Intelligent power distribution cabinet and power distribution system

Abstract

The invention discloses an intelligent power distribution cabinet and a power distribution system, the intelligent power distribution cabinet comprises a control system, a converter and an energy storage battery, and the control system is configured to collect the electric quantity of the energy storage battery, the output power PPCS of the converter, the charging load PLload and the on-off state of the power distribution system in real time; in response to switch-on of the power distribution system switch, the control system is further configured to enable all the charging piles to be directly powered by the external power supply when the charging load is smaller than or equal to the available capacity of the external power supply; when the charging load is larger than the available capacity of the external power supply, the converter is started, and the energy storage battery provides power PPCS exceeding the available capacity of the external power supply for the charging pile; the method is applied to PPCSgt; when the electric quantity of the energy storage battery is lower than a preset threshold value, setting part of charging piles as limited service but not influencing the charging; the method is applied to PPCSgt; and when the power of the energy storage battery is used up or the energy storage battery fails, partial charging piles are disconnected. According to the invention, more charging piles can be connected without increasing the investment of an external power supply, and the utilization efficiency of the power supply is improved.

Description

Technical Field

[0001] This application relates to the field of power distribution systems, and more particularly to an intelligent power distribution cabinet. This application also relates to a power distribution system including the intelligent power distribution cabinet. Background Technology

[0002] With the rapid development of electric vehicles, urban power resources for charging facilities are becoming increasingly scarce, especially in community scenarios where the "last mile" of charging is located, where available power capacity has been exhausted. The cost of adding dedicated power capacity to support the construction of charging facilities is high, making it difficult to achieve sustainable investment returns in community charging scenarios.

[0003] Based on actual charging system operation data, community charging stations typically use 7kW AC charging piles. Due to the long parking time of vehicles, the actual power utilization rate is low (the average daily charging volume of community public charging piles is about 10kWh, and a 7kW charging pile operates continuously for about 1.5 hours). Traditional power distribution systems, due to power capacity limitations, can only allocate available capacity according to a predetermined number and cannot directly connect more charging piles. Without control, connecting more charging piles simultaneously will lead to power overload. Summary of the Invention

[0004] This invention provides an intelligent power distribution cabinet that can connect more AC / DC charging piles in scenarios such as community charging stations without increasing external power supply investment, thereby improving power utilization efficiency.

[0005] In a first aspect of the invention, an intelligent power distribution cabinet is provided, comprising a control system, a converter, and an energy storage battery, wherein the converter is connected to an external power source, the control system, and the energy storage battery, respectively, and the control system is further configured to communicate with a charging pile; the control system is configured to collect data in real time on the energy storage battery charge and the converter output power P. PCS Charging load P Load and the status of the power distribution system switch; in response to the closing of the power distribution system switch, the control system is further configured to:

[0006] Under charging load P Load When the external power supply capacity is less than or equal to the available external power supply capacity, all charging stations are directly powered by the external power supply, where the available external power supply capacity is P. Power -P Band P Power P is the rated power of the external power supply. Band The control hysteresis set for the control system;

[0007] Under charging load P Load When the power supply capacity exceeds the available external power source capacity, the inverter is activated to supply power P to the charging station from the energy storage battery, exceeding the available external power source capacity.PCS That is, P PCS =P Load -(P Power -P Band );

[0008] At the inverter output power P PCS When the energy storage battery capacity is >0 and the energy storage battery capacity is lower than the predetermined threshold, some charging piles will be set to restricted service but this will not affect the current charging. After the current charging is completed, the charging piles with restricted service will be temporarily prohibited from charging again until the energy storage battery has the predetermined capacity value.

[0009] At the inverter output power P PCS When the energy storage battery is depleted or malfunctions, disconnect some charging stations to ensure that the charging load does not exceed the available capacity of the external power source.

[0010] In a second aspect of the invention, a power distribution system is provided, comprising an intelligent power distribution cabinet according to the first aspect of the invention and a plurality of charging piles.

[0011] By replacing the existing traditional power distribution cabinet with the intelligent power distribution cabinet of this invention, charging stations can be dynamically expanded without changing the original power supply. This allows existing charging stations to connect to more charging piles, alleviating "last mile" anxiety, improving power utilization efficiency, and dynamically adjusting the charging load by adjusting the number of available charging piles when the energy storage battery fails or has low power, thus enhancing the user experience. Simultaneously, the energy storage battery can also fully utilize off-peak electricity at lower prices, reducing the operating costs of charging stations.

[0012] Other features and advantages of the present invention will become clearer after reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a power distribution system according to an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of a power distribution system according to another embodiment of the present invention.

