CN113224816B - Isolation interface, gating network, protection and equalization circuit and method for series battery pack - Google Patents

Isolation interface, gating network, protection and equalization circuit and method for series battery pack Download PDF

Info

Publication number
CN113224816B
CN113224816B CN202110531681.4A CN202110531681A CN113224816B CN 113224816 B CN113224816 B CN 113224816B CN 202110531681 A CN202110531681 A CN 202110531681A CN 113224816 B CN113224816 B CN 113224816B
Authority
CN
China
Prior art keywords
switch
battery pack
group
series battery
series
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110531681.4A
Other languages
Chinese (zh)
Other versions
CN113224816A (en
Inventor
谢弘洋
李睿
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Jiaotong University
Original Assignee
Shanghai Jiaotong University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Jiaotong University filed Critical Shanghai Jiaotong University
Priority to CN202110531681.4A priority Critical patent/CN113224816B/en
Publication of CN113224816A publication Critical patent/CN113224816A/en
Application granted granted Critical
Publication of CN113224816B publication Critical patent/CN113224816B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
    • H02J7/0014—Circuits for equalisation of charge between batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/18—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for batteries; for accumulators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • H02M3/33584—Bidirectional converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J2207/20—Charging or discharging characterised by the power electronics converter

Abstract

The invention provides a series battery pack protection and equalization circuit with an isolation interface and a gating network and a control method; meanwhile, a corresponding isolation interface and a gating network circuit are provided; by switching a switch in a gating network and an isolation interface of the series battery pack and the bidirectional power conversion and isolation functions of an isolation type bidirectional direct-current converter in the isolation interface of the series battery pack, the invention can realize the isolation of a fault battery when a single battery or a plurality of batteries in the series battery pack have faults, block the current flowing through the fault battery, ensure the safety of the battery pack, and simultaneously, the non-fault battery can still be connected into an external circuit through the invention to realize normal charging and discharging operation; when the battery pack works normally and has no battery fault, the battery pack can be connected into an external circuit with extremely low loss, and meanwhile, the battery pack has the charge state balancing function of the series battery pack, so that the efficient and safe operation of the battery pack is ensured.

