An energy storage vehicle power supply system achieving local seamless hot plug and global power supply non-inductive cut-off

Abstract

The application discloses a kind of energy storage vehicle power supply systems achieving local seamless hot plug and global power supply non-inductive cut-off, including total direct-current bus, multiple detachable battery branches, and isolation type bidirectional direct-current converter corresponding with each battery branch, and central control system.The locking detection piece of quick release connector outputs the unlocking state transition before power contact starts to separate;Central control system latches target branch power and the available power margin of the rest online branches according to this, makes target branch current decay to safety threshold and synchronously improves the output of the rest branches according to complementary power reference trajectory, and locks target direct-current converter after confirmation.When battery branch is inserted, central control system executes current-limiting pre-charging, voltage matching and complementary soft start in turn.The system makes branch electrical isolation prior to contact separation, and reduces bus power and voltage disturbance caused by branch increase and decrease.

Description

Technical Field

[0001] This invention relates to the field of mobile energy storage and high-voltage DC power supply technology, specifically to a power supply system that utilizes the mechanical state precedence signal of a quick-release connector, a branch-isolated bidirectional DC-DC converter, and complementary power regulation of a central control system to achieve online insertion or removal control of battery branches in an energy storage vehicle.

[0002] The present invention also relates to the connection relationship between the detachable battery pack, quick-release connector, branch power conversion unit and main DC bus in the above power supply system, as well as current zeroing, power compensation, current limiting pre-charge and soft start control during branch switching. Background Technology

[0003] Mobile energy storage vehicles typically power an onboard high-voltage DC bus via multiple battery packs, which then output power to external loads or devices requiring recharging via onboard conversion equipment. The combined operation of multiple battery packs expands energy storage capacity and output power, and allows for flexible configuration of the number of battery packs based on mission duration. To minimize downtime for recharging or maintenance, the battery packs can also be detachable, enabling the replacement of insufficiently charged or maintenance-required battery packs during power supply missions.

[0004] In DC power supply scenarios, the current does not have periodic zero-crossing points. If the power contacts of a loaded branch begin to separate while there is still branch current, a continuous arc may form between the contacts, causing connector ablation and temperature rise. Relying solely on personnel to stop the branch output and then remove the battery pack according to a predetermined operating sequence may still result in a time lag between the branch's electrical state and the actual mechanical action, making it difficult to ensure that each contact separation corresponds to a confirmed low-current state.

[0005] When multiple battery packs are connected in parallel directly or in parallel to the same main DC bus via a power conversion unit, the sudden disconnection of any battery branch will result in a short-term loss of its output power. Similarly, the direct connection of any battery branch will alter the equivalent impedance on the bus side and charge the output capacitor. These changes can cause bus voltage shifts, inrush currents, or transient overloads in other branches, thereby affecting the continuity of the energy storage vehicle's output.

[0006] For example, Chinese patent application CN103227583A discloses a hot-swappable converter system for new energy and energy storage systems. It sets up a bidirectional DC / DC converter and a hot-swappable power switch between the battery array and the DC bus. During hot insertion, the output voltage is adjusted until the voltage difference across the hot-swappable power switch is less than a specified threshold, at which point the switch closes. During hot removal, the output current of the bidirectional DC / DC converter to be removed is adjusted until it is less than a specified current threshold, at which point the hot-swappable power switch opens. Current sharing among the remaining converters is achieved through communication. This scheme enables live insertion and removal of the energy storage battery array. However, based on its disclosure, the hot-removal control relies on actively adjusting the converter current after the hot-removal procedure is initiated. It does not involve utilizing the pre-unlocked state of the connector to form a defined control time window before the power contacts separate, nor does it disclose the synchronous generation of complementary compensation trajectories for the remaining branches according to the power reduction of the target branch to constrain the continuity of the total power of the bus.

[0007] For example, Chinese patent application CN103296726A discloses a battery energy storage module, its control method, and an energy storage power supply system. Multiple battery energy storage modules can be connected in parallel to the bus and can be disassembled or installed during system operation. This scheme detects the output voltage of the battery pack and the bus voltage. When the difference between the two is large, the battery pack is charged or discharged through pre-charge and pre-discharge circuits. The battery pack is then connected to the bus after the voltage difference is less than a preset value to reduce the inrush current at the moment of connection. From its disclosure, this scheme focuses on voltage matching and module-level protection before connection. It does not provide specific coordination mechanisms for the sequential constraints of mechanical action and electrical isolation when the loaded branch is pulled out, the synchronous power takeover of other online branches during the current reduction process of the target branch, or the continuous correction based on bus feedback.

[0008] Existing branch protection can shut down power devices after an abnormality occurs based on electrical quantities such as overcurrent, undervoltage, or communication interruption, and connectors can also provide feedback on their insertion status through auxiliary contacts. However, if there is no definite sequential relationship between the mechanical status signal and the power conversion control, the controller may only receive the status change after the power contacts have already begun to separate; if the output command of the target branch is simply set to zero without synchronously transferring its original power, the bus will still experience a power step caused by the target branch's disconnection.

[0009] Therefore, it is necessary to establish a coordinated relationship between the mechanical travel of the quick-release connector, the independent power regulation of each battery branch, and the feedback regulation of the main DC bus, so that the control system can identify the intention to pull out before the power contacts separate and complete the current decay of the target branch, while the remaining online battery branches continuously take over the power released by the target branch; for the insertion process, it is also necessary to complete the output side pre-charging before connecting to the bus and continuously transfer the branch power after grid connection. Summary of the Invention

[0010] The purpose of this invention is to provide a power supply system for energy storage vehicles that enables seamless hot-swapping of parts and seamless disconnection of power supply throughout the entire system, in order to solve the problem of lack of coordinated control between the mechanical plugging and unplugging of detachable battery branches and electrical isolation, and between the addition and reduction of branches and the power balance of the bus.

[0011] To achieve the above objectives, the present invention provides a power supply system for an energy storage vehicle. The system includes a main DC bus, multiple battery branches, branch sensors, bus sensors, and a central control system. The main DC bus is connected to the external output interface of the energy storage vehicle. Each battery branch includes a removable battery pack, a quick-release connector, and an isolated bidirectional DC-DC converter. The removable battery pack is connected to the input terminal of the corresponding isolated bidirectional DC-DC converter via the quick-release connector, and the output terminals of each isolated bidirectional DC-DC converter are connected in parallel to the main DC bus.

[0012] The quick-release connector includes power contacts and a locking detection element. The locking detection element is positioned along the movement path of the mechanical lock and outputs an unlock state transition when the unlocking action enters the pre-separation stroke. The state switching position of the locking detection element is located before the electrical contact termination position of the power contacts, thus creating a mechanical time window between the unlock state transition reaching the central control system and the start of power contact separation.

[0013] Branch sensors collect the branch current and voltage of each battery branch, while bus sensors collect the bus voltage and total power of the main DC bus. The central control system communicates with the locking detection device, branch sensors, bus sensors, the battery management interface of the removable battery pack, and each isolated bidirectional DC-DC converter.

[0014] When the central control system receives an unlock state transition from any locking detection device, it identifies the corresponding battery branch as the target branch, obtains the current output power of the target branch and the available power margin of the remaining online battery branches, and generates the first set of complementary power reference trajectories. The output current of the target branch decays according to the first set of complementary power reference trajectories, and the increased output power of the remaining online battery branches follows the decreased output power of the target branch. After the output current of the target branch meets the safety confirmation conditions, the central control system locks the isolated bidirectional DC-DC converter of the target branch, ensuring that electrical isolation is completed before the power contacts begin to separate.

