Disconnectable energy storage power supply system and method for lane-based orderly charging station

Abstract

The application relates to a detachable energy storage power supply system and method for a lane-type orderly charging station, which comprises a fixedly-installed energy conversion unit, at least two groups of detachable and integrally-assembled electric energy storage units and a dispatching controller; the energy conversion unit is electrically connected with a charging terminal and has bidirectional conversion capability, and is provided with a controlled bidirectional pre-charging branch; the electric energy storage units are connected to the same work station through power plug-in components, and are respectively provided with battery-side main contactors; when being replaced, a new unit is connected to the work station while being powered online, and the main contactor is kept open; the bidirectional voltage tracking is carried out through the pre-charging branch with the direct-current bus voltage as a target; after the voltage difference reaches a standard, the main contactor of the new unit is closed to realize short-time parallel connection; then the main contactor of the old unit is opened again and the old unit is removed. According to the application, the energy storage units can be replaced integrally and uninterruptedly without relying on commercial power or independent buffer elements, impact current is avoided, and the continuous power supply of the charging terminal is ensured.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle charging infrastructure technology, and more specifically, to a separable energy storage power supply system and method for lane-type orderly charging stations. Background Technology

[0002] With the rapid growth of electric vehicle ownership, high-power fast charging, supercharging, and megawatt-level heavy-duty truck charging scenarios are placing increasingly higher demands on the instantaneous power supply capacity of charging stations. In scenarios such as highway service areas, along national and provincial highways, in urban-rural fringe areas, mining areas, and ports, the power grid side generally faces constraints such as insufficient transformer capacity, poor grid power quality, or even no grid access. To alleviate these constraints, the industry commonly deploys battery-electrical energy storage systems (BESS) at charging stations as power buffers and energy transport devices. Against this backdrop, the uninterrupted power supply capability of the energy storage side has become a key element in ensuring the continuous operation of charging stations in weak grid and off-grid scenarios. The so-called uninterrupted power supply capability of the energy storage side refers to the ability of the charging station to continuously output power to lane-based orderly charging terminals even when the energy storage unit needs to go offline due to depletion of power, decline in health status, temperature alarms, or dispatch instructions.

[0003] A search revealed Chinese Patent Publication No. CN212649118U, which discloses a containerized vehicle-mounted mobile energy storage device. The battery and inverter are integrated into the same vehicle body. The vehicle drives into a charging station to discharge, and once the battery is depleted, the vehicle drives away to a central charging point for recharging. US Patent Publication No. US12459392B1 discloses a field-maintainable, modular charging station where the battery, PCS (Power Conversion System), and charging terminal are highly integrated into a unified, replaceable box-type module for easy overall maintenance and replacement.

[0004] To address the issue that charging stations struggle to maintain uninterrupted power supply to charging terminals when energy storage units need to be offline, a problem particularly prominent in weak grid and off-grid scenarios, the aforementioned existing technologies have the following shortcomings: In the Chinese patent CN212649118U solution, the entire vehicle must be driven away from the site to a centralized point for recharging; during the time window between driving away and the next energy storage vehicle entering the station, the charging station completely loses its energy storage and power supply capabilities and cannot maintain continuous output during the period when vehicles are queuing to enter the station.

[0005] In the US patent US12459392B1, since the battery and converter are bound to the same replaceable module, the overall offline of the module means that the PCS will exit operation synchronously. It is necessary to wait for the grid or on-site power supply to be completed and the entire module to be put back into operation, which makes it difficult to guarantee uninterrupted operation. In the absence of grid power, since there is no available power supply channel, this solution cannot actually achieve on-site replacement of energy storage units.

[0006] Therefore, how to achieve on-site rotation of energy storage units without relying on mains power or large-capacity buffer components has become a pressing technical problem for the industry. Summary of the Invention

[0007] In order to achieve on-site rotation of energy storage units and uninterrupted power supply to charging terminals without relying on mains power or large-capacity buffer components, this invention provides a separable energy storage power supply system for lane-type orderly charging stations.

[0008] The technical solution of this invention is as follows: A separable energy storage power supply system for lane-type orderly charging stations includes: The fixed-installation energy conversion unit is electrically connected to the charging terminal, has bidirectional conversion capability, and is equipped with a controlled bidirectional pre-charging branch. At least two sets of energy storage units that can be disassembled as a whole are provided, each equipped with a battery-side main contactor, and connected to the same workstation of the energy conversion unit via a power connector that can be repeatedly switched on and off. The scheduling controller is configured to execute sequentially during rotation: Step 1: While the first energy storage unit is powered online, connect the second energy storage unit to the workstation and keep its battery-side main contactor disconnected. Step 2: Through the pre-charging branch, with the real-time voltage of the DC bus of the energy conversion unit as the target value, the energy conversion unit performs bidirectional voltage tracking on the second energy storage unit until the voltage difference between the two is less than a preset threshold. Step 3: Close the main contactor on the battery side of the second energy storage unit to connect the two sets of energy storage units in parallel on the DC bus for a short time. Step 4: Disconnect the main contactor on the battery side of the first energy storage unit and remove it from the workstation, so that the second energy storage unit can continue to supply power to the charging terminal.

[0009] As a preferred embodiment of the present invention, the controlled bidirectional pre-charging branch includes a bidirectional DC / DC converter, one side of which is connected to the DC bus of the energy conversion unit, and the other side is connected to the positive and negative terminals of the power connector of the energy storage unit to be stored at the workstation via an isolating switch.

[0010] As a preferred embodiment of the present invention, the preset threshold is not greater than 1% of the rated voltage of the DC bus, or not greater than 5V.

[0011] As a preferred embodiment of the present invention, the scheduling controller is further configured to set a duration upper limit Tmax for the short-term parallel connection, and to forcibly execute step 4 before the parallel connection duration reaches Tmax; wherein Tmax≤30 seconds.