Description

Isolation interface, gating network, protection and equalization circuit and method for series battery pack
Technical Field
The invention relates to the technical field of battery energy storage, in particular to an isolation interface, a gating network, a protection and equalization circuit and a control method of a series battery pack based on an isolation type converter.
Background
With the continuous development of battery technology, the battery energy storage plays an increasingly important role in various aspects of social production and life by virtue of high energy density and stable energy storage characteristics. Taking large-capacity energy storage as an example, along with the continuous increase of installed capacity of new energy power generation and the continuous development of an intelligent power grid, higher and higher requirements are provided for the capacity and functions of an energy storage system, a battery energy storage system has the advantages of no moving parts, no special requirements for a field, easiness in capacity expansion and good dynamic characteristics, and the battery energy storage system is increasingly widely applied to occasions such as frequency modulation and peak shaving on the side of a power grid, emergency guarantee of loads on the side of a user, smooth fluctuation of power of renewable energy sources and the like. Batteries are also an indispensable part of the fields of reserve power supplies, electric vehicles, electric tools, lighting, and the like. The safe operation of the battery also becomes an urgent problem to be solved in the battery application process.
The capacity and voltage of a single battery cell are small, so that the direct application cannot be realized. Therefore, in practical application scenarios, batteries are usually connected in series and parallel to form a battery pack according to required voltage levels and capacities. The voltage output by the battery pack can be increased by connecting a plurality of battery cells in series. In practical application, the battery monomers are usually connected in series to obtain standard modules with voltage levels of 48V, 60V, 72V and the like, and then the standard series battery module is connected in series to boost the voltage when higher voltage is needed; and when larger charging and discharging current is needed, the standard series battery module is connected in parallel for capacity expansion. The single batteries are connected in series and parallel and then connected into an external circuit, so that the battery pack can be suitable for different application requirements and is also an important mode for practical application of the battery.
However, the series-parallel connection of a large number of batteries also presents a series of problems and challenges that limit the development of battery energy storage. In the parallel state, battery circulation caused by the inconsistency of the battery cells increases battery loss, reduces battery life and increases the risk of failure. In the series state, the currents flowing through the cells in the series battery pack must be equal at all times, thereby causing two main problems of cell protection and cell balancing.
For battery protection, due to inconsistency of factory characteristics and running states of battery monomers, aging and damage degrees of the battery monomers in the same series battery pack are different, when a certain battery monomer reaches the upper limit of service life or breaks down, the current flowing through the battery monomer needs to be reduced to zero, otherwise, the damage or the fault of the battery monomer is further aggravated by charge and discharge currents in a normal working state, meanwhile, the battery heats and rises in temperature, even faults of adjacent batteries are caused, and more serious accidents are caused. However, for a series-connected battery pack, the operation of withdrawing one single battery needs to withdraw the entire series-connected battery pack together, and for high-voltage battery energy storage applications, hundreds of single batteries are often connected in series to reach a required voltage level, and at this time, the failure of a single battery will cause a large number of normal batteries in the same battery string to be forced to withdraw from operation; meanwhile, the more the number of the batteries connected in series is, the greater the probability that a single battery in the battery pack connected in series fails is; therefore, the problem of protecting the batteries in the series battery pack greatly increases the running cost of the system and restricts the improvement of the reliability of the battery energy storage system.
In the normal operation process of the battery, due to the inconsistency of the factory characteristics of the battery monomers and the difference of the operation state and the temperature, in the actual operation process, the capacity difference exists among the battery monomers, and although the same charge and discharge current flows through each battery in the series battery pack, the charge state of each battery is different. For a series of battery cells connected in series, during the charging process, there may be a situation that a certain battery is fully charged and the rest batteries are not fully charged, and in order to avoid overcharging the battery, the rest batteries cannot be further fully charged; similarly, during the discharging process, there may be a situation where a certain battery capacity has reached the minimum allowable state of charge, and the remaining batteries can still be further discharged, at which time, in order to avoid the damage of the battery cells caused by the over-discharge, all the battery cells connected in series will stop continuing the discharging. Therefore, the inconsistent performance of the battery cells can limit the available capacity of the whole energy storage system, waste of configured capacity is caused, and the cost of the energy storage system is increased. In order to solve the problem of inconsistent battery charge states in the series battery packs, two means, namely battery screening and battery balancing, are usually adopted. The battery screening refers to testing the performance of each battery core when the battery leaves a factory, and selecting the battery cores with consistent performance to be connected in series and in parallel to form a battery module. This process requires a significant expenditure of time and labor costs. And the battery equalization is that after the batteries form a battery string, the state of charge of each battery core is always kept consistent through two modes of passive equalization or active equalization.
In the prior art, the following methods for protecting faulty cells in series-connected battery packs or balancing cells in series-connected battery packs have been proposed:
(1) The Chinese patent application with publication number CN112186857A provides a series battery protection circuit, which realizes the isolation and protection functions of single-cell fault batteries by matching a corresponding control and buffer circuit for each single-cell battery series switch. However, the switch connected in series for each battery means that a large number of switch on-resistances are connected in series in the circuit in normal operation, which brings additional loss in normal operation of the series battery pack, and is not suitable for application scenarios with a large number of batteries in series and large charging and discharging currents.
(2) Chinese patent application with publication number CN111030265A proposes a single battery protection circuit in a battery pack, which realizes the bypass and protection functions for a faulty battery cell by connecting a single-pole double-throw switch controlled by a relay coil in series for each battery cell. However, the introduction of a large number of relay switches also results in that the resistance loss of the series battery pack during normal operation increases with the number of series batteries; meanwhile, the relay cannot cut off large direct current, and the protection circuit is not suitable for application scenes with large number of series batteries and large charging and discharging current.
(3) Chinese patent application publication No. CN110867921A proposes a method for directly balancing batteries inside a series battery pack, in which a flyback converter is used to connect battery monomers to be balanced, so as to realize direct active balancing between high-charge state monomers and low-charge state monomers. The method introduces more power electronic switches, increases the system cost, can only realize the battery balancing function, and has single functionality.
No description or report of the similar technology to the invention is found at present, and similar data at home and abroad are not collected yet.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a series battery pack isolation interface circuit based on an isolation type bidirectional direct current converter, a series battery pack gating network circuit, a series battery pack protection and equalization circuit with an isolation interface and a gating network and a control method.
According to an aspect of the present invention, there is provided a series battery isolation interface circuit, comprising: a first isolated bidirectional DC converter, a second isolated bidirectional DC converter, a first switch S 1 A second switch S 2 First bypass switch S 1c A second bypass switch S 2c And a positive switch S of the battery pack PB Battery negative switch S NB Positive pole switch S of converter PT Converter negative pole switch S NT An external circuit positive terminal, an external circuit negative terminal, a series battery pack positive terminal P B And negative terminal N of series battery B (ii) a Wherein:
the first isolation type bidirectional direct current converter and the second isolation type bidirectional direct current converter are both of a two-port structure, and a positive end I and a negative end II of a first port of the first isolation type bidirectional direct current converter respectively form a battery connecting terminal I and a battery connecting terminal II; a positive terminal III and a negative terminal IV of a first port of the second isolated bidirectional direct current converter form a battery connecting terminal III and a battery connecting terminal IV respectively;
the first switch S 1 The positive end I of the first port of the first isolation type bidirectional direct current converter is connected with the positive end of the second port of the first isolation type bidirectional direct current converter, and the second switch S 2 Connecting a negative end IV of a first port of the second isolation type bidirectional direct current converter with a negative end of a second port; the first bypass switch S 1c The positive end and the negative end of the second port of the first isolated bidirectional direct current converter are connected, and the second bypass switch S 2c Connecting the positive end and the negative end of a second port of the second isolated bidirectional direct current converter; the negative end of the second port of the first isolated bidirectional direct current converter is connected with the positive end of the second port of the second isolated bidirectional direct current converter;
the positive end of the second port of the first isolation type bidirectional direct current converter is connected with the positive electrode switch S of the converter PT One end of said converter positive switch S PT The other end of the switch is connected with the positive end of the external circuit; the negative end of the second port of the second isolated bidirectional direct current converter is connected with the negative switch S of the converter NT Of the converter negative pole switch S NT The other end of the first switch is connected with the negative end of the external circuit; the battery positive switch S PB Is connected with the positive end of the external circuit, and the positive pole switch S of the battery pack PB And the other end of the same is connected with the positive end P of the series battery pack B Connecting; the battery negative switch S NB Is connected with the negative end of the external circuit, and the negative pole switch S of the battery pack NB And the other end of the battery pack is connected with the negative end N of the series battery pack B And (4) connecting.
According to another aspect of the present invention, there is provided a series battery gating network circuit comprising: the converter comprises a switch group I, a switch group II, a switch group III, a switch group IV, a converter connecting terminal I, a converter connecting terminal II, a converter connecting terminal III and a converter connecting terminal IV; wherein:
the switch groups I to IV respectively comprise N switches S; wherein:
one end of each of N switches S in the switch group I is connected to the converter connecting terminal I, and the first switch S in the switch group I I，0 The other end of the first group of switches forms a positive end connection end of a series battery pack, and the rest N-1 switches S in the switch group I I，1 、S I，2 ……S I，N-1 The other end of the battery pack forms a connecting end of a series battery pack;
one end of each of N switches S in the switch group II is connected to the converter connecting terminal II, and the Nth switch S in the switch group II is connected to the converter connecting terminal II II，N The other end of the switch group II forms a negative end connecting end of the series battery pack, and the rest N-1 switches S in the switch group II II，1 、S II，2 ……S II，N-1 The other end of the battery pack forms a connecting end of a series battery pack;