[0015] When the central control system detects that the battery branch to be connected has been inserted, it controls the corresponding isolated bidirectional DC-DC converter to sequentially perform current-limited pre-charging and voltage matching. After the battery branch to be connected meets the grid-connected matching conditions, the central control system generates a second set of complementary power reference trajectories, causing the battery branch to be connected to increase its output power along the continuous soft-start trajectory, and causing the original online battery branches to synchronously restore their output power according to their respective allocation weights.

[0016] Furthermore, each isolated bidirectional DC-DC converter includes an output-side capacitor, a controllable power switch, and a local current controller. The local current controller adjusts the controllable power switch according to the current reference value issued by the central control system; after the target branch is blocked, the isolated bidirectional DC-DC converter blocks the reverse current from the main DC bus to the target branch.

[0017] Furthermore, the central control system determines the potential power margin based on the state of charge, temperature, health status, allowable output power, and current output power of each online battery branch, and generates short-term load power predictions based on the total bus power and its changing trend over the most recent control cycles. The central control system uses a comprehensive optimization objective, considering the bus power gap, branch status constraints, and branch power change rate, to continuously calculate compensation power and adaptively allocate weights under constraints on allowable output power, state of charge, temperature, health status, and converter power change rate for each branch. When an online battery branch reaches any constraint boundary, the central control system continues to optimize the allocation of unallocated compensation power among the remaining online battery branches with potential power margins.

[0018] Furthermore, the central control system generates a feedback correction based on the deviation between the bus voltage and the bus reference voltage, and adds the feedback correction to the power reference value of each online battery branch according to the assigned weights. The blocking conditions for the target branch include that the output current of the target branch remains within the safe current threshold for a preset confirmation period, and that the bus voltage remains within the allowable voltage deviation range for the same preset confirmation period.

[0019] This invention also provides a seamless hot-swap control method for battery branches in energy storage vehicles, comprising: receiving an unlock state transition and determining a target branch before the power contacts begin to separate; obtaining the current output power of the target branch and the available power margin for the remaining online battery branches; causing the target branch to reduce its output power according to a power reduction trajectory, and causing the remaining online battery branches to synchronously increase their output power according to a compensation trajectory; blocking the corresponding isolated bidirectional DC-DC converter when the output current of the target branch meets the safety confirmation conditions; performing current-limiting pre-charging and voltage matching on the battery branch to be connected; and after meeting the grid connection matching conditions, causing the battery branch to be connected to soft-start and causing the original online battery branches to synchronously revert their output power.

[0020] This invention achieves the following beneficial effects: By positioning the locking detection element before the electrical contact termination position of the power contacts, the central control system obtains a time window to complete current reduction and status confirmation of the target branch before contact separation; through isolated bidirectional DC-DC converters corresponding to each removable battery pack, the target branch can be independently adjusted and isolated, and reverse current to the bus can be blocked; by using the same continuous change function to generate complementary power reference trajectories for the target branch and other branches, the power changes caused by the exit or entry of the target branch are continuously transferred between branches; through bus feedback correction, current-limiting pre-charging, and voltage matching, bus voltage deviation and access surges during hot-plugging can be reduced. The aforementioned quick-release connector mechanical timing, independent bidirectional switching of branches, predictive dynamic power allocation, and bus closed-loop correction together form a complete underlying control link from mechanical action perception to branch power execution and then to the stability of the vehicle bus, raising the system integration threshold and technology replication threshold of high-power hot-plugging solutions for energy storage vehicles, and facilitating the formation of sustainable and reusable technological barriers. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the energy storage vehicle power supply system in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the battery branch disconnection control process in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the battery branch insertion control process in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the functional modules and data flow of the central control system in an embodiment of the present invention.

[0025] Figure 5 This is a timing diagram illustrating the sequence between the unlock signal, branch power adjustment, and power contact separation in an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram showing the positional relationship of the quick-release connector in the locked connection, unlocked pre-separation, and power contact separation states in an embodiment of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings. The following embodiments are used to illustrate the connection relationship and control process between the components, and are not intended to limit the number of removable battery packs, rated voltage, rated power, or specific power topology of the isolated bidirectional DC-DC converter. As long as the power of the corresponding battery branch can be independently adjusted according to the reference value issued by the central control system, and branch isolation can be achieved in the blocked state, the present invention can be implemented.

[0028] In this specification, an online battery branch refers to a battery branch where the quick-release connector is in an effective connection state, the corresponding isolated bidirectional DC-DC converter has been connected to the grid, and it is allowed to carry the bus power; a target branch refers to a battery branch to be removed, determined by the central control system based on the unlocking state transition; and a battery branch to be connected refers to a battery branch that has been detected as being in the insertion position but has not yet completed a soft start. The branch output power is positive when it sends power to the total DC bus and negative when it absorbs power from the total DC bus.

[0029] The term "seamless hot-swap in this manual" means that during the insertion or removal of a single battery branch, the other online battery branches remain operational. The target branch to be removed completes current attenuation and electrical isolation before the power contacts begin to separate, and the branch to be connected continuously bears power after completing current-limited pre-charging and voltage matching. "Global power supply seamless disconnection" means that during the addition or removal of the above branches, the external output interface does not experience a power interruption directly caused by the switching of the target branch, and the bus voltage remains within the set allowable deviation range. The terms "seamless" and "seamless" are technical descriptions of the control objectives and judgment conditions, and do not imply that the relevant physical quantities are absolutely zero under any operating condition.

[0030] The following embodiments 1 to 10 correspond to claims 1 to 10 in numerical order. Subsequent embodiments further explain the corresponding additional technical features, control steps, and their functions based on the disclosure of the foregoing embodiments; identical components, signals, and parameters not repeated herein retain their meanings from the foregoing embodiments.

[0031] Example 1: See Figure 1 The energy storage vehicle power supply system includes a central control system 100, multiple battery branches 200, a main DC bus 300, bus sensors 310, and an external output interface 400. Figure 1 Taking four battery branches 200-1 to 200-4 as an example, the actual number can be set to two or more depending on the required capacity and power of the energy storage vehicle. Each battery branch 200 includes a removable battery pack 210, a quick-release connector 220, a locking detection element 221, an isolated bidirectional DC-DC converter 230, and a branch sensor 240.

[0032] The removable battery pack 210 internally houses cell groups and a battery pack-level management unit. The battery pack-level management unit collects cell voltage, battery pack current, temperature, state of charge (SOC), and state of health (SOC), and outputs the current allowable charging power and current allowable discharging power based on the cell's allowable current, temperature protection limits, and the battery pack's SOC. The central control system 100 reads these statuses via CAN bus, Ethernet, or other vehicle communication interfaces. Communication frames carry branch identifiers and sampling timestamps to correlate the status of different battery branches with the same control cycle.

[0033] Branch sensor 240 can be installed on the output side of isolated bidirectional DC-DC converter 230, or it can utilize existing voltage and current sampling circuits within the converter. Bus sensor 310 is installed on the main DC bus 300 to acquire bus voltage and bus current. The central control system 100 determines the current bus load power based on the bus voltage and bus current. ; In the formula, Indicates time Bus load power, in watts; Indicates time Total DC bus voltage, in volts; Indicates time Bus current flowing to the external output interface 400, in amperes; Indicates the sampling time used by the control system. During discharge power supply... When the value is positive, the external power supply charges the battery branch through the external output interface 400. Take the negative value.

[0034] See Figure 4 The central control system 100 includes a status acquisition module 110, a hot-swap event recognition module 120, a power margin and weight calculation module 130, a converter control module 140, and a bus feedback correction module 150. These modules can be implemented by program function units within the same controller, or they can be implemented collaboratively by the on-board main controller and the local controllers of each isolated bidirectional DC-DC converter 230. The status acquisition module 110 timestamps the battery pack status, connector status, branch electrical status, and bus electrical status, and discards old data that exceeds the valid time window.