[0012] As a preferred embodiment of the present invention, the bidirectional voltage tracking adopts closed-loop control of constant voltage outer loop combined with current limiting inner loop, and its current limiting value does not exceed the rated current of the smaller of the pre-charging branch or the power connector.

[0013] As a preferred embodiment of the present invention, the power connector includes a graded closing structure of precharge contacts and main contacts, wherein the precharge contacts make contact before the main contacts and then disconnect from the main contacts.

[0014] As a preferred embodiment of the present invention, the workstation is further provided with a mechanical locking mechanism and an electrical interlocking circuit. The scheduling controller is allowed to close the main contactor in step 3 only when the mechanical locking is in place and the electrical interlocking circuit is connected.

[0015] As a preferred technical solution of the present invention, each group of energy storage units is independently configured with a battery management system, an insulation monitoring device, a temperature monitoring device and a fire protection unit, and when it leaves the work station, a leakage resistor is automatically connected between the positive and negative terminals of its power connector.

[0016] As a preferred embodiment of the present invention, the number of energy storage units is not less than three sets, of which at least one set is in an online power supply state, at least one set is in a standby state, and at least one set is in an offline power replenishment or maintenance state.

[0017] As a preferred embodiment of the present invention, the scheduling controller triggers the rotation when any of the following conditions are met: the state of charge (SOC) of the online energy storage unit is lower than a set lower limit, the state of health (SOH) is lower than a set lower limit, any temperature sensor exceeds its limit, the BMS reports a critical alarm, or an external scheduling instruction is received.

[0018] As a preferred embodiment of the present invention, the scheduling controller is communicatively connected to the orderly charging queue management module of the lane-type orderly charging station. Based on the charging demand and power curve of subsequent vehicles in the queue, it predicts the available power supply time of the online energy storage unit and actively triggers the rotation before the time arrives.

[0019] As a preferred embodiment of the present invention, it further includes a replacement actuator located between the workstation and the external transfer channel, wherein the replacement actuator is selected from one or more of the following: an electric forklift with a roller channel, a rail-mounted RGV, an AGV, and a drawer-type robotic arm.

[0020] This invention also provides a separable energy storage power supply method using the separable energy storage power supply system for lane-type orderly charging stations as described above. The charging station includes a fixedly installed energy conversion unit with bidirectional conversion capability and at least two sets of detachable energy storage units connected to the DC bus of the energy conversion unit via a repeatedly switchable electrical interface. The packaging form, dimensions, rated capacity, rated voltage, and chemical system of the energy storage units are not limited. The method includes: Step S1: The energy conversion unit supplies power to at least one charging terminal via the first energy storage unit; Step S2: While the first energy storage unit is kept online, the second energy storage unit is connected to the DC bus side of the energy conversion unit through the electrical interface, and the main contactor on the battery side of the second energy storage unit is kept in the open state. Step S3: Through the controlled bidirectional pre-charging branch of the energy conversion unit, the second energy storage unit is subjected to bidirectional voltage tracking with the real-time voltage of the DC bus of the energy conversion unit as the target value until the voltage difference between the two is less than a preset threshold. Step S4: Close the main contactor on the battery side of the second energy storage unit to connect the two sets of energy storage units in parallel on the DC bus for a short time. The output current of the energy conversion unit to the charging terminal remains continuous during the parallel connection. Step S5: Disconnect the battery-side main contactor of the first energy storage unit and disconnect the entire first energy storage unit from the energy conversion unit, so that the second energy storage unit continues to supply power to the charging terminal.

[0021] As a preferred technical solution of the present invention, the energy storage unit is selected from any one or more combinations of containerized energy storage modules, cabinet-type energy storage modules, and modular energy storage packs, with a rated capacity of any value from 10kWh to 5000kWh and a rated voltage of any value from 200VDC to 1500VDC; when the energy storage unit is a modular energy storage pack, several energy storage packs are logically and virtually combined into a group of energy storage units before steps S1 to S5 are uniformly applied.

[0022] As a preferred embodiment of the present invention, the number of charging terminals is one or more, the rated power of a single gun of each charging terminal is any value from 7kW to 2400kW, and the number of charging guns of each charging terminal is unlimited.

[0023] As a preferred technical solution of the present invention, the preset threshold in step S3 is not greater than 1% of the rated voltage of the DC bus, or not greater than 5V, whichever is smaller.

[0024] As a preferred technical solution of the present invention, if the duration of the short-term parallel connection in step S4 exceeds 30 seconds, the scheduling controller will forcibly execute step S5 before the duration of the parallel connection reaches the duration limit.

[0025] As a preferred technical solution of the present invention, the chemical systems of different energy storage units are selected independently and are allowed to be different from each other. The chemical systems are selected from any one of lithium iron phosphate, ternary lithium, sodium ion, and semi-solid lithium batteries.

[0026] According to the above-described solution, the beneficial effects of this invention are as follows: This invention ensures uninterrupted output current to the charging terminal throughout the entire process of EESU assembly and disassembly. Specifically, the second energy storage unit is connected and participates in parallel power supply before the first energy storage unit is disconnected from the DC bus. During the short-term parallel connection of the two energy storage units on the DC bus, they jointly support the bus voltage, and the main power circuit of the energy conversion unit does not experience undervoltage or open circuit. Therefore, compared with the traditional disconnect-then-connect type switching, this invention maintains continuous power supply to the lane-type orderly charging terminal throughout the entire process of EESU physical replacement.

[0027] This invention enables uninterrupted switching without relying on mains power or independent large-capacity energy storage buffer components. The energy required for voltage matching of the energy storage unit to be connected is exchanged only internally between the energy conversion unit and the energy storage unit to be connected, without the need for external AC power compensation or long-term connection of large-capacity supercapacitors or independent energy storage components on the DC bus.

[0028] When the main contactor of the second energy storage unit of the present invention is closed, its terminal voltage is close enough to the DC bus voltage. The instantaneous value of the circulating current determined by ΔU / R is limited to the allowable range of the component, thereby avoiding arcing, overvoltage spikes and common-mode impacts that are common under conditions of hot plugging and hard switching, and thus avoiding the impact current and arcing at the moment the main contactor is closed.

