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CN-122026464-A - System and method for controlling new energy bidirectional charging pile to realize discharge backflow prevention and charging demand management

CN122026464ACN 122026464 ACN122026464 ACN 122026464ACN-122026464-A

Abstract

The invention discloses a system and a method for controlling a new energy bidirectional charging pile to realize discharge backflow prevention and charging demand management, wherein the system comprises a power grid household ammeter, a current transformer CT, a backflow preventer, a bidirectional charging pile V2G and a household load, wherein the backflow preventer is used for coordinating electric energy distribution. The power limiting function in the charging mode is realized, the total electric power of the charging pile is prevented from exceeding the maximum capacity allowed by the power grid, the backflow preventing function in the discharging mode is realized, the power grid fluctuation caused by reverse inflow of electric energy fed back by a vehicle into the power grid is avoided, the advanced functions such as dynamic capacity increasing are realized, the power distribution is flexibly adjusted according to the real-time load of the power grid, and the resource utilization rate is improved. The anti-reflux device is positioned in the control center, acquires the incoming line power of the power grid, the local load data and the running state of the bidirectional charging pile in real time, generates a power adjustment instruction according to a control strategy, and sends the power adjustment instruction to the charging pile, so that the safety and the efficiency control of the power grid are realized on the basis of being compatible with the existing charge-discharge logic executed according to the order.