[0035] The hot-plug event recognition module 120 debouncingly monitors the state of the locking detection element 221. When a consistent unlock level is detected for multiple consecutive control cycles, an unlock state transition is confirmed; when an insertion level is detected for multiple consecutive control cycles and branch communication is valid, an insertion event is confirmed. The required number of consecutive control cycles is determined based on the contact bounce time of the detection element, the sampling period, and the communication validity determination time. Its purpose is to prevent single-intrusion triggering of branch power transfer.

[0036] For example, when the central control system 100 uses a 1-millisecond control cycle, it can detect a consistent state for 3 consecutive control cycles and then confirm that the locking detection element 221 has switched to a stable state, with a corresponding detection debouncing time of 3 milliseconds. For local control links that use high-priority CAN or vehicle Ethernet message transmission, the command transmission design target can be set to 1 to 5 milliseconds, and the worst-case message queuing, verification, and execution delays can be included in the command time described in Example 2.

[0037] In this invention, the safe current threshold, continuous confirmation duration, and allowable voltage deviation range are all control parameters determined based on the system hardware capabilities. Specifically, the safe current threshold is determined based on the allowable breaking current of the power contacts and the residual current capability of the isolated bidirectional DC-DC converter after blocking; the continuous confirmation duration is determined based on the time required for detector debouncing, branch current sampling and filtering, and state stability determination, and is included in the mechanical time window; the allowable voltage deviation range is determined based on the bus rated voltage and the DC input tolerance of the external load. The selection of these parameters should also satisfy the constraint described in Example 2 that the total delay of detection, command transmission, current reduction, and confirmation is less than the mechanical time window.

[0038] Based on the above structure, when the central control system 100 receives an unlock state transition from any locking detection element 221, it identifies the corresponding battery branch 200 as the target branch, reads the current output power of the target branch and the available power margin of the other online battery branches, generates the first set of complementary power reference trajectories, causing the current of the target branch to continuously decay and the corresponding power to be synchronously taken over by the other online branches; when the current of the target branch meets the safety conditions, its isolated bidirectional DC-DC converter 230 is blocked. When the battery branch to be connected is detected to be inserted, the central control system 100 controls the corresponding isolated bidirectional DC-DC converter 230 to perform current-limited pre-charging and voltage matching, and generates the second set of complementary power reference trajectories after the grid connection matching conditions are met, causing the branch to be connected to soft start and the original online branches to synchronously revert to their output power.

[0039] The central control system 100 can be implemented using an automotive-grade microcontroller, digital signal processor, or field-programmable gate array. The status acquisition module 110 and hot-swap event recognition module 120 can operate on high-priority interrupt tasks, while the power margin and weight calculation module 130 and bus feedback correction module 150 can operate on fixed-cycle tasks. The converter control module 140 issues control commands via communication messages with frame counting and cyclic redundancy check. If a command message is not updated within its validity period, each isolated bidirectional DC-DC converter 230 maintains its current limit value or enters a blocked state according to a preset safety strategy.

[0040] The central control system 100 in this invention can also be implemented in a distributed manner. The on-board main controller is responsible for determining the target branch, the bus power target, and the weights allocated to each branch. The local controllers of each isolated bidirectional DC-DC converter 230 synchronously generate the power reference value for their respective branch based on the broadcast trajectory start time and trajectory parameters. Each local controller uses the same clock source or is synchronized via a bus clock to ensure that the power reduction trajectory of the target branch corresponds in time with the compensation trajectories of the other branches.

[0041] The central control system 100 can also communicate with the cloud / fleet dispatching system via the vehicle-mounted communication gateway, receive the optimal cost function dispatching instructions generated by the cloud, and coordinate the operation of the mother vehicle and the daughter vehicles accordingly. In this power supply system, the cloud dispatching instructions serve as the input of the task-level power target. The local central control system 100 still independently performs lockout state identification, mechanical time window verification, target branch current reduction and blocking, pre-charging of the branch to be connected, and grid connection matching. The cloud dispatching does not replace the local safety confirmation conditions.

[0042] The technical advantage of this embodiment lies in integrating mechanical pre-detection, independent branch power conversion, bus status acquisition, and complementary power adjustment during insertion and removal into a single power supply architecture. This allows a single battery branch to be disconnected or connected without interrupting the operation of other branches. This solves the technical problem of simultaneously ensuring the safety isolation of local branches and the continuity of power supply to the energy storage vehicle during the replacement of removable battery packs.

[0043] Example 2: The power contact 222 of the quick-release connector 220 is used to establish a high-voltage connection between the removable battery pack 210 and the input terminal of the isolated bidirectional DC-DC converter 230. The locking detection element 221 can be a normally closed or normally open microswitch, or a Hall position sensor, photoelectric position sensor, or limit switch. Regardless of the detection element used, its installation position ensures that the detection state changes in the initial stage of the mechanical lock moving from the locked position to the unlocked position, and the power contact 222 only ends the electrical contact after the mechanical lock continues to move or the plug continues to be pulled out.

[0044] See Figure 6 In the locked connection state, the mechanical lock keeps the fixed socket 220a and movable plug 220b of the quick-release connector 220 relatively fixed, the power contacts 222 maintain sufficient contact overlap, and the locking detection element 221 is in a pressed state. When the operator begins to unlock, the mechanical lock first leaves the locked position and releases the locking detection element 221; at this time, the power contacts 222 still maintain electrical contact. Only after the movable plug 220b continues to move in the pull-out direction does the power contacts 222 begin to separate.

[0045] The mechanical movement time between the state switching position of the locking detection element 221 and the electrical contact termination position of the power contact 222 is defined as the mechanical time window. The central control system 100, communication link, and isolated bidirectional DC-DC converter 230 need to complete event confirmation, command transmission, target branch current attenuation, and safety status confirmation within this mechanical time window. Their relationship is as follows: ; In the formula, This indicates the detection time required to complete debouncing and event confirmation after the state of the locking detection element 221 changes; This indicates the command time required for the central control system 100 to generate control commands and transmit them to the isolated bidirectional DC-DC converter 230; This indicates the time required for the actual current in the target branch to decrease from the pre-unlock current to within the safe current threshold. This indicates the confirmation time required for the target branch current and bus voltage to meet the confirmation conditions. This represents the mechanical time window between the output of the unlocked state from the locking detection element 221 and the start of separation of the power contact 222. All the above time values ​​are in seconds.

[0046] The time window can be determined through displacement-time testing on the connector sample. Specifically, the movable plug 220b is moved at a specified maximum manual pull-out speed, and the state switching time of the locking detection element 221 and the contact resistance transition time of the power contact 222 are recorded. The difference between the two is the mechanical time window for this test. The minimum value obtained from multiple tests is used as a design constraint, and the detection debouncing time and the target branch current reduction time are selected accordingly. According to the quick-release structure described in the technical disclosure, the physical window formed by the locking detection preceding the separation of the power contact is usually in the range of tens to hundreds of milliseconds. For specific products, the minimum measured time window of the connector under the most unfavorable pull-out conditions shall prevail.

[0047] As an example of a set of executable controller parameter designs, for an energy storage vehicle power supply system with an approximately 800V HVDC bus and a branch current of around 100A, the lower limit of the minimum mechanical time window can be set within the range of 60ms to 120ms; the detection debouncing time can be set to 2ms to 5ms, the command generation and vehicle communication transmission time can be set to 2ms to 5ms, the target branch current decay time can be set to 20ms to 40ms, and the continuous state confirmation time can be set to 5ms to 10ms, ensuring that the sum of the above times retains a control margin of no less than 10ms relative to the minimum mechanical time window. The safe current threshold can be set according to 0.5% to 1% of the rated branch current, and must not exceed the allowable breaking current of the selected power contact at the corresponding DC voltage level; the allowable bus voltage deviation can be set according to ±1% to ±3% of the rated bus voltage.