one end of each of N switches S in the group III switch set is connected to the converter connecting terminal III, and the first switch S in the group III switch set III，0 The other end of the first group of switches forms a positive end connection end of a series battery pack, and the rest N-1 switches S in the group III of switches III，1 、S III，2 ……S III，N-1 The other end of the battery pack forms a connecting end of a series battery pack;
one end of each of N switches S in a switch group IV is connected to the converter connecting terminal IV IV，N The other end of the group IV switch group forms a negative end connecting end of the series battery group, and the rest N-1 switches S in the group IV switch group IV，1 、S IV，2 ……S IV，N-1 The other end of which forms a series battery connection end.
According to a third aspect of the present invention, there is provided a series battery protection and equalization circuit comprising: the series battery pack, the series battery pack isolation interface circuit and the series battery pack gating network circuit are connected in series; wherein:
the battery connecting terminals I-IV of the series battery pack isolation interface circuit are correspondingly connected with the converter connecting terminals I-IV of the series battery pack gating network circuit respectively;
the series battery pack includes N batteries B connected in series, wherein:
the first switch S in the group I of switches I，0 Is connected to the series battery positive terminal P B The rest N-1 switches S in the switch group I I，1 、S I，2 ……S I，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the Nth switch S in the second group of switches II，N Is connected to the negative end N of the series battery B The rest N-1 switches S in the switch group of the second group II，1 、S II，2 ……S II，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the first switch S in the group III switch group III，0 Is connected to the series battery positive terminal P B The rest N-1 switches S in the group III switch group III，1 、S III，2 ……S III，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the Nth switch S in the IV group switch group IV，N Is connected to the negative terminal N of the series battery B The rest N-1 switches S in the IV group of switches IV，1 、S IV，2 ……S IV，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the positive end P of the series battery pack B And the negative terminal N of the series battery pack B The two ends of the battery pack are respectively connected with the terminals at the two ends of the series battery pack;
the external circuit positive end and the external circuit negative end of the series battery pack isolation interface circuit form an external circuit port of the series battery pack protection and equalization circuit;
the positive end P of the series battery pack B The negative terminal N of the series battery pack B The battery connecting terminals I-IV realize power interaction with the series battery pack; the external circuit port enables power interaction with an external circuit.
According to a fourth aspect of the present invention, there is provided a control method for the protection and equalization circuit of the series battery pack, including any one or more of the operation modes a to K.
According to a fifth aspect of the present invention, a method for controlling the isolation and protection of a faulty battery in a protection and equalization circuit of a series battery pack is provided, wherein according to a battery fault state detected by a battery management system, any one or any plurality of working modes are selected from the working methods, and the faulty battery is isolated from a power loop, so that a current flowing through the faulty battery is zero, and meanwhile, a non-faulty battery can still be connected to an external circuit to normally work, thereby completing normal battery charging or discharging; according to the working mode, as many normal batteries as possible are connected into the circuit to continue working, and on the basis, the sum of the number of the batteries connected into the external circuit through the first isolation type bidirectional direct current converter and the second isolation type bidirectional direct current converter is minimized, so that the lowest power converter loss is realized.
According to a sixth aspect of the present invention, there is provided a balancing control method of the protection and balancing circuit for a series battery pack, when a battery management system detects that there is no battery fault and there is a battery in the series battery pack that needs to be balanced, the battery in the series battery pack is balanced.
Due to the adoption of the technical scheme, compared with the prior art, the invention has the following beneficial effects:
according to the series battery pack isolation interface circuit, the series battery pack gating network circuit, the series battery pack protection and equalization circuit and the control method based on the isolation type bidirectional direct current converter, provided by the invention, when a battery fails or is damaged, the failed battery can be isolated from a power loop, so that the failed battery does not participate in charging and discharging any more, the failed battery is protected, the aggravation of the failure and the occurrence of the accident are avoided, when the battery pack works normally, the series battery pack is connected into an external circuit by only two switches, and the problems that the existing series battery pack protection circuit needs to be connected into a large number of switches in series and the loss is increased are avoided; meanwhile, the battery balancing function is achieved, when no battery fault exists in the battery pack, the electric quantity transfer among the battery monomers can be achieved through an active balancing mode, and the purpose of eliminating the inconsistent battery charge states in the series battery packs is achieved.
According to the series battery pack isolation interface circuit based on the isolation type bidirectional direct current converter, the series battery pack gating network circuit, the series battery pack protection and equalization circuit and the control method, through switching of the switches in the series battery pack gating network and the series battery pack isolation interface and the bidirectional power conversion and isolation functions of the isolation type bidirectional direct current converter in the series battery pack isolation interface, when a single battery or a plurality of batteries in the series battery pack are in fault, the isolation of the fault battery can be realized, the current flowing through the fault battery is blocked, the safety of the battery pack is guaranteed, and meanwhile, the non-fault battery can still be connected to an external circuit through the isolation type bidirectional direct current converter, so that normal charging and discharging operation is realized; when the battery pack works normally and has no battery fault, the battery pack can be connected into an external circuit with extremely low loss, and meanwhile, the battery pack has the charge state balancing function of the series battery pack, so that the efficient and safe operation of the battery pack is ensured.
Drawings
To further clarify the above and other advantages and features of embodiments of the present invention, a more particular description of embodiments of the invention will be rendered by reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings, the same or corresponding parts will be denoted by the same or similar reference numerals for clarity.
Fig. 1 shows a block diagram of an isolation interface circuit of a series battery in an embodiment of the invention.
Fig. 2 illustrates one embodiment of a series battery isolation interface circuit.
Fig. 3 shows a circuit diagram of a series battery gating network in an embodiment of the invention.
Fig. 4 shows a structure diagram of a protection and equalization circuit of a series battery pack according to an embodiment of the present invention.
Fig. 5 to 15 are circuit diagrams showing the series battery protection and equalization circuit in the operation modes a to K according to a preferred embodiment of the present invention.
Fig. 16 shows a flow chart of a method for controlling the isolation and protection of a faulty battery of a protection and equalization circuit of a series battery pack according to an embodiment of the present invention.
Fig. 17 is a schematic diagram illustrating an equalization control method of the series battery protection and equalization circuit according to an embodiment of the present invention; the circuit diagram is characterized in that the circuit diagram is a circuit diagram of a series battery pack protection and equalization circuit for discharging working conditions of a high-charge-state battery, and the circuit diagram is a circuit diagram of a series battery pack protection and equalization circuit for charging working conditions of a low-charge-state battery.
Fig. 18 shows an embodiment of an equalization method based on a bidirectional flyback converter in a series battery protection and equalization circuit; wherein, (a) is a circuit diagram of the discharge working condition of the series battery pack protection and equalization circuit to the high-charge state battery, and (b) is a circuit diagram of charging working conditions of the series battery pack protection and equalization circuit on the low-charge-state battery.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the concept of the invention. All falling within the scope of the invention.
Fig. 1 is a block diagram of an isolation interface circuit of a series battery pack according to an embodiment of the present invention.
As shown in fig. 1, the serial battery isolation interface circuit provided in this embodiment may include: the battery pack comprises a series battery pack positive end, a series battery pack negative end, four battery connecting terminals I, II, III and IV, an external circuit positive end and an external circuit negative end; wherein:
the positive end of the series battery pack, the negative end of the series battery pack and the four battery connection ports I, II, III and IV realize power interaction with the series battery pack; the external circuit positive end and the external circuit negative end realize power interaction with the external circuit.
The method can also comprise the following steps: a first isolated bidirectional DC converter, a second isolated bidirectional DC converter, a first switch S 1 Second switch S 2 First bypass switch S 1c Second bypass switch S 2c Positive pole switch S of battery pack PB Negative pole switch S of battery pack NB Positive pole switch S of converter PT Negative pole switch S of converter NT (ii) a Wherein:
the first isolation type bidirectional direct current converter and the second isolation type bidirectional direct current converter are both a two-port network, a first port of the first isolation type bidirectional direct current converter is provided with a positive end I and a negative end II, and the positive end I and the negative end II are battery connecting terminals I and II; the first port of the second isolation type bidirectional direct current converter is provided with a positive end III and a negative end IV, and the positive end III and the negative end IV are battery connecting terminals III and IV.
First switch S 1 A second switch S for connecting the positive terminal I of the first port and the positive terminal of the second port of the first isolated bidirectional DC converter 2 And connecting the negative end IV of the first port of the second isolated bidirectional direct current converter with the negative end of the second port. First bypass switch S 1c A second bypass switch S connected with the positive and negative terminals of the second port of the first isolated bidirectional DC converter 2c And the positive end and the negative end of the second port of the second isolated bidirectional direct current converter are connected. The negative end of the first isolated bidirectional direct current converter is connected with the positive end of the second isolated bidirectional direct current converter.
The positive end of the second port of the first isolated bidirectional DC converter is connected with a converter positive switch S PT One end of (1) transformingPositive pole switch S PT The other end of the switch is connected with the positive end of an external circuit. The negative end of the second port of the second isolated bidirectional direct current converter is connected with a negative switch S of the converter NT One terminal of (1), negative pole switch S of the converter NT The other end of the first switch is connected with the negative end of an external circuit. Battery positive switch S PB The positive end of an external circuit is connected with the positive end of the series battery pack, and the negative switch of the battery pack is connected with the negative end of the external circuit and the negative end of the series battery pack.
Fig. 2 is a block diagram of an isolation interface circuit of a series battery pack according to a preferred embodiment of the present invention.
As shown in fig. 2, the series battery isolation interface circuit provided in the preferred embodiment may include, based on a bidirectional flyback converter: the battery pack comprises a series battery pack positive end, a series battery pack negative end, four battery connecting terminals I, II, III and IV, an external circuit positive end and an external circuit negative end; wherein:
the power interaction with the series battery pack is realized by the positive end of the series battery pack, the negative end of the series battery pack and the four battery connecting terminals I, II, III and IV; and the external circuit positive end and the external circuit negative end realize power interaction with the external circuit.
The method can also comprise the following steps: first transformer T 1 Switch S 1a 、S 1b First capacitor C 1 Second transformer T 2 Switch S 2a 、S 2b Second capacitance C 2 First switch S 1 A second switch S 2 First bypass switch S 1c Second bypass switch S 2c Positive pole switch S of battery pack PB Negative pole switch S of battery pack NB Positive pole switch S of converter PT Negative pole switch S of converter NT (ii) a Wherein:
first transformer T 1 One end of the primary side is connected with a switch S 1a One end of (1), a first transformer T 1 The dotted terminal of the secondary side is connected with a first capacitor C 1 The positive terminal of the first transformer T 1 Switch S for connecting different name end of secondary side 1b One end of (a); first transformer T 1 The other end of the primary side is connected with a battery connecting terminal I and a switch S 1a The other end of the battery is connected with a battery connecting terminal II; switch S 1b To another one ofEnd connected with a first capacitor C 1 The negative terminal of (a). The circuit constitutes a first bidirectional flyback converter, which, when operating, switches S 1a At duty cycle D 1 Switch, switch S 1b Complementary conduction, voltage gain G of the converter 1 Is defined as a first capacitor voltage V C1 Potential difference V with battery connection terminals I and II B1 It is provided with and (4) a ratio.
A second transformer T 2 One end of the primary side is connected with a switch S 2a One end of (1), a second transformer T 2 The same-name end of the secondary side is connected with a second capacitor C 2 Positive terminal of (a), a second transformer T 2 Switch S for connecting different name end of secondary side 2b One end of (a); a second transformer T 2 The other end of the primary side is connected with a battery connecting terminal III and a switch S 2a The other end of the battery is connected with a battery connecting terminal IV; switch S 2b Is connected with a second capacitor C 2 The negative terminal of (a). The circuit constitutes a second flyback bidirectional converter, which, when operating, switches S 2a At duty cycle D 2 Switch, switch S 2b Complementary conduction, voltage gain G of the converter 2 Defined as the second capacitor voltage V C2 Potential difference V with battery connection terminals III and IV B2 It is provided with and (4) a ratio.
First switch S 1 Connecting the battery connection terminal I with the first capacitor C 1 A second switch S 2 Connecting the battery connection terminal IV with a second capacitor C 2 The negative terminal of (a). First bypass switch S 1c Is connected with a first capacitor C 1 Positive and negative terminals of the first and second bypass switches S 2c Connecting a second capacitor C 2 A positive terminal and a negative terminal. A first capacitor C 1 Negative terminal of (2) and second capacitor C 2 Is connected to the positive terminal of the switch.
A first capacitor C 1 Is connected with the positive pole switch S of the converter PT One terminal of (1), a converter positive electrode switch S PT The other end of the first switch is connected with the positive end of an external circuit. Second capacitor C 2 Is connected with the negative pole switch S of the converter NT One terminal of (1), negative pole switch S of the converter NT The other end of the second switch is connected with the negative end of the external circuit. Battery positive switch S PB Connecting external circuit positive terminal with series battery packThe positive terminal and the battery pack negative terminal switch are connected with the negative terminal of the external circuit and the negative terminal of the series battery pack.
Fig. 3 is a circuit diagram of a gating network of a series battery according to an embodiment of the present invention.
As shown in fig. 3, the serial battery gating network circuit structure provided in this embodiment may include: switch groups I, II, III, IV, and converter connection terminals I, II, III, IV. Wherein:
the switch groups I, II, III and IV comprise N switches S; wherein:
the group I switch group comprises N switches S which are respectively: s I，0 、S I，1 ……S I，N-1 (ii) a The group II switch group comprises N switches S which are respectively: s. the II，1 、S II，2 ……S II，N-1 、S II，N (ii) a The group III switch group includes N switches S which are respectively: s III，0 、S III，1 ……S III，N-1 (ii) a The group IV of switches includes N switches S, which are respectively: s IV，1 、S IV，2 ……S IV，N-1 、S IV，N . Wherein:
switch S in group I switch group I，0 、S I，1 ……S I，N-1 Are connected to the transformer connection terminal I. Switch S I，0 The other end of the first group of switches is used as the connecting end of the positive end of the series battery pack and is used for being connected to the positive end of the series battery pack, and the rest N-1 first group of switches S I，1 、S I，2 ……S I，N-1 The other end of the first and second terminals is respectively used as a connecting end of the series battery pack and is used for connecting with a battery connecting end between two adjacent batteries in the series battery pack, namely, the 1 st battery connecting end, the 2 nd battery connecting end and the N-1 st battery connecting end.
Switch S in group II switch group II，1 、S II，2 ……S II，N-1 、S II，N Are connected to the transformer connection terminal II. Switch S II，N The other end of the first group II switch S is used as the connection end of the negative end of the series battery pack and is used for being connected to the negative end of the series battery pack, and the rest N-1 second group II switches S II，1 、S II，2 ……S II，N-1 Another end of (2)And the connecting ends are respectively used as the connecting ends of the series battery pack and are used for being connected with the cell connecting end between two adjacent cells in the series battery pack, namely the 1 st cell connecting end, the 2 nd cell connecting end and the N-1 st cell connecting end.
Switch S in group III switch group III，0 、S III，1 ……S III，N-1 Are connected to the transformer connection terminal III. Switch S III，0 The other end of the first group III switch S is used as the connection end of the positive end of the series battery pack and is used for being connected to the positive end of the series battery pack, and the rest N-1 group III switches S III，1 、S III，2 ……S III，N-1 The other end of the first and second terminals is respectively used as a connecting end of the series battery pack and is used for connecting with a battery connecting end between two adjacent batteries in the series battery pack, namely, the 1 st battery connecting end, the 2 nd battery connecting end and the N-1 st battery connecting end.
Switch S in group IV switch group IV，1 、S IV，2 ……S IV，N-1 、S IV，N Are connected to the transformer connection terminal IV. Switch S IV，N The other end of the first group of switches S is used as the connection end of the negative end of the series battery pack and is used for being connected to the negative end of the series battery pack, and the rest N-1 group IV switches S IV，1 、S IV，2 ……S IV，N-1 The other end of the first battery and the other end of the second battery are respectively used as connecting ends of the series battery pack and are used for being connected with a battery connecting end between two adjacent batteries in the series battery pack, namely the 1 st battery connecting end, the 2 nd battery connecting end and the N-1 st battery connecting end.
Fig. 4 is a structural diagram of a protection and equalization circuit of a series battery pack according to an embodiment of the present invention.
As shown in fig. 4, the protection and equalization circuit for a series battery pack provided in this embodiment is based on an isolated bidirectional dc converter, and may include: n batteries B 1 、B 2 ……B N The series battery pack, the isolation interface circuit of the series battery pack in any of the above embodiments of the present invention, and the gating network circuit of the series battery pack in any of the above embodiments of the present invention are sequentially connected in series. Wherein:
series battery pack positive terminal and series of series battery pack isolation interface circuitCell B in the battery pack 1 The negative terminal of the series battery pack isolation interface circuit and the battery B in the series battery pack are connected N I.e. the positive and negative terminals of the series battery are connected to the terminals at the two ends of the series battery, respectively.
First switch S in group I switch group I，0 The connection end of the positive end of the series battery pack is connected to the positive end P of the series battery pack B The rest N-1 switches S in the switch group I I，1 、S I，2 ……S I，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs; nth switch S in group II switch group II，N Is connected to the negative terminal N of the series battery pack B The rest N-1 switches S in the switch group of the II group II，1 、S II，2 ……S II，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs; first switch S in group III switch group III，0 The connection end of the positive end of the series battery pack is connected to the positive end P of the series battery pack B The remaining N-1 switches S in the group III switch set III，1 、S III，2 ……S III，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs; nth switch S in group IV switch group IV，N Is connected to the negative terminal N of the series battery pack B The rest N-1 switches S in the switch group of the IV group IV，1 、S IV，2 ……S IV，N-1 The connection terminals of the series battery pack are respectively connected with the connection terminals of N-1 batteries formed between the N batteries B connected in series in the series battery pack. That is, the 1 st connection end, the 2 nd connection end to the Nth connection end of the N-1 series battery pack connection ends of the series battery pack gating network circuit are respectively connected with the battery B in the series battery pack 1 Negative electrode of (1), and battery B 2 To battery B N-1 Negative electrode of (1), namely battery B 2 Positive electrode of (1), and battery B 3 To battery B N The positive electrodes of (a) and (b) are connected.
The positive pole of the series battery pack is connected with the positive end of the series battery pack isolation interface and the positive end of the series battery pack gating network, and the negative pole of the series battery pack is connected with the negative end of the series battery pack isolation interface and the negative end of the series battery pack gating network.
The converter connection terminals I, II, III, IV are connected to the battery connection terminals I, II, III, IV, respectively.
The external circuit positive end and the external circuit negative end of the series battery pack isolation interface are external circuit ports of the series battery pack protection and equalization circuit.
An embodiment of the present invention provides a working method of the protection and equalization circuit for a series battery pack in any one of the above embodiments of the present invention, including any one or more of the following working modes.
Fig. 5 is a circuit diagram of the protection and equalization circuit for a series battery pack in the basic operation mode a according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 5, the battery positive switch S in the series battery isolation interface PB And battery negative switch S NB The other switches in the series battery pack protection and equalization circuit are all turned off when the battery pack is switched on; and the first isolated bidirectional direct current converter and the second isolated bidirectional direct current converter in the series battery pack isolation circuit do not work.
In the basic operating mode A, all the cells of the series battery pack pass through the switch S PB And switch S NB And an external circuit is connected in series to carry out normal battery charging and discharging. The number of the additional switches connected in series is irrelevant to the number of the batteries of the battery pack connected in series, so that the functions of isolating and protecting the single batteries in a fault state are realized, the resistance and the loss introduced in a normal working state are extremely low, and the switch which needs to conduct normal charging and discharging current for a long time only has a switch S PB And switch S NB And two types of low-on-resistance switches can be conveniently selected during design, and the overall cost of the system can be controlled.
Fig. 6 is a circuit diagram of the protection and equalization circuit for series battery in the basic operation mode B according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 6, the converter positive switch S in the series battery isolation interface PT A second switch S 2 Converter negative pole switch S NT Conducting S in group I switch in series battery gating network I，i-1 On, S in the second set of switches II，j Conducting S in group III switches III，k-1 Conducting, S in group IV switch IV，m Conducting, wherein i, j, k and m are integers which are more than 1 and less than N, i is less than or equal to j, j is less than k-1, k is less than or equal to m; and the rest switches in the series battery pack protection and equalization circuit are all turned off. And a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter in the series battery pack isolation circuit work normally.