[0015] For clarity, these figures are schematic and simplified, showing only the details necessary for understanding the invention, while omitting other details. Detailed Implementation

[0016] The embodiments and examples of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] The scope of the invention will become apparent from the detailed description given below. However, it should be understood that while the detailed description and specific examples illustrate preferred embodiments of the invention, they are given for illustrative purposes only.

[0018] Figure 1 A schematic diagram of a power distribution system according to an embodiment of the present invention is shown. The power distribution system includes an intelligent charging cabinet and multiple charging piles.

[0019] In this embodiment, the intelligent power distribution cabinet includes a control system, a converter, and an energy storage battery. The converter is connected to an external power source, the control system, and the energy storage battery, respectively. The control system communicates with the charging pile. The external power source is AC 380V. The control system is configured to collect data on the energy storage battery charge and the converter output power P in real time. PCS Charging load P Load (i.e., the total load power formed by all charging piles in the process of charging) and the switching status of the power distribution system.

[0020] In response to the closing of the power distribution system switch, the control system is also configured to:

[0021] -When the charging load P Load When the external power supply capacity is less than or equal to the available external power supply capacity, all charging stations are directly powered by the external power supply, and all charging stations are fully operational; where the available external power supply capacity is P. Power -P Band P Power P is the rated power of the external power supply. Band It is a control hysteresis loop designed to stabilize the control system;

[0022] -When the charging load P Load When the power supply capacity exceeds the available external power source capacity, the inverter is activated to supply power P to the charging station from the energy storage battery, exceeding the available external power source capacity. PCS That is, P PCS =P Load -(P Power -P Band );

[0023] -When the charging load is high, i.e., P PCSWhen the SOC of the energy storage battery is below 0 and the SOC is below a predetermined threshold (e.g., SOC < 30%), some charging piles are pre-set to restricted service without affecting the current charging. These restricted charging piles can be those added due to capacity expansion as a result of implementing this invention, or a subset of all charging piles. This ensures that after the current charging session, the remaining charging piles (excluding those with restricted service) do not exceed the available external power capacity. Once the current charging session is complete, the restricted charging piles will be temporarily prohibited from charging again until the energy storage battery reaches the predetermined charge level. This is to regulate the charging load when the output capacity is insufficient. The predetermined charge level is the threshold at which the energy storage battery can resume operation. If set too high, such as 100%, the disabled charging piles will remain disabled when the charge level is below 100%, resulting in low equipment utilization and a poor user experience. If set too low, the energy storage battery will start discharging again before it has charged significantly, unable to sustain operation for long, and may even have to be shut down before supporting even one user's charging. Therefore, the predetermined power level can be preset according to different sites and load scales, such as 60%, 70%, 80% of the full capacity of the energy storage battery, etc. In another embodiment, a multi-level strategy can also be adopted, setting a corresponding number or proportion of charging piles to restricted service based on the energy storage battery capacity and the current charging service, so as to minimize the impact of service prohibition on users. That is, the control is adjusted based on the prediction of the current charging service situation. For example, when all charging piles are outputting at full power, if the battery capacity is less than 50%, half of the charging piles can be prohibited from the next service in advance; because at this pace, it is expected that the battery may be discharged in this round, without having to wait until the user has started charging again to find that the power is insufficient and forcibly terminate charging; another situation is that although the charging piles are all charging, they are not at full power, most of them are almost fully charged and the power is very small. In this case, it can be considered not to prohibit the next charging, or conservatively predict that 1-2 of the charging piles will be prohibited from the next charging. In other words, different control mechanisms can be formed under different SOCs to make users feel that the power is sufficient at all times, thereby improving the user experience.

[0024] -When the charging load is high, i.e., P PCS When the battery level is >0 and the energy storage battery is depleted or malfunctions (determined by the battery availability status provided by the battery management system), disconnect some charging stations to ensure that the charging load does not exceed the available capacity of the external power supply and avoid overload tripping of the station-level power supply due to external power overload. Since the low battery level prohibition does not affect the current / current charging process, actively disconnecting some charging stations is advantageous if continuous charging leads to depletion of the energy storage battery and entry into a protection state, or if the energy storage battery malfunctions. The disconnected charging stations can be those newly added due to the expansion of capacity as a result of implementing this invention, or some of the charging stations, ensuring that the charging load of the remaining charging stations does not exceed the available capacity of the external power supply.

[0025] - When the energy storage battery charge is below a predetermined threshold and the remaining usable capacity of the external power supply exceeds the minimum charging power of the inverter, i.e., P Power -P Band -P Load >P PCS-Charge-Min The energy storage battery is charged through the inverter until the energy storage battery reaches the predetermined power value.

[0026] Therefore, when the power distribution system switch is closed, based on the 380V incoming line, the power distribution system operates in grid-connected mode, using the control system to charge and discharge the energy storage battery, and providing expanded power for existing and new loads. Maximum output power is increased by P. PCS That is, the external power supply can be P Power Through the intelligent power distribution cabinet of this invention, the maximum output power P max For P Power +P PCS .

