CN110994742B

CN110994742B - System and method for parallel charging operation of multiple battery packs

Info

Publication number: CN110994742B
Application number: CN201911377061.9A
Authority: CN
Inventors: 段志刚
Original assignee: Beijing Xingda Zhilian Technology Co ltd
Current assignee: Beijing Xingda Zhilian Technology Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2021-11-19
Anticipated expiration: 2039-12-27
Also published as: CN110994742A

Abstract

The invention relates to the field of battery energy storage conversion power supply, in particular to a system and a method for charging and operating a plurality of battery packs in parallel, which adopt an electric type controlled charging battery pack and a method for converting charging by utilizing a built-in switch of a compound switching protection, so that the battery pack becomes a charging component with a specific controlled electric type, the input volt-ampere characteristic of the charging component is controlled, and the equivalent input impedance is controlled; the intelligent programmable modular device is programmable, limited in input power and input current, unidirectional in charging and intelligent programmable. The invention has the advantages of good performance in the whole parameter range, applicability in the whole scene, clear principle of the method, easy realization, simple control, simple and convenient selection of the implementation scheme, few specifications and varieties and low cost. Therefore, the performance of the parallel charging system of the power battery pack is greatly improved, the cost performance is high, modularization, component equipment and intellectualization are realized, the parallel charging system can adapt to various working environments, the design is simpler and more efficient, and the system operation has high usability, maintainability and reliability.

Description

System and method for parallel charging operation of multiple battery packs

Technical Field

The invention relates to the field of battery energy storage conversion power supply, in particular to a system and a method for parallel charging operation of multiple power battery packs.

Background

The power battery pack is a core component of the new energy equipment; the power single battery core has low rated voltage and low rated capacity, so a plurality of battery cores are combined into the whole energy storage component in a series-parallel connection mode, which is commonly called a power battery pack; the key points of the battery pack design comprise monomer voltage, monomer capacity, a monomer series-parallel connection mode and a battery system management mode. The charge and discharge management of the battery pack is a key technology used by a system, a management unit BPU (broadband protection unit) in the battery pack is commonly called as a protection board, the conventional technology consists of two field effect transistors which are oppositely arranged and provides the protection for the over-charge and over-discharge opening and closing of the battery pack, as shown in figure 1, the BPU monitors the over-voltage, over-temperature charge, under-voltage and over-current discharge of single cells in a battery pack string, the charge process is completed by a specially configured charger according to the specified battery charge standard process and the specified parameters of a manufacturer, the charge coordination between the charger and the battery pack is carried out in a one-to-one mode, the detection and the adjustment are carried out by a matched charger, a six-section charge process diagram of a power lithium battery (pre-charge, constant current, constant voltage, micro-charge, re-charge and full stop) is given in figure 3, wherein the design intentions of the 4 th section to the 5 section are designed to give consideration to the quick charge and the standard charge performance and are matched with the energy receiving characteristics of the lithium battery, the charging speed is improved, and the service life is prolonged. The two stages of processes, namely the conventional four-stage standard charging process [ pre-charging, constant current, constant voltage and full stop ] are removed. The conventional battery pack does not participate in the management of the charging process, and the battery pack is charged by a shaping charger provided by a manufacturer or certified for matching; if the battery pack is charged by external energization according to the original energized electric type characteristic, the charging electric type of the battery pack is not controlled, and the charger configuration implements the electric type characteristic and parameter control. When the external configuration setting parameter is not the rated recommended value and is greatly out of range, the battery pack is in a possibly abnormal electrical environment and is in an electrochemical abnormal or physical high-risk state.

The power lithium battery pack is a high-energy low-resistance active dynamic working component in an operating equipment environment, so that two conventional lithium battery pack finished products cannot be directly connected in parallel. When the voltage platforms and the residual capacities are different, direct parallel connection means that circulating current charging and discharging occur between the battery packs, and at the moment, uncontrolled through current is extremely large, internal loss and heating are serious and accumulate for a long time due to low battery impedance, and even the batteries are damaged. When two conventional lithium battery packs are directly connected in parallel and then connected to a conventional charger for charging, the charger cannot identify the current actual working state of each single battery pack according to the characteristic parameters of each charging stage of the battery pack, and the parameter values after parallel connection are misread and an incorrect charging process is implemented accordingly, so that the parallel battery packs cannot be charged effectively and reliably according to the standard process. In the prior art, three groups of power lithium battery packs are used and are connected in series with power diodes in a limited back direction and connected to the same rectifier 55V/16A for charging, as shown in figure 2. When 48V16Ah lithium iron or ternary lithium battery is adopted, the maximum charging input current can reach 7-21A/0.4-1.3C, the power diode is limited to prevent backflow discharge, and the high-rate battery can tolerate wide-range voltage and current charging. Compared with a preset or overcurrent current limiting value Ici of a charger and the number n of parallel battery packs, the difference of the maximum value and the minimum value of the charging current is large, wherein Ich.max is larger than or equal to Ici, Ich.min is smaller than or equal to Ici/n, and n is not suitable to be large; in the charging process, the diode loss is large, heat dissipation needs to be added, charging also depends on communication to monitor the charging voltage and current or capacity of each battery pack, and constant voltage charging is affected by the nonlinear differential pressure of the diode and needs to be detected and corrected respectively. The scheme is not suitable for specialized and industrialized design targets and is not suitable for a general parallel power battery charging system. That is to say, in the current technical scheme, the power charging port can only effectively and reliably charge one group of battery packs in a fixed certain period of time, but cannot effectively charge a plurality of parallel battery packs in the whole process. In particular, the output characteristics of the conventional battery pack are standard bidirectional voltage source characteristics, and in a charging state, the danger of charging the low-voltage battery pack with large current by the relatively high voltage connected in parallel exists, so that the working of an effectively controlled parallel charging system cannot be realized.

The large power battery system is formed by a large energy package consisting of a plurality of monomers, the monomers are connected in series and parallel according to a preset sequence to form blocks, sheets and layers, and then the large energy package system is formed. The design is only implemented in a primary installation mode and is assembled in a static state at one time, and the design is not disassembled during operation. In this way, the parallel battery sub-components need to be independently detected and managed, otherwise, the parallel battery sub-components are unbalanced in parallel for a long time to cause insufficient charging, so that the charging and discharging capacities of the whole battery pack and the system are greatly and rapidly attenuated and the battery pack and the system are invalid. In addition, the design, production and use processes are complex, the system failure rate caused by element failure is high, and the maintenance and the repair are difficult.