[0029] In this invention, the potential difference between the two sets of EESUs is pre-compressed to below a preset threshold during the instantaneous parallel connection, and the amplitude and duration of the circulating current are controlled, so that the overlapping parallel connection itself does not damage the battery side and the connector, thereby ensuring that there is no observable circulating current between the two sets of energy storage units when the main contactor is closed.

[0030] Furthermore, the replaced energy storage units become independent, mobile assets that can be transported to the back-end or other locations for slow charging, SOH calibration, individual unit consistency management, and even cross-site scheduling; the charging station resumes normal operation after the rotation is completed. Attached Figure Description

[0031] Figure 1 This is a system block diagram of the present invention; Figure 2 This is a flowchart of the method of the present invention; Figure 3 This is a flowchart of the method in Example 5. Detailed Implementation

[0032] To better understand the purpose, technical solution, and technical effects of this invention, the invention will be further explained and described below in conjunction with the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. It is also stated that the embodiments described below are only for explaining this invention and are not intended to limit this invention.

[0033] It should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Example 1

[0034] like Figure 1 As shown, a separable energy storage power supply system for lane-type orderly charging stations is applied to supercharging stations in highway service areas. It includes an energy conversion unit, a first energy storage unit (EESU-A), a second energy storage unit (EESU-B), a dispatch controller, workstations, and a replacement actuator.

[0035] The energy conversion unit is fixedly installed inside the charging station's equipment room and will not be moved throughout the entire lifespan of the charging station. Its enclosure is an IP54-rated steel cabinet, which is rigidly connected to the equipment room's concrete foundation via anchor bolts. The AC side of the energy conversion unit is permanently connected to the charging station's 10kV / 0.4kV low-voltage distribution cabinet via an 800kVADyn11 isolation transformer. Its DC side is led to the DC bus via a 2×120mm² copper busbar. The rated voltage of the DC bus is 800VDC, with an allowable fluctuation range of ±5%. The energy conversion unit is equipped with a 500kW bidirectional energy storage converter (model ST500KTL-3P), four 125kW bidirectional DC / DC converters, a DC bus combiner, and a controlled bidirectional pre-charge branch. The DC bus combiner consists of a busbar, a 1600A / 1500VDC disconnector, a 1250A / 1500VDC circuit breaker, a set of zinc oxide surge arresters, and a set of surge protectors.

[0036] The controlled bidirectional pre-charging branch consists of a 30kW bidirectional DC / DC converter, two sets of 100A / 1500VDC contactors, and a set of 10Ω, 5kW nickel-chromium alloy current-limiting resistors connected in parallel. Its input side is connected in parallel to the DC bus, and its output side is led to the positive and negative terminals of the power connector of the energy storage unit to be stored at the workstation via a 100A disconnect switch and a set of foolproof pins.

[0037] A set of 50mF, 1000VDC metallized thin-film DC support capacitors is connected in parallel to the DC bus of the energy conversion unit. These capacitors absorb voltage spikes during switching operations and provide millisecond-level energy buffering for the charging terminals during transient switching. The output of the energy conversion unit is led to the DC buses of two 480kW liquid-cooled supercharging terminals via four 250A DC circuit breakers. The two supercharging terminals have a total of four charging guns, which receive power allocation from the dispatch controller according to the lane-type orderly charging protocol.

[0038] Both the first and second energy storage units are packaged in 20ft containerized containers, with dimensions of 6058mm × 2438mm × 2591mm. Each unit has a capacity of 500kWh, a voltage rating of 800VDC, and a lithium iron phosphate chemistry. Internally, each energy storage unit contains a battery pack consisting of 256 series-2 parallel 280Ah cells, a battery management system with a master controller and multiple slave controllers, a 1000A / 1500VDC battery-side main contactor, a pre-charge contactor connected in parallel with the main contactor and a 5Ω current-limiting resistor, a 1000A DC fuse, an insulation monitoring device, twelve temperature sensors, an independent fire suppression unit using perfluorohexanone, and an independent water-cooled temperature control circuit. The battery management system collects the voltage (sampling accuracy ±2mV), cell temperature (sampling accuracy ±0.5℃), group terminal voltage, group terminal current, and insulation resistance of each cell string, and reports the above parameters to the scheduling controller via the CAN communication bus (baud rate 500kbps) with a reporting period of 100ms.

[0039] After each power storage unit leaves the workstation, a set of 1kΩ, 200W ceramic energy dissipation resistors are automatically connected between the positive and negative terminals of its power connector through a set of normally closed mechanical switches, so that the power connectors maintain a safe residual pressure of less than 60VDC during transportation; the bottom of the container is provided with forklift holes and four corner lifting lugs, and the long side of the container is provided with positioning pin holes and docking flanges.

[0040] The workstation is located above the mating surface of the energy conversion unit. From top to bottom, the mating surface of the workstation is equipped with a set of high-current DC power connectors, a set of CAN / Ethernet hybrid communication signal connectors, a set of mechanical guiding and blind-fit alignment mechanisms, and a set of mechanical locking mechanisms. The high-current DC power connector is a water-cooled connector rated at 1000A / 1500VDC, comprising four cores: a positive power electrode, a negative power electrode, a PE electrode, and an equipotential ground electrode. It includes a graded closing structure with pre-charge contacts and main contacts. The conductive path length of the pre-charge contacts is 8mm shorter than that of the main contacts. Therefore, during the closing process, the pre-charge contacts contact 30ms to 50ms before the main contacts, and during the opening process, the pre-charge contacts open 30ms to 50ms after the main contacts, preventing the main contacts from arcing under load.

