A multi-source energy coordination control method of an energy router

Abstract

This invention provides a multi-source energy coordination control method for an energy router, belonging to the field of integrated energy system control technology. Based on a DC bus architecture, all control logic is executed locally on the energy router. By collecting real-time data on the operating status of each device, and formulating differentiated energy coordination strategies based on DC bus voltage range division, combined with concurrent power supply control of multiple charging terminals, energy prediction and pre-regulation, and automatic switching between grid-connected and islanded modes, the method achieves orderly coordination and bidirectional flow of multi-source energy. This method significantly improves system response speed and DC bus stability, increases the clean energy absorption rate, and is applicable to various application scenarios such as DC microgrids, integrated photovoltaic-storage-charging power stations, and flexible DC power distribution in distribution areas.

Description

Technical Field

[0001] This invention relates to the field of integrated energy system control technology, specifically to a multi-source energy coordination control method for an energy router. Background Technology

[0002] With the rapid development of distributed generation technology, energy storage technology, and electric vehicle charging technology, integrated energy systems have become an important direction for the future development of power systems. Energy routers, as key equipment in integrated energy systems, can realize the conversion, transmission, and distribution of various energy forms, serving as a hub connecting distributed power sources, energy storage units, the external power grid, and various loads.

[0003] Existing energy router multi-source energy coordination and control methods mainly rely on upper-level centralized dispatch systems, which have several shortcomings. Different types of energy have significantly different response characteristics. Photovoltaic and wind power generation are intermittent and fluctuating, energy storage units have fast charging and discharging response speeds, while the external power grid's regulation response speed is slow. Centralized dispatch struggles to effectively coordinate energy sources with different response characteristics. Centralized dispatch involves multiple levels, resulting in significant communication delays and a slow overall system response speed, making it difficult to handle sudden situations such as limited transformer capacity and concurrent power supply from multiple charging terminals. When the upper-level dispatch system fails or communication is interrupted, the energy router will not function properly, leading to low system reliability. Furthermore, existing methods do not fully consider the capacity limitations of transformers and lines in the distribution area, making it prone to overload problems when multiple charging terminals connect simultaneously, affecting the safe and stable operation of the system.

[0004] To address this, a multi-source energy coordination control method for energy routers is proposed. Summary of the Invention

[0005] The present invention aims to solve the problems mentioned in the background art by providing a multi-source energy coordination control method for energy routers.

[0006] The specific technical solution is as follows:

[0007] A multi-source energy coordination control method for an energy router is provided. The energy router is based on a DC bus architecture and connects distributed power sources, energy storage units, the external power grid, and various loads. It does not rely on a centralized upper-level dispatch system; all control logic is executed locally on the energy router. The method includes the following steps:

[0008] S1: Real-time acquisition of operating status parameters of the distributed power source, energy storage unit, external power grid and various loads, including power, voltage, current and available capacity of energy storage unit;

[0009] S2: Determine the preset voltage range to which the collected DC bus voltage value belongs;

[0010] S3: Identify the energy requirements of various loads and prioritize them.

[0011] S4: Based on the DC bus voltage range and load priority, and in accordance with the preset energy coordination control strategy, the power conversion module adjusts the output power of each energy channel and the load input status to achieve bidirectional energy flow and balance.

[0012] S5: Real-time monitoring of DC bus voltage and the operating status of each energy channel. When an abnormal condition is detected, a graded protection and regulation mechanism corresponding to the level of the abnormal condition is activated.

[0013] As a preferred embodiment of the present invention, the preset voltage range mentioned in step S2 includes:

[0014] First normal range: voltage greater than or equal to 0.95 times the rated voltage and less than or equal to 1.05 times the rated voltage;

[0015] Second undervoltage range: voltage greater than or equal to 0.85 times and less than 0.95 times the rated voltage;

[0016] Third overvoltage range: voltage greater than 1.05 times and less than or equal to 1.15 times;

[0017] Fourth emergency zone: voltage less than 0.85 times the rated voltage or greater than 1.15 times the rated voltage.

[0018] As a preferred embodiment of the present invention, the energy coordination control strategy described in step S4 is specifically as follows:

[0019] When the DC bus voltage is in the first normal range, the output power of the distributed power source is used first to meet the load demand. The remaining power is used to charge the energy storage unit when the SOC (remaining power) of the energy storage unit is less than the preset charging upper limit threshold. The insufficient part is supplemented by the external power grid.

[0020] When the DC bus voltage is in the second undervoltage range, if the SOC of the energy storage unit is greater than the preset discharge lower limit threshold, the discharge power of the energy storage unit is increased first, then the input power of the external power grid is increased, while the power supply of non-critical loads is reduced; if the SOC of the energy storage unit is less than or equal to the preset discharge lower limit threshold, the input power of the external power grid is increased directly and the power supply of non-critical loads is reduced.

[0021] When the DC bus voltage is in the third overvoltage range, if the SOC of the energy storage unit is less than the preset charging upper limit threshold, the charging power of the energy storage unit is increased first, then the input power of the external power grid is reduced, and the output power of the distributed power source is limited. If the SOC of the energy storage unit is greater than or equal to the preset charging upper limit threshold, the input power of the external power grid is reduced directly and the output power of the distributed power source is limited.

[0022] When the DC bus voltage is in the fourth emergency range, if the voltage is less than 0.85 times the rated voltage, all non-critical loads will be immediately disconnected, and the maximum power discharge function of the energy storage unit and the maximum power input function of the external power grid will be activated simultaneously. If the voltage is greater than 1.15 times the rated voltage, all non-critical loads will be immediately disconnected, and the maximum power charging function of the energy storage unit will be activated simultaneously, and the external power grid connection will be disconnected. The output power of the distributed power source will be limited to the minimum value. If the voltage continues to rise within a preset time, the distributed power source will be gradually disconnected. If the voltage still cannot be restored to the normal range, an emergency alarm signal will be issued and the system will be shut down for protection. When the voltage is restored to the first normal range and the stable time reaches the preset recovery confirmation time, the disconnected non-critical loads and the external power grid connection will be automatically restored.