[0048] If the actual current of the target branch fails to drop to the safe current threshold within the mechanical time window, the central control system 100 immediately issues a hardware blocking command to the target isolated bidirectional DC-DC converter 230 and records the branch current reduction timeout fault. For quick-release connectors 220 with controllable mechanical locks, the central control system 100 can also keep the mechanical lock closed until the actual current meets the safety confirmation conditions; for connectors without controllable mechanical locks, the mechanical time window of the connector is designed with a margin sufficient to meet the total control delay based on the most unfavorable pull-out speed.

[0049] The technical advantage of this embodiment lies in that, by switching the state of the locking detection element 221 before the power contact 222 begins to separate, and constraining the total delay of detection, communication, current reduction, and confirmation with a mechanical time window measured at the most unfavorable pull-out speed, the electrical control actions have a clear and verifiable sequential margin. This solves the technical problem that relying solely on manual operation sequences or electrical abnormal signals after contact separation makes it difficult to ensure that the DC-loaded connector completes low-current reduction before contact separation.

[0050] Example 3: The input terminal of the isolated bidirectional DC-DC converter 230 is connected to the corresponding removable battery pack 210, and the output terminal is connected in parallel to the main DC bus 300. The isolated bidirectional DC-DC converter 230 can adopt a dual active bridge, a phase-shifted full bridge, or other bidirectional converter topologies with high-frequency isolation. Its local current controller receives the operating mode, current reference value, and lockout command issued by the central control system 100, and returns the actual input voltage, actual output voltage, actual branch current, device temperature, and fault status to the central control system 100.

[0051] The isolated bidirectional DC-DC converter 230 further includes an output-side capacitor, a controllable power switch, and a local current controller. The output-side capacitor is used to stabilize the converter bus-side port voltage; the local current controller drives the controllable power switch according to the current reference value issued by the central control system 100, enabling the corresponding branch to independently increase or decrease current. After the central control system 100 issues a blocking command, the local current controller stops generating effective PWM drive and uses the reverse current blocking state of the converter to prevent the main DC bus 300 from flowing back to the blocked target branch.

[0052] The technical advantage of this embodiment lies in that each detachable battery pack is paired with an isolated bidirectional DC-DC converter that has independent current closed-loop and reverse current blocking capabilities, so that branch power regulation, blocking, and isolation do not depend on the power outage of the vehicle bus. This solves the technical problems that when multiple battery branches share a bus, a single branch may still be subject to reverse power feed from the bus after it is disconnected, and that branches cannot be independently controlled and isolated.

[0053] Example 4: See Figure 2 When the hot-plug event recognition module 120 confirms the first When the battery branch undergoes an unlocked state transition, the first... The battery branch is identified as the target branch, and the unlocking time is recorded as... The output power of the target branch latched by the central control system 100. The output power of the remaining online battery branches and the total power of the bus are also considered. If the target branch is in a charging state, the same process is used to transfer its absorbed power in the negative power direction. For ease of explanation, the following example shows each battery branch discharging to the total DC bus 300.

[0054] To avoid directly switching the power reference value of the target branch from its current value to zero, the central control system 100 uses a trajectory function that continuously varies from zero to one. One possible trajectory function is: ; In the formula, Indicates time The dimensionless trajectory value; Indicates normalized time; This indicates the moment when the unlock event is confirmed and power transfer begins; Indicates the preset power transfer time; Indicates when When less than zero, take zero; when Take 1 if it is greater than 1, otherwise take 1. A cubic polynomial makes The slopes at both the starting and ending points of the transition are zero to reduce abrupt changes in the slope of the reference value. Alternatively, other trajectory functions that are monotonically continuous with a zero starting point and a one ending point can be used.

[0055] From a control mechanism perspective, the first-order rate of change of the cubic polynomial trajectory is zero at both the start and end of the power transfer, ensuring that the branch power reference value generated by this trajectory does not experience abrupt slope jumps at the start and end of the transfer, thereby reducing abrupt changes in the reference value received by the local current controller. The cubic polynomial is used to obtain the aforementioned boundary characteristics with lower computational complexity; it is not a requirement to use this specific function. Other trajectory functions that satisfy monotonicity, continuity, a zero start point, a one end point, and can satisfy the branch current loop response constraints can also be used.

[0056] The power reduction reference trajectory of the target branch is generated according to the following formula: ; In the formula, Indicates time The target branch power reference value; This indicates the output power of the target branch latched when the unlock state transition is reached; Represents the dimensionless trajectory value; Indicates the target branch index; Indicates the current control moment. With... From zero to one, The output power decreases continuously from zero before unlocking.

[0057] The first branch other than the target branch The compensated power reference trajectory for each online battery branch is generated according to the following formula: ; In the formula, Indicates time The Reference value for the power of an online battery branch; This indicates the latched state when the unlock transition is reached. Output power of the online battery branch; Indicates the first The compensation power allocation weight for each online battery branch; This indicates the output power before the target branch is unlocked; Represents the dimensionless trajectory value; This represents the set of online battery branch indices excluding the target branch before unlocking; express Index of any branch in the [various] path.

[0058] When none of the online battery branches reach their allowable output power and conversion losses are ignored, the power reduction reference trajectory of the target branch and the compensation power reference trajectories of the other branches satisfy the following: ; In the formula, Indicates the target branch at time [time]. The power reference value; Indicates the first The remaining online battery branches at time The power reference value; Indicates the first time the unlock event occurs. The latched output power of the online battery branch; This represents the set of online battery branch indices prior to the unlock event. Indicates from Remove the target branch index The resulting set of indices; Indicates the target branch index; express The online battery branch index is used. This equation indicates that the sum of the power reference values ​​of each branch during power transfer remains the same as the total branch power before unlocking.

[0059] The technical advantage of this embodiment lies in that, upon the occurrence of an unlocking event, the reference power of the target branch and other online branches is latched, and mutually compensating power reduction and power increase trajectories are generated using the same continuous trajectory function, so that the power released by the target branch is continuously transferred to the other branches in time. This solves the technical problems of bus power step jump, bus voltage abrupt change, and short-term power interruption perceived by external loads caused by directly setting the target branch command to zero.

[0060] Example 5: The power margin and weight calculation module 130 first determines the allowable output power of each online battery branch in the current state. For the first... The allowable output power of the online battery branch is jointly limited by the allowable output power of the battery pack and the allowable output power of the isolated bidirectional DC-DC converter. ; In the formula, Indicates the first The permissible output power of an online battery branch; This indicates that the battery pack level management unit is based on the first State of charge of a battery branch , representing temperature and health status The defined battery pack's allowable output power; Indicates the first The permissible output power of an isolated bidirectional DC-DC converter at current device temperature and bus voltage; This indicates that the smaller value among the constraints within the parentheses should be selected. This indicates the serial number of the online battery branch. This can be obtained by looking up the state of charge-temperature-allowable current mapping table calibrated during the battery production stage, and multiplied by a factor reflecting capacity retention. Correction factor.

[0061] Before the power transfer begins, the central control system 100 latches the current output power of each online battery branch and calculates the output power that each branch can continue to increase: ; In the formula, Indicates the first The power margin for each online battery branch; Indicates the first The permissible output power of an online battery branch; This indicates the latched number when the unlock state transition is received. Output power of the online battery branch; This indicates taking the maximum value among the quantities within the parentheses. Using zero as the lower limit prevents branches whose current output power has already reached or exceeded the allowable output power from receiving positive compensation power.

[0062] When the sum of the available power margins of online battery branches other than the target branch is greater than zero, the central control system 100 determines the first branch according to the available power margin. Weighting of each online battery branch: ; In the formula, Indicates the first The compensation power allocation weight for each online battery branch; Indicates the first The power margin for each online battery branch; This represents the set of online battery branch indices prior to the unlock event. Indicates the index of the target branch; Indicates the online battery branch index used for summation; Indicates from Remove the target branch index The resulting set of online battery branch indexes. (Complete) All values ​​are not less than zero and their sum is one. If a branch reaches the allowable output power, the branch is removed from the set and the weights are recalculated using the remaining margin.