Disclosure of Invention

The invention aims to solve the technical problem that a multi-battery pack cannot be charged and operated in parallel at the same time in the prior art, and provides a system and a method for charging and operating a multi-battery pack power bus in parallel.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a multi-battery pack parallel charging operation system comprises a plurality of electrically controlled charging battery packs BRPi, i is not less than 2; the system is provided with a power bus; all positive ends of the multiple electric type controlled charging battery packs are connected with each other and then receive power supply from the positive end of the power bus, and all negative ends of the multiple electric type controlled charging battery packs are connected with each other and then receive power supply from the negative end of the power bus, so that a multi-battery pack parallel charging operation system is formed; the electric type controlled rechargeable battery pack is the same type of electric type rechargeable battery pack; the electric type controlled rechargeable battery pack is characterized in that basic electric type parameters of the rechargeable battery pack are that a charging input voltage Chvin and a charging input current ChIin are in an effective preset range and are controlled; the extended electrical parameter charging input equivalent impedance ChRin and the charging input volt-ampere power ChPin are controlled; associated with the electrical type parameter current limit and charging input voltage are controlled, and the volt-ampere power and charging input voltage are controlled.

A power bus arranged in the electric type controlled charging battery pack is accessed in a shunt power distribution mode, namely a shunt power distribution unit BDU is configured between the power bus and the battery pack; the BDU includes: the short-circuit resistant direct-current low-voltage power fuse F, the shunt switch control switch pQ, the intelligent power distribution controller DCU, the shunt current and voltage measuring ports vDP and iDP, the address coding measuring port pADR, the single-wire serial communication port BPC and the double-wire serial communication port RS [ RS +, RS- ].

The system is provided with a battery cabin and a quick connection socket which are butted with a battery pack wiring port; setting a multi-battery pack charging system controller CMU; setting a system power bus operating voltage Vpb.set and a current limit Ipb.set; setting a system power bus shunt circuit preset maximum charging current limit Ipc.set; the electric type controlled charging battery BRP is a built-in switch conversion charging battery.

Furthermore, the system is controlled in a set effective charging working range, and the built-in switch conversion charging battery pack is a compound switching protection built-in voltage reduction switch conversion charging battery pack.

Furthermore, the system is controlled in a set effective charging working range, and the built-in switch conversion charging battery pack is a compound switching protection built-in boost switch conversion charging battery pack.

Furthermore, the system is controlled in a set effective charging working range, and the built-in switch conversion charging battery pack is a built-in buck-boost switch conversion charging battery pack with compound switching protection.

Further, the system configures a battery pack communication port BPC, a charging identification port SCD and an address interface bADR; the system configures the corresponding resistance of each battery pack address interface ADRi according to the coding serial number; connecting the communication line BPC in the system; and establishing a serial communication protocol transceiving information and instruction of the parallel charging operation system.

Furthermore, the power bus shunt power distribution unit BDU and the shunt on-off switch pQ are matched with the intelligent power distribution controller DCU to be used for shunt battery pack reverse connection protection, overcurrent protection, overtime charging and command controlled closing; the intelligent distribution controller DCU obtains and monitors the voltage of the battery pack string through communication of the communication line BPC in the system, and is used for closing the shunt switch pQ and protecting the abnormal high voltage of the shunt battery port from reversely flowing back to the distribution interface to lead to the high voltage of the power bus when the overvoltage exceeds the maximum value of the effective working range, so that overvoltage stop charging of other parallel battery packs on the bus is avoided.

Furthermore, the CMU is used for managing the output voltage and the current limiting value of the bus source device according to design configuration communication and configuring the maximum charging current limiting value of the BDU; the CMU is connected with a system communication line, exchanges the state and parameters of each battery pack, and issues commands according to broadcasting, grouping and address division; the system controller is used for analyzing and counting the characteristic quantity of the charging system according to a design configuration function algorithm.

Furthermore, the system shunt current limit is defined by the ratio K1 of the three-gear controlled values; the K1 is 1, and the system shunt rated current limit ipc.set is K1 × ipc.set; the specific configuration steps of each battery pack and shunt charging input current limit Ipc include:

the value of an input power bus is lower than the rated voltage, and the current limiting value is automatically adjusted down by the battery pack;

the monitor protocol adjusts the preset value of the power bus and the protocol battery pack adjusts the set value;

the system designs a default value according to the hardware position, and the battery pack is configured according to address identification;

and the monitor sends down an adjusting set value corresponding to the address and the battery pack communication protocol.

Furthermore, the system shunt current limit is defined by the ratio K0 of the three-gear controlled values; 2> K0>1, which refers to system shunt large current limit ipc.set-K0 × ipc.set; the specific configuration steps of each battery pack and shunt charging input current limit Ipc include:

Furthermore, the system shunt current limit is defined by the ratio K2 of the three-gear controlled values; the 1> K2>0.3 indicates a system shunt small current limit ipc.set which is K2 × ipc.set; the specific configuration steps of each battery pack and shunt charging input current limit Ipc include:

The operation method of any one of the parallel charging operation systems described above, comprising the steps of:

1) starting charging;

2) setting conventional parameters of the parallel charging operation system;

3) setting control parameters of the parallel charging operation system;

4) when the input charging voltage accessed by the battery pack exceeds the upper limit, the battery pack is closed automatically and waits to be charged, and when the charging voltage drops and exceeds the lower limit, the battery pack automatically closes charging until the charging voltage meets the effective charging input voltage range;

5) the parameter setting of the charging power bus of the parallel charging operation system comprises the following steps:

51) the system charging power bus is preset with voltage Vpb.set, the power-on default is set as a rated constant voltage charging value Vcv of the battery pack, and when more than one battery type is provided and the Vcv values are different, the highest value is selected; if the engineering error and the line voltage drop are considered, increasing the amplitude value of the preset voltage Vpb.set1 of the power bus to be less than 1V improves the reliability and the availability;

52) the system charging power bus preset voltage Vpb.set is dynamically adjusted to a system planning operation value Vsp; the Vsp is calculated according to an agreed planning algorithm in an agreed effective working range of the system according to voltage charging parameters of all parallel battery packs in the system; the system is set according to a monitor menu during operation and issues an instruction to the power bus controller to set a planning operation value after the system cooperates with all battery packs in the system;

53) the system charging power bus preset voltage Vpb.set is dynamically adjusted to a system fast charging operation value Vsq; and the Vsq is calculated by the voltage charging current-limiting parameter of each parallel battery pack in the system according to a planning algorithm in the agreed effective quick charging range of the system.