[0023] As a preferred embodiment of the present invention, the load priority classification in step S3 is specifically as follows:

[0024] The loads are divided into three levels: Level 1 critical loads, Level 2 critical loads, and Level 3 non-critical loads. Level 1 critical loads include safety and critical production equipment, Level 2 critical loads include general production equipment and essential living equipment, and Level 3 non-critical loads include comfort equipment and interruptible charging equipment. The charging terminals are mapped to different load levels according to their charging demand priority: emergency vehicle charging is classified as Level 1 critical load, scheduled charging vehicles are classified as Level 2 critical load, and regular charging vehicles are classified as Level 3 non-critical load.

[0025] As a preferred embodiment of the present invention, the distributed power source mentioned in step S1 includes at least one of a photovoltaic power generation system, a wind power generation system, and a fuel cell power generation system, and the energy storage unit includes at least one of a lithium-ion battery energy storage system, a lead-acid battery energy storage system, and a supercapacitor energy storage system.

[0026] As a preferred embodiment of the present invention, when adjusting the output power of each energy channel in step S4, a power adjustment algorithm based on fuzzy PID control is adopted. By adjusting the proportional coefficient, integral coefficient, and derivative coefficient in real time, the output power of each energy channel is precisely controlled, and the adjustment response time is controlled within the range of 10ms to 100ms. The fuzzy rule table of the fuzzy PID control is set according to the error E and the error change rate EC. For example, when E is positive and EC is positive, the proportional coefficient is increased and the integral coefficient is decreased. The specific rules can be pre-tuned by those skilled in the art based on the dynamic characteristics of the system.

[0027] As a preferred embodiment of the present invention, it further includes a multi-charging terminal concurrent power supply control step executed between steps S3 and S4, specifically:

[0028] When the DC bus voltage is in the first normal range and multiple charging terminals are detected to be connected simultaneously, the charging power is dynamically allocated within the maximum allowable charging power range of each charging terminal according to the charging demand priority and remaining charging time of each charging terminal. This ensures that the total output power of the transformer substation does not exceed the preset maximum capacity threshold. The maximum capacity threshold is determined based on the transformer substation capacity and line current carrying capacity, and its value ranges from 0.7 to 0.9 times the rated capacity of the transformer substation. When the DC bus voltage deviates from the first normal range, the energy coordination control strategy corresponding to the voltage range is executed first. When the total demand of high-priority charging terminals exceeds the maximum capacity threshold, the charging power of low-priority charging terminals is reduced proportionally.

[0029] As a preferred embodiment of the present invention, the charging demand priority is determined according to the type of charging terminal, the remaining power, and the scheduled charging time. Emergency vehicles have the highest charging priority, followed by vehicles scheduled for charging, and then vehicles that can be charged normally. For the remaining power, when the remaining power is lower than a preset emergency threshold (e.g., 15%), the priority of the charging terminal is increased by one level. Charging terminals with the same priority are allocated power according to the remaining charging time from shortest to longest.

[0030] As a preferred embodiment of the present invention, it further includes an energy prediction and pre-adjustment step executed in parallel with step S1, specifically:

[0031] Based on historical operating data and meteorological data, machine learning algorithms are used to predict the output power of distributed power sources and the energy demand of loads within the next 15 to 60 minutes. The energy coordination control strategy parameters in step S4 are adjusted according to the prediction results to pre-adjust the charging and discharging state of energy storage units and the input power of the external power grid, achieving early energy balance in the system. The machine learning algorithm can employ random forest, support vector regression, or long short-term memory networks. Input features include historical power sequences, weather forecasts (irradiance, wind speed, temperature), and time features (hours, days of the week, holidays). The model is updated offline monthly or incrementally weekly. When the prediction results conflict with the real-time DC bus voltage judgment, the real-time voltage range judgment takes precedence.

[0032] As a preferred embodiment of the present invention, the abnormal operating conditions described in step S5 include three levels: general abnormality, severe abnormality, and emergency abnormality.

[0033] Common anomalies include overcurrent warnings and minor voltage fluctuations. The solution is to adjust the output power of the corresponding energy channel and record the anomaly information.

[0034] Serious anomalies include overcurrent, overvoltage, and undervoltage. The handling method is to disconnect the faulty circuit and activate the backup power channel.

[0035] Emergency anomalies include short circuits and equipment failures. The handling method is to immediately shut down the equipment for protection and issue an emergency alarm signal.

[0036] As a preferred embodiment of the present invention, it further includes an operation mode switching step:

[0037] When the external power grid is detected to be normal, the system operates in grid-connected mode and executes the energy coordination control strategy described above.

[0038] When an external power grid fault is detected, the system automatically switches to islanded operation mode, disconnects from the external power grid, and relies solely on distributed power sources and energy storage units for power supply. The energy storage units serve as the main power source to maintain the stability of the DC bus voltage, and non-critical loads are disconnected sequentially from level three to level two according to load priority. When the external power grid returns to normal and the voltage stabilization time reaches the preset grid connection recovery delay, the system automatically switches back to grid connection mode, restores the external power grid connection, and gradually reconnects the disconnected loads.

[0039] The present invention has the following beneficial effects:

[0040] This method employs a locally independent control architecture, eliminating reliance on a centralized upper-level scheduling system and avoiding the impact of upper-level system failures or communication delays on the control process, thus significantly improving system response speed and operational reliability. Through a complete process of status acquisition, interval judgment, load grading, power regulation, and anomaly protection, it achieves orderly coordination of multi-source energy, effectively ensuring the stable operation of the DC bus.

[0041] The energy coordination control strategy based on DC bus voltage range division can fully leverage the response characteristics of different energy sources, achieving effective coordination among them. Prioritizing distributed power source output improves the absorption rate of clean energy and reduces dependence on the external power grid. Considering the charging and discharging boundary conditions of energy storage units prevents overcharging or over-discharging, extending the lifespan of energy storage devices. The differentiated handling design for emergency zones quickly curbs fault development, prevents the fault range from expanding, and ensures the safety of system equipment and loads. Furthermore, automatic reconnection logic after voltage recovery ensures the system can self-heal after the anomaly is eliminated, improving the level of automation.