Inventors

  • LI QINGSONG

Assignees

  • 深圳市能效电气技术有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The system for controlling the new energy bidirectional charging pile to realize discharge anti-reflux and charging demand management is characterized by comprising a power grid household ammeter, a current transformer CT, an anti-reflux device, a bidirectional charging pile V2G, a household load and a cloud platform, wherein, The power grid household ammeter is used for metering household electricity consumption and is connected to a public power grid; the current transformer CT is used for monitoring electrical parameters of voltage and current transmitted to the family side by the public power grid, transmitting the monitored data to the anti-reflux device and providing data support for the anti-reflux device; the household load is used for consuming electric energy at the household side; The bidirectional charging pile V2G realizes energy interaction with a public power grid and the household load through charging and discharging of the electric automobile; The anti-reflux device is connected with the bidirectional charging pile V2G in a communication way, controls the reasonable distribution of electric energy between the household load and the bidirectional charging pile V2G, and prevents electric energy from flowing back into a public power grid from the household side; The cloud platform is used for being connected with a power grid household ammeter, a current transformer CT, an anti-reflux device, a bidirectional charging pile V2G and a household load through a 4G/5G communication network, has a V2G scheduling function and a charging pile management function, and simultaneously realizes functions of remote monitoring, data uploading and storing, order management and warning pushing, and is a core support for system remote control and data tracing.
  2. 2. The system for controlling new energy bidirectional charging piles to realize discharge backflow prevention and charging demand management according to claim 1, wherein the backflow prevention device comprises a data acquisition and load monitoring unit for constructing a multidimensional data acquisition network, and the data acquisition object comprises: the power grid side data are obtained by collecting the voltage U, the current I, the active power P, the reactive power Q and the load change rate dP/dt of the regional power distribution network in real time through a voltage sensor, a current sensor and a power analyzer, wherein the sampling frequency is not lower than 1Hz, and the capturing of the dynamic fluctuation of the power grid load is ensured; user side data, namely acquiring a user-set upper limit of the electricity charge of the required amount, charging reservation information and a historical charging load curve through the cloud platform; And collecting parameters of the current charging power of each bidirectional charging pile V2G, the charging state of the battery of the electric automobile, the battery temperature and the charging interface state, and ensuring that the power adjustment meets the safety requirement of the battery of the electric automobile.
  3. 3. The system for controlling the new energy bi-directional charging pile to realize the discharge anti-reflux and the charging demand management as claimed in claim 1, wherein the bi-directional charging pile V2G comprises a multi-dimensional sensing unit, a cooperative control unit, a bi-directional power executing unit, a user interaction unit and a safety protection unit, wherein, The multidimensional sensing unit is used for realizing comprehensive sensing of power grid states and load demands through combination of a plurality of types of sensors and real-time data fusion; the cooperative control unit is used for realizing discharge anti-backflow active control logic and charge demand dynamic optimization logic; The bidirectional power execution unit is used for realizing the input and output power control of the battery of the electric automobile in a charging and discharging mode, accurately adjusting the power fed back to a public power grid through Pulse Width Modulation (PWM) control according to a battery discharging maximum output power Pmax command issued by the cooperative control unit in the discharging mode, and ensuring that the power does not exceed a locking upper limit; The safety protection unit is used for guaranteeing the reliability and usability of the system, comprises an overcurrent protection relay, an overvoltage protection module, a temperature sensor and a leakage protection module, wherein when countercurrent, overcurrent, overvoltage or overheat of equipment is detected, a main circuit is immediately cut off, a fault signal is sent to the cooperative control unit, and meanwhile, the user interaction unit alarms; the user interaction unit is used for guaranteeing the usability of the system; all real-time operation data are synchronously uploaded to the cloud platform to realize data centralized monitoring and tracing, once an alarm is triggered, the system can be informed through a background prompt, and meanwhile, 4G and the cloud platform can be linked to push alarm information to operation and maintenance personnel to ensure that abnormal conditions are found and processed in time.
  4. 4. The system for controlling the new energy bi-directional charging pile to realize the discharge anti-reflux and the charging demand management as claimed in claim 3, wherein the multi-dimensional sensing unit comprises a power grid parameter sensing subunit, a vehicle state sensing subunit and a user demand sensing subunit, The power grid parameter sensing subunit is used for collecting parameters of current, voltage and power factor of the public power grid in real time, calculating the total local load consumption power P_load of the current public power grid, and providing basic data for anti-backflow control; The vehicle state sensing subunit is a data acquisition module connected with a battery management system BMS of the new energy automobile through a CAN bus and is used for supporting reading parameters of a battery state of charge (SOC), allowable charge and discharge power (P_veh_max/P_veh_min) and battery temperature, acquiring the real-time state of a vehicle battery and avoiding power regulation failure caused by the limitation of the battery; the user demand perception subunit is used for converting user demands into quantized priority parameters and providing decision basis for charging demand distribution.
  5. 5. The system for controlling new energy bidirectional charging piles to realize discharge backflow prevention and charge demand management according to claim 4, wherein the discharge backflow prevention active control logic is used for predicting a local load minimum power consumption value to be P_load_min in a preset time period through an ARIMA prediction model according to the local load total power consumption P_load of a current public power grid acquired by the power grid parameter sensing subunit and historical load fluctuation data, setting a discharge feedback power upper limit Pmax to be less than the local load minimum power consumption value P_load_min, and adjusting Pmax in real time if P_load_min is detected to be reduced by a preset value in a preset time period.
  6. 6. The system for controlling new energy bidirectional charging piles to realize discharge backflow prevention and charging demand management according to claim 4, wherein the charging demand dynamic optimization logic adopts a target weighted optimization algorithm, an objective function is the degree of power grid load balance and the degree of user demand satisfaction, the power grid state is divided into multiple stages according to the load rate data acquired by the power grid parameter sensing subunit, the power grid load state and the user demand are updated once every preset time, and the charging power of each charging pile is dynamically adjusted according to the power grid load state and the user demand, so that local overload or energy waste is avoided.