[0041] The mechanical guiding and blind insertion alignment mechanism includes two 25mm diameter tapered guide pins, a set of floating self-aligning flanges, and a set of return springs, allowing blind insertion within a ±8mm alignment deviation range. The mechanical locking mechanism employs two sets of rotating hooks in conjunction with two sets of redundant microswitches. The rotating hooks are driven by a 24VDC motor. After locking, both sets of redundant microswitches simultaneously close, sending a "locking effective" signal back to the dispatch controller via an independent hardwire. Another hardwire parallel to the "locking effective" signal forms an electrical interlocking circuit, with the connector's PE pole and the equipotential grounding pole forming a closed loop. The dispatch controller only allows the "close battery-side main contactor" command when the mechanical locking is complete and the electrical interlocking circuit is active. An additional insulation monitoring probe is installed between the positive and negative poles of the connector to measure the insulation resistance to ground at the mating surface before the main contactor closes. The next action is only permitted if the measurement result is not less than 500Ω / V. When the connector is not mated, a spring-driven anti-misoperation mechanical baffle automatically shields the electrodes.

[0042] A steel platform roller channel, 1.5m wide and 3m long, is laid in front of the workstation. The roller spacing is 200mm and the single roller can bear 2t. The actuator is an electric forklift with a rated load of 8t, which works with the platform roller channel to push the entire energy storage unit in and out. The time required for a single push-in or move-out action is less than 8 minutes.

[0043] The dispatch controller is integrated into the control cabinet of the energy conversion unit. The hardware platform is an industrial-grade embedded controller based on ARM Cortex-A53, with a real-time Linux operating system. The software implementation includes a parameter acquisition module, a state machine scheduling module, a voltage tracking closed-loop module, a communication gateway module, and a human-machine interface module. The dispatch controller communicates via CAN bus with the PCS controller, DC / DC controller, pre-charge branch controller, battery management system of the first energy storage unit, and the replacement actuator of the second energy storage unit. It collects real-time data on the state of charge (SOC), state of health (SOH), temperature, cycle count, and insulation resistance of each energy storage unit, and communicates via Ethernet with the charging station control system and the cloud-based energy management platform. It should be noted that the state of charge (SOC) is the remaining capacity of the battery, usually expressed as a percentage. The state of health (SOH) is the current degree of aging / deterioration of the battery, also often expressed as a percentage; it reflects the battery's ability to store and release energy relative to its pristine state. A new battery has a SOH close to 100%.

[0044] During system operation, the dispatch controller first compares the SOC and SOH of the first and second energy storage units. The unit with the higher SOC and SOH is selected as the online group (designated as the first energy storage unit). The battery management system of this group is then commanded to close the pre-charge contactor, allowing the current-limiting resistor to participate in the circuit and soft-start the supporting capacitor within the energy conversion unit. Once the voltage difference between the first energy storage unit and the DC bus voltage is less than 5V, the main contactor is closed, and the pre-charge contactor is opened. The first energy storage unit is then connected to the DC bus via the power connector. The bidirectional energy storage converter of the energy conversion unit, along with four DC / DC converters, collaboratively outputs power to the DC buses of the two supercharging terminals. The dispatch controller distributes power to each charging gun according to the lane-based orderly charging protocol. Simultaneously, the second energy storage unit is located in a standby position outside the workstation, and its battery-side main contactor remains open.

[0045] When the dispatch controller detects that the SOC of the first energy storage unit is lower than the set lower limit SOCmin=15%, or the SOH is lower than the set lower limit SOHmin=70%, or the temperature of any cell is higher than 55℃, or the temperature of any cell is lower than −10℃, or the battery management system reports a critical alarm, or the insulation resistance is lower than the set threshold, the rotation process is triggered. The electric forklift is ordered to push the second energy storage unit into the workstation from the standby position. The energy storage unit completes blind insertion and alignment under the guidance of the floating self-aligning flange and the tapered guide pin. The mechanical locking mechanism closes the rotating hook under the drive of the 24V motor and sends the "locking effective" signal back to the dispatch controller. The dispatch controller simultaneously checks the continuity of the electrical interlock circuit and the insulation resistance to ground. After all three conditions are met, the next step is performed. At this time, the main contactor on the battery side of the second energy storage unit remains open.

[0046] Subsequently, the dispatch controller commands the energy conversion unit to close the isolating switch and contactor between the pre-charging branch and the second energy storage unit, and starts the bidirectional DC / DC converter into voltage tracking mode. The voltage tracking closed loop adopts a constant voltage outer loop plus a PI current-limiting inner loop structure. The outer loop takes the real-time DC bus voltage Vbus (sampling period 1ms) as the reference and the voltage VB at the second energy storage unit as the feedback. The outer loop PI parameters are Kpv=0.5 and Kiv=20. The outer loop outputs a reference current Iref. The upper limit of the amplitude of Iref is set to the rated current of the pre-charging branch of 75A (estimated based on 30kW÷400V and with a margin). The inner loop takes Iref as the reference and the inductor current as the feedback. The inner loop PI parameters are Kpi=0.1 and Kii=200. The duty cycle of the bidirectional DC / DC converter is driven at a switching frequency of 20kHz. If VB is lower than Vbus, the current flows from the DC bus into the second energy storage unit; if VB is higher than Vbus, the current flows from the second energy storage unit back to the DC bus. Throughout the tracking process, the first energy storage unit continues to independently supply power to the charging terminal, and the main power circuit output of the energy conversion unit remains unaffected. When the difference between VB and Vbus is less than the preset threshold ΔVth for 100ms consecutively, the scheduling controller commands the battery management system of the second energy storage unit to close its battery-side main contactor. In this embodiment, ΔVth = 5V, and it is required to be no greater than 1% of Vbus, whichever is smaller. The first and second energy storage units are briefly connected in parallel on the DC bus. During this period, the output current of the energy conversion unit to the two supercharging terminals remains continuous without significant drop. The instantaneous circulating current amplitude, calculated according to ΔU / Rloop, is limited to within 50A, far below the component stress limit. The maximum parallel operation time, Tmax, is set to 30 seconds. At any point before Tmax is reached, the scheduling controller commands the battery management system of the first energy storage unit to first disconnect the main contactor, then the pre-charge contactor. An electric forklift then moves the first energy storage unit out of the workstation. During this movement, a leakage resistor is automatically connected to both ends of the power connector of the first energy storage unit to maintain a safe residual voltage. From this point on, the second energy storage unit independently supplies power to the charging terminal. The energy conversion unit shuts off the isolation switch between the pre-charge branch and the workstation, and the system returns to a steady state of single-unit online operation.