[0063] The local current controller adjusts the PWM duty cycle of the power switch according to the current reference value. If the actual power of any online battery branch reaches... The central control system 100 limits the power reference value of this branch to [value missing]. The remaining compensation power, which has not yet been undertaken, is redistributed to branches that still have room for power increase. This process is repeated until the remaining compensation power is zero or all branches have reached their allowable output power.

[0064] To enable power take-off to anticipate changes in external load within the mechanical time window, the power margin and weight calculation module 130 further establishes a short-term load prediction window. In each rolling control cycle, the most recent... The total bus power and the power difference between adjacent sampling points for each control cycle are used to calculate the current load change trend by weighted averaging or recursive least squares estimation of the power difference, and based on this, the predicted bus load power for several future control cycles is generated. When the external output interface 400 can receive the planned power or power negotiation information of the external load, the planned power is used as the feedforward correction amount of the predicted value; when the external load does not provide planned power, short-term prediction is completed only using the historical sequence of bus power.

[0065] The central control system 100 uses the compensation power increment of each online battery branch in the prediction time domain as the optimization variable to establish a multi-objective cost function that simultaneously includes bus power gap penalty, branch state constraint penalty, and power change rate penalty. Specifically, the bus power gap penalty ensures that the sum of the compensation power of each online branch tracks the sum of the target branch's released power and the predicted load change; the branch state constraint penalty increases as the state of charge approaches the lower limit, the temperature approaches the protection threshold, or the health state declines; and the power change rate penalty limits sudden changes in power commands between adjacent control cycles. The optimization constraints include at least the current allowable output power, available power margin, allowable state of charge range, allowable temperature range, health state threshold, and allowable power change rate of the isolated bidirectional DC-DC converter for each branch.

[0066] The aforementioned optimization problem can be solved in each control cycle using quadratic programming, the active set method, or other constraint optimization methods that satisfy real-time requirements. The calculated compensation power increments for each branch are normalized according to all positive compensation increments to obtain the adaptive allocation weights for the current control cycle. When any branch reaches the allowable output power, temperature limit, state of charge limit, or converter power change rate limit, that branch is fixed at the corresponding boundary, and the remaining compensation amount is resolved only for the remaining available branches. If the optimization solution fails to converge within a specified time, the allocation method based on the proportion of available power margin described in Example 5 is reverted, thus balancing algorithm enhancement and control real-time performance.

[0067] The technical advantage of this embodiment is that it constrains the compensation power distribution to the real-time availability of each battery branch, and automatically redistributes the remaining compensation amount after the branch reaches its power limit. This avoids pushing branches with low charge, limited temperature, poor health, or those already close to their allowable output limit to overload in order to maintain the bus power. This solves the technical problem that average allocation or fixed weights cannot reflect the dynamic margin of the branches and are prone to local overload during multi-branch management.

[0068] Example 6: Since the actual system has sampling errors, communication delays, and conversion losses, the bus feedback correction module 150 corrects the aforementioned feedforward power reference value based on the bus voltage deviation. The bus voltage deviation is defined as: ; In the formula, Indicates time Bus voltage deviation; This indicates the bus reference voltage corresponding to the power supply task of the energy storage vehicle; This indicates that the bus sensor 310 is at time [time missing]. The actual bus voltage collected; Indicates the current control moment. A positive value indicates that the actual bus voltage is lower than the bus reference voltage.

[0069] The bus feedback correction module 150 can generate the total power correction amount using proportional-integral regulation: ; In the formula, Indicates time The total power correction for bus feedback; This represents the proportionality factor used to convert bus voltage deviation into power correction, expressed in watts per volt. This represents the integral coefficient used for power correction of the integral of the bus voltage deviation, expressed in watts per (volt-second). Indicates the bus voltage deviation; Represents the integral variable; Indicates the start time of this power transfer; Indicates the current control moment. and The settings can be configured using the bus equivalent capacitance, allowable voltage deviation, and converter current loop bandwidth, and an upper limit for the correction amount can be set to prevent integral saturation.

[0070] here The dimension of is Watt / (V·s). Multiplying it by the time integral of the bus voltage deviation yields the Watt, thus aligning with the dimension of the total feedback power correction. When setting the parameters, adjustments can be made initially when the integral action is weak or off. This allows for sufficiently rapid correction of bus voltage disturbances, and then gradually increases... To eliminate steady-state deviation; at the same time, limiting or anti-integral saturation treatment is set for the integral term and total power correction, so that the feedback correction is coordinated with the response capability of the local current loop of each branch.

[0071] During engineering tuning, the initial value of the proportional coefficient can be determined based on the total DC bus equivalent capacitance, bus reference voltage, and desired bus voltage closed-loop time constant. The proportional coefficient should be directly proportional to the product of the bus equivalent capacitance and bus reference voltage, and inversely proportional to the desired closed-loop time constant. The integral time constant is then set to 3 to 10 times the aforementioned bus voltage closed-loop time constant, and the integral coefficient is determined accordingly. To avoid competition between the bus voltage loop and the local current loops of each isolated bidirectional DC-DC converter, the bus voltage closed-loop bandwidth is set to a certain percentage of the local current loop bandwidth. The following tests are conducted using three simulation or bench conditions: bus reference voltage step, load power step, and target branch exit. These tests check whether the bus voltage is always within the allowable deviation range, whether the feedback correction amount is continuously saturated, and whether the current in each branch is continuously oscillating. Based on these tests, the proportional coefficient and integral coefficient are iteratively adjusted.

[0072] The converter control module 140 converts the feedforward power reference value and the bus feedback correction value into the first... Reference current values ​​for each online battery branch: ; In the formula, Indicates time Issued to the Current reference value for an isolated bidirectional DC-DC converter 230; Indicates the first The feedforward power reference value for each online battery branch; Indicates the first The weighting of each online battery branch; This indicates the total power correction amount for bus feedback; Indicates time The actual bus voltage; This indicates the index of the online battery branch that will provide compensation. The target branch is selected by... The calculated current reference value is not superimposed with positive compensation correction to ensure that the current continues to decay.

[0073] After the actual current in the target branch decays, the central control system 100 does not directly block the converter based on a single sampling point, but instead checks both the target branch current and the bus voltage simultaneously during the continuous confirmation time: ; In the formula, Indicates the target branch at the sampling time The actual branch current; This indicates the safe current threshold that allows power contacts to disconnect; Indicates the sampling time The actual bus voltage; Indicates the bus reference voltage; Indicates the allowable bus voltage deviation; Indicates the duration of continuous confirmation; Indicates the current confirmation time; Indicates the sampling time within the confirmation window; Indicates the interval Take the maximum value within the range. Only when both inequalities are satisfied is the target branch considered to be in an isolable state.

[0074] After confirming that the target branch is in an isolable state, the central control system 100 sends a PWM blocking command to the corresponding isolated bidirectional DC-DC converter 230 and enables its reverse current blocking state. After the latching detection element 221 outputs an unlocked state transition, the operator continues to move the movable plug 220b, and the power contact 222 only begins to separate afterward. Thus, when the power contact 222 begins to separate, the target branch has already completed current attenuation and electrical isolation.

[0075] See Figure 5 ,exist After a transition to the unlocked state is detected, the current in the target branch continuously decreases from the pre-unlock current, while the compensation power of the remaining online battery branches increases synchronously. When the target branch current meets the safety confirmation condition, the central control system 100 blocks the isolated bidirectional DC-DC converter 230 of the target branch; later than of At that moment, power contact 222 begins to physically disconnect. The bus voltage remains between the allowable upper and lower limits throughout the power transfer process.