  7. 7. The method for controlling the new energy bidirectional charging pile to realize the discharge backflow prevention and the charging demand management is used for solving the problems of easy discharge backflow and low charging demand management efficiency of the existing bidirectional charging pile by controlling the new energy bidirectional charging pile to realize the discharge backflow prevention and the charging demand management system according to any one of claims 1-6, and is characterized by comprising the following steps: Step one, the anti-reflux device performs data acquisition, wherein the data acquisition content comprises voltage U, current I, active power P, reactive power Q and load change rate dP/dt; The method comprises the steps of carrying out power limiting control in a charging mode, dynamically adjusting the charging power of one or more charging piles by monitoring regional power grid load, a user electricity charge threshold and the running state of the charging piles in real time, avoiding that the total charging power exceeds the power grid safe bearing upper limit or the user electricity charge threshold, and finally realizing the dual targets of power grid load peak clipping and charging cost optimization; In the V2G discharging process, the electric automobile battery feeds electricity to the public power grid, and the discharging power is dynamically regulated or a discharging loop is cut off by monitoring the power flow direction and the power grid admitting capacity in real time, so that the feeding power is ensured not to exceed the real-time available capacity of the power grid, the reverse flow of electric energy into the upper power grid is avoided, the reverse flow is generated, and the power grid frequency, the voltage stability and the safety of power distribution equipment are ensured; and on the basis of dynamic change of the load of the power grid, capacity utilization rate of the charging pile and charging and discharging requirements of batteries of the electric vehicle, optimizing capacity distribution through a software algorithm on the premise of not modifying power grid hardware, converting fixed capacity of the charging pile into dynamic adjustable capacity, improving the available capacity of the charging pile in a load valley period, recovering the basic capacity in a load peak period, and finally improving the utilization rate of the charging pile and the power grid capacity configuration flexibility.
  8. 8. The method for controlling the new energy bidirectional charging pile to realize the discharge backflow prevention and the charging demand management as set forth in claim 7, wherein the step two, the specific step of power limiting control in the charging mode includes: Step 2.1, setting hysteresis loops with preset widths and a control target, wherein the control target is to stabilize the total power input by a power grid at a preset proportion of total power limiting so as to reduce frequent switching of power; step 2.2, monitoring regional power grid load, a user electricity charge threshold value and a charging pile running state in real time; Step 2.3, when the total power input by the power grid exceeds the preset total power consumption limiting, the charging power of the charging pile is required to be immediately regulated down to prevent the power grid from overload, wherein the downward regulating triggering condition is that the total power input by the power grid is greater than the total power consumption limiting, and when the total power input by the power grid is smaller than the charging target power, the charging power of the charging pile is required to be immediately regulated up, and the upward regulating triggering condition is that the total power input by the power grid is greater than the preset proportional value of the total power consumption limiting; And 2.4, after the local load power P load and the charging target power are summed by the summer, the charging power P V2G of the bidirectional charging pile at the output end is obtained after gain adjustment with a gain coefficient of k and execution delay Za -1 of control command P cmd are delayed, and the output power P V2G is fed back to the summer after being delayed by feedback delay Zb -1 of a feedback loop, so as to form closed loop control.
  9. 9. The method for controlling the new energy bidirectional charging pile to realize the discharge backflow prevention and the charging demand management as claimed in claim 7, wherein the specific step of controlling the backflow prevention in the discharge mode comprises the following steps: Step 3.1, setting a discharge target power and a control error; When the total power input by the power grid is negative, the electric energy reversely flows into the public power grid to generate reverse flow, and the discharge power needs to be adjusted downwards to inhibit the reverse flow; Step 3.3, after the local load power P load and the discharge target power are summed by a summer, the discharge power P V2G of the bidirectional charging pile at the output end is obtained after gain adjustment with a gain coefficient of-k and execution delay Za -1 of control command P cmd are performed, and after feedback delay Zb -1 of a feedback loop and negative feedback of-1 link are performed on the output power P V2G , a feedback signal P V2G is reversely sent back to a summing point to form closed loop control; And 3.4, when the total input power of the power grid is positive but approaches to the countercurrent threshold, the system performs fine adjustment, namely, the discharge power is slightly reduced to enlarge the safety margin and avoid entering the countercurrent state, when the actual input power of the power grid exceeds the countercurrent threshold, the system enters the countercurrent state, and when the control error becomes negative, the system greatly reduces the discharge power, quickly inhibits countercurrent and returns to the safety state.
  10. 10. The method for controlling the new energy bidirectional charging pile to realize the discharge backflow prevention and the charging demand management as claimed in claim 7, wherein the step four, the specific step of dynamic capacity increasing control, comprises the following steps: Step 4.1, setting hysteresis loops with preset widths, target power and control errors, wherein the target power is a preset proportion of total power consumption limiting, and the control errors are obtained by subtracting the total power input by an actual power grid from the target power; step 4.2, monitoring regional power grid load, a user demand electricity charge threshold value and a charging pile running state in real time, and when the total power input by the power grid is positive and the available capacity is positive, adjusting the charging power upwards so as to fully utilize the power grid resources; Step 4.3, after the negative local load power P load and the charging target power are summed by the summer, the charging power P V2G of the bidirectional charging pile at the output end is obtained after the gain adjustment with the gain coefficient of k and the execution delay Za -1 of the control command P cmd are delayed, and the output power P V2G is fed back to the summer after being delayed by the feedback delay Zb -1 of the feedback loop, so as to form closed loop control; Step 4.4, setting the upper limit charging power to be 0.1P max P thrshld , when the total power input by the power grid is negative, but the absolute value is far smaller than the countercurrent threshold, the discharge power is adjusted upwards so as to improve the discharge efficiency of the bidirectional charging pile; And 4.5, after the negative local load power P load and the upper limit charging power are summed by a summer, the discharge power P V2G of the bidirectional charging pile at the output end is obtained after the gain adjustment with the gain coefficient of-k and the execution delay Za -1 of the control command P cmd are delayed, and after the output power P V2G is delayed by the feedback delay Zb -1 of the feedback loop and the negative feedback of the link-1, the feedback signal P V2G is reversely sent back to the summing point to form closed loop control.