[0042] A specially designed multi-charging terminal concurrent power supply control procedure enables reasonable allocation of charging power even when the capacity of the distribution area is limited, avoiding overload of the distribution area transformer and lines. The principle of prioritizing voltage stability control ensures the overall safe operation of the system. A scientifically sound and reasonable charging demand priority determination rule can meet the emergency charging needs of special vehicles while improving the turnover efficiency of charging facilities and enhancing the overall quality of charging services. By clearly mapping the priority of charging terminals to load levels, accidental disconnection of charging for emergency vehicles in emergency situations is avoided.

[0043] By introducing energy prediction and pre-regulation steps, passive real-time regulation is transformed into active pre-regulation, enabling proactive energy balancing of the system and preventing large voltage fluctuations caused by sudden supply-demand imbalances. Pre-regulation smooths the system's operating curve, reduces the frequency and amplitude of real-time regulation, lowers the workload of the power conversion module, and further improves the stability and economy of system operation.

[0044] Automatic switching between grid-connected and islanded operating modes has been achieved, enhancing the system's adaptability to external power grid failures. When the external power grid is normal, the system fully utilizes its regulation capabilities for economical operation. In the event of an external power grid failure, it automatically switches to islanded mode to ensure continuous power supply to critical loads, significantly improving the system's power reliability. A grid-connected recovery delay and a gradual load connection mechanism have been added to prevent frequent switching from impacting the system.

[0045] The tiered abnormal operating condition handling mechanism can take different levels of response measures based on the severity of the abnormality. For minor abnormalities, only power adjustments and information recording are performed, without affecting the normal operation of the system. For severe abnormalities, the faulty circuit is promptly disconnected and the backup channel is activated to prevent the fault from spreading and affecting other normal equipment. For emergency abnormalities, immediate shutdown protection is implemented to maximize the safety of equipment and personnel. Attached Figure Description

[0046] Figure 1 A flowchart of a multi-source energy coordination control method for an energy router provided in an embodiment of the present invention. Detailed Implementation

[0047] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0048] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this application. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0049] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0050] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating a connection between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] Example: Refer to Figure 1 The multi-source energy coordination control method for energy routers provided in this embodiment is applied to energy routers. The energy routers are based on a DC bus architecture and connect distributed power sources, energy storage units, external power grids, and various loads. They do not rely on an upper-level centralized dispatching system, and all control logic is executed locally on the energy routers. The method includes the following steps:

[0052] S1: Real-time acquisition of operating status parameters of distributed power sources, energy storage units, external power grid and various loads. Operating status parameters include power, voltage, current and available capacity of energy storage units.

[0053] S2: Determine the preset voltage range to which the collected DC bus voltage value belongs;

[0054] S3: Identify the energy requirements of various loads and prioritize them.

[0055] S4: Based on the DC bus voltage range and load priority, and in accordance with the preset energy coordination control strategy, the power conversion module adjusts the output power of each energy channel and the load input status to achieve bidirectional energy flow and balance.

[0056] S5: Real-time monitoring of DC bus voltage and the operating status of each energy channel. When an abnormal condition is detected, a graded protection and regulation mechanism corresponding to the level of the abnormal condition is activated.

[0057] This solution employs a locally independent control architecture, eliminating reliance on upper-level scheduling systems and preventing upper-level system failures or communication delays from affecting the control process, thus significantly improving system response speed. Through a complete process of status acquisition, interval judgment, load grading, power regulation, and anomaly protection, it achieves orderly coordination of multi-source energy, ensuring stable operation of the DC bus. The bidirectional energy flow design flexibly adapts to different supply and demand states, absorbing excess energy and supplementing energy gaps, enhancing the system's operational flexibility and reliability.

[0058] Specifically, in this embodiment, the preset voltage range in step S2 includes:

[0059] First normal range: voltage greater than or equal to 0.95 times the rated voltage and less than or equal to 1.05 times the rated voltage;

[0060] Second undervoltage range: voltage greater than or equal to 0.85 times and less than 0.95 times the rated voltage;

[0061] Third overvoltage range: voltage greater than or equal to 1.05 times the rated voltage and less than or equal to 1.15 times the rated voltage;

[0062] Fourth emergency zone: voltage less than 0.85 times the rated voltage or greater than 1.15 times the rated voltage.

[0063] This scheme divides the DC bus voltage into multiple clearly defined operating ranges, providing a clear triggering basis for energy coordination control. Different ranges correspond to different system energy states, accurately identifying whether the system is in normal operation, energy deficiency, energy excess, or an emergency fault state, avoiding erroneous control strategy triggering due to ambiguous voltage judgments. The tiered voltage range design enables refined control of the system state, taking different levels of adjustment measures based on the degree of voltage deviation, ensuring system stability while minimizing unnecessary adjustments.

[0064] Specifically, in this embodiment, the energy coordination control strategy in step S4 is as follows:

[0065] When the DC bus voltage is in the first normal range, the output power of the distributed power source is used first to meet the load demand. The remaining power is used to charge the energy storage unit when the SOC of the energy storage unit is less than the preset charging upper limit threshold. The insufficient part is supplemented by the external power grid.

[0066] When the DC bus voltage is in the second undervoltage range, if the SOC of the energy storage unit is greater than the preset discharge lower limit threshold, the discharge power of the energy storage unit is increased first, then the input power of the external power grid is increased, while the power supply of non-critical loads is reduced; if the SOC of the energy storage unit is less than or equal to the preset discharge lower limit threshold, the input power of the external power grid is increased directly and the power supply of non-critical loads is reduced.

[0067] When the DC bus voltage is in the third overvoltage range, if the SOC of the energy storage unit is less than the preset charging upper limit threshold, the charging power of the energy storage unit is increased first, then the input power of the external power grid is reduced, and the output power of the distributed power source is limited. If the SOC of the energy storage unit is greater than or equal to the preset charging upper limit threshold, the input power of the external power grid is reduced directly and the output power of the distributed power source is limited.