Further, the method comprises the following steps:

6) in the appointed effective charging input working range, the one-way charging work is realized, and the charging input controlled volt-ampere characteristic has two basic modes: the charging input end corresponds to an equivalent preset current limiting load point, and is an input voltage stabilizing section when the load is smaller than the preset current limiting load point value, and is an input current limiting section when the load is larger than the preset current limiting load point value; the constant current limit preset value can be a certain value point in an effective charging input working range stipulated by a system memory or a communication protocol, and the value range is selected to be 30-200% of the ratio of the rated charging input current limit Ici.lim or Ipc.set of the battery pack.

Further, the method comprises the following steps:

7) when the charging input current limiting ratio of the rechargeable battery pack is lower than 100%, the battery pack adjusts corresponding derating current and time parameter values in the charging process according to corresponding charging input power;

8) judging a full charge condition, namely that the return difference between the battery voltage and a rated constant voltage charge value Vcv is less than or equal to 0.1V, and the battery charge current is less than 5% of an input current limit Ipc, stopping charging; otherwise, continuing charging;

9) and finishing charging.

The multi-battery pack parallel charging operation system and the method have the following beneficial effects that:

the invention adopts an electric type controlled charging battery pack and a method of converting charging by using a built-in switch of a compound switching protection, so that the battery pack becomes a charging component with a specific controlled electric type, the input volt-ampere characteristic of the charging component is controlled, and the equivalent input impedance is controlled; the intelligent programmable modular device is programmable, limited in input power and input current, unidirectional in charging and intelligent programmable. Particularly, the battery pack in the prior art has the output characteristic of a standard bidirectional voltage source, and has the danger of large current flowing backwards in a discharging process relative to a low-voltage battery pack in a charging state, so that the work of an effectively controlled parallel charging operation system cannot be realized. The built-in conversion charging battery pack realizes the control of the input current, the input power and the equivalent input impedance which are peculiar to power conversion through the conversion and the control of the power switch, avoids unexpected reverse flow current, enables the battery pack to become a modular equipment assembly with input end electric type controlled management, realizes the function of the effective controlled parallel charging of a multi-battery pack power bus, enables the rated charging current of a system to select the design of the sum of the rated charging current of all the battery packs, and forms a modular distributed parallel charging operation system. The modularized system has excellent convenience and extensibility, and the design operation capacity is greatly improved; for different design targets focusing on the difference scenes of system electrical indexes such as ampere current, volt-ampere power, ampere-hour capacity, watt-hour energy and the like, the design of the modularized parallel system can focus on, clearly, concisely and quickly completing and implementing later-stage operation, and the system operation has extremely high availability, maintainability and reliability; is the preferred solution for large or complex systems.

The invention has the advantages of good performance in the whole parameter range, applicability in the whole scene, clear principle of the method, easy realization, simple control, simple and convenient selection of the implementation scheme, few specifications and varieties and low cost. Therefore, the performance of the parallel charging operation system of the power battery pack is greatly improved, the cost performance is high, modularization, component equipment and intellectualization are realized, the parallel charging operation system can adapt to various working environments, the design is simpler and more efficient, and the system operation has high usability, maintainability and reliability.

Drawings

FIG. 1 is a schematic diagram of a common positive/negative terminal single port protection board open/close circuit of a prior art battery pack;

FIG. 2 is a schematic diagram of a prior art common positive/negative side battery with three sets of parallel charging diodes in series;

FIG. 3 is a schematic time flow diagram of six-segment controlled charging curves for a lithium-ion power battery pack in accordance with the present invention;

FIG. 4 is a graph of equivalent charging conductance G and input Ch of a battery pack and B-type parameters of a battery string according to the present invention;

FIG. 5A is a schematic diagram of a conventional battery-connected high power charger;

FIG. 5B is a comparison of the present invention electrical controlled battery pack connected to a high power charger;

FIG. 6 is a schematic diagram of a common positive side half-bridge buck conversion battery pack parallel charging circuit according to the present invention;

FIG. 7 is a schematic diagram of a parallel charging circuit for a common-negative full-bridge buck-boost conversion battery pack according to the present invention;

FIG. 8 is a schematic diagram of the matching characteristics of the built-in conversion charging input and output voltage range of the present invention;

fig. 9 is a schematic diagram of the input voltage controlled current-voltage characteristic associated with the conversion current-limiting of the battery pack of the present invention;

FIG. 10 is a schematic illustration of the principle of the power bus branching distribution unit of the present invention;

FIG. 11 is a circuit example 1 of an application scheme of the multi-battery parallel charging operation system of the present invention;

FIG. 12 is a circuit example 2 of an application scheme of the multi-battery parallel charging operation system of the present invention;

FIG. 13 is a circuit example 3 of an application scheme of the multi-battery parallel charging operation system of the present invention;

FIG. 14 is a circuit example 4 of an application scheme of the multi-battery parallel charging operation system of the present invention;

fig. 15 is a flow chart illustrating an operation method of the multi-battery parallel charging operation system according to the present invention.

Detailed Description

In the system, a power bus arranged in the electric type controlled rechargeable battery pack is accessed in a shunt power distribution mode, namely a shunt power distribution unit BDU is configured between the power bus and the battery pack; the BDU includes: the short-circuit resistant direct-current low-voltage power fuse F, the shunt switch control switch pQ, the intelligent power distribution controller DCU, the shunt current and voltage measuring ports vDP and iDP, the address coding measuring port pADR, the single-wire serial communication port BPC and the double-wire serial communication port RS [ RS +, RS- ]; the DCU is coded according to the measurement address of the pADR port, monitors the shunt voltage and current parameters according to the measurement ports vDP and iDP, judges and executes turn-off protection according to preset overcurrent and overvoltage upper limits, or receives a turn-off protection instruction of the CMU.

In the system, a battery cabin and a quick connection socket are configured to be in butt joint with a battery pack wiring port; setting a multi-battery pack charging system controller CMU; setting a system power bus operating voltage Vpb.set and a current limit Ipb.set; setting a system power bus shunt circuit preset maximum charging current limit Ipc.set; the electric type controlled charging battery BRP is a built-in switch conversion charging battery.

The system is controlled in a set effective charging working range, the built-in switch conversion charging battery pack is a combined on-off protection built-in voltage reduction switch conversion charging battery pack.