In the basic operation mode B, although the battery B 1 To battery B i-1 And battery B j+1 To battery B k-1 And battery B m+1 To battery B N The current path is not connected with the battery B through the current path under the action of the isolation converter 1 To battery B i-1 And battery B j+1 To battery B k-1 And battery B m+1 To battery B N Thus, in basic operating mode B, battery B is implemented 1 To battery B i-1 And battery B j+1 To battery B k-1 And battery B m+1 To battery B N The other batteries are still connected to an external circuit for charging and discharging. If the voltage gain of the first isolated bidirectional DC converter is G 1 The voltage gain of the second isolated bidirectional DC converter is G 2 The cell voltage is V bat At this time, the external circuit port voltage V o Comprises the following steps:
V o ＝[(j-i+1)G 1 +(m-k+1)G 2 ]V bat
fig. 7 is a circuit diagram of the protection and equalization circuit for a series battery pack in the basic operation mode C according to a preferred embodiment of the present invention.
In the preferred embodiment, the converter positive switch S in the series battery isolation interface is shown in fig. 7 PT A first switch S 1 A second switch S 2 Second converter bypass switch S 2c Battery negative switch S NB Conducting S in group I switch in series battery gating network I，i-1 Conducting S in the second set of switches II，j Conducting, S in the IV group switch IV，k-1 Conducting, wherein i, j and k are integers which are more than 1 and less than or equal to N, i is less than or equal to j, and j is less than k-1; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolation type bidirectional direct current converter in the series battery pack isolation circuit works normally, and the second isolation type bidirectional direct current converter does not work by a bypass.
In the basic operation mode C, although the battery B 1 To battery B i-1 And battery B j+1 To battery B k-1 Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B 1 To battery B i-1 And battery B j+1 To battery B k-1 Thus, in basic operating mode C, battery B is realized 1 To battery B i-1 And battery B j+1 To battery B k-1 The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝[(j-i+1)G 1 +(N-k+1)]V bat
fig. 8 is a circuit diagram of the protection and equalization circuit for series battery in the basic operation mode D according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 8, the battery positive switch S in the series battery isolation interface PB First converter bypass switch S 1c A first switch S 1 A second switch S 2 Converter negative pole switch S NT Conducting S in group I switch in series battery gating network I，j On, S in group III switch III，k-1 S in group IV switch IV，m Conducting, wherein j, k and m are integers which are more than or equal to 1 and less than N, j is less than k-1, k is less than or equal to m; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolated bidirectional direct current converter in the series battery pack isolation circuit does not work by a bypass, and the second isolated bidirectional direct current converter works normally.
In the basic operation mode D, although the battery B j+1 To battery B k-1 And battery B m+1 To battery B N Still connected in series within the battery pack, but again due to the isolating converter, there is no current path through cell B j+1 To battery B k-1 And battery B m+1 To battery B N Thus, in the basic operation mode D, the battery B is realized j+1 To battery B k-1 And battery B m+1 To battery B N The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝[j+(m-k+1)G 2 ]V bat
fig. 9 is a circuit diagram of the series battery protection and equalization circuit in the basic operation mode E according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 9, the converter positive switch S in the series battery isolation interface PT A second converter bypass switch S 2c A second switch S 2 Battery negative switch S NB Conducting S in group I switch in series battery gating network I，0 S in group II switch II，j Conducting, S in group IV switch IV，k-1 Conducting, wherein j and k are integers which are more than or equal to 1 and less than or equal to N, and j is less than k-1; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolation type bidirectional direct current converter in the series battery pack isolation circuit works normally, and the second isolation type bidirectional direct current converter does not work by a bypass.
In the basic operation mode E, although the battery B j+1 To battery B k-1 Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B j+1 To battery B k-1 Thus, in the basic operation mode E, the battery B is realized j+1 To battery B k-1 The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝[jG 1 +(N-k+1)]V bat
fig. 10 is a circuit diagram of the series battery protection and equalization circuit in the basic operation mode F according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 10, the battery positive switch S in the series battery isolation interface PB A first switch S 1 First converter bypass switch S 1c Converter cathode switch S NT Conducting S in group I switch in series battery gating network I，j On, S in group III switch III，k-1 Conducting, S in group IV switch IV，N Conducting, wherein j and k are integers which are more than or equal to 1 and less than or equal to N, and j is less than k-1; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolated bidirectional direct current converter in the series battery pack isolation circuit does not work by a bypass, and the second isolated bidirectional direct current converter works normally.
In the basic operation mode F, although the battery B j+1 To battery B k-1 Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B j+1 To battery B k-1 Thus, in the basic operation mode F, the battery B is realized j+1 To battery B k-1 The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝[j+(N-k+1)G 2 ]V bat
fig. 11 is a circuit diagram of the protection and equalization circuit for series battery in the basic operation mode G according to a preferred embodiment of the present invention.
In the preferred embodiment, the converter positive switch S in the series battery isolation interface is shown in fig. 11 PT A second switch S 2 Converter cathode switch S NT Conducting S in group I switch in series battery gating network I，i-1 On, S in group II switch II，j On, S in group III switch III，j Conducting, S in the IV group switch IV，m Conducting, wherein i, j and m are integers which are more than 1 and less than N, i is less than or equal to j, and j is less than m; and the rest switches in the series battery pack protection and equalization circuit are all turned off. A first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter in the series battery pack isolation circuit work normally.
In the basic operation mode G, although the battery B 1 To battery B i-1 And battery B m+1 To battery B N Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B 1 To battery B i-1 And battery B m+1 To battery B N Thus, in the basic operation mode G, the battery B is realized 1 To battery B j-1 And battery B m+1 To battery B N The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝[(i-j+1)G 1 +(m-j)G 2 ]V bat 。
fig. 12 is a circuit diagram of the protection and equalization circuit for a series battery pack in the basic operation mode H according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 12, the converter positive switch S in the series battery isolation interface PT First converter bypass switch S 1c A second switch S 2 Battery negative switch S NB Conducting S in group III switch in series battery gating network III，i-1 On, S in group IV switch IV，m Conducting, wherein i and m are integers which are more than 1 and less than N, and i is less than or equal to m; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolated bidirectional direct current converter in the series battery pack isolation circuit does not work by a bypass, and the second isolated bidirectional direct current converter works normally.
In the basic operation mode H, although the battery B 1 To battery B i-1 Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B 1 To battery B i-1 Thus, in basic operating mode H, battery B is realized 1 To battery B i-1 The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝[(m-i+1)G 1 +(N-m)]V bat
fig. 13 is a circuit diagram of the protection and equalization circuit for series battery in the basic operation mode I according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 13, the converter positive switch S in the series battery isolation interface PT First converter bypass switch S 1c A second switch S 2 Converter negative pole switch S NT Conducting S in group III switch in series battery gating network III，i-1 On, S in group IV switch IV，N Conducting, wherein i is an integer greater than 1 and less than or equal to N; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolated bidirectional direct current converter in the series battery pack isolation circuit does not work by a bypass, and the second isolated bidirectional direct current converter works normally.
In the basic operation mode I, although the battery B 1 To battery B i-1 Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B 1 To battery B i-1 Thus, in basic operating mode I, battery B is implemented 1 To battery B i-1 The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝(N-i+1)G 2 V bat
fig. 14 is a circuit diagram of the protection and equalization circuit for series-connected battery packs of the present invention in the basic operation mode J.
In the preferred embodiment, as shown in fig. 14, the battery positive switch S in the series battery isolation interface PB A first switch S 1 A second converter bypass switch S 2c Converter cathode switch S NT Conducting S in group I switch in series battery gating network I，i Conducting S in group II switch II，m Conducting, wherein i and m are integers which are more than or equal to 1 and less than N, and i is less than m; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolated bidirectional direct current converter in the series battery pack isolation circuit works normally, and the second isolated bidirectional direct current converter is not worked by a bypass.
In the basic operation mode J, although the battery B m+1 To battery B N Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B m+1 To battery B N Thus, in basic operating mode J, battery B is realized m+1 To battery B N The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝[i+(m-i)G 2 ]V bat
fig. 15 is a circuit diagram of the protection and equalization circuit for series battery in the basic operation mode K according to a preferred embodiment of the present invention.
In the preferred embodiment, as shown in fig. 15, the converter positive switch S in the series battery isolation interface PT A first switch S 1 A second converter bypass switch S 2c Converter cathode switch S NT Conducting, I-th group switch in series battery gating networkS in Guanzhong I，0 On, S in group II switch II，N Conducting, wherein m is an integer greater than or equal to 1 and less than N; and the rest switches in the series battery pack protection and equalization circuit are all turned off. The first isolation type bidirectional direct current converter in the series battery pack isolation circuit works normally, and the second isolation type bidirectional direct current converter does not work by a bypass.
In the basic operation mode K, although the battery B is used m+1 To battery B N Still connected in series within the battery pack, but again due to the action of the isolating converter, there is no current path through cell B m+1 To battery B N Thus, in the basic operation mode K, the battery B is realized m+1 To battery B N The other batteries are still connected to an external circuit for charging and discharging. At this time, the voltage V of the external circuit port o Comprises the following steps:
V o ＝mG 1 V bat
fig. 16 is a flowchart of a method for controlling the isolation and protection of a faulty battery in a protection and equalization circuit of any one of the series-connected battery packs according to an embodiment of the present invention.
As shown in fig. 16, in the method for isolating and protecting a faulty battery according to the fault state of the battery detected by the battery management system in this embodiment, any one or any multiple working modes are selected from any one of the working methods in the above embodiments of the present invention to isolate the faulty battery from the power loop, so that the current flowing through the faulty battery is zero, and it is ensured that the battery that is not faulty can still be connected to an external circuit to normally work, thereby completing normal battery charging or discharging; according to the working mode, as many normal batteries as possible are connected into the circuit to continue working, and on the basis, the sum of the number of the batteries connected into the external circuit through the first isolation type bidirectional direct current converter and the second isolation type bidirectional direct current converter is minimized, so that the lowest power converter loss is realized.
As a preferred embodiment, when the battery management system detects that there is no battery fault and all batteries in the series battery pack operate normally, the battery management system sends an instruction to the switch and the isolated converter in the protection and equalization circuit of the series battery pack, so that the protection and equalization circuit of the series battery pack operates according to the basic operation mode a and waits for the next fault detection.