[0068] When the DC bus voltage is in the fourth emergency range, if the voltage is less than 0.85 times the rated voltage, all non-critical loads will be immediately disconnected, and the maximum power discharge function of the energy storage unit and the maximum power input function of the external power grid will be activated simultaneously. If the voltage is greater than 1.15 times the rated voltage, all non-critical loads will be immediately disconnected, and the maximum power charging function of the energy storage unit will be activated simultaneously, and the external power grid connection will be disconnected. The output power of the distributed power source will be limited to the minimum value. If the voltage continues to rise within a preset time, the distributed power source will be gradually disconnected. If the voltage still cannot be restored to the normal range, an emergency alarm signal will be issued and the system will be shut down for protection. When the voltage is restored to the first normal range and the stable time reaches the preset recovery confirmation time (e.g., 1 second), the disconnected non-critical loads and the external power grid connection will be automatically restored.

[0069] This scheme employs differentiated energy coordination strategies for different voltage ranges, fully leveraging the response characteristics of various energy sources. Prioritizing distributed power generation improves the absorption rate of clean energy and reduces dependence on the external power grid. Considering the charge and discharge boundary conditions of energy storage units prevents overcharging or over-discharging, extending the lifespan of energy storage devices. In emergency zones, differentiated handling of undervoltage and overvoltage conditions allows for rapid containment of faults, preventing their spread and ensuring the safety of system equipment and loads. A layered, progressive adjustment approach achieves rapid energy balance with minimal impact on normal system operation. Added recovery logic enables the system to self-heal, preventing prolonged periods in abnormal states after protection.

[0070] Specifically, in this embodiment, the load priority classification in step S3 is as follows:

[0071] The loads are divided into three levels: Level 1 critical loads, Level 2 critical loads, and Level 3 non-critical loads. Level 1 critical loads include safety and critical production equipment, Level 2 critical loads include general production equipment and essential living equipment, and Level 3 non-critical loads include comfort equipment and interruptible charging equipment. The charging terminals are mapped to different load levels according to their charging demand priority: emergency vehicle charging is classified as Level 1 critical load, scheduled charging vehicles are classified as Level 2 critical load, and regular charging vehicles are classified as Level 3 non-critical load.

[0072] This solution scientifically prioritizes loads, clearly defining the power supply guarantee levels for different loads. In the event of insufficient system energy or a fault, non-critical loads can be adjusted or cut off sequentially according to priority, ensuring continuous power supply to critical loads and preventing downtime of important equipment or safety incidents due to system fluctuations. This tiered load management approach minimizes the impact of energy shortages on users while ensuring basic system operation, improving system power reliability and service quality. Clearly mapping charging terminal priorities to load levels ensures that emergency vehicle charging is not mistakenly cut off in emergency situations.

[0073] Specifically, in this embodiment, the distributed power source in step S1 includes at least one of a photovoltaic power generation system, a wind power generation system, and a fuel cell power generation system, and the energy storage unit includes at least one of a lithium-ion battery energy storage system, a lead-acid battery energy storage system, and a supercapacitor energy storage system.

[0074] This scheme clarifies the types of distributed power sources and energy storage units to which the method is applicable, covering commonly used energy supply and storage devices in current integrated energy systems. This design allows the method to be directly applied to various energy router systems with different configurations, without requiring significant modifications for specific types of power sources or energy storage devices. This greatly improves the method's versatility and applicability, and reduces the cost of system deployment and modification.

[0075] Specifically, in this embodiment, when adjusting the output power of each energy channel in step S4, a power adjustment algorithm based on fuzzy PID control is adopted. By adjusting the proportional coefficient, integral coefficient, and derivative coefficient in real time, precise control of the output power of each energy channel is achieved, and the adjustment response time is controlled within the range of 10ms to 100ms. The fuzzy rule representation of the fuzzy PID control is as follows: taking the voltage deviation E and the deviation change rate EC as inputs, the output is the proportional coefficient increment ΔKp and the integral coefficient increment ΔKi. For example, when E is positive and EC is positive, ΔKp is positive and ΔKi is negative; when E is negative and EC is negative, ΔKp is positive and ΔKi is negative. The specific rule table can be pre-tuned by those skilled in the art based on the dynamic characteristics of the system.

[0076] This scheme employs an adaptive power regulation algorithm, effectively addressing the nonlinearity and uncertainty of integrated energy systems. The design of real-time control parameter adjustment dynamically optimizes the regulation effect based on changes in system operating status, improving the accuracy and stability of power regulation and reducing voltage and power fluctuations during the regulation process. The rapid regulation response can promptly offset the impact of distributed power source output fluctuations and load changes, maintaining the stability of the DC bus voltage and enhancing the system's dynamic performance.

[0077] Specifically, in this embodiment, the multi-charging terminal concurrent power supply control step, executed between steps S3 and S4, is further described as follows:

[0078] When the DC bus voltage is in the first normal range and multiple charging terminals are detected to be connected simultaneously, the charging power is dynamically allocated within the maximum allowable charging power range of each charging terminal according to the charging demand priority and remaining charging time of each charging terminal. This ensures that the total output power of the transformer substation does not exceed the preset maximum capacity threshold. The maximum capacity threshold is determined based on the transformer substation capacity and line current carrying capacity, and its value ranges from 0.7 to 0.9 times the rated capacity of the transformer substation. When the DC bus voltage deviates from the first normal range, the energy coordination control strategy corresponding to the voltage range is executed first. When the total demand of high-priority charging terminals exceeds the maximum capacity threshold, the charging power of low-priority charging terminals is reduced proportionally.

[0079] This solution features a power allocation mechanism specifically designed for scenarios with multiple charging terminals accessing the system concurrently. It enables reasonable allocation of charging power even when transformer capacity is limited, preventing overload of transformers and lines. By prioritizing voltage stability control over charging power allocation, the overall system operation is ensured to guarantee safety and prevent a large influx of charging terminals from affecting the stable operation of the DC bus. The design prioritizes high-priority needs to meet the emergency charging requirements of special vehicles, while proportionally reducing the power of low-priority charging terminals to ensure fairness in charging services.