The system is controlled in a set effective charging working range, the built-in switch conversion charging battery pack is a combined on-off protection built-in boost switch conversion charging battery pack.

The system is controlled in a set effective charging working range, the built-in switch is used for converting the rechargeable battery pack, and the built-in voltage-boosting switch is used for converting the rechargeable battery pack in a combined opening and closing protection mode.

The system is provided with a battery pack communication port BPC, a charging identification port SCD and an address interface bADR; the system configures the corresponding resistance of each battery pack address interface ADRi according to the coding serial number; connecting the communication line BPC in the system; and establishing a serial communication protocol transceiving information and instruction of the parallel charging operation system.

In the system, the power bus shunt power distribution unit BDU and the shunt on-off switch pQ are matched with the intelligent power distribution controller DCU to be used for shunt battery pack reverse connection protection, overcurrent protection, overtime charging and instruction controlled closing; the intelligent distribution controller DCU obtains and monitors the voltage of the battery pack string through communication of the communication line BPC in the system, and is used for closing the shunt switch pQ and protecting the abnormal high voltage of the shunt battery port from reversely flowing back to the distribution interface to lead to the high voltage of the power bus when the overvoltage exceeds the maximum value of the effective working range, so that overvoltage stop charging of other parallel battery packs on the bus is avoided.

Distribution unit and group battery along separate routes, address interface ADR, the usage still includes: referring to the composite signal, charge identification SCD is described by voltage section of SAD analog quantity, and address ADR is described by voltage parameter value field; the BDU is used for carrying out communication conversion connection on the butted battery pack according to ADR; the current position working state of the shunt battery is detected by the BDU by utilizing the address ADR and the in-place BH contact in combination with the voltage difference and current parameters of the battery pack, wherein the working state comprises manual pressing, motor pushing, in-place locking, in-place charging and full-charge retention.

In the system, a controller CMU of the multi-battery pack charging system manages output voltage and a current limiting value of a bus source device according to design configuration communication, and configures a maximum charging current limiting value of a BDU (bus bar branching unit); the CMU is connected with a system communication line, exchanges the state and parameters of each battery pack, and issues commands according to broadcasting, grouping and address division; the system controller is used for analyzing and counting the characteristic quantity of the charging system according to a design configuration function algorithm.

In the system, the shunt current limit of the system is defined by the ratio K1 of three-gear controlled values; the K1 is 1, and the system shunt rated current limit ipc.set is K1 × ipc.set; the specific configuration steps of each battery pack and shunt charging input current limit Ipc include:

In the system, the shunt current limit of the system is defined by the ratio K0 of three-gear controlled values; 2> K0>1, which refers to system shunt large current limit ipc.set-K0 × ipc.set; the specific configuration steps of each battery pack and shunt charging input current limit Ipc include:

In the system, the shunt current limit of the system is defined by the ratio K2 of three-gear controlled values; the 1> K2>0.3 indicates a system shunt small current limit ipc.set which is K2 × ipc.set; the specific configuration steps of each battery pack and shunt charging input current limit Ipc include:

The operation method of any one of the parallel charging operation systems includes the steps of:

1) starting charging;

2) the conventional parameter setting of the parallel charging operation system comprises the following steps:

the following parameters are set or adjusted:

the rated voltage Vnom of the charging power bus is 48V, the power Pnom of the charging bus is 5KW,

the charging shunt or battery access number N is 12, and the ampere hour Ah of the charging battery is 16 Ah;

3) setting control parameters of the parallel charging operation system;

adjusting the following parameters after power-on default setting or power-on:

a charging voltage effective range, a maximum value Vpb.max, a minimum value Vpb.min,

charging power bus preset voltage power-on default value vpb.set,

a current-limiting power-on default value Ipc.set is preset in the charging shunt circuit;

51) the system charging power bus is preset with voltage Vpb.set, the power-on default is set as a rated constant voltage charging value Vcv of the battery pack, and when more than one battery type is provided and the Vcv values are different, the highest value is selected; if the engineering error and the line voltage drop are considered, the preset voltage Vpb.set1 of the power bus is increased by an amplitude value smaller than 1V, for example, increased by about 0.6V, so that the reliability and the availability are improved;

The operation method of the charging system further comprises the following steps:

9) and finishing charging.

The built-in switch conversion rechargeable battery pack is a high-efficiency electric type controlled rechargeable battery pack, and the effective charging input working ranges are respectively as follows according to different conversion modes:

the effective working range input voltage of the buck-boost conversion mode is as follows: the working range of the voltage is met, namely the working range is smaller than the maximum value and larger than the minimum value, and the friendly working range is as follows: the charging voltage is up to a constant voltage charging preset value Vcv to be charged of the battery pack and is down to a battery pack pre-charging voltage value Vpc.set;

the input voltage of the effective working range of the boost conversion mode is as follows: the voltage working range is met, namely the voltage working range is smaller than the maximum value, larger than the minimum value and smaller than the to-be-charged voltage constant current starting value Vcc.low or the pre-charged voltage value Vpc.set of the battery pack;

the input voltage of the effective working range of the voltage reduction conversion mode is as follows: the voltage working range is met, namely the voltage working range is smaller than the maximum value, larger than the minimum value and larger than the preset value Vcv of the constant voltage charging to be charged of the battery pack;

the built-in conversion battery packs with three different switch conversion types of voltage boosting, voltage reducing and voltage boosting have different effective charging input working ranges;

the built-in conversion battery pack works in an effective charging input working range, and a conversion input side works according to two modes, wherein the first mode is rated voltage and current working, and the second mode is power limiting working; at the charging input port: the voltage and current are controlled, the power is controlled, the equivalent impedance is in a controlled state, the lower limit is the power bus voltage, and the equivalent impedance value corresponding to the preset current limit is set.

The built-in conversion battery pack works in an effective charging input working range, and a conversion output side works in two types of modes, wherein the first type of the conversion battery pack works in a constant voltage mode, and the second type of the conversion battery pack works in a constant current mode; the charging conversion operation is adjusted according to parameters of each section of the flow of constant current pre-charging PC, constant current charging CC, constant voltage charging CV and full-capacity charging stop FS preset in the battery pack, the parameters comprise charging voltage, charging current and charging time, a controller in the battery pack adjusts and converts pulse width according to preset voltage and current correspondingly, and each section of the charging operation is performed step by step according to the charging preset flow until the charging of the battery pack is completed.

The embodiments of the present invention will be further described with reference to the accompanying drawings.