[0076] The technical advantage of this embodiment lies in the further introduction of bus voltage feedback correction on the basis of complementary power feedforward. It employs a dual-condition confirmation process—"the target branch current remains below the safety threshold and the bus voltage remains within the allowable deviation range"—before blocking the target converter. This ensures that both power balance error and status confirmation error are subject to closed-loop constraints. This solves the technical problems that sampling errors, communication delays, and conversion losses may still lead to bus voltage deviations when relying solely on open-loop power tracing, and that single-point current sampling is insufficient to reliably determine safe disconnection.

[0077] Example 7: See Figure 3 When a battery branch is inserted, the movable plug 220b enters the fixed socket 220a and the locking detection element 221 returns to the inserted position. The central control system 100 first reads the branch identification, polarity, terminal voltage, state of charge, temperature, health status, and allowable charge / discharge power of the battery pack 210 to be connected, and checks whether the communication frame is within the valid time window. If there is an abnormal polarity, abnormal insulation status, excessive temperature, or invalid communication, the central control system 100 keeps the corresponding isolated bidirectional DC-DC converter 230 locked and outputs a fault status.

[0078] After the status verification is passed, the central control system 100 puts the isolated bidirectional DC-DC converter 230 to be connected to the branch into the current-limiting pre-charge mode. The isolated bidirectional DC-DC converter 230 uses its controllable power switch to establish voltage to the output capacitor, and the pre-charge current reference value can be determined as follows: ; In the formula, Indicates the first Reference value for the pre-charge current of the battery branch to be connected; This indicates the upper limit of the precharge current amplitude, determined by the surge capability of the isolated bidirectional DC-DC converter 230 and the quick-release connector 220. Indicates the first The output-side equivalent capacitance of an isolated bidirectional DC-DC converter 230; This indicates the bus voltage at the start of pre-charge; Indicates the first The output voltage of an isolated bidirectional DC-DC converter 230 at the start of precharge; Indicates the expected precharge duration; Indicates will Limit to the lower limit and upper limit between; This indicates the index of the battery branch to be connected. If... Higher than ,but For negative values, the local controller will not exceed The reverse current releases the energy of the output-side capacitor.

[0079] The expected precharge duration is determined by back-calculating the output-side equivalent capacitance, the port voltage difference at the start of precharge, and the upper limit of the precharge current, so that the unlimited precharge current reference value does not exceed the surge capacity allowed by the hardware. When the calculated reference value reaches the upper limit of the precharge current, the voltage matching condition should be met by extending the precharge process, rather than shortening the time by increasing the precharge current.

[0080] Taking an approximately 800V bus as an example, when the equivalent capacitance of the output side of the converter to be connected is 2 millifarads, the voltage difference between the output side and the bus is 40V when entering pre-charging, and the main voltage establishment process is expected to be completed within 50 milliseconds, the average pre-charging current obtained from the capacitor charging relationship is approximately 1.6A. If the upper limit of the pre-charging current is set to 5A, this design value is within the current limiting range. When the output side voltage reaches more than 95% of the bus voltage, soft start is entered by combining the relative deviation criterion, which can limit the capacitor charging surge within the preset hardware capability range.

[0081] During the pre-charging process, the central control system 100 continuously acquires the output voltage of the isolated bidirectional DC-DC converter 230 to be connected and calculates its relative deviation from the bus voltage. The grid connection matching condition can be expressed as: ; In the formula, This indicates the relative deviation between the output voltage and the bus voltage of the isolated bidirectional DC-DC converter 230 to be connected; Indicates the first The output voltage of the isolated bidirectional DC-DC converter 230 to be connected; Indicates the current bus voltage; This indicates the preset grid connection deviation threshold; This indicates the index of the battery branch to be connected. The surge current allowed by the grid connection, the equivalent impedance on the output side, and the bus voltage level can be determined. In the insertion scenario described in the technical disclosure, soft start can be initiated when the output side voltage reaches more than 95% of the bus voltage, which is equivalent to a relative deviation of no more than 5%. Other bus levels and connector specifications should be recalibrated according to the actual allowable surge current.

[0082] Once the relative deviation is no greater than the preset grid connection deviation threshold, the battery branch to be connected begins soft start. The reference value of the output power of the branch to be connected increases according to the following formula: ; In the formula, Indicates the time when the battery branch to be connected is at time The power reference value; This indicates the target output power of the branch to be connected, as determined by the central control system 100 based on the total load demand and the status of each branch. This represents the soft-start trajectory value that changes continuously from zero to one. Indicates the index of the battery branch to be connected; This indicates the current control moment during soft start. A negative value indicates that the branch to be connected is connected to the grid in the charging direction.

[0083] To prevent the increased output power of the branch to be connected from being added to the external output power, the original online battery branch synchronously reduces its output power according to the allocation weight determined by the power reduction space: ; In the formula, Indicates the first during soft boot. The power reference value of the original online battery branch; This indicates the latched number at the start of soft boot. The original online battery branch output power; Indicates the first The callback allocation weight of the original online battery branch; Indicates the target output power of the battery branch to be connected; Indicates the soft-start trajectory value; This represents the set of original online battery branch indices before the soft start begins; express The index of any branch in the dataset. The callback assignment weight is obtained by normalizing the subtractable power space between the current output power of each original online battery branch and its minimum stable output power.

[0084] Once the soft-start trajectory is completed and the actual current of the branch to be connected remains continuously within the allowable deviation range of the target current, the central control system 100 marks the branch as an online battery branch. Thereafter, this branch, along with other online battery branches, participates in routine power distribution and the calculation of potential power margins for subsequent hot-swap events.

[0085] The technical advantage of this embodiment lies in the fact that before the branch to be connected actually undertakes the power of the bus, it first completes state verification, current-limiting pre-charging, and port voltage matching. Then, it adds the output of the new branch through continuous soft-start trajectory and synchronously calls back the original online branch, thereby limiting the charging surge of the output-side capacitor and maintaining the continuity of the total branch power. This solves the technical problems of inrush current caused by port voltage difference when a detachable battery branch is directly connected to the common DC bus, and bus disturbance caused by the sudden increase in total output power after the new branch is connected to the grid.

[0086] Example 8: See Figure 2 and Figure 3This embodiment provides a seamless hot-swap control method for battery branches in an energy storage vehicle. During the unplugging process, before the power contact 222 of the quick-release connector 220 begins to separate, an unlocking state transition generated by the locking detection element 221 is received, and the corresponding battery branch is identified as the target branch; the current output power of the target branch and the power margin for the remaining online battery branches are obtained; the target branch is controlled to reduce its output power according to the power reduction trajectory, and the remaining online battery branches are controlled to increase their output power according to the corresponding compensation trajectory; after the output current of the target branch is within the safe current threshold, the isolated bidirectional DC-DC converter 230 of the target branch is blocked, so that it completes electrical isolation before the power contact 222 begins to physically separate.

[0087] During insertion, the system receives the insertion status of the battery branch to be connected and controls the corresponding isolated bidirectional DC-DC converter 230 to perform current-limited pre-charging. After the branch to be connected meets the grid-connection matching conditions, it increases its output power along a continuous soft-start trajectory, and the original online battery branch synchronously reverts its output power. The above steps can be used for both the discharge power supply state and the charging state from an external DC power source to each battery branch after the power sign is inverted.

[0088] During charging, the external output interface 400 receives external DC power output, and the isolated bidirectional DC-DC converter 230 transmits the bus power to each removable battery pack 210. At this time, the power of each branch is negative. When a disconnection event occurs, the absolute value of the charging power of the target branch gradually decreases to zero, and the remaining online battery branches increase the power absorbed according to the allowable charging power margin, so that the total power absorbed by the bus from the external power source remains continuous.