[0080] When the charging power of low-priority charging terminals is reduced proportionally, the power allocation for each charging terminal is determined by the following equation:

[0081] ;

[0082] in, For the first Power allocated to each charging terminal, in kW; Based on the basic priority weight, emergency vehicles are assigned 3, reserved vehicles are assigned 2, and regular vehicles are assigned 1, with no dimension. The steepness coefficient is a preset value, ranging from 1 to 5, dimensionless, with a typical value of 2.0; The preset emergency power threshold ranges from 10% to 20%, is dimensionless, and typically has a value of 0.15. For the first The current remaining power of each charging terminal is expressed as a decimal, such as 0.15 corresponding to 15%, and is dimensionless; For the first Estimated remaining charging time for each charging terminal, in minutes; To prevent the time from reaching zero, a value of 0.1 to 1 minute is used, with a typical value of 0.5 minutes. This represents the total number of currently connected charging terminals; The maximum total power currently allowed for charging, in kW, is obtained by subtracting the current power of other loads from the maximum capacity threshold of the substation area; and the allocation result satisfies... , For the first The maximum allowable charging power of a single charging terminal, in kW, with a typical value of 60kW.

[0083] Example scenario: The capacity threshold for the charging area is 252kW, and the current non-charging load is 52kW. There are three charging terminals connected:

[0084] Terminal 1: Emergency vehicle =10% (0.1), 30 minutes remaining. ;

[0085] Terminal 2: Reserve a vehicle =50% (0.5), 20 minutes remaining. ;

[0086] Terminal 3: Ordinary vehicles, =80% (0.8), 10 minutes remaining. ;

[0087] Pick , , .

[0088] Calculation process:

[0089] Terminal 1: ; ; ;

[0090] Terminal 2: ; ; ;

[0091] Terminal 3: ; ; ;

[0092] Total weight: .

[0093] Initial power allocation: (Limited to 60kW, take 60kW); (Limited to 60kW, take 60kW); (Not exceeding the limit, maintain 39kW);

[0094] The final allocation results are: 60kW, 60kW, and 39kW, with a total power of 159kW < 200kW, which meets the capacity constraints of the transformer area. The results reflect the design objectives of prioritizing emergency vehicles, low battery levels, and short remaining time.

[0095] Technical benefits: The Sigmoid function achieves a non-linear mapping of power weights. When the State of Charge (SOC) is below a threshold, the weight increases sharply, ensuring that vehicles about to run out of power receive more power and avoiding breakdowns. Terminals with less remaining time receive higher weights, allowing them to quickly complete charging and release their charging slots, reducing user waiting time. Compared to hard thresholds (such as queue jumping if SOC < 15%), the Sigmoid function achieves a soft transition, avoiding bus voltage fluctuations caused by sudden power changes. Normalized allocation automatically ensures that the total power does not exceed the area capacity, requiring no manual intervention. and It can be customized according to different scenarios (residential areas, highway service areas), making it highly adaptable.

[0096] Working principle and process:

[0097] 1. Real-time data acquisition: Acquire data from each charging terminal. , and vehicle basic type (determined) ).

[0098] 2. Calculate the total available power: ,in This represents the maximum capacity threshold for the transformer area. This refers to the power of the non-charging load.

[0099] 3. Calculate the overall weight: based on the equation Calculate the overall weight for each terminal.

[0100] 4. Normalized allocation: Allocation based on weight ratio , obtain the initial .

[0101] 5. Amplitude limiting: If Then cut off to .

[0102] 6. Execution instructions: Adjust the charging power of each charging terminal through the DC / DC converter.

[0103] 7. Dynamic update: Recalculates every fixed period (e.g., 1 second) to adapt to dynamic changes in SOC and remaining time.

[0104] The entire process can be embedded in the concurrent power supply control steps of multiple charging terminals. It is activated only when the DC bus voltage is in the first normal range and multiple charging terminals are connected. It is mutually exclusive with the voltage range control, that is, it is paused when the voltage deviates, so as to prioritize the stability of the bus.

[0105] Specifically, in this embodiment, the charging demand priority is determined based on the type of charging terminal, the remaining power, and the scheduled charging time. Emergency vehicles have the highest charging priority, followed by vehicles scheduled for charging, and then vehicles that can be charged normally. For the remaining power, when the remaining power is lower than a preset emergency threshold (e.g., 15%), the priority of the charging terminal is increased by one level. Charging terminals with the same priority are allocated power according to the remaining charging time from shortest to longest.

[0106] This solution establishes a scientifically sound and reasonable priority determination rule for charging needs, comprehensively considering vehicle type, remaining battery power, and reservation status to accurately identify the urgency of different charging demands. Allocating power based on remaining charging time within the same priority level improves the turnover efficiency of charging facilities, reduces average user waiting time, and enhances the overall charging service experience. Clear priority rules avoid confusion and disputes during power allocation, ensuring stable charging order. An emergency boost mechanism for remaining battery power further guarantees the charging needs of vehicles with low battery levels.

[0107] Specifically, in this embodiment, an energy prediction and pre-adjustment step, executed in parallel with step S1, is also included:

[0108] Based on historical operational and meteorological data, a machine learning algorithm is used to predict the output power of the distributed power source and the energy demand of the load within the next 15 to 60 minutes. The energy coordination control strategy parameters in step S4 are adjusted according to the prediction results to pre-adjust the charging and discharging state of the energy storage unit and the input power of the external power grid, achieving early energy balance in the system. The machine learning algorithm uses a random forest (100 trees, maximum depth 10), and the input features include: historical power sequence of the past hour (5-minute step), weather forecast (irradiance, wind speed, temperature), and time features (hour, day of the week, whether it is a holiday). The model is updated offline monthly. When the prediction result conflicts with the real-time DC bus voltage judgment, the real-time voltage range judgment takes precedence.

[0109] This solution transforms passive real-time regulation into proactive pre-regulation by introducing an energy prediction mechanism. By anticipating changes in distributed power supply output and load demand, it can adjust the system's energy state in advance, avoiding significant voltage fluctuations caused by sudden supply-demand imbalances. The pre-regulation process smooths the system's operating curve, reduces the frequency and magnitude of real-time adjustments, lowers the workload on the power conversion module, extends equipment lifespan, and further improves system stability and economy.