[0027] In grid-connected mode, backfeeding to the grid is generally not permitted. However, in application scenarios such as virtual power plants, the control system responds to control commands from the upper-level platform and feeds back power to the grid when the energy storage meets the reverse power feeding conditions. The reverse power feeding condition refers to the fact that the amount of power fed in the control command does not exceed the current available energy capacity of the energy storage. For example, if all parts of the energy storage system are operating normally and receive a command to discharge 50kW to the grid, and if the charging load requires 20kW, and the converter's maximum output is 100kW, the available energy capacity excluding the charging load is 100kW - 20kW = 80kW > 50kW. In this case, the energy storage meets the reverse power feeding condition. If the required discharge is 100kW, considering the charging load of 20kW, the maximum reverse power feeding from the energy storage is 80kW < 100kW, and therefore the reverse power feeding condition is not met. Furthermore, if the energy storage system malfunctions, the reverse power feeding condition will also not be met.

[0028] In response to the disconnection of the power distribution system switch, the control system is also configured to:

[0029] -This makes the charging load P Load The entire charging load P is handled by the energy storage battery and is controlled in real time. Load Not exceeding the maximum output power P of the converter PCS-max When the energy storage battery's output capacity is limited (SOC is below a set threshold, or the battery's state of being is limited), PCS-max The control system performs real-time adjustments to ensure dynamic P Load No more than P PCS-max ;

[0030] - When the energy storage battery fails, all charging stations will be prohibited from providing services until the energy storage battery is restored to operation.

[0031] Therefore, when the power distribution system switch is disconnected, the power distribution system operates in off-grid mode, and charging services and capacity expansion in off-grid mode are realized through energy storage batteries.

[0032] In this embodiment, the control system can also be configured to collect parking space occupancy status information and prioritize the availability of remaining power distribution cabinet capacity for unoccupied parking spaces. Parking space occupancy status information can be obtained through sensors such as ultrasonic probes and geomagnetic sensors, thereby assisting the control system in providing a more intelligent control strategy and opening up more available charging spaces to users in need.

[0033] Traditional power distribution systems are typically pre-planned and designed from top to bottom, generally avoiding situations where power capacity is exceeded. However, in the case of electric vehicle charging, existing power sources are insufficient or underutilized. By replacing traditional power distribution cabinets with the intelligent power distribution cabinet of this invention, charging stations can be dynamically expanded without altering the original power supply. This allows existing charging stations to connect to more charging piles, alleviating "last mile" anxiety and improving power utilization efficiency. When the energy storage battery malfunctions or has low charge, the charging load can be dynamically adjusted by regulating the number of available charging piles. Furthermore, the energy storage battery can fully utilize off-peak electricity at lower prices, reducing costs.

[0034] The intelligent power distribution cabinet of this invention can work in two modes (grid-connected and off-grid) to meet different small power supply scenarios and can be applied to small charging stations (20kW~100kW) in communities, workplaces and other places.

[0035] In addition, although the cost of the intelligent distribution cabinet of this invention is higher than that of the traditional distribution cabinet, besides the advantages mentioned above, the design of this invention is also advantageous from the perspective of the entire power system, because it solves the problem of power imbalance in a decentralized manner and reduces the pressure on the large power grid.

[0036] Figure 2 A schematic diagram of a power distribution system according to another embodiment of the present invention is shown. This embodiment's power distribution system also includes an intelligent charging cabinet and multiple charging piles. In this embodiment, the intelligent power distribution cabinet includes a control system, a converter, and an energy storage battery, as well as a power conversion module. The input of the power conversion module is connected to AC220V, and the output of the power conversion module is connected to the converter and the energy storage battery. When the power distribution system switch is off, the control system is also configured to collect information from the power conversion module in real time. When the energy storage battery charge is lower than a set value, the power conversion module triggers charging of the energy storage battery. For example, charging begins when the energy storage battery charge is lower than 70%, and the set value can also be set to other values ​​such as 100%, 80%, etc.

[0037] In one embodiment, the power conversion module can be an on-board charger (OBC). On-board chargers (OBCs) are mature products. Currently, electric vehicles are typically charged at home using a 220V single-phase AC power supply. The vehicle has an OBC responsible for converting AC to DC to charge the battery. Due to limitations in vehicle size and cost, the power output is generally low, around 7kW. This embodiment utilizes a mature OBC, employing a very limited power source, such as a 7kW home charger, to replenish the energy storage battery, and then provides power externally through the converter (PCS). When the energy storage battery is operating normally and has sufficient charge, this effectively amplifies the power supply, increasing the maximum output power from 7kW to the converter's maximum output power (P). PCS-max It supports more charging stations.