In the invention, the electric environment comprises power battery packs formed by battery packs with 24V, 36V, 48V, 60V, 72V, 110V, 220V, 240V, 400V or other voltages as rated working voltages. The battery packs are used in high-power equipment or systems and are designed according to a hot backup parallel system, the battery packs comprise a plurality of same or approximately same components, an appointed effective charging working range and a battery with controlled and matched electric type are adopted, the BRP-HB of the built-in half-bridge buck conversion charging type battery is good in performance and low in cost, and the BRP-FB of the built-in full-bridge buck-boost conversion charging type battery is excellent in performance. For example, three 48V16Ah batteries are connected in parallel on an electric express vehicle charging pile, three 48V16Ah batteries are connected in parallel on an electric off-road vehicle charging interface, twelve 48V16Ah batteries are connected in parallel on a 48V communication base station standby power supply energy storage charging system, and 4 × 3 48V16Ah batteries are connected in parallel on a 48V power battery charging station. When the power charging system works, a modular system mode of multi-battery pack power bus parallel charging design is adopted, so that compared with numerous split charging devices in the prior art, the power charging system is superior in performance, more efficient, more convenient, more industrialized and more intelligent, and has the capacity of field expansion and real-time replacement.

The charging input type of each battery pack in the system is controlled, the charging is changed and adjusted by adopting a built-in switch, the built-in process is completed according to preset multi-section parameters, and the charging is automatically and intelligently completed by the inside of the battery pack. FIG. 3 is a six-stage charging flow chart of lithium battery [ precharging, constant current, constant voltage, micro-charging, recharging, full stop ]. When the built-in conversion rechargeable battery is charged according to the sectional implementation, the charging voltage, the charging current and the charging power of the battery pack string are in an intelligent controlled state. The right side of fig. 4 shows that the relation between the B-side electrical type parameter of the battery string and the equivalent charging conductance Gch is in a controlled state, and the left side of fig. 4 shows that the electrical type parameter equivalent to the battery input P-side is also in a controlled state because of the direct-current power bus power conversion. Further, it can be seen that fig. 5A shows a conventional battery BP, when a high-power charger with 10C charging current is connected, the peak charging current at the input side of the battery pack reaches 10C, the equivalent input impedance is as low as a rated value of 1/10, the instantaneous power reaches 10 times, the total charging energy storage is large, the heat generation is serious, and the risk of capacity and time tolerance is large. Fig. 5B shows a switch-embedded switching power-converting controlled parallel rechargeable battery pack BRP, which is connected to a charger with 10C charging current or a dc power bus. Because the built-in switch of the battery pack is used for converting, regulating and charging, the electrical types of the input side and the output side of the battery pack are controlled, the peak charging current is only the preset constant current 1C, the equivalent input impedance is the rated value rin.

FIG. 6 is a schematic diagram of the parallel charging of a built-in half-bridge buck-boost conversion rechargeable battery pack BRP-HB, and FIG. 7 is a schematic diagram of the parallel charging of a built-in full-bridge buck-boost conversion rechargeable battery pack BRP-FB; due to the special power conversion performance of the built-in conversion regulation charger of the composite open-close protection, the charging input current, the input power and the equivalent input impedance of the BRP of the battery pack are controlled, the inherent uncontrolled low resistance, large current and high power characteristics of the original battery pack are avoided, the controlled parallel connection of the multiple battery packs can effectively operate, and a distributed modular system is formed.

Fig. 8 is a schematic diagram of the working relationship between the input voltage for efficient charging and the string voltage of the battery pack during buck-boost, and boost conversion of the internal conversion rechargeable battery pack. The effective charging input working ranges are different due to three different conversion types; the built-in half-bridge buck-boost conversion parallel charging type battery pack BRP-HB has good performance and low cost, and the built-in full-bridge buck-boost conversion parallel charging type battery pack BRP-FB has excellent performance and high cost performance.

Fig. 9 is a schematic diagram of three-stage controlled characteristics of input voltage and input current limit of a typical internal conversion charging battery pack, where the left side is an input voltage and current limit volt-ampere controlled characteristic, and the right side is an input voltage and power controlled characteristic, where it can be seen that, for a battery charging input voltage, i.e., a charging power bus voltage Vpc, a mode of adjusting the charging input current limit linear association and automatic following the charging input voltage is configured above a constant voltage charging voltage Vcv of the battery pack, a current limit coefficient K0 is 1-2, Vcv < Vpb < Vnup, and a linear slope is 1C/1V is configured in this stage a0, and a charging input current limit reducing, i.e., a reduced power K1 is configured below a rated voltage Vnom of the battery pack, i.e., a segmented mode of 0.5, and Vnlp < b < Vnla; the BRP battery pack is set according to the electric controlled mode, the battery pack automatically regulates and controls the charging segmented mode and the input power according to the charging input voltage segmented value, external communication is not needed in the charging process, and autonomous intelligent management is achieved according to a distributed design concept.

Fig. 10 is a schematic diagram of a typical power bus branching distribution unit BDU, in which a branching switch is composed of dual field effect transistors pQC1 and pQD1 connected in series in opposite directions, pQC1 is turned off to charge a blocking battery pack, pQD1 is turned off to reverse-flow a power bus to destroy a charging system when the blocking battery pack is turned off at an abnormal high voltage, and a controller DCU1 monitors a branching fuse F1, a battery voltage vDP, a charging current iDP, a connection battery pack serial port BPC, and a connection system serial communication RS by using a single-chip MCU.

In particular, in order to achieve a certain set energy management target of the charging system, for example, the charging system can be configured according to physical positions, segmented according to voltages, distributed according to average charging current, distributed according to current capacity of batteries, distributed according to dynamic internal resistance of batteries, distributed according to internal temperature rise of batteries, and the like, battery pack state, charging and energy related information can be transmitted according to communication addresses and communication protocols, charging current limiting or power limiting parameter adjusting instructions can be intelligently sent, dynamic intelligent distributed parallel charging of multiple battery packs can be achieved, and systematic high-level intelligent management can be achieved.

Battery pack embodiment 1 in which a plurality of battery packs are charged in parallel for operation, as shown in fig. 11; the method comprises the following steps of protecting a built-in half-bridge step-down rechargeable battery pack BRP-HB by adopting a composite open-close mode, selecting a lithium battery with the capacity of 48V16Ah, and connecting three battery packs in parallel to form a charging pile for an eSCotter of a professional electric motorcycle for urban express; and a constant-voltage current-limiting power bus charging power supply 54V/2KW is configured.