[0089] The technical advantage of this embodiment lies in organizing branch disconnection and insertion into separate process flows: "early mechanical intent identification—continuous power transfer—electrical isolation" and "status confirmation—current limiting pre-charging—matching grid connection—continuous power takeover," respectively. This ensures that hot-swap control has clear triggering and closed-loop termination conditions. This solves the technical problem of traditional hot-swap control, which only focuses on the on / off state of local switches and lacks synchronous control of the power continuity of the entire bus.

[0090] Example 9: Based on the pull-out control method of Example 8, this example further latches the total bus power, target branch output power, and output power of each online battery branch when the unlock state transition arrives; the available power margin is determined based on the difference between the allowable output power and the current output power of each online battery branch. The central control system 100 simultaneously uses the total bus power and its changing trend from the most recent control cycles to form a short-term load power prediction, and uses the bus power gap, the degree of limitation of each branch's state, and the power change rate as comprehensive objectives. Under the constraints of branch allowable output power, state of charge, temperature, health state, and converter power change rate, it continuously solves for the compensation power of each branch, thereby forming an adaptive compensation allocation weight. The power reduction trajectory of the target branch and the compensation trajectory of the remaining online branches are generated using the same continuous change function, so that the power reduction of the target branch corresponds to the power increase of the remaining branches; simultaneously, the power reference value of each online branch is corrected based on the deviation between the bus voltage and the reference voltage.

[0091] In an exemplary discharge condition of this embodiment, the first When a target branch experiences an unlocking event, the central control system 100 latches its output power before unlocking and calculates the potential power margin for the remaining online battery branches. Branches with larger potential power margins are assigned larger compensation weights, while branches with smaller potential power margins limited by state of charge, temperature, or health status are assigned smaller compensation weights. After normalization of the compensation weights, the sum of the compensation power for the remaining online battery branches corresponds to the power released by the target branch. This example illustrates the relationship between the assigned weights and real-time available capacity, and does not preset fixed rated power or fixed weight values.

[0092] Power transfer time The detection time, command time, current reduction time, confirmation time, and safe current threshold are all determined based on the connector's mechanical travel, the specified maximum pull-out speed, the current loop response of the isolated bidirectional DC-DC converter, and the power contact's allowable breaking conditions, rather than using isolated fixed values ​​independent of specific hardware. For specific products, the minimum mechanical time window obtained by the connector sample under the most unfavorable pull-out conditions should be used as a constraint, ensuring that the sum of the detection time, command time, current reduction time, and confirmation time is less than this mechanical time window; the power transfer duration should also ensure that the target branch can reach the safe current threshold within this window.

[0093] If the total available power margin of the remaining online battery branches is less than the current output power of the target branch, the central control system 100 prioritizes increasing the output power of each online battery branch to the allowable output power and sends a command to reduce the required power to an external load with power negotiation capability through the external output interface 400. If the external load does not support power negotiation, a hot-plug restriction warning is output, and the target branch current is still reduced to zero with the highest priority based on the safe current threshold. This abnormal process does not change the hardware relationship in which the latching detection element 221 separates the output signal before the power contact 222.

[0094] The technical advantage of this embodiment lies in combining power latching, dynamic margin, weight allocation, continuous trajectory, and bus feedback into a repeatable branch takeover algorithm, and explaining the constraint relationship between the mechanical time window and the power transfer duration and confirmation duration through parameter determination relationships. This solves the power imbalance problems caused by the lack of a clear benchmark for compensation during hot pull-out, inconsistent branch takeover capabilities, and the difficulty of the open-loop trajectory in offsetting actual losses and delays.

[0095] Example 10: Based on the insertion control method of Example 8, this example, after verifying the completion status and communication validity of the battery branch to be connected, charges the output capacitor of the isolated bidirectional DC-DC converter 230 with a current not exceeding the preset pre-charge current limit, and calculates the relative deviation between the output capacitor voltage and the total DC bus voltage in real time. When the relative deviation is not greater than the preset grid connection deviation threshold, the current-limited pre-charge ends, a continuous soft-start trajectory is generated according to the target output power of the battery branch to be connected, and a callback trajectory complementary to the soft-start trajectory is generated based on the power reduction space of the original online battery branch.

[0096] In an exemplary insertion scenario of this embodiment, for the approximately 800V high-voltage DC bus scenario described in the technical disclosure, the central control system 100 first limits the pre-charge current, causing the output voltage of the isolated bidirectional DC-DC converter 230 to be connected to gradually approach the bus voltage. When the output voltage reaches more than 95% of the bus voltage, and the preset grid connection deviation threshold is met according to the relative deviation formula, soft start is initiated. The soft start duration and the target output power of the branch to be connected are determined based on the bus load demand, the power reduction space of the original online battery branch, and the allowable power change rate of the isolated bidirectional DC-DC converter, and are not preset to fixed values. The power added by the branch to be connected is synchronously yielded by the original online battery branch according to the callback allocation weight.

[0097] If the branch to be connected fails to meet the grid connection matching conditions after the preset pre-charge timeout period during the pre-charge period, or if the pre-charge current continues to reach the upper limit of the pre-charge current, the central control system 100 blocks the corresponding isolated bidirectional DC-DC converter 230 and outputs a pre-charge fault status. After checking the output side capacitor, bus voltage sampling, power switch and communication status and clearing the fault, the pre-charge process will only restart when the insertion confirmation is received again.

[0098] The technical advantage of this embodiment lies in using a constrained pre-charge current and relative deviation of port voltage to jointly constrain the access timing, and then completing the power transfer between the old and new branches using a complementary trajectory after the grid connection conditions are met; at the same time, it sets up pre-charge timeout and current limiting anomaly handling, so that the access process has a determinable failure exit mechanism. This can solve the technical problems of surges caused by port voltage mismatch of the branch to be connected, sudden changes in bus power caused by direct grid connection, and the lack of safe termination conditions due to continuous occupation of the branch by pre-charge anomalies.

[0099] The aforementioned energy storage vehicle power supply system is not limited to battery pack replacement within a single vehicle, but can also be used for mobile energy storage compartments, detachable energy storage modules, or modular DC power supplies with a common DC bus. Identical components, data, and control relationships in various embodiments can be combined, as long as the combined scheme still ensures that the mechanical unlocking intent is recognized before the power contact separation, and that complementary power transfer is performed during branch electrical isolation or grid connection.

[0100] The above embodiments illustrate the composition and operation of the present invention. Those skilled in the art can adjust the sensor type, communication method, power conversion topology, trajectory function, or parameter tuning method without altering the mechanical pre-detection, branch independent isolation, and complementary power transfer relationships described in the present invention.