[0047] The first energy storage unit, after being removed, was transported to the charging station's back-end site by a dedicated flatbed truck. At this back-end site, it was charged to 95% SOC using a 100kW slow-charging device. Then, the back-end battery testing equipment performed individual cell consistency calibration, SOH assessment, and necessary individual cell re-sorting. After processing, it was returned to its spare position as a backup unit for the station. In a field test, the voltage of the second energy storage unit actively tracked from 760V to 798V in 18 seconds. After a parallel connection of 6 seconds, the first energy storage unit was removed. Throughout the entire handover process, the output current of the four charging guns from both supercharging terminals remained continuous without any drop, with the highest instantaneous current deviation being less than 2A. Example 2

[0048] A separable energy storage power supply system for lane-type orderly charging stations is described, otherwise the same as in Embodiment 1, except that: this embodiment is applied to emergency fast charging scenarios without mains power on national and provincial highways. The AC side of the energy conversion unit is not connected to the public power grid but only operates as an island power source for lane-type orderly charging terminals. The rated capacity of the bidirectional energy storage converter is reduced from 500kW to 120kW, the DC / DC converter is changed from four 125kW units to two 60kW units, and the isolation transformer and grid-connected protection unit are eliminated and replaced by a set of voltage and current dual closed-loop control software modules dedicated to island operation.

[0049] The rated capacity of the bidirectional DC / DC converter in the pre-charging branch was reduced from 30kW to 10kW, and the current-limiting resistor value was adjusted from 10Ω to 20Ω. Three energy storage units were configured on-site: the first, second, and third energy storage units. The packaging of the energy storage units was changed from a 20ft container to an outdoor energy storage cabinet with dimensions of 2200mm×1200mm×2300mm. Each unit has a capacity of 200kWh, a voltage rating of 800VDC, and the chemical system remains lithium iron phosphate. At any given time, at least one of the three energy storage units is in an online power supply state, at least one is in a standby state already located outside the workstation, and at least one is in an offline replenishment state at a centralized photovoltaic replenishment station located 30km east of the charging station. The three energy storage units cycle through these three states.

[0050] In addition to the four-step rotation defined in Example 1, the scheduling controller maintains a status scheduling table to record the current location, current SOC, and next action time of each group of energy storage units. This table communicates with the centralized photovoltaic power replenishment station and a transport pickup truck via a 4G wireless module. Disconnected energy storage units are transported by pickup truck to the photovoltaic power replenishment station for slow charging and undergo individual unit consistency testing. They are then transported back by pickup truck to serve as new backup access points.

[0051] In addition to five built-in trigger conditions—SOC, SOH, temperature, battery management system alarms, and insulation resistance—the dispatch controller also receives cross-site dispatch instructions from the backend. When the backend needs to transfer the standby group of this station to another separable energy storage power supply system located 50km south of the charging station in the same area as its standby group, the dispatch controller actively triggers the rotation process, provided that the SOC of the currently online group at this station is higher than the safety threshold. The standby group in the standby position is "reversely" switched into the work position in a four-step sequence and then transported by pickup truck to the other charging station. This embodiment fully utilizes the characteristics of the energy conversion unit being fixed and the energy storage unit being independently movable, enabling energy storage assets to be flexibly dispatched between multiple sites in the area as "independent and mobile assets." A single pickup truck can complete up to six round trips of energy storage unit dispatching between this station, the centralized photovoltaic power replenishment station, and another charging station per day. Example 3

[0052] An improvement on Embodiment 1 is that a separable energy storage power supply system for lane-type orderly charging stations is applied to the orderly charging scenario of heavy trucks in mining areas. The energy conversion unit consists of four 630kW bidirectional energy storage converters connected in parallel and fixedly installed on an 800mm thick reinforced concrete foundation. The bidirectional energy storage converters are connected in parallel through a set of parallel controllers to achieve droop control and power balancing. The bidirectional DC / DC converter of the pre-charging branch is upgraded from one 30kW to four 125kW converters connected in parallel to match the synchronous tracking requirements of the four energy storage units. The energy storage unit adopts a modular energy pack form. Each energy pack has external dimensions of 600mm×400mm×220mm, a capacity of 100kWh, a voltage rating of 800VDC, and a chemical system of lithium iron phosphate. Each energy pack is independently equipped with a BMU, a 600A main contactor, a pre-charge contactor, and a set of temperature sensors. 24 energy packs are configured on site and combined into two arrays of 12 packs each to form the first energy storage unit and the second energy storage unit, respectively. The 12 energy packs in a single array are connected in parallel to each other via a busbar and then led out to the array-level power connector.

[0053] The workstation replacement mechanism has been changed from the electric forklift with roller channel in Example 1 to a rail-mounted RGV automatic bag changing device. The RGV is driven by a servo motor with a rated power of 5kW and moves back and forth between the workstation and the energy bag warehouse along a double-rail steel track with a total length of 60m. The maximum running speed is 1.2m / s and the positioning accuracy is ±2mm. The unlocking, gripping, transportation, alignment and locking actions at the single bag level are all automatically completed by the double-claw manipulator and torque control bolt tightening device on the RGV.