Battery pack embodiment 2 in which a plurality of battery packs are charged in parallel for operation, as shown in fig. 12; the method comprises the following steps that a built-in full-bridge boost-buck rechargeable battery pack BRP-FB is protected by adopting a composite switch, a lithium battery with the capacity of 48V16Ah is selected as the battery, and three battery packs are connected in parallel to form an on-vehicle charging port and are used for an eMotor of the cross-country sports electric motorcycle; a constant voltage current-limiting power supply 54-57V/2-6KW is arranged outside the vehicle.

Battery pack embodiment 3 in which a plurality of battery packs are charged in parallel for operation, as shown in fig. 13; a built-in full-bridge boost-buck rechargeable battery pack BRP-FB is adopted, and twelve 48V16Ah battery packs are adopted and used for energy storage and charging of a standby power supply of a 48V communication base station; a [ 48-56V/50A ] 6/18KW rectifier system is selected to configure a power bus, and a solar direct current converter is reserved to be connected into the power bus.

Battery pack embodiment 4 in which a plurality of battery packs are charged in parallel for operation, as shown in fig. 14; the battery charging and replacing cabinet adopts a built-in full-bridge buck-boost charging battery pack BRP-FB, adopts twelve 48V16Ah battery packs, is used for charging and replacing a 48V power lithium battery, and comprises four groups of sub-machine frames and a sub-machine frame, wherein three battery bins are configured; a rectifier power supply 54V30A multiplied by 4/6.5KW is selected to form a power bus, a monitor CMU, a distribution unit BDU and a battery cabin BHU are configured, and a power bus parallel charging operation system is formed.

The power bus is adopted to implement the parallel connection integrated large system in a modularized way, and the modularized parallel connection way is adopted for charging, so that the superiority, the availability, the maintainability and the reliability of the technical scheme are greatly improved, the integration capability of the battery pack system is greatly improved, and the capability of the charging system is improved; therefore, for the battery pack used for moving out or replacing the battery pack system in operation, the adoption of the power bus for charging multiple battery packs is very important, and meanwhile, the effective multiple battery pack parallel charging operation technology can greatly improve the technical performance of the charging system, reduce the cost of a battery power system and improve the economic benefit.

As shown in fig. 11, a system embodiment 1 for parallel charging operation of multiple battery packs according to the present invention includes:

the controlled electric battery pack BRPi, i is 1-3 to form a parallel charging operation system; the anodes P + of all the battery packs are connected, and the cathodes P-are connected;

selecting a single bus serial communication port BPC to be vacant, connecting an address state port SAD of the battery pack to P +, and detecting the battery pack as a charging mode;

selecting an effective charging working range of the system and the battery pack, and further comprising:

nominal voltage: vnom ═ 48.0V, (+ 16.7%, -12.5%) Vnom;

nominal range: the upper limit Vnup is 56.0V, the lower limit Vnlp is 42.0V;

default presetting: the power bus voltage Vpb is 54.6V, and the shunt current limit Ipc is 12A;

selecting a rated specification of a charging power bus: R2K-48[ AC220V/54.6V36A ]; selecting a built-in half-bridge voltage reduction charging battery pack BRP-HB; selecting a battery pack voltage capacity rated specification of 48V16 Ah;

choose for use group battery electricity core, include: lithium iron phosphate, ternary lithium batteries or modified lithium manganese; selecting a charging input: voltage Vci is 42-54.6V, and current limiting Ici is 12A; charging segmentation parameters: vpc 42V, Icc 11A/0.7C, Vcv 54.6V.

As shown in fig. 12, an embodiment 2 of the system for parallel charging operation of multiple battery packs according to the present invention includes:

selecting a controlled electric battery pack BRPi, i is 1-3 to form a parallel charging operation system; the anodes P + of all the battery packs are connected, and the cathodes P-are connected;

selecting a single bus serial communication port SAD, connecting the single bus serial communication port SAD with an external charging state signal SC, connecting the single bus serial communication port SAD with a P + from a charging side, and configuring a charging mode; selecting a single bus serial communication port BPC serial port to be vacant;

nominal voltage: vnom ═ 48.0V, (+ 16.7%, -12.5%) Vnom;

nominal range: the upper limit Vnup is 56.0V, the lower limit Vnlp is 42.0V;

selecting a rated specification of a charging power bus: R6K-48[ AC220V/57V/100A ]; R4K-48 [ AC220V/54.6V/75A ]; R2K-48[ AC220V/54.6V/36A ];

selecting a built-in full-bridge buck-boost rechargeable battery pack BRP-FB; selecting a battery pack voltage capacity rated specification of 48V16 Ah;

choose for use group battery electricity core, include: lithium iron phosphate or ternary lithium batteries; selecting a charging input voltage: vci is 42-57V, charging input current limiting: -Ici-16 +8 (Vci-55) a, 57V > Vci > 55V;

Ici＝16A，55V>Vci>45V；Ici＝8A，45V>Vci>42V；

charging segmentation parameters: vpc 42V, Icc 10/16/32A, Vcv V54.6V.

As shown in fig. 13, an embodiment 3 of the system for parallel charging operation of multiple battery packs according to the present invention includes:

selecting a controlled electric battery pack BRPi, i is 1-n, and n is 12 to form a parallel charging operation system; the anodes P + of all the battery packs are connected, and all the cathodes P-are connected, and are connected with the corresponding shunt distribution output positive end DP + and the negative end DP-; all branch distribution input positive terminals DP + and negative terminals DP-are correspondingly connected into positive terminals PB + and negative terminals PB-of the power buses;

resistors RDi are connected in series between all the power distribution units BDU and P + and the power distribution unit addresses ADR; resistors RHI are connected in series between all the battery bins BHU, P + and the single bus serial communication port SAD; the monitor, all the power distribution units, the battery bins and the communication bus BPC of the battery pack are connected;

nominal voltage: vnom ═ 48.0V, (+ 16.6%, -12.5%) Vnom;

nominal range: the upper limit Vnup is 56.0V, the lower limit Vnlp is 42.0V;

friendly application: upper bound Vnua ═ 51.0V, lower bound Vnla ═ 45.0V, ± (4-7)%;

default presetting: power bus voltage Vpb 54.6V; shunt current limit Ipc-16A;

selecting a rated specification of a charging power bus: R6K-48[ AC220V/54.6V/200A ];

