the grid parameter sensing subunit, the grid state is divided into multiple levels, and the grid load state and user demand are updated every predetermined time interval. The charging power of each charging pile is dynamically adjusted according to the grid load state and user demand to avoid local overload or energy waste.

7. A method for controlling bidirectional charging piles for new energy vehicles to achieve discharge reverse current prevention and charging demand management, used to solve the problems of easy discharge reverse current and inefficient charging demand management of existing bidirectional charging piles by means of the control system for controlling bidirectional charging piles for new energy vehicles to achieve discharge reverse current prevention and charging demand management as described in any one of claims 1-6, characterized in that, Specifically, the following steps are included: Step 1: The anti-backflow device collects data, including voltage U, current I, active power P, reactive power Q, and load change rate dP / dt. Step 2, power limiting control in charging mode; by monitoring the regional power grid load, user demand electricity fee threshold and charging pile operation status in real time, the charging power of one or more charging piles is dynamically adjusted to avoid the total charging power exceeding the upper limit of the power grid's safe carrying capacity or the user's set demand electricity fee threshold, and ultimately achieve the dual goals of power grid load peak shaving and charging cost optimization. Step 3, Anti-reverse current control in discharge mode; During V2G discharge, the electric vehicle battery feeds power to the public power grid. By monitoring the power flow and grid acceptance capacity in real time, the discharge power is dynamically adjusted or the discharge circuit is cut off to ensure that the power fed does not exceed the real-time available capacity of the grid, avoid the reverse flow of power into the upstream grid, and ensure the stability of grid frequency and voltage and the safety of power distribution equipment. Step 4, Dynamic Capacity Increase Control: Based on the dynamic changes in grid load, the utilization rate of charging pile capacity, and the charging and discharging needs of electric vehicle batteries, without modifying the grid hardware, the capacity allocation is optimized through software algorithms, transforming the fixed capacity of charging piles into dynamically adjustable capacity. During periods of low load, the available capacity of charging piles is increased, and during periods of high load, the basic capacity is restored, ultimately improving the utilization rate of charging piles and the flexibility of grid capacity configuration.

8. The method for controlling bidirectional charging piles for new energy vehicles to achieve discharge reverse current prevention and charging demand management as described in claim 7, characterized in that, Step two, the specific steps of power limiting control in charging mode, include: Step 2.1: Set a hysteresis loop of a predetermined width and a control target, wherein the control target is to stabilize the total power input to the grid at a predetermined proportion of the total power consumption limit in order to reduce frequent power switching; Step 2.2: Monitor the regional power grid load, user demand electricity fee threshold, and charging pile operation status in real time; Step 2.3: When the total power input to the grid exceeds the preset total power consumption limit, the charging power of the charging pile must be immediately reduced to prevent grid overload. The reduction trigger condition is: total power input to the grid > total power consumption limit; when the total power input to the grid is less than the charging target power, the charging power of the charging pile must be immediately increased. The increase trigger condition is: total power input to the grid < a predetermined percentage of the total power consumption limit. Step 2.4, Local load power P load After being summed with the target charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of k. cmd Execution delay Za -1 After the delay, the charging power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 The delayed feedback is sent to the summer to form a closed-loop control.

9. The method for controlling bidirectional charging piles for new energy vehicles to achieve discharge reverse current prevention and charging demand management as described in claim 7, characterized in that, Step three, the specific steps of the anti-reverse current control in the discharge mode, include: Step 3.1: Set the target discharge power and control error; Step 3.2: Monitor the total power input to the power grid and the operating status of the charging pile in real time; when the total power input to the power grid is negative, it indicates that the power is flowing into the public power grid in reverse, and a reverse flow occurs. The discharge power needs to be reduced to suppress the reverse flow. Step 3.3, Local load power P load After being summed with the discharge target power by a summer, the power is then adjusted and controlled by a gain adjustment and control command P with a gain coefficient of -k. cmd Execution delay Za -1 After the delay, the discharge power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 After the delay and -1 negative feedback loop, the feedback signal P will be... V2G The summation point is fed back in reverse to form a closed-loop control. Step 3.4: When the total power input to the grid is positive but close to the reverse current threshold, and the system detects a small error, the system performs fine-tuning: slightly reducing the discharge power to increase the safety margin and avoid entering the reverse current state; when the actual grid input power exceeds the reverse current threshold, the system enters the reverse current state, and the control error becomes negative, the system significantly reduces the discharge power to quickly suppress the reverse current and restore to a safe state.

10. The method for controlling bidirectional charging piles for new energy vehicles to achieve discharge reverse current prevention and charging demand management as described in claim 7, characterized in that, Step four, the specific steps of dynamic capacity expansion control, include: Step 4.1: Set the hysteresis width, target power, and control error, where the target power is a predetermined proportion of the total power consumption limit, and the control error is the target power minus the actual total power input to the power grid. Step 4.2: Monitor the regional power grid load, user demand electricity fee threshold, and charging pile operation status in real time; when the total power input to the power grid is positive and the available capacity is positive, increase the charging power to make full use of power grid resources; Step 4.3, negative local load power P load After being summed with the target charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of k. cmd Execution delay Za -1 After the delay, the charging power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 The delayed feedback is sent to the summer to form a closed-loop control. Step 4.4, set the upper limit charging power to: 0.1P max P thrshld When the total power input to the grid is negative, but the absolute value is much smaller than the reverse current threshold, the discharge power is increased to improve the discharge efficiency of the bidirectional charging pile. Step 4.5, negative local load power P load After being summed with the upper limit charging power by a summer, it is then subjected to gain adjustment and control command P with a gain coefficient of -k. cmd Execution delay Za -1 After the delay, the discharge power P of the bidirectional charging pile at the output end is obtained. V2G Output power P V2G Feedback delay Zb via the feedback loop -1 After the delay and -1 negative feedback loop, the feedback signal P will be... V2G The data is fed back to the summation point in reverse, forming a closed-loop control.

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