[0054] In addition to operating according to the four-step rotation sequence described in Example 1, the dispatch controller also links with the mining area vehicle dispatch system via an industrial Ethernet interface to obtain the charging demand and power curves of subsequent heavy-duty trucks in the lane-type orderly charging queue in real time. It estimates the available power supply time t of the current online energy storage unit using the formula t=(SOC−SOCmin)×Cap÷Pload, where SOC is the SOC of the current online energy storage unit, SOCmin is 15%, Cap is the single array capacity of 1200kWh, and Pload is the sliding average power demand of each heavy-duty truck in the subsequent queue. The statistical window is 30 minutes. When t is less than the time required to complete the current queue, the dispatch controller starts the rotation process 5 to 10 minutes before t arrives, selecting the lowest point in the power curve of the subsequent queue as the rotation window. This ensures that the overlapping and parallel handover occurs during natural power troughs, minimizing the impact on the charging experience of heavy-duty trucks.

[0055] The timing, thresholds, and control laws for all actions other than the predictive rotation are the same as in Example 1. This predictive rotation mechanism reduces the perceptible impact of the rotation process on vehicle charging in typical mining scenarios, i.e., the instantaneous change in current of any charging gun is reduced to less than 1A. Example 4

[0056] An improvement on Embodiment 1 is a separable energy storage and power supply system for lane-type orderly charging stations. This embodiment is applied to flexible charging stations in urban-rural fringe areas. The energy storage unit's packaging form is changed from a 20ft container type to a standard 4U drawer-type energy pack. Each pack has dimensions of 600mm × 420mm × 180mm, a capacity of 25kWh, a voltage rating of 200VDC, and a weight of approximately 60kg. The workstation consists of a metal cabinet capable of accommodating 16 energy packs. Each drawer of the cabinet is equipped with a set of 200A power connectors, a set of communication connectors, a set of mechanical guiding and blind-plug alignment mechanisms, and a set of rotary hook mechanical locking mechanisms.

[0057] The workstation replacement mechanism has been changed from the electric forklift with roller channel in Example 1 to a drawer-type robotic arm. Under the command of the scheduling controller, the robotic arm pulls out or pushes in a single energy pack from the front of the workstation, and the time required for a single pull-out or push-in action is less than 30 seconds. The scheduling controller virtually combines the 16 energy packs into 4 groups of energy storage units with a voltage level of 800VDC and a single group capacity of 100kWh according to the topology of "4 packs in series to form 1 group". These energy storage units are then uniformly connected to the same DC bus of the energy conversion unit. Externally, it still presents at least two groups of energy storage units that can be disassembled as a whole. The four-step timing sequence of bidirectional voltage tracking and overlapping parallel connection is also applicable at the group level after virtual combination, and the closed-loop parameters of the pre-charging branch for tracking the terminal voltage of the virtual group to be entered are the same as in Example 1.

[0058] The extracted power packs are delivered by operating vehicles to back-end charging points for slow charging and consistency calibration, and then returned to the same station or other charging stations in the same area as backup packs. This achieves logistics-style dispatch of power assets within urban and rural areas in a low-cost and low-barrier manner. The dispatch controller shares the location, SOC, and SOH information of the power packs with other charging stations in the same area through a cloud-based energy management platform, and generates a transportation task list and arrival time window for the power packs based on the principle of optimal distance and transportation cost. Example 5

[0059] like Figure 2 and Figure 3 As shown, a separable energy storage power supply method using any of the systems described in Embodiments 1 to 4 includes the following steps.

[0060] Step 1: The dispatch controller selects the first energy storage unit as the online group. The energy conversion unit supplies power to the lane-type orderly charging terminal through the first energy storage unit. The bidirectional energy storage converter and DC / DC converter of the energy conversion unit distribute power to each charging gun according to the lane-type orderly charging protocol.

[0061] Step 2: The dispatch controller monitors the SOC, SOH, cell temperature, battery management system alarm status, insulation resistance, and lane-based orderly charging queue prediction information of the first energy storage unit in real time. When any of the following conditions are met: the SOC of the first energy storage unit is below the set lower limit, the SOH is below the set lower limit, any temperature sensor exceeds the limit, the battery management system reports a critical alarm, the insulation resistance is below the set threshold, an external cross-site dispatch command is received, or the available energy supply time t predicted based on the lane-based orderly charging queue is less than the time required to complete the current queue, the controller commands the replacement actuator to connect the second energy storage unit from its standby position to the same station of the energy conversion unit. The energy storage unit completes the alignment through a mechanical guide and blind insertion alignment mechanism. The mechanical locking mechanism closes and sends a "locking effective" signal back to the dispatch controller. The dispatch controller simultaneously verifies the continuity of the electrical interlocking circuit and the insulation resistance to ground. After all three conditions are met, the next step is initiated. During this process, the main contactor on the battery side of the second energy storage unit remains open.

[0062] Step 3: The dispatch controller commands the energy conversion unit to close the isolating switch and contactor between the controlled bidirectional pre-charging branch and the second energy storage unit. Using the real-time voltage of the energy conversion unit's DC bus as the outer loop target value and the smaller of the rated current of the pre-charging branch or the power connector as the inner loop current limiting value, a bidirectional voltage tracking closed-loop control system with a constant voltage outer loop and a PI current limiting inner loop is initiated. If the voltage at the second energy storage unit's terminal is lower than the DC bus voltage, energy is injected into the second energy storage unit from the DC bus; if the terminal voltage is higher than the DC bus voltage, energy is drawn back from the second energy storage unit to the DC bus, until the difference between the second energy storage unit's terminal voltage and the DC bus voltage is less than a preset threshold ΔVth for 100ms consecutively. ΔVth is the smaller of 1% and 5V of the rated DC bus voltage.

[0063] Step 4: The dispatch controller commands the battery management system of the second energy storage unit to close its main contactor on the battery side. The first energy storage unit and the second energy storage unit are connected in parallel on the DC bus for a short time. During this period, the output current of the energy conversion unit to the charging terminal remains continuous and without significant drop. The upper limit of the parallel connection time Tmax is set to no more than 30 seconds.