selecting a battery pack voltage capacity rated specification of 48V16 Ah;

selecting a built-in full-bridge boost-buck piezoelectric rechargeable battery pack BRP-FB;

choose group battery electricity core for use as power new forms of energy type, include: lithium iron phosphate LiFe, ternary lithium battery Li3Y, modified lithium manganese LiMn or nickel hydrogen NiH;

the method for selecting six sections of built-in charging processes of the battery pack comprises the following steps:

selecting a charging input: voltage Vci is 42-54.6V, and current limiting Ici is 16A;

selecting a section corresponding to the charging process: pre-charging, constant current, constant voltage and stopping charging;

charging segmentation parameters: vpc 42V, Icc 16/32A, Vcv V54.6V;

selecting a monitoring rectifier power supply, calculating voltage Vpb.set and current limit Ipc.set, and comprising the following steps:

when the rectifier 6 × 3 is 18KW, the following settings are set: vpb 56.0V, Ipc 24A;

when the rectifier 4 × 3 is 12KW, the following settings are set: vpb 55.0V, Ipc 16A;

when the rectifier 2 × 3 ═ 6KW, settings are: vpb 54.6V, Ipc 8A;

selecting a charging system controller CMU to manage each battery pack; the method comprises the following steps:

collecting port voltage vDP, current iDP and current capacity C of each shunt battery pack;

and the selected battery pack broadcasts an address to issue instructions of Vpb.set and Ipc.set.

As shown in fig. 14, a system embodiment 4 for parallel charging operation of multiple battery packs according to the present invention includes:

selecting a controlled electric battery pack BRPi, i is 1-n, and n is 12 to form a parallel charging operation system; 4 sub-machine frames are arranged in the selected charging and converting cabinet, and 3 battery bins are arranged in each sub-machine frame; positive ends P + and negative ends P-of all battery packs BRP are connected with corresponding branch distribution output positive ends and negative ends, and all branch distribution input positive ends DP + and negative ends DP-are connected with positive ends PB + and negative ends PB-of the power bus;

selecting a monitor and all battery packs, wherein communication buses BPCs of the battery packs are connected; selecting all power distribution units BDU, P + and power distribution unit addresses ADR to be connected with resistors RDi in series;

selecting all battery packs corresponding to the battery bins, and connecting resistors Rhi in series between P + and the single bus serial communication port SAD;

nominal voltage: vnom ═ 48.0V, (+ 16.6%, -12.5%) Vnom;

nominal range: the upper limit Vnup is 56.0V, the lower limit Vnlp is 42.0V;

default presetting: power bus voltage Vpb 54.6V; shunt current Ipc-16A;

selecting a rated specification of a charging power bus: r4830 by 4[ AC220V/54.6V/120A ]; selecting a battery pack voltage capacity rated specification of 48V16 Ah; selecting a built-in full-bridge boost-buck piezoelectric rechargeable battery pack BRP-FB; further comprising:

selecting a battery cell as a new power energy type, namely lithium iron phosphate LiFe, ternary lithium battery Li3Y, modified lithium manganese LiMn or nickel hydrogen NiH;

selecting a charging input: voltage Vci is 42-54.6V, and current limiting Ici is 10A;

charging segmentation parameters: vpc 42V, Icc 8A, Vcv 54.6V;

monitoring a rectifier power supply, calculating a shunt current limit ipc.set, comprising:

when the serial number of the battery pack address is 1-3, the corresponding setting is as follows: Ipc-12A;

when the address serial number of the battery pack is 4-6, correspondingly setting: Ipc-10A;

when the address serial number of the battery pack is 7-12, correspondingly setting: Ipc-8A;

monitoring and calculating the reduction of the batteries to be charged, and limiting the current according to an intelligent menu or the input current of a specific battery pack specified by an upper computer command to a maximum current limiting point of 32A/2C;

collecting the voltage Vp, the current Ip and the current capacity C of each battery pack port;

and issuing an Ipc.set instruction by the corresponding address of the selected battery pack.

In embodiment 1, the parallel charge operation system is: the positive and negative ends of all the batteries are respectively connected in parallel; the parallel charging of the system is realized by independently connecting and matching the voltage, current, impedance and ampere-hour characteristics input by charging a plurality of battery packs according to the built-in conversion charging regulation characteristics and the built-in voltage, current and electric type convention parameters of each battery, the power bus power supply in the system is preset according to the rated constant voltage value Vcv of the battery, and the shunt charging input of the power bus is limited according to the battery capacity coefficient of 0.7C; the system is simple and compatible with conventional wiring, and the parallel charging performance of the system is greatly improved.

In embodiment 2, the parallel charge operation system is: the positive and negative ends of all batteries are respectively connected in parallel, signal ports SAD of all battery packs are connected in parallel and then connected to a charging port, an externally-matched charging state signal SC is connected to a P + end to be in a charging state in a default mode, an externally-connected charger corresponds to different power and voltage levels and provides different charging rates, when a 54.6V/2KW charger is configured, quick charging QC is completed in about 3 hours according to the charging speed of 0.5C, when a 56V/4KW charger is configured, quick charging FC is completed in about 2 hours according to the charging speed of 1C, and when a 57V/6KW charger is configured, 85% ultra-quick charging SC is completed in about 0.5 hour according to the charging speed of 2C. According to the system, a high-performance intelligent modularized built-in conversion charging battery is configured, an intelligent charging port current-limiting voltage automatic matching adjusting mode is built in the battery, and the built-in intelligent level is greatly improved while the charging performance of the system is improved.

In embodiment 3, the parallel charging operation system is configured with a shunt unit BDU, a battery compartment BHU, two positive and negative ends corresponding to all battery packs connected in parallel, a monitoring unit and communication buses BPC of all battery packs connected in parallel, and address ports ADRi of each shunt power distribution unit are connected by P + to matching resistors RDi corresponding to BDU01-12 #; the SADi corresponding to the address state port of each battery bin is connected with each matching resistor RHI through P < + > and corresponds to [ BRP ] BHU01-12#, monitoring is mainly carried out by default, a built-in bidirectional full-bridge conversion topology buck-boost conversion battery pack is adopted, a charging system corresponds to different power levels and provides different charging rates, when 2 3KW charging modules are configured, quick charging QC is completed in about 3 hours according to 0.5C rate of charging, when 4 3KW charging modules are configured, the voltage of a charging bus is adjusted to 56V, a charging branch circuit completes quick charging FC in about 1.5 hours according to 16A/1C rate, and when a 57V/6KW charger is configured, charging is completed in about 1 hour according to 24A/1.5C rate of charging, 95% of ultrafast charging SC is completed. The system is designed according to a standard modular system, and the interaction and intellectualization of a system controller are realized, so that the system is a standard mode of a multi-battery pack intelligent parallel operation system.