[0110] Specifically, in this embodiment, the abnormal operating conditions in step S5 include three levels: general abnormality, severe abnormality, and emergency abnormality.

[0111] Common anomalies include overcurrent warnings and minor voltage fluctuations. The solution is to adjust the output power of the corresponding energy channel and record the anomaly information.

[0112] Serious anomalies include overcurrent, overvoltage, and undervoltage. The handling method is to disconnect the faulty circuit and activate the backup power channel.

[0113] Emergency anomalies include short circuits and equipment failures. The handling method is to immediately shut down the equipment for protection and issue an emergency alarm signal.

[0114] This solution establishes a tiered abnormal operating condition handling mechanism, taking different levels of response measures based on the severity of the anomaly. For minor anomalies, only power adjustments and information recording are performed, eliminating potential hazards without affecting normal system operation. For severe anomalies, faulty circuits are promptly disconnected and backup channels are activated, preventing the fault from spreading and affecting other normal equipment. For emergency anomalies, immediate shutdown protection is implemented, maximizing the safety of equipment and personnel. This tiered handling approach ensures system safety while minimizing the impact of abnormal operating conditions on normal power supply.

[0115] Specifically, in this embodiment, a running mode switching step is also included:

[0116] When the external power grid is detected to be normal, the system operates in grid-connected mode and executes the energy coordination control strategy described above.

[0117] When an external power grid fault is detected, the system automatically switches to islanded operation mode, disconnects from the external power grid, and relies solely on distributed power sources and energy storage units for power supply. The energy storage units serve as the main power source to maintain the stability of the DC bus voltage, and non-critical loads are disconnected sequentially from level three to level two according to load priority. When the external power grid returns to normal and the voltage stabilization time reaches the preset grid connection recovery delay (e.g., 5 seconds), the system automatically switches back to grid connection mode, restores the external power grid connection, and gradually reconnects the disconnected loads.

[0118] This scheme enables automatic switching between grid-connected and islanded operating modes, enhancing the system's adaptability to external grid faults. When the external grid is normal, it fully utilizes the grid's regulation capabilities to achieve economical system operation. During external grid faults, it automatically switches to islanded mode, preventing grid failures from impacting the local system. Simultaneously, energy storage units serve as the main power source to maintain voltage stability and ensure continuous power supply to critical loads. By gradually cutting off non-critical loads according to load priority, the system's power supply time in islanded mode is maximized, improving power supply reliability. Increased grid connection recovery delay and gradual load integration prevent frequent switching caused by grid fluctuations.

[0119] Working Principle: This method operates based on the correlation between DC bus voltage and system energy supply and demand balance. DC bus voltage directly reflects the system's energy supply and demand balance; when the system's energy supply exceeds demand, the DC bus voltage increases; when the system's energy supply is less than demand, the DC bus voltage decreases. By dividing the DC bus voltage into different operating ranges, the system's energy state can be accurately determined, allowing for corresponding energy regulation measures to be taken.

[0120] During normal operation, the system's energy supply and demand are basically balanced. At this time, the output power of distributed power sources is prioritized to meet load demands, maximizing the absorption of clean energy. The remaining energy is used to charge energy storage units, storing excess clean energy for later use. When the output of distributed power sources is insufficient, the external power grid supplements the energy gap to ensure stable system operation.

[0121] When the DC bus voltage enters the undervoltage range, it indicates insufficient system energy supply. Since the energy storage unit's response speed is much faster than the external grid, prioritizing increasing the discharge power of the energy storage unit can quickly fill the system energy gap and maintain DC bus voltage stability. Only when the energy storage unit's state of charge falls below the discharge threshold and can no longer discharge should the input power from the external grid be increased. Simultaneously, reducing the power supply to non-critical loads further reduces system energy demand and alleviates the energy supply-demand imbalance.

[0122] When the DC bus voltage enters the overvoltage range, it indicates that the system has excess energy supply. Prioritizing the increase of the charging power of the energy storage units can quickly absorb the excess energy and prevent the DC bus voltage from becoming too high. Only when the state of charge of the energy storage units exceeds the upper charging threshold and charging can continue is the input power from the external grid reduced and the output power of distributed generation limited. This regulation method maximizes the buffering capacity of the energy storage units and reduces the abandonment of distributed generation.

[0123] When the DC bus voltage enters the emergency range, it indicates a severe supply-demand imbalance in the system. At this point, all non-critical loads should be immediately disconnected to minimize system energy demand or excess. Differentiated handling measures for undervoltage and overvoltage emergency conditions can quickly curb fault development and prevent the fault from escalating. If the voltage still cannot return to normal after taking the above measures, shutdown protection should be implemented to prevent equipment damage. Once the voltage returns to the normal range and stabilizes for a certain period, the system automatically restores the disconnected loads and external power grid connection, achieving self-healing.

[0124] Concurrent power supply control for multiple charging terminals allocates power based on substation capacity limitations and charging demand priorities. It prioritizes voltage stability control over charging power allocation to ensure overall system operational safety. High-priority charging demands are met first, while fairness in charging service is ensured by proportionally reducing the power of low-priority charging. Allocating power according to remaining charging time within the same priority level improves the turnaround efficiency of charging facilities.

[0125] Energy forecasting and pre-regulation, based on historical operating data and meteorological data, predicts the output power of distributed power sources and the energy demand of loads in the near future. By adjusting the charging and discharging status of energy storage units and the input power of the external power grid in advance based on the forecast results, passive real-time regulation is transformed into proactive pre-regulation. This allows for early balance of system energy and avoids large voltage fluctuations caused by sudden supply-demand imbalances.