Description

System and method for controlling new energy bidirectional charging pile to realize discharge backflow prevention and charging demand management Technical Field The invention relates to the technical field of new energy charging piles, in particular to a system and a method for controlling a new energy bidirectional charging pile to realize discharge backflow prevention and charging demand management. Background With the large-scale popularization of new energy automobiles and the continuous promotion of smart grid construction, a bidirectional charging pile becomes a core hub device for vehicle-network interaction (V2G) ecology. The energy bidirectional interaction system is characterized by energy bidirectional interaction capability, on one hand, the energy bidirectional interaction system can be used as a charging terminal to draw electric energy from a power grid to supplement energy for a power battery of a new energy automobile, so that daily travel duration requirements of users are met, and on the other hand, the electric energy stored by the power battery of the automobile can be reversely fed back to the power grid to realize bidirectional energy circulation of the automobile-power grid. The core value of the technology is represented by double-end energization, the power grid side can stabilize load fluctuation (such as peak clipping and valley filling) by means of distributed energy storage potential of a large number of new energy automobiles, the running stability of the power grid and the renewable energy consumption efficiency are improved, and the user side can obtain extra income through peak-valley electricity price difference, so that the economy and flexibility of energy utilization are realized. Therefore, the bidirectional charging pile is regarded as a key node for connecting the traffic and energy fields, and is an important support for constructing a source network charge storage integrated energy system. There are two major core pain points in the prior art, and multiple hazards are derived: One is the problem of reverse flow interference during discharge. In the V2G discharging mode, when the bidirectional charging pile feeds back electric energy to the power grid, the bidirectional charging pile needs to be accurately matched with real-time load consumption of a local power grid (such as a distribution network of a residential district and a district). However, the prior art lacks dynamic load matching and quick regulation capability, when the feedback power exceeds the local instant load consumption, the redundant electric energy forms reverse flow and is directly injected into an upper power grid, and the damage has multidimensional destructiveness that firstly, the reverse flow electric energy can cause the deviation of the power grid frequency from the rated value (50 Hz of power frequency in China), voltage fluctuation or distortion and exceed the allowable deviation range of power grid dispatching, secondly, the safety of power grid equipment is damaged, the impact current caused by the reverse flow can exceed the rated bearing capacity of equipment such as a transformer, a line switch and the like, the long-term operation can easily cause insulation aging and overheat damage and even induce short-circuit faults, thirdly, the metering and dispatching order is destroyed, the reverse flow can cause the data distortion of a power grid metering system, the accuracy of power transaction settlement is influenced, and meanwhile, the load prediction and instruction execution of a dispatching center are interfered, and the ordered running state of the power grid is broken. And secondly, the problems of load response lag and resource allocation imbalance in the charging process are solved. Under the traditional charging mode, the charging management mechanism of the existing bidirectional charging pile has obvious rigidity defects, dynamic synergy with power grid load and user demands cannot be formed, namely, the power grid load real-time response capability is lacked, a large number of vehicles are intensively charged in a power consumption peak period (such as a power consumption concentration period of people in evening), the load of a regional distribution network is suddenly increased, the line bearing limit is easily broken through, power supply faults such as voltage drop and equipment tripping are caused, the power grid has a large number of idle power generation capacity in a power consumption valley period (such as early morning), the charging pile is still charged in a fixed mode, the energy utilization efficiency is low, the power generation side capacity waste is caused, the resource allocation is lack of differential adaptation, the charging resource adopts a one-cut mode, and the user differential demands (such as the fast charging demand of emergency travel, the slow charging demand of daily commute, the time window demand of reserved charging and the like) are not