[0064] Step 5: Before the parallel connection time reaches Tmax, the dispatch controller commands the battery management system of the first energy storage unit to first disconnect the main contactor and then disconnect the pre-charge contactor. The replacement actuator then moves the first energy storage unit out by self-movement. During the movement, the energy leakage resistor is automatically connected to both ends of the power connector of the first energy storage unit to maintain a safe residual voltage during the movement. The second energy storage unit then independently supplies power to the lane-type orderly charging terminal.

[0065] Step 6: The first energy storage unit removed from the workstation is transported by a dedicated transport vehicle to the back-end station of the charging station or other charging stations in the same area. At the back-end station, it is recharged by slow charging equipment and undergoes single-cell consistency calibration, SOH assessment and necessary single-cell re-sorting by battery testing equipment. Alternatively, it can be directly connected to the workstation of other charging stations as a new backup group, thereby realizing cross-station scheduling of energy storage units within the region.

[0066] Step 7: After the rotation is completed, the dispatch controller updates its internal status scheduling table and reports the timestamp, participating group, tracking duration, parallel connection duration, and final threshold convergence value of this rotation to the backend and other charging stations in the same area via the cloud energy management platform. This information serves as the basis for subsequent optimization and maintenance. The hardware structure, control law parameters, and specific action processes involved in the above method steps are fully elaborated in Examples 1 to 4, respectively.

[0067] It should be noted that the above embodiments one to four are illustrated using four typical scenarios: supercharging stations in highway service areas, emergency stations on national and provincial highways without mains power, stations in heavy-duty truck mining areas, and flexible stations in urban-rural fringe areas. However, the separable energy storage power supply system and method described in this invention are not limited to these four scenarios. This invention does not impose any constraints on the packaging form, dimensions, rated capacity, rated voltage, or chemical system of the energy storage unit, nor on the number of charging terminals, the rated power of a single charging gun, or the number of charging guns.

[0068] Regarding the packaging form of the energy storage unit, the energy storage unit of the present invention may be selected from any or a combination of the following forms, but not limited to: (a) containerized energy storage modules, including but not limited to 20ft standard containers, 10ft containers, 40ft containers, or containers of any non-standard size; (b) cabinet-type energy storage modules, including but not limited to outdoor integrated energy storage cabinets, indoor standard cabinets, or explosion-proof cabinets; (c) modular energy storage packages, including but not limited to standard 19-inch rack-mount, 4U / 6U / 8U drawer-type, pallet-type, or forklift pallet-type. Any independent package that can be moved into / out of the work area as a whole or in a whole package, and whose ports can be repeatedly electrically connected to the power connector of the energy conversion unit, regardless of its geometric shape (cubic prism, cylinder, or other arbitrary shape), falls within the scope of the energy storage unit of the present invention.

[0069] Regarding the rated capacity of the energy storage unit, this invention does not limit the capacity of a single energy storage unit. In actual engineering, the capacity of a single unit can be flexibly configured according to the power level of the charging station and the expected power supply duration, and its range covers, but is not limited to, 10kWh to 5000kWh. For example, the single energy pack of a charging station in a suburban area can be as low as 10kWh to 25kWh, the cabinet-type energy storage module of a community slow charging station can be configured with 50kWh to 100kWh, the outdoor energy storage cabinet of a fast charging station on national and provincial highways can be configured with 100kWh to 500kWh, the container-type energy storage module of a supercharging station in a highway service area can be configured with 500kWh to 2000kWh, and the ultra-large container energy storage module of a heavy truck charging station in a port or mining area can be configured with 2000kWh to 5000kWh. Furthermore, the rated capacities of different groups of energy storage units within the same charging station are allowed to be different; for example, the first energy storage unit is 500kWh while the second energy storage unit is 300kWh. The bidirectional voltage tracking and overlapping parallel handover timing described in this invention are also applicable to this asymmetric configuration, and the scheduling controller only needs to adjust the rotation trigger threshold according to the actual capacity of each group.

[0070] Regarding the rated voltage of the energy storage unit, this invention does not limit the rated voltage level of the energy storage unit; its DC port voltage can be flexibly set according to the DC bus voltage of the energy conversion unit and the number of batteries connected in series, and its range covers, but is not limited to, 200VDC to 1500VDC. For example: using a 200V level can be adapted to small energy storage packs in community 7kW to 20kW slow charging scenarios; using a 400V level can be adapted to passenger car 60kW to 120kW fast charging scenarios; using a 750V to 800V level can be adapted to supercharging scenarios (as in Example 1); using a 1000V to 1500V level can be adapted to megawatt-level heavy truck charging scenarios. When the rated voltages of different groups of energy storage units are different, the bidirectional DC / DC converter in the pre-charging branch of the energy conversion unit can be designed according to a wide range of voltage input, so that the same pre-charging branch can perform bidirectional voltage tracking for energy storage units of different voltage levels.

[0071] Regarding the chemical system of the energy storage unit, this invention does not limit the battery chemical system used in the energy storage unit; each group of energy storage units can independently select lithium iron phosphate, ternary lithium (including nickel cobalt manganese and nickel cobalt aluminum), sodium-ion batteries, semi-solid-state lithium batteries, all-solid-state lithium batteries, lithium manganese oxide batteries, or other commercial electrochemical energy storage systems, and different groups of energy storage units within the same charging station are allowed to have different chemical systems. The difference in chemical system is only reflected in different open-circuit voltage curves and different SOC-OCV mapping relationships. For the bidirectional voltage tracking mechanism of this invention, this difference can be adapted simply by the scheduling controller tracking the real-time terminal voltage reported by each group of BMS, without any structural changes to the tracking control law itself. For example, the first energy storage unit uses a lithium iron phosphate system (3.2V per cell, 256 cells in series, 819V at the group terminal), while the second energy storage unit uses a sodium ion system (3.1V per cell, 258 cells in series, 800V at the group terminal). The open-circuit voltage-SOC curves of the two are different, but the pre-charge branch always uses the measured DC bus voltage as the outer loop setpoint and the voltage at the group terminal to be entered as the outer loop feedback value during the tracking process. Tracking can be completed without knowing the battery chemical system type, and the ΔVth convergence criterion is also applicable.