As a preferred embodiment, when the battery management system detects that a battery in the series battery pack has a fault, the battery management system sends out a fault alarm and takes protection and isolation measures for the battery at the same time, the battery management system firstly determines continuous normal available battery intervals, and when the number of the continuous normal available battery intervals is more than 1, two continuous normal available battery intervals B with the largest number of batteries are selected i ～B j 、B k ～B m And i, j, k and m are integers which are more than or equal to 1 and less than or equal to N, i is less than or equal to j, j is less than k-1, k is less than or equal to m, and then: when i is not equal to 1 and m is not equal to N, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode B; when i is not equal to 1 and m is equal to N, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode C; when i is equal to 1 and m is not equal to N, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode D; when i is equal to 1, m is equal to N and j is less than N-k +1, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode E; when i is equal to 1, m is equal to N and j is more than N-k +1, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode F; when i is equal to 1 and m is equal to N and j = N-k +1 is satisfied, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit follows the instructionThe basic operation mode E or the basic operation mode F operates.
As a preferred embodiment, when the battery management system determines that the number of the continuous normal available battery intervals is only 1, the continuous normal available battery interval B is determined i ～B m And i and m are integers which are more than or equal to 1 and less than or equal to N, and i is less than or equal to m, at the moment: when i is not equal to 1 and m is not equal to N, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode G, and at the moment, the series battery pack protection and equalization circuit works according to a basic working mode G
Figure GDA0003885079900000181
When i is not equal to 1, m is equal to N and i is not equal to N, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode H; when I is not equal to 1, m is equal to N, and I is equal to N, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode I; when i is equal to 1, m is not equal to N, and m is not equal to 1, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode J; when i is equal to 1, m is not equal to N, and m is equal to 1, the battery management system sends an instruction to a switch and an isolation type converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to a basic working mode K.
Fig. 17 (a) and (b) are schematic diagrams of an equalization control method of the protection and equalization circuit of the series battery pack according to any one of the above embodiments of the present invention, where (a) is a circuit diagram of the protection and equalization circuit of the series battery pack for a discharge condition of a high-state-of-charge battery, and (b) is a circuit diagram of the protection and equalization circuit of the series battery pack for a charge condition of a low-state-of-charge battery.
As shown in (a) and (b) of fig. 17, the embodiment provides a balancing control method for balancing batteries in a series battery pack by using a balancing strategy when a battery management system detects that there is no battery fault and there are batteries in the series battery pack that need to be balanced, wherein:
battery positive switch S in series battery isolation interface PB Battery negative switch S NB Conducting, converter positive switch S PT Converter cathode switch S NT Turning off, and normally connecting the series battery pack with the main circuit for charging and discharging;
meanwhile, a first switch S in the isolation interface of the series battery pack 1 A second switch S 2 Turning off; in fig. 17 (a) and (b), the first isolated bidirectional dc converter is used for cell balancing, and the first converter bypasses the switch S 1c Off, second converter bypass switch S 2c Conducting; when battery B j Requiring discharge, battery B k S in group I switch of series battery gating network when charging is needed to realize state of charge balance of series battery I，j-1 S in group II switch II，j The first isolated bidirectional DC converter works normally and is powered on by the battery B j Discharging to obtain a first isolated bidirectional DC converter second port capacitor C 1 Charging; then S in the group I switch I，j-1 S in group II switch II，j Off, S in group I switch I，k-1 S in group II switch II，k The first isolated bidirectional DC converter works normally when the other switches are turned off, and a capacitor C is arranged at the second port of the first isolated bidirectional DC converter 1 Discharge to battery B k Charging; the charge and discharge processes are alternately carried out to realize that the electric quantity is supplied to the battery B j To battery B k The charge state balance of the series battery packs is realized.
Fig. 17 (a) and (b) show an implementation method for battery equalization using a first isolated bidirectional dc converter, which may also be implemented by a second isolated bidirectional dc converter. At this time, the first converter bypass switch S 1c Conducting, second converter bypass switchS 2c Turning off; when battery B j Requiring discharge, battery B k S in group III switch of series battery gating network when charging is required to achieve state of charge equalization of series battery III，j-1 S in group IV switch IV，j The second isolated bidirectional DC converter works normally and is powered on by the battery B j Discharging to charge the second port capacitor of the second isolated bidirectional DC converter; thereafter, S in group III switch III，j-1 S in group IV switch IV，j Off, S in group III switch III，k-1 S in group IV switch IV，k The second isolated bidirectional DC converter works normally and discharges to battery B through the second port capacitor of the second isolated bidirectional DC converter k Charging; the charge and discharge processes are alternately carried out to realize that the electric quantity is supplied to the battery B j To battery B k The charge state balance of the series battery packs is realized.
Fig. 18 (a) and (b) are schematic diagrams of an equalization control method of the series battery protection and equalization circuit in a preferred embodiment of the present invention, where (a) is a circuit diagram of the series battery protection and equalization circuit for a discharge condition of a high-state-of-charge battery, and (b) is a circuit diagram of the series battery protection and equalization circuit for a charge condition of a low-state-of-charge battery.
As shown in (a) and (b) of fig. 18, the equalizing method provided by the preferred embodiment is based on a bidirectional flyback converter, and when the battery management system detects that there is no battery fault and there is a battery in the series battery pack that needs to be equalized, the equalizing strategy is adopted to equalize the batteries in the series battery pack, where:
battery positive switch S in series battery isolation interface PB Battery negative switch S NB Conducting, converter positive switch S PT Converter cathode switch S NT Turning off, and normally connecting the series battery pack with the main circuit for charging and discharging;
meanwhile, a first switch S in the isolation interface of the series battery pack 1 A second switch S 2 Turning off; in FIG. 18, the first bi-direction is appliedFlyback converter T 1 Cell balancing, first converter bypass switch S 1c Off, second converter bypass switch S 2c Conducting; when battery B j Requiring discharge, battery B k S in group I switch of series battery gating network when charging is needed to realize state of charge balance of series battery I，j-1 S in group II switch II，j The first bidirectional flyback converter T is switched on, the other switches are switched off 1 Normal operation, switch S 1a And switch S 1b Alternately conducted by the battery B j Discharging as the first bidirectional flyback converter T 1 Second port capacitance C 1 Charging; then S in the group I switch I，j-1 S in group II switch II，j Off, S in group I switch I，k-1 S in group II switch II，k The first bidirectional flyback converter T is switched on, the other switches are switched off 1 Normal operation, switch S 1a And switch S 1b Alternatively conducting the first bidirectional flyback converter T 1 Second port capacitor C 1 Discharged to battery B k Charging; the charge and discharge processes are alternately carried out to realize that the electric quantity is supplied to the battery B j To battery B k The charge state balance of the series battery packs is realized.
Fig. 18 (a) and (b) show an implementation method for battery equalization by using a first isolated bidirectional dc converter, and the equalization strategy of the series battery protection and equalization circuit of the present invention may also be implemented by using a second isolated bidirectional dc converter. At this time, the first converter bypass switch S 1c Conducting, second converter bypass switch S 2c Turning off; when battery B j Requiring discharge, battery B k S in group III switch of series battery gating network when charging is required to achieve state of charge equalization of series battery III，j-1 S in group IV switch IV，j The second bidirectional flyback converter works normally and is powered on by the battery B j Discharging to charge the second port capacitor of the second isolated bidirectional DC converter; thereafter, S in group III switch III，j-1 Group IVS in switch IV，j Off, S in group III switch III，k-1 S in group IV switch IV，k The second isolated bidirectional direct current converter works normally, and the capacitor at the second port of the second bidirectional flyback converter discharges the battery B k Charging; the charge and discharge processes are alternately carried out to realize that the electric quantity is supplied to the battery B j To battery B k The charge state balance of the series battery packs is realized.
The embodiment of the invention provides a series battery pack isolation interface circuit, a series battery pack gating network circuit, a series battery pack protection and equalization circuit and a control method based on an isolation type bidirectional direct current converter. Through the technical scheme provided by the embodiment of the invention, the protection and equalization circuit of the series battery pack can be designed by utilizing the isolated bidirectional direct current converter and the switch gating network circuit, and compared with the existing protection circuit and equalization circuit, the technical scheme provided by the embodiment of the invention can provide an equalization function for the series battery pack when the battery works normally, solve the problem of unbalanced charge state among battery cores in the series battery pack and improve the benefit and reliability of the battery pack; when a single battery in the battery pack has a fault, the technical scheme provided by the embodiment of the invention can realize the isolation and protection of the single battery with the fault, cut off the current path flowing through the fault battery core, and avoid the aggravation and spread of the fault, and the normal single battery core still can be connected to an external circuit to carry out normal charging and discharging. The technical scheme provided by the embodiment of the invention realizes the combination of the battery protection function and the battery balancing function in one circuit, and is favorable for reducing the element number, the volume and the cost of a battery management system. Compared with the single battery core single protection circuit of the existing series battery pack, the technical scheme provided by the embodiment of the invention realizes the isolation of the fault battery core single through the two isolation type bidirectional direct current converters and the battery gating network, so that a bypass switch is not required to be independently configured for each battery, and when the battery pack normally works and has no battery core fault, the whole battery pack only passes through the positive electrode switch S of the battery pack PB And battery negative switch S NB Two main switches are connected to an external circuit. Therefore, in terms of circuit design, the battery positive electrode switch S is selected as a switch with low on-resistance PB And battery negative switch S NB Extremely low loss can be realized when the battery pack works normally; and the rest switches in the circuit only work for a short time when a single battery cell in the battery pack breaks down, so the switches can not bring loss to the normal operation of the battery pack. In the aspect of system cost, only two switches with low on-resistance need to be selected, and the other switches with lower cost and larger on-resistance can be selected as switches with lower on-resistance, so that the technical scheme provided by the embodiment of the invention can realize the functions of single battery cell protection and balance on the premise of low cost and low loss, and the benefit and the reliability of the battery energy storage system are practically improved.
The foregoing description has described specific embodiments of the present invention. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims (10)