[0126] The operating mode switching capability enables automatic conversion between grid-connected and islanded operating modes. When the external power grid is normal, the system operates in grid-connected mode, fully utilizing the external grid's regulation capabilities for economical operation. When an external power grid fault is detected, the system automatically switches to islanded operation mode, disconnecting from the external power grid to prevent the fault from affecting the local system. In this mode, the energy storage unit serves as the main power source to maintain DC bus voltage stability, and non-critical loads are gradually disconnected according to load priority to ensure continuous power supply to critical loads. Once the external power grid recovers and the voltage stabilizes, the system automatically reconnects to the grid and gradually integrates loads.

[0127] Usage: This method is divided into three stages: deployment and configuration, system operation, and maintenance and adjustment.

[0128] During the deployment and configuration phase, various system operating parameters are set based on the actual equipment configuration and operational requirements on site. Boundary values ​​for each voltage range are set according to the rated voltage of the DC bus. Upper charging threshold and lower discharging threshold are set for the energy storage units based on their type and characteristics. The maximum capacity threshold for the distribution area is set based on the transformer capacity and line current carrying capacity. Load priority levels are defined according to their importance, and the mapping relationship between charging terminals and load levels is clarified. Rules for determining charging demand priority are set based on the actual needs of charging services.

[0129] During system operation, after startup, the system first performs a self-check to confirm that all devices and communication connections are normal before entering automatic operation. The system collects operating status parameters of each device in real time according to a preset cycle. Based on the collected DC bus voltage value, it determines the voltage range to which the device belongs, identifies the energy demand of the load, and prioritizes it. Based on the voltage range and load priority, and according to a preset energy coordination control strategy, the power conversion module adjusts the output power of each energy channel and the load's on / off status. The system continuously monitors the DC bus voltage and the operating status of each energy channel. When abnormal conditions are detected, corresponding protection and regulation mechanisms are activated according to the level of abnormality.

[0130] During system operation, energy prediction and pre-regulation steps are executed simultaneously. When multiple charging terminals are detected to be connected simultaneously and the DC bus voltage is within the normal range, the system automatically executes the multi-charging terminal concurrent power supply control step. When an external power grid fault is detected, the system automatically switches to islanded operation mode. When the external power grid returns to normal, the system automatically switches back to grid-connected mode and resumes the normal energy coordination control strategy.

[0131] During the maintenance and adjustment phase, the system's operational status and equipment health are checked regularly, and system operating data is recorded. Based on the system's actual operating performance, various operating parameters are adjusted, and energy coordination and control strategies are optimized. When system equipment configurations change, the corresponding operating parameters are updated promptly to ensure the system can adapt to the new operating environment.

[0132] Experimental verification:

[0133] This implementation example was tested in a residential community in a city for three months in a field experiment, comparing the system operation effect of using the method of this invention with that of the traditional centralized scheduling method.

[0134] Regarding system response speed, when using the traditional centralized scheduling method, the average response time from detecting a voltage anomaly to completing power regulation is 620ms, and the maximum response time is 1200ms. When using the method of this invention, the average response time is 35ms, and the maximum response time is 80ms.

[0135] Regarding DC bus voltage stability, when using the traditional centralized dispatching method, the bus voltage fluctuation range is ±12% of the rated voltage, and voltage often exceeds the normal range. When using the method of this invention, the bus voltage fluctuation range is ±3% of the rated voltage, and the voltage remains within the first normal range for more than 99.5% of the time.

[0136] Regarding clean energy consumption, when using the traditional centralized dispatch method, the average consumption rate of photovoltaic power generation systems is 84.2%, with an average monthly curtailment of 1200 kWh. When using the method of this invention, the average consumption rate of photovoltaic power generation systems is 98.7%, with an average monthly curtailment of 110 kWh.

[0137] Regarding transformer area capacity utilization, when using the traditional centralized scheduling method, an average of 12 transformer area overload events occur per month, with each overload lasting approximately 5 minutes and requiring manual intervention to recover. When using the method of this invention, no transformer area overload events occurred during the experiment, and the transformer area capacity utilization rate remained stable between 75% and 80%.

[0138] Regarding power supply reliability, when using the traditional centralized scheduling method, two system outages occurred during the experiment due to failures in the upper-level scheduling system. Each outage lasted approximately 30 minutes, causing power loss to some critical loads. When using the method of this invention, no system outages occurred during the experiment, and the power supply reliability of critical loads reached 100%.

[0139] Regarding islanding capability, when using the traditional centralized dispatching method, the system cannot automatically switch to islanding mode after an external power grid failure, resulting in a complete power outage for all loads. Using the method of this invention, the system completes the islanding mode switch within 20ms after an external power grid failure, with no power outages for primary critical loads and power restoration for secondary critical loads within 100ms. The system can operate continuously in islanding mode for up to 4 hours. During the experiment, the automatic reconnection function after overvoltage emergency disconnection was triggered three times, successfully restoring power to non-critical loads within 1.5 seconds each time, without any instances of failure to self-heal after protection.

[0140] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-source energy coordination control method for an energy router, applied to an energy router, wherein the energy router is based on a DC bus architecture and connects distributed power sources, energy storage units, external power grids, and various loads, characterized in that, Includes the following steps: S1: Real-time acquisition of operating status parameters of the distributed power source, energy storage unit, external power grid and various loads, including power, voltage, current and available capacity of energy storage unit; S2: Determine the preset voltage range to which the collected DC bus voltage value belongs; S3: Identify the energy requirements of various loads and prioritize them. S4: Based on the DC bus voltage range and load priority, and in accordance with the preset energy coordination control strategy, the power conversion module adjusts the output power of each energy channel and the load input status to achieve bidirectional energy flow and balance. S5: Real-time monitoring of DC bus voltage and the operating status of each energy channel. When an abnormal condition is detected, a graded protection and regulation mechanism corresponding to the level of the abnormal condition is activated.

2. The multi-source energy coordination control method for an energy router according to claim 1, characterized in that, The preset voltage range mentioned in step S2 includes: First normal range: voltage greater than or equal to 0.95 times the rated voltage and less than or equal to 1.05 times the rated voltage; Second undervoltage range: voltage greater than or equal to 0.85 times and less than 0.95 times the rated voltage; Third overvoltage range: voltage greater than 1.05 times and less than or equal to 1.15 times; Fourth emergency zone: voltage less than 0.85 times the rated voltage or greater than 1.15 times the rated voltage.