[0072] Regarding the number and power of charging terminals, this invention does not limit the number of charging terminals, the number of charging guns, or the rated power of a single charging gun. One or more charging terminals can be connected to the output side of the energy conversion unit. The rated power of a single charging gun for each charging terminal can be any value from 7kW (AC slow charging), 20kW-60kW (DC fast charging), 120kW-480kW (supercharging), and 600kW-2400kW (megawatt-level heavy truck charging). The total number of charging guns can be 1 to N (N is determined by the rated capacity of the energy conversion unit and the scheduling strategy). Regardless of the configuration of the number and power of the charging terminals, the four-step rotation sequence defined in steps 1 to 4 of claim 1 applies; the scheduling controller only needs to adjust the rotation trigger threshold and the Pload parameter in the prediction algorithm according to the real-time total power demand of the charging terminals.

[0073] Regarding the external dimensions of the energy storage unit, this invention does not limit the length, width, height, or weight of the energy storage unit. The power and signal connectors on the workstation mating surfaces can be designed as standardized adapters, compatible with energy storage units of different shapes by using mechanical guide structures of different sizes (adjusting the guide pin spacing and flange position); alternatively, various specifications of workstation adapter frames can be configured for different shapes. For example, the same energy conversion unit can serve two workstations simultaneously. Workstation A accepts a 20ft containerized module, while workstation B accepts several 4U drawer-type energy packs, which are virtually combined into a group of energy storage units. The two workstations share the same pre-charging branch (selectively connected via a disconnect switch). The four-step switching sequence of this invention is also applicable to this multi-workstation configuration.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A separable energy storage power supply system for lane-type orderly charging stations, characterized in that, include: The fixed-installation energy conversion unit is electrically connected to the charging terminal, has bidirectional conversion capability, and is equipped with a controlled bidirectional pre-charging branch. At least two sets of energy storage units that can be disassembled as a whole are provided, each equipped with a battery-side main contactor, and connected to the same workstation of the energy conversion unit via a power connector that can be repeatedly switched on and off. The scheduling controller is configured to execute sequentially during rotation: Step 1: While the first energy storage unit is powered online, connect the second energy storage unit to the workstation and keep its battery-side main contactor disconnected. Step 2: Through the pre-charging branch, with the real-time voltage of the DC bus of the energy conversion unit as the target value, the energy conversion unit performs bidirectional voltage tracking on the second energy storage unit until the voltage difference between the two is less than a preset threshold. Step 3: Close the main contactor on the battery side of the second energy storage unit to connect the two sets of energy storage units in parallel on the DC bus for a short time. Step 4: Disconnect the main contactor on the battery side of the first energy storage unit and remove it from the workstation, so that the second energy storage unit can continue to supply power to the charging terminal.

2. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, The controlled bidirectional pre-charge branch includes a bidirectional DC / DC converter, one side of which is connected to the DC bus of the energy conversion unit, and the other side is connected to the positive and negative terminals of the power connector of the energy storage unit to be stored at the workstation via an isolating switch.

3. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, The scheduling controller is also configured to set a duration upper limit Tmax for short-term parallel connection, and to forcibly execute step 4 before the parallel connection duration reaches Tmax; wherein Tmax≤30 seconds.

4. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, The bidirectional voltage tracking employs a closed-loop control combining a constant voltage outer loop and a current-limiting inner loop, with the current-limiting value not exceeding the rated current of the smaller of the pre-charging branch or the power connector.

5. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, The workstation is also equipped with a mechanical locking mechanism and an electrical interlocking circuit. The dispatch controller will only allow the main contactor to close in step 3 when the mechanical locking is in place and the electrical interlocking circuit is connected.

6. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, The number of energy storage units shall be no less than three sets, of which at least one set shall be in online power supply state, at least one set shall be in standby state, and at least one set shall be in offline power replenishment or maintenance state.

7. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, The scheduling controller triggers rotation when any of the following conditions are met: the state of charge of the online energy storage unit is lower than the set lower limit, the health status is lower than the set lower limit, any temperature sensor exceeds the limit, the BMS reports a critical alarm, or an external scheduling instruction is received.

8. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, The scheduling controller is communicatively connected to the orderly charging queue management module of the lane-type orderly charging station. Based on the charging demand and power curve of subsequent vehicles in the queue, it predicts the available power supply time of the online energy storage unit and actively triggers the rotation before the time is reached.

9. The separable energy storage power supply system for lane-type orderly charging stations according to claim 1, characterized in that, It also includes a replacement actuator located between the workstation and the external transfer channel, wherein the replacement actuator is selected from one or more of the following: an electric forklift with a roller channel, a rail-mounted RGV, an AGV, and a drawer-type robotic arm.

10. A method for using a separable energy storage power supply system for a lane-type orderly charging station as described in any one of claims 1 to 9, characterized in that, include: Step S1: The energy conversion unit supplies power to at least one charging terminal via the first energy storage unit; Step S2: While the first energy storage unit is kept online, the second energy storage unit is connected to the DC bus side of the energy conversion unit through the electrical interface, and the main contactor on the battery side of the second energy storage unit is kept in the open state. Step S3: Through the controlled bidirectional pre-charging branch of the energy conversion unit, the second energy storage unit is subjected to bidirectional voltage tracking with the real-time voltage of the DC bus of the energy conversion unit as the target value until the voltage difference between the two is less than a preset threshold. Step S4: Close the main contactor on the battery side of the second energy storage unit to connect the two sets of energy storage units in parallel on the DC bus for a short time. The output current of the energy conversion unit to the charging terminal remains continuous during the parallel connection. Step S5: Disconnect the battery-side main contactor of the first energy storage unit and disconnect the entire first energy storage unit from the energy conversion unit, so that the second energy storage unit continues to supply power to the charging terminal.

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