1. A series battery isolation interface circuit, comprising: a first isolated bidirectional DC converter, a second isolated bidirectional DC converter, a first switch S 1 A second switch S 2 First bypass switch S 1c A second bypass switch S 2c The positive electrode switch S of the battery pack PB Battery negative switch S NB Positive pole switch S of converter PT Converter cathode switch S NT An external circuit positive terminal, an external circuit negative terminal, a series battery pack positive terminal P B And negative terminal N of series battery B (ii) a Wherein:
the first isolation type bidirectional direct current converter and the second isolation type bidirectional direct current converter are both of a two-port structure, and a positive end I and a negative end II of a first port of the first isolation type bidirectional direct current converter respectively form a battery connecting terminal I and a battery connecting terminal II; a positive terminal III and a negative terminal IV of a first port of the second isolated bidirectional direct current converter form a battery connecting terminal III and a battery connecting terminal IV respectively;
the first switch S 1 Connecting the positive terminal I of the first port of the first isolated bidirectional DC converter with the positive terminal of the second port, and connecting the second switch S 2 Connecting a negative end IV of a first port of the second isolation type bidirectional direct current converter with a negative end of a second port; the first bypass switch S 1c The positive end and the negative end of the second port of the first isolation type bidirectional direct current converter are connected, and the second bypass switch S 2c Connecting the positive end and the negative end of a second port of the second isolated bidirectional direct current converter; the negative end of the second port of the first isolated bidirectional direct current converter is connected with the positive end of the second port of the second isolated bidirectional direct current converter;
the positive end of the second port of the first isolated bidirectional direct current converter is connected with the converter positive switch S PT One end of said converter positive switch S PT The other end of the first switch is connected with the external circuit positive end; the negative end of the second port of the second isolated bidirectional direct current converter is connected with the negative switch S of the converter NT Of the converter negative pole switch S NT The other end of the first switch is connected with the negative end of the external circuit; the battery positive switch S PB Is connected with the positive end of the external circuit, and the positive pole switch S of the battery pack PB And the other end of the same is connected with the positive end P of the series battery pack B Connecting; the battery negative pole switch S NB Is connected with the negative end of the external circuit, and the negative pole switch S of the battery pack NB And the other end of the battery pack is connected with the negative end N of the series battery pack B Connecting;
the positive end P of the series battery pack B The negative terminal N of the series battery pack B The four battery connecting terminals I-IV are used for realizing power interaction with a series battery pack, and the external circuit positive terminal and the external circuit negative terminal are used for realizing power interaction with an external circuit; when the battery is in fault or damaged, the fault battery is isolated from the power loop, so that the fault battery does not participate in charging and discharging any more, and when the battery pack works normally, the series battery pack is connected into the power loop by only two switchesAnd an external circuit.
2. A series battery gating network circuit, comprising: the inverter comprises a first group switch group, a second group switch group, a third group switch group, a fourth group switch group, an inverter connecting terminal I, an inverter connecting terminal II, an inverter connecting terminal III and an inverter connecting terminal IV; wherein:
the first group of switches to the fourth group of switches comprise N switches S; wherein:
one end of each of N switches S in the switch group I is connected to the converter connecting terminal I, and the first switch S in the switch group I I，0 The other end of the first group of switches forms a positive end connection end of a series battery pack, and the rest N-1 switches S in the switch group I I，1 、S I，2 ……S I，N-1 The other end of the battery pack forms a connecting end of a series battery pack;
one end of each of N switches S in the switch group II is connected to the converter connecting terminal II, and the Nth switch S in the switch group II is connected to the converter connecting terminal II II，N The other end of the group II switch group forms a negative end connecting end of the series battery group, and the rest N-1 switches S in the group II switch group II，1 、S II，2 ……S II，N-1 The other end of the battery pack forms a connecting end of a series battery pack;
one end of each of N switches S in a group III switch group is connected to the converter connection terminal III, the first switch S in the group III switch group III，0 The other end of the first group of switches forms the positive terminal connecting terminal of the series battery pack, and the rest N-1 switches S in the group III of switches III，1 、S III，2 ……S III，N-1 The other end of the battery pack forms a connecting end of a series battery pack;
one end of each of N switches S in a switch group IV is connected to the converter connecting terminal IV IV，N The other end of the group IV switch group forms a negative end connecting end of the series battery group, and the rest N-1 switches S in the group IV switch group IV，1 、S IV，2 ……S IV，N-1 The other end of the battery pack forms a connecting end of a series battery pack;
the connection end of the series battery pack is connected to the positive end of the series battery pack, the connection end of the series battery pack negative end is connected to the negative end of the series battery pack, and the connection end of the series battery pack is connected with the connection end of the battery between two adjacent batteries in the series battery pack to realize power interaction with the series battery pack; when the battery is in fault or damaged, the fault battery is isolated from the power loop, so that the fault battery does not participate in charging and discharging any more, and when the battery pack works normally, the series battery pack is connected to an external circuit by only two switches.
3. A series battery protection and equalization circuit, comprising: a series battery, a series battery isolation interface circuit of claim 1, and a series battery gating network circuit of claim 2; wherein:
the battery connecting terminals I-IV of the series battery pack isolation interface circuit are respectively and correspondingly connected with the converter connecting terminals I-IV of the series battery pack gating network circuit;
the series battery pack includes N batteries B connected in series, wherein:
the first switch S in the group I of switches I，0 Is connected to the series battery positive terminal P B The rest N-1 switches S in the switch group I I，1 、S I，2 ……S I，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the Nth switch S in the second group of switches II，N Is connected to the negative terminal N of the series battery B The rest N-1 switches S in the switch group of the second group II，1 、S II,2 ……S II，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the first switch S in the group III switch group III，0 Positive terminal of series battery packThe connection end is connected to the positive end P of the series battery pack B The rest N-1 switches S in the group III switch group III，1 、S III，2 ……S III，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the Nth switch S in the IV group switch group IV，N Is connected to the negative terminal N of the series battery B The rest N-1 switches S in the IV group of switches IV，1 、S IV，2 ……S IV，N-1 The connecting ends of the series battery packs are respectively connected with N-1 battery connecting ends formed among N batteries B connected in series in the series battery packs;
the positive end P of the series battery pack B And the negative terminal N of the series battery pack B The two terminals are respectively connected with the terminals at the two ends of the series battery pack;
the external circuit positive end and the external circuit negative end of the series battery pack isolation interface circuit form an external circuit port of the series battery pack protection and equalization circuit;
the positive end P of the series battery pack B The negative terminal N of the series battery pack B The battery connecting terminals I-IV realize power interaction with the series battery pack; the external circuit port enables power interaction with an external circuit.
4. A control method for a series battery protection and equalization circuit according to claim 3, characterized by comprising any one or more of the following operation modes:
the working mode A is as follows: battery pack positive electrode switch S in series battery pack isolation interface circuit PB And a battery negative electrode switch S NB The protection and equalization circuit is connected with the series battery pack, and other switches in the protection and equalization circuit of the series battery pack are all switched off; the first isolation type bidirectional direct current converter and the second isolation type bidirectional direct current converter in the series battery pack isolation interface circuit do not work;
and the working mode B: the series battery pack isolation interface circuitInverter positive switch S in PT A second switch S 2 And a negative switch S of the converter NT Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，i-1 Conducting, switch S in group II switch group II，j Conducting, switch S in group III switch group III，k-1 Conducting, switch S in group IV switch group IV，m Conducting, wherein i, j, k and m are integers which are more than 1 and less than N, i is less than or equal to j, j is less than k-1, and k is less than or equal to m; the other switches in the series battery pack protection and equalization circuit are all turned off; a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter in the series battery pack isolation interface circuit work normally;
and a working mode C: converter positive switch S in the series battery isolation interface circuit PT A first switch S 1 A second switch S 2 A second bypass switch S 2c And battery negative switch S NB Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，i-1 Conducting, switch S in the group II switch set II，j Conducting, switch S in group IV switch group IV，k-1 Conducting, wherein i, j and k are integers which are more than 1 and less than or equal to N, i is less than or equal to j, and j is less than k-1; the other switches in the series battery pack protection and equalization circuit are all turned off; a first isolated bidirectional direct current converter in the series battery pack isolation interface circuit works normally, and a second isolated bidirectional direct current converter is bypassed and does not work;
and a working mode D: battery pack positive electrode switch S in series battery pack isolation interface circuit PB First bypass switch S 1c A first switch S 1 A second switch S 2 And converter negative switch S NT Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，j Conducting, switch S in group III switch group III，k-1 Switch S in group IV switch group IV，m Conducting, wherein j, k and m are integers which are more than or equal to 1 and less than N, and j is less than k-1,k is less than or equal to m; the other switches in the series battery pack protection and equalization circuit are all turned off; the first isolated bidirectional direct current converter in the series battery pack isolation interface circuit is not operated by a bypass, and the second isolated bidirectional direct current converter is operated normally;
and a working mode E: converter positive switch S in the series battery isolation interface circuit PT A second bypass switch S 2c A second switch S 2 And battery negative switch S NB Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，0 Conducting, switch S in group II switch group II，j Conducting, switch S in group IV switch group IV，k-1 Conducting, wherein j and k are integers which are more than or equal to 1 and less than or equal to N, and j is less than k-1; the other switches in the series battery pack protection and equalization circuit are all turned off; a first isolated bidirectional direct current converter in the series battery pack isolation interface circuit works normally, and a second isolated bidirectional direct current converter is bypassed and does not work;
and the working mode F: battery pack positive electrode switch S in series battery pack isolation interface circuit PB A first switch S 1 First bypass switch S 1c And converter negative switch S NT Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，j Conducting, switch S in group III switch group III，k-1 Conducting, switch S in group IV switch group IV，N Conducting, wherein j and k are integers which are more than or equal to 1 and less than or equal to N, and j is less than k-1; the other switches in the series battery pack protection and equalization circuit are all turned off; the first isolated bidirectional direct current converter in the series battery pack isolation interface circuit is not operated by a bypass, and the second isolated bidirectional direct current converter is operated normally;
the working mode G is as follows: converter positive switch S in the series battery isolation interface circuit PT A second switch S 2 And a negative switch S of the converter NT Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，i-1 Conducting, switch S in the group II switch set II，j Conducting, switch S in group III switch group III，j Conducting, switch S in group IV switch group IV，m Conducting, wherein i, j and m are integers which are more than 1 and less than N, i is less than or equal to j, and j is less than m; the other switches in the series battery pack protection and equalization circuit are all turned off; a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter in the series battery pack isolation interface circuit work normally;
and the working mode H: converter positive switch S in the series battery isolation interface circuit PT First bypass switch S 1c A second switch S 2 And battery negative switch S NB Conducting, the switch S in the group III switch group in the series battery gating network circuit III，i-1 Conducting, switch S in group IV switch group IV，m Conducting, wherein i and m are integers which are more than 1 and less than N, and i is less than or equal to m; the other switches in the series battery pack protection and equalization circuit are all turned off; a first isolation type bidirectional direct current converter in the series battery pack isolation interface circuit does not work by a bypass, and a second isolation type bidirectional direct current converter works normally;