In embodiment 4, the parallel charging operation system adopts 4 sub-machine frames connected in parallel, each sub-machine frame is configured with 3 battery compartments BHU corresponding to the power distribution unit BDU to connect the battery packs in parallel, a connection communication line BPC and each battery pack address state SADi are matched with the in-place signal BH to be identified as a charging state, a power distribution unit address ADR is matched with a resistance RDi to identify a device number B01-12#, and the BPC is converted through an RS communication interface to exchange communication data with the battery packs; the system adopts a built-in bidirectional full-bridge conversion topology buck-boost conversion battery pack, the system takes Vcv as a preset voltage Vpb.set, shunt current is preset to be 0.75C current-limiting in the battery pack, and the power-on regulation is completed by a monitoring unit CMU after the battery pack is inserted according to a physical position, wherein the 01-03# position is quickly charged according to 0.75C, the 04-06# position is quickly charged according to 0.63C, the 07-12# position is quickly charged according to 0.5C, the number of rectifiers and the reduction of a battery to be charged are dynamically monitored in the operation of the system, an intelligent menu is released after planning calculation, or the quick charging input current-limiting of a specific battery pack specified by an upper computer USB/TCPIP interface and a communication command is released, and the maximum can reach a 32A/2C current-limiting point; the method is a software connection optimization mode for the multi-battery pack self-powered hot standby distributed parallel charging operation.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A multi-battery parallel charging operation system is characterized in that,

the system comprises a plurality of electrically controlled rechargeable battery packs BRPi, i ≧ 2;

the system is provided with a power bus;

all positive ends of the multiple electric type controlled charging battery packs are connected with each other and then receive power supply from the positive end of the power bus, and all negative ends of the multiple electric type controlled charging battery packs are connected with each other and then receive power supply from the negative end of the power bus, so that a multi-battery pack parallel charging operation system is formed;

the electric type controlled rechargeable battery pack is the same type of electric type rechargeable battery pack;

the electric type controlled rechargeable battery pack is characterized in that basic electric type parameters of the rechargeable battery pack are that a charging input voltage Chvin and a charging input current ChIin are in an effective preset range and are controlled; the extended electrical parameter charging input equivalent impedance ChRin and the charging input volt-ampere power ChPin are controlled; the associated electrical parameter current limit and charging input voltage are controlled, and the volt-ampere power and the charging input voltage are controlled;

a power bus arranged in the electric type controlled charging battery pack is accessed in a shunt power distribution mode, namely a shunt power distribution unit BDU is configured between the bus and the battery pack; the BDU includes: the system comprises an anti-short-circuit direct-current low-voltage power fuse F, a shunt switching control switch pQ, an intelligent power distribution controller DCU, shunt current and voltage measuring ports vDP and iDP, an address coding measuring port pADR, a single-wire serial communication port BPC and a two-wire serial communication port RS [ RS +, RS- ], wherein a single-field effect tube or a double-field effect tube or a relay is adopted;

configuring a battery compartment and a quick connection socket to be in butt joint with a battery pack wiring port;

setting a multi-battery pack charging system controller CMU;

setting a system power bus operating voltage Vpb.set and a current limit Ipb.set;

setting a system power bus shunt circuit preset maximum charging current limit Ipc.set;

the electric type controlled charging battery BRP is a built-in switch conversion charging battery.

2. The operating system of claim 1, wherein:

3. The operating system of claim 1, wherein:

4. The operating system of claim 1, wherein:

5. The operating system according to claim 2, 3 or 4, characterized in that:

the system is provided with a battery pack communication port BPC, a charging identification port SCD and an address interface bADR;

the system configures the corresponding resistance of each battery pack address interface ADRi according to the coding serial number;

connecting the communication line BPC in the system;

and establishing a serial communication protocol transceiving information and instruction of the parallel charging operation system.

6. The operating system of claim 5, wherein:

the bus shunt power distribution unit BDU and the shunt on-off switch pQ are matched with the intelligent power distribution controller DCU to be used for shunt battery pack reverse connection protection, overcurrent protection, overtime charging and instruction controlled closing;

the intelligent distribution controller DCU obtains and monitors the voltage of the battery pack string through communication of the communication line BPC in the system, and is used for closing the shunt switch pQ and protecting the abnormal high voltage of the shunt battery port from reversely flowing back to the distribution interface to lead to the high voltage of the power bus when the overvoltage exceeds the maximum value of the effective working range, so that overvoltage stop charging of other parallel battery packs on the bus is avoided.

7. The operating system of claim 6, wherein:

the CMU (charge control unit) of the multi-battery pack charging system is used for managing output voltage and current limiting values of bus source equipment according to design configuration communication and configuring the maximum charging current limiting value of a BDU (bus bar branching unit);

the CMU is connected with a system communication line, exchanges the state and parameters of each battery pack, and issues commands according to broadcasting, grouping and address division;

the system controller is used for analyzing and counting the characteristic quantity of the charging system according to a design configuration function algorithm.

8. The operating system of claim 7, wherein:

the shunt current limit of the system is defined by the ratio K1 of three-gear controlled values;

k1=1, referring to the system shunt rated current limit ipc.set = K1 × ipc.set;

the specific configuration steps of each battery pack and shunt charging input current limit Ipc include:

9. The operating system of claim 7, wherein:

the shunt current limit of the system is defined by the ratio K0 of three-gear controlled values;

2> K0>1, which refers to system shunt large current limit ipc.set = K0 × ipc.set;

10. The operating system of claim 7, wherein:

the shunt current limit of the system is defined by the ratio K2 of three-gear controlled values;

1> K2>0.3, referring to system shunt small current limit ipc.set = K2 × ipc.set;

11. A method of operating a parallel charging operation system according to any preceding claim, comprising the steps of:

1) starting charging;

2) setting conventional parameters of the parallel charging operation system;

3) setting control parameters of the parallel charging operation system;

5) the parameter setting of the charging bus of the parallel charging operation system comprises the following steps:

12. The operation method of the charge operation system according to claim 11, comprising the steps of:

13. The operation method of the charge operation system according to claim 12, comprising the steps of:

9) and finishing charging.