[0038] The various embodiments described herein, or their specific features, structures, or characteristics, may be suitably combined in one or more embodiments of the invention. Furthermore, various aspects of the invention may be implemented using software, hardware, firmware, or combinations thereof, and / or other computer-implemented modules or devices that perform the described functions. Software implementations of the invention may include executable code stored in a computer-readable medium and executed by one or more processors. Computer-readable media may include computer hard disk drives, ROMs, RAMs, flash memory, portable computer storage media such as CD-ROMs, DVD-ROMs, flash drives, and / or other devices having a Universal Serial Bus (USB) interface, and / or any other suitable tangible or non-transitory computer-readable medium or computer memory on which executable code may be stored and executed by a processor. The invention may be used in conjunction with any suitable operating system.

[0039] Unless explicitly stated otherwise, the singular forms “a” and “the” used herein include the plural meaning (i.e., meaning “at least one”). It should be further understood that the terms “having,” “comprising,” and / or “including” as used in the specification indicate the presence of the described features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The term “and / or” as used herein includes any and all combinations of one or more of the listed related items.

[0040] The foregoing has described some preferred embodiments of the present invention. However, it should be emphasized that the present invention is not limited to these embodiments, but can be implemented in other ways within the scope of the present invention. Those skilled in the art can make various modifications and variations to the present invention based on the inventive concept and without departing from the scope of the present invention, and such modifications or variations still fall within the protection scope of the present invention.

Claims

1. An intelligent power distribution cabinet, comprising a control system, characterized in that, The intelligent power distribution cabinet also includes a converter and an energy storage battery, wherein the converter is connected to an external power source, the control system, and the energy storage battery, respectively. The control system is also used to communicate with the charging pile. The control system is configured to collect the energy storage battery power and the converter output power P in real time. PCS Charging load P Load and the status of the power distribution system switch; in response to the closing of the power distribution system switch, the control system is further configured to: Under charging load P Load When the external power supply capacity is less than or equal to the available external power supply capacity, all charging stations are directly powered by the external power supply, where the available external power supply capacity is P. Power -P Band P Power P is the rated power of the external power supply. Band The control hysteresis set for the control system; Under charging load P Load When the power supply capacity exceeds the available external power source capacity, the inverter is activated to supply power P to the charging station from the energy storage battery, exceeding the available external power source capacity. PCS That is, P PCS =P Load -(P Power -P Band ); At the inverter output power P PCS When the energy storage battery capacity is >0 and the energy storage battery capacity is lower than the predetermined threshold, some charging piles will be set to restricted service but this will not affect the current charging. After the current charging is completed, the charging piles with restricted service will be temporarily prohibited from charging again until the energy storage battery has the predetermined capacity value. At the inverter output power P PCS When the energy storage battery is depleted or malfunctions, disconnect some charging stations to ensure that the charging load does not exceed the available capacity of the external power source.

2. The intelligent power distribution cabinet according to claim 1, characterized in that, The control system is also configured to: When the energy storage battery charge is lower than a predetermined threshold and the remaining available capacity of the external power supply exceeds the minimum charging power of the inverter, the energy storage battery is charged through the inverter until the energy storage battery charge reaches the predetermined charge value.

3. The intelligent power distribution cabinet according to claim 1, characterized in that, The control system is also configured to: In response to the control instructions from the higher-level platform, the energy storage system sends power back to the grid when the conditions for reverse power transmission are met.

4. The intelligent power distribution cabinet according to claim 1, characterized in that, In response to the disconnection of the power distribution system switch, the control system is further configured to: This makes the charging load P Load The entire charging load P is handled by the energy storage battery and is controlled in real time. Load Not exceeding the maximum output power P of the converter PCS-max ; In the event of a battery failure, all charging stations shall be prohibited from providing services to the public.

5. The intelligent power distribution cabinet according to claim 4, characterized in that, The intelligent power distribution cabinet also includes a power conversion module. The input of the power conversion module is used to connect to AC220V, and the output of the power conversion module is connected to the inverter and the energy storage battery. The control system is also configured to collect information from the power conversion module in real time. When the energy storage battery power is lower than a set value, the power conversion module triggers charging of the energy storage battery.

6. The intelligent power distribution cabinet according to claim 5, characterized in that, The power conversion module is a vehicle charger.

7. The intelligent power distribution cabinet according to claim 5, characterized in that, The power conversion module information includes operating status, charging current, charging voltage, and / or abnormal information.

8. The intelligent power distribution cabinet according to claim 1 or 4, characterized in that, The control system is also configured to collect parking space occupancy status information and prioritize the use of the remaining capacity of the power distribution cabinet for unoccupied parking spaces.

9. A power distribution system, characterized in that, The power distribution system includes an intelligent power distribution cabinet according to any one of claims 1-8 and includes multiple charging piles.

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