Claims

1. A power supply system for energy storage vehicles that enables seamless local hot-swapping and seamless global power supply disconnection, characterized in that, include: The main DC bus is used to connect the external output interface of the energy storage vehicle; Multiple battery branches are provided, each including a removable battery pack, a quick-release connector, and an isolated bidirectional DC-DC converter. The removable battery pack is connected to the input terminal of the corresponding isolated bidirectional DC-DC converter via the quick-release connector, and the output terminals of each isolated bidirectional DC-DC converter are connected in parallel to the main DC bus. The quick-release connector includes a power contact and a locking detection element. The locking detection element is disposed on the movement path of the mechanical lock and configured to output an unlock state transition when the unlocking action enters the pre-separation stroke. Along the pull-out direction of the quick-release connector, the state switching position of the locking detection element is located before the electrical contact termination position of the power contact, so as to form a mechanical time window between the unlock state transition and the start of separation of the power contact. Branch sensors are used to collect the branch current and branch voltage of each of the battery branches; bus sensors are used to collect the bus voltage and total power of the total DC bus. The central control system is communicatively connected to the locking detection device, the branch sensor, the bus sensor, the battery management interface of the detachable battery pack, and each of the isolated bidirectional DC-DC converters. The central control system is used to determine the corresponding battery branch as the target branch when it receives the unlocking state transition of any of the locking detection devices, obtain the current output power of the target branch and the allowable output power and current output power of the online battery branches other than the target branch, determine the power margin of each online battery branch according to the allowable output power and the current output power, and determine the allocation weight of the compensation power according to the power margin. The same trajectory function, continuously varying from zero to one, is used to generate a power reduction reference trajectory for the target branch and a compensation power reference trajectory for the online battery branch. This ensures that the output current of the target branch continuously decays, and that the increased output power of the online battery branch follows the decreased output power of the target branch. The total delay of event confirmation, command transmission, target branch current decay, and safety status confirmation is less than the mechanical time window. When the output current of the target branch remains within the safety current threshold and the bus voltage remains within the allowable voltage deviation range during the continuous confirmation period, the isolated bidirectional DC-DC converter of the target branch is blocked. When the insertion status of the battery branch to be connected is detected, the corresponding isolated bidirectional DC-DC converter is controlled to sequentially perform current-limited pre-charging and voltage matching. After meeting the grid connection matching conditions, a second set of complementary power reference trajectories is generated to soft-start the battery branch to be connected and to synchronously restore the output power of the original online battery branch.

2. The energy storage vehicle power supply system according to claim 1, characterized in that, The locking detection element is a micro switch or position sensor installed on the mechanical lock movement path of the quick-release connector; the mechanical time window is determined by displacement-time testing of the connector sample, the test records the state switching time of the locking detection element and the electrical contact termination time of the power contact, and the minimum time difference obtained from multiple tests under the specified maximum pull-out speed is used as the design constraint; the sum of the detection debounce time, command transmission time, target branch current attenuation time and state confirmation time of the central control system is less than the mechanical time window.

3. The energy storage vehicle power supply system according to claim 1, characterized in that, Each of the isolated bidirectional DC-DC converters includes an output-side capacitor, a controllable power switch, and a local current controller. The local current controller is used to control the controllable power switch in response to the current reference value issued by the central control system, and to block the reverse current from the main DC bus to the target branch after the target branch is blocked.

4. The energy storage vehicle power supply system according to claim 1, characterized in that, The central control system is used to latch the total bus power and the output power of each online battery branch before unlocking when it receives the unlock state transition, and to take the output power of the target branch before unlocking as the power to be compensated; the trajectory function takes the values ​​of zero and one at the power transfer start and end points, respectively, and the first-order rate of change at the power transfer start and end points is zero. The central control system continuously reduces the output power of the target branch according to the trajectory function, and synchronously allocates the compensation power corresponding to the reduction amount of the target branch to the other online battery branches according to the allocation weight.

5. The energy storage vehicle power supply system according to claim 4, characterized in that, The central control system is used to determine the corresponding power margin for each online battery branch based on its state of charge, temperature, health status, allowable output power, and current output power. It also generates a predicted load power value in the prediction time domain based on the total bus power and its changing trend over the most recent control cycles. Using the bus power gap in the prediction time domain, the degree of constraint on the state of each online battery branch, and the power change rate of each online battery branch as optimization objectives, and under constraints on the allowable output power, state of charge, temperature, health status, and the power change rate of the isolated bidirectional DC-DC converter, the system continuously determines the compensation power and adaptive allocation weights for each online battery branch. When any online battery branch reaches its constraint boundary, the remaining compensation power is re-optimized and allocated among the remaining online battery branches with power margins for expansion.

6. The energy storage vehicle power supply system according to claim 4, characterized in that, The central control system is used to generate a feedback correction amount including a proportional term and an integral term based on the deviation between the bus voltage and the bus reference voltage, and to set a limit on the feedback correction amount. The limited feedback correction amount is then superimposed on the power reference value of each of the online battery branches according to the allocated weight. The safe current threshold, continuous confirmation time, and allowable voltage deviation range are determined according to the connector allowable breaking current and converter blocking residual current, detection and sampling stabilization time, bus rated voltage, and external load input tolerance, respectively.

7. The energy storage vehicle power supply system according to claim 1, characterized in that, The central control system is used to determine a pre-charge current reference value based on the output-side equivalent capacitance of the corresponding isolated bidirectional DC-DC converter, the initial voltage difference between the output-side capacitor and the bus, and the expected pre-charge duration after the battery branch to be connected is inserted into place, and to limit the pre-charge current reference value within the upper limit of the pre-charge current; when the relative deviation between the voltage of the output-side capacitor and the bus voltage is not greater than a preset grid connection deviation threshold, the output power of the battery branch to be connected is increased to the target output power along a continuous soft-start trajectory, and the output power of each online battery branch is synchronously reduced according to the allocation weight of the online battery branches.

8. A seamless hot-swap control method for battery branches in an energy storage vehicle, characterized in that, A power supply system for energy storage vehicles, including a main DC bus and multiple battery branches connected in parallel to the main DC bus, is provided. Each battery branch includes a removable battery pack, a quick-release connector, and an isolated bidirectional DC-DC converter. The quick-release connector outputs an unlock state transition when the unlocking action enters the pre-separation stroke, and a mechanical time window is formed between the unlock state transition and the start of power contact separation. The method includes: receiving the unlock state transition of any of the quick-release connectors and determining the corresponding battery branch as the target branch; obtaining the current output power of the target branch and the potential power margin of the remaining online battery branches, and determining the allocation weight based on the potential power margin; and applying the same trajectory function that continuously changes from zero to one to the target branch. The target branch reduces its output power according to the power reduction trajectory, and the remaining online battery branches synchronously increase their output power according to the compensation trajectory; the total delay of event confirmation, command transmission, target branch current decay, and status confirmation is less than the mechanical time window, and the isolated bidirectional DC-DC converter of the target branch is blocked when the output current of the target branch and the bus voltage continuously meet the safety confirmation conditions within the continuous confirmation time; the insertion status of the battery branch to be connected is received, and the corresponding isolated bidirectional DC-DC converter is controlled to perform current-limited pre-charging; and after the battery branch to be connected meets the grid matching conditions, the battery branch to be connected increases its output power along the soft-start trajectory, and the original online battery branches synchronously revert to their output power.

9. The seamless hot-swap control method according to claim 8, characterized in that, The process involves reducing the output power of the target branch according to a power reduction trajectory, and synchronously increasing the output power of the remaining online battery branches according to a compensation trajectory. This includes: determining the total bus power, the output power of the target branch, and the output power of each online battery branch when the latch-unlock state transition is reached; determining the power increase margin based on the difference between the allowable output power and the current output power of each online battery branch; predicting the load power in the subsequent control window based on the total bus power and its changing trend in the most recent control cycles, and determining the compensation power and adaptively allocating weights under constraints of allowable output power, state of charge, temperature, health status, and converter power change rate, with the bus power gap, branch state limitation, and power change rate as targets; generating the power reduction trajectory and the compensation trajectory according to the same continuous change function, so that the power reduction of the target branch corresponds to the power increase of the remaining online battery branches; and providing feedback correction to the power reference value of each online battery branch based on the bus voltage deviation.

10. The seamless hot-swap control method according to claim 8, characterized in that, Controlling the corresponding isolated bidirectional DC-DC converter to perform current-limited pre-charging includes: after the completion status and communication validity verification of the battery branch to be connected, charging the output-side capacitor of the isolated bidirectional DC-DC converter with a current not exceeding the preset pre-charging current limit; calculating the relative deviation between the voltage of the output-side capacitor and the bus voltage in real time; ending the current-limited pre-charging when the relative deviation is not greater than the preset grid-connected deviation threshold; generating a continuous soft-start trajectory based on the target output power of the battery branch to be connected, and generating a callback trajectory complementary to the continuous soft-start trajectory based on the power reduction space of the original online battery branch.

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