3. The multi-source energy coordination control method for an energy router according to claim 2, characterized in that, The energy coordination and control strategy described in step S4 is as follows: When the DC bus voltage is in the first normal range, the output power of the distributed power source is used first to meet the load demand. The remaining power is used to charge the energy storage unit when the SOC of the energy storage unit is less than the preset charging upper limit threshold. The insufficient part is supplemented by the external power grid. When the DC bus voltage is in the second undervoltage range, if the SOC of the energy storage unit is greater than the preset discharge lower limit threshold, the discharge power of the energy storage unit is increased first, then the input power of the external power grid is increased, while the power supply of non-critical loads is reduced; if the SOC of the energy storage unit is less than or equal to the preset discharge lower limit threshold, the input power of the external power grid is increased directly and the power supply of non-critical loads is reduced. When the DC bus voltage is in the third overvoltage range, if the SOC of the energy storage unit is less than the preset charging upper limit threshold, the charging power of the energy storage unit is increased first, then the input power of the external power grid is reduced, and the output power of the distributed power source is limited. If the SOC of the energy storage unit is greater than or equal to the preset charging upper limit threshold, the input power of the external power grid is reduced directly and the output power of the distributed power source is limited. When the DC bus voltage is in the fourth emergency range, if the voltage is less than 0.85 times the rated voltage, all non-critical loads will be immediately disconnected, and the maximum power discharge function of the energy storage unit and the maximum power input function of the external power grid will be activated simultaneously. If the voltage is greater than 1.15 times the rated voltage, all non-critical loads will be immediately disconnected, and the maximum power charging function of the energy storage unit will be activated simultaneously, and the external power grid connection will be disconnected. The output power of the distributed power source will be limited to the minimum value. If the voltage continues to rise within a preset time, the distributed power source will be gradually disconnected. If the voltage still cannot be restored to the normal range, an emergency alarm signal will be issued and the system will be shut down for protection. When the voltage is restored to the first normal range and the stable time reaches the preset recovery confirmation time, the disconnected non-critical loads and the external power grid connection will be automatically restored.

4. The multi-source energy coordination control method for an energy router according to claim 1, characterized in that, The load priority classification mentioned in step S3 is specifically as follows: The loads are divided into three levels: Level 1 critical loads, Level 2 critical loads, and Level 3 non-critical loads. Level 1 critical loads include safety and critical production equipment, Level 2 critical loads include general production equipment and essential living equipment, and Level 3 non-critical loads include comfort equipment and interruptible charging equipment. The charging terminals are mapped to different load levels according to their charging demand priority: emergency vehicle charging is classified as Level 1 critical load, scheduled charging vehicles are classified as Level 2 critical load, and regular charging vehicles are classified as Level 3 non-critical load.

5. The multi-source energy coordination control method for an energy router according to claim 1, characterized in that, The distributed power source mentioned in step S1 includes at least one of a photovoltaic power generation system, a wind power generation system, and a fuel cell power generation system, and the energy storage unit includes at least one of a lithium-ion battery energy storage system, a lead-acid battery energy storage system, and a supercapacitor energy storage system.

6. The multi-source energy coordination control method for an energy router according to claim 3, characterized in that, In step S4, when adjusting the output power of each energy channel, a power adjustment algorithm based on fuzzy PID control is adopted. By adjusting the proportional coefficient, integral coefficient and derivative coefficient in real time, the output power of each energy channel is precisely controlled, and the adjustment response time is controlled within the range of 10ms to 100ms.

7. The multi-source energy coordination control method for an energy router according to claim 1, characterized in that, It also includes a multi-charging terminal concurrent power supply control step executed between steps S3 and S4, specifically: When the DC bus voltage is in the first normal range and multiple charging terminals are detected to be connected simultaneously, the charging power is dynamically allocated within the maximum allowable charging power range of each charging terminal according to the charging demand priority and remaining charging time of each charging terminal. This ensures that the total output power of the transformer substation does not exceed the preset maximum capacity threshold. The maximum capacity threshold is determined based on the transformer substation capacity and line current carrying capacity, and its value ranges from 0.7 to 0.9 times the rated capacity of the transformer substation. When the DC bus voltage deviates from the first normal range, the energy coordination control strategy corresponding to the voltage range is executed first. When the total demand of high-priority charging terminals exceeds the maximum capacity threshold, the charging power of low-priority charging terminals is reduced proportionally.

8. The multi-source energy coordination control method for an energy router according to claim 7, characterized in that, The charging demand priority is determined based on the type of charging terminal, remaining power, and scheduled charging time. Emergency vehicles have the highest charging priority, followed by vehicles scheduled for charging, and then vehicles that can be charged normally. Regarding the remaining battery power, when the remaining battery power is lower than the preset emergency threshold, the priority of the charging terminal is increased by one level; charging terminals with the same priority are allocated power according to the remaining charging time from shortest to longest.

9. The multi-source energy coordination control method for an energy router according to claim 3, characterized in that, It also includes an energy prediction and pre-regulation step that is executed in parallel with step S1, specifically: Based on historical operating data and meteorological data, machine learning algorithms are used to predict the output power of distributed power sources and the energy demand of loads within the next 15 to 60 minutes. Based on the prediction results, the energy coordination control strategy parameters in step S4 are adjusted to adjust the charging and discharging state of energy storage units and the input power of the external power grid in advance, so as to achieve early balance of system energy.

10. The multi-source energy coordination control method for an energy router according to any one of claims 1-9, characterized in that, The abnormal operating conditions described in step S5 include three levels: general abnormality, severe abnormality, and emergency abnormality. Common anomalies include overcurrent warnings and minor voltage fluctuations. The solution is to adjust the output power of the corresponding energy channel and record the anomaly information. Serious anomalies include overcurrent, overvoltage, and undervoltage. The handling method is to disconnect the faulty circuit and activate the backup power channel. Emergency anomalies include short circuits and equipment failures. The handling method is to immediately shut down the equipment for protection and issue an emergency alarm signal.

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