the working mode I is as follows: converter positive switch S in the series battery isolation interface circuit PT First bypass switch S 1c A second switch S 2 And a negative switch S of the converter NT Conducting, the switch S in the group III switch group in the series battery gating network circuit III，i-1 Conducting, switch S in group IV switch group IV，N Conducting, wherein i is an integer greater than 1 and less than or equal to N; the other switches in the series battery pack protection and equalization circuit are all turned off; a first isolation type bidirectional direct current converter in the series battery pack isolation interface circuit does not work by a bypass, and a second isolation type bidirectional direct current converter works normally;
working mode J: battery pack positive electrode switch S in series battery pack isolation interface circuit PB A first switch S 1 A second bypass switch S 2c Andconverter negative switch S NT Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，i Conducting, switch S in group II switch group II，m Conducting, wherein i and m are integers which are more than or equal to 1 and less than N, and i is less than m; the other switches in the series battery pack protection and equalization circuit are all turned off; a first isolated bidirectional direct current converter in the series battery pack isolation interface circuit works normally, and a second isolated bidirectional direct current converter is bypassed and does not work;
the working mode K is as follows: converter positive switch S in the series battery isolation interface circuit PT A first switch S 1 A second bypass switch S 2c And converter negative switch S NT Conducting, the switch S in the I group switch group in the series battery group gating network circuit I，0 Conducting, switch S in group II switch group II，N Conducting, wherein m is an integer greater than or equal to 1 and less than N; the other switches in the series battery pack protection and equalization circuit are all turned off; the first isolated bidirectional direct current converter in the series battery pack isolation interface circuit works normally, and the second isolated bidirectional direct current converter is not worked by a bypass.
5. A method for isolating and protecting faulty cells in a protection and equalization circuit of a series battery pack according to claim 3, wherein, according to the battery fault status detected by the battery management system, any one or more operation modes are selected from the control method of claim 4, so as to isolate the faulty cells from the power loop, so that the current flowing through the faulty cells is zero, and meanwhile, the non-faulty cells are ensured to still be connected to an external circuit to normally operate, thereby completing normal battery charging or discharging; according to the working mode, as many normal batteries as possible are connected into the circuit to continue working, and on the basis, the sum of the number of the batteries connected into the external circuit through the first isolation type bidirectional direct current converter and the second isolation type bidirectional direct current converter is minimized, so that the lowest power converter loss is realized.
6. The method according to claim 5, wherein when the battery management system detects that there is no battery fault, that is, when all the batteries in the series battery pack operate normally, the battery management system sends instructions to the switches in the series battery pack protection and equalization circuit and the first and second isolated bidirectional dc converters, so that the series battery pack protection and equalization circuit operates in the operating mode a.
7. The method according to claim 5, wherein when the battery management system detects that there is a battery failure in the series battery pack, the battery management system determines continuous normal available battery intervals, and when the number of continuous normal available battery intervals is greater than 1, selects two continuous normal available battery intervals B with the largest number of batteries i ～B j And B k ～B m Wherein i, j, k and m are integers which are more than or equal to 1 and less than or equal to N, i is less than or equal to j, j is less than k-1, k is less than or equal to m, and then:
when i is not equal to 1 and m is not equal to N, the battery management system sends an instruction to a switch in the series battery pack protection and equalization circuit and a first isolation type bidirectional direct current converter and a second isolation type bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode B;
when i is not equal to 1 and m is equal to N, the battery management system sends an instruction to a switch in the series battery pack protection and equalization circuit and a first isolation type bidirectional direct current converter and a second isolation type bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode C;
when i is equal to 1 and m is not equal to N, the battery management system sends an instruction to a switch in the series battery pack protection and equalization circuit and a first isolation type bidirectional direct current converter and a second isolation type bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode D;
when i is equal to 1, m is equal to N and j is less than N-k +1, the battery management system sends instructions to a switch in the series battery pack protection and equalization circuit and a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode E;
when i is equal to 1, m is equal to N and j is more than N-k +1, the battery management system sends instructions to a switch in the series battery pack protection and equalization circuit and a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter, so that the series battery pack protection and equalization circuit works in the working mode F;
when i is equal to 1, m is equal to N, and j = N-k +1 is satisfied, the battery management system sends an instruction to a switch in the series battery pack protection and equalization circuit and a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter, so that the series battery pack protection and equalization circuit operates in the operating mode E or the operating mode F.
8. The method according to claim 5, wherein when the battery management system detects that there is a battery failure in the series battery pack, the battery management system determines a continuous normal usable battery interval, and when the number of continuous normal usable battery intervals is only 1, determines the continuous normal usable battery interval B i ～B m Wherein i and m are integers greater than or equal to 1 and less than or equal to N, and i is less than or equal to m, at this time:
when i is not equal to 1 and m is not equal to N, the battery management system sends instructions to a switch in the series battery pack protection and equalization circuit and a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode G, and at the moment, the series battery pack protection and equalization circuit works according to the working mode G
Figure FDA0003885079890000071
When i is not equal to 1, m is equal to N, and i is not equal to N, the battery management system sends instructions to a switch, a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter in the series battery pack protection and equalization circuit, so that the series battery pack protection and equalization circuit works according to the working mode H;
when I is not equal to 1, m is equal to N, and I is equal to N, the battery management system sends instructions to a switch in the series battery pack protection and equalization circuit and a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode I;
when i is equal to 1, m is not equal to N, and m is not equal to 1, the battery management system sends instructions to a switch in the series battery pack protection and equalization circuit and a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode J;
when i is equal to 1, m is not equal to N, and m is equal to 1, the battery management system sends instructions to a switch in the series battery pack protection and equalization circuit, a first isolated bidirectional direct current converter and a second isolated bidirectional direct current converter, so that the series battery pack protection and equalization circuit works according to the working mode K.
9. The balancing control method of the series battery protection and balancing circuit of claim 3, wherein when the battery management system detects that there is no battery fault and there is a battery in the series battery to be balanced, the balancing control method for balancing the battery in the series battery comprises:
battery pack positive electrode switch S in series battery pack isolation interface circuit PB And battery negative switch S NB Conducting, the positive electrode switch S of the converter in the series battery isolation interface circuit PT And the converter is negativePole switch S NT Turning off, wherein the series battery pack is normally connected with a main circuit to charge and discharge; and the transfer of electric quantity between the batteries in the series battery pack is completed through a first isolated bidirectional direct current converter or a second isolated bidirectional direct current converter in the isolation interface of the series battery pack, so that the charge state balance of the series battery pack is realized.
10. The balancing control method according to claim 9, wherein the transferring of the electric quantity between the batteries in the series battery pack is accomplished through a first isolated bidirectional dc converter in the series battery pack isolation interface, so as to achieve the state of charge balancing of the series battery pack, and the method includes:
first switch S in series battery pack isolation interface circuit 1 And a second switch S 2 Turning off; when the first isolation type bidirectional direct current converter is used for battery equalization, the first bypass switch S 1c Off, the second bypass switch S 2c Conducting; when the battery B in the series battery pack j Battery B requiring discharge k When charging is needed to realize the charge state equalization of the series battery pack, the switch S in the group I switch group in the series battery pack gating network circuit I，j-1 And switch S in group II switch group II，j The first isolated bidirectional direct current converter works normally when the first isolated bidirectional direct current converter is switched on and the other switches are switched off, and the battery B j Discharging to charge a second port capacitor of the first isolated bidirectional direct current converter; then, a switch S in the I group switch group in the series battery group gating network circuit I，j-1 And switch S in group II switch group II，j Turn off, switch S in group I switch group in the series battery gating network circuit I，k-1 And switch S in group II switch group II，k The first isolated bidirectional direct current converter works normally, and the second port capacitor of the first isolated bidirectional direct current converter discharges the battery B k Charging; the above-mentioned charge and discharge processes are alternatively implemented to implement electric quantityThe battery B j To the battery B k Transferring to realize the state of charge balance of the series battery packs;
the step of completing the transfer of electric quantity between the batteries in the series battery pack through the second isolated bidirectional direct current converter in the isolation interface of the series battery pack to realize the charge state balance of the series battery pack comprises the following steps:
the method is realized through a second isolated bidirectional direct current converter in the series battery pack isolation interface circuit; at this time, the first bypass switch S 1c On, the second bypass switch S 2c Turning off; when the battery B is used j The battery B needing discharging k When charging is needed to realize the state of charge balance of the series battery pack, the switch S in the group III switch group of the series battery pack gating network circuit III，j-1 And switch S in group IV switch set IV，j The second isolated bidirectional direct current converter works normally when the second isolated bidirectional direct current converter is switched on and other switches are switched off, and the battery B j Discharging to charge a second port capacitor of the second isolated bidirectional direct current converter; then, the switch S in the group III switch group in the series battery gating network circuit III，j-1 And switch S in group IV switch group IV，j Turn off, switch S in group III switch group in the series battery gating network circuit III，k-1 And switch S in group IV switch group IV，k The second isolated bidirectional direct current converter works normally, and the second port capacitor of the second isolated bidirectional direct current converter discharges the battery B k Charging; the charge and discharge processes are alternately carried out to finish the electric quantity from the battery B j To the battery B k And transferring to realize the state of charge balance of the series battery packs.
CN202110531681.4A 2021-05-17 2021-05-17 Isolation interface, gating network, protection and equalization circuit and method for series battery pack Active CN113224816B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110531681.4A CN113224816B (en) 2021-05-17 2021-05-17 Isolation interface, gating network, protection and equalization circuit and method for series battery pack

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110531681.4A CN113224816B (en) 2021-05-17 2021-05-17 Isolation interface, gating network, protection and equalization circuit and method for series battery pack

Publications (2)

Publication Number Publication Date
CN113224816A CN113224816A (en) 2021-08-06
CN113224816B true CN113224816B (en) 2022-12-20

Family

ID=77092074

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110531681.4A Active CN113224816B (en) 2021-05-17 2021-05-17 Isolation interface, gating network, protection and equalization circuit and method for series battery pack

Country Status (1)

Country Link
CN (1) CN113224816B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116131417B (en) * 2023-04-19 2023-08-01 宁波均胜新能源研究院有限公司 Equalization circuit, equalization control method and charger

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109038760A (en) * 2018-02-07 2018-12-18 无锡瓴芯电子科技有限公司 A kind of series-connected cell group modularization active equalization system and method

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101867205B (en) * 2010-06-02 2012-08-22 奇瑞汽车股份有限公司 Device and method for maintaining lithium ion battery pack
CN101917047B (en) * 2010-08-20 2014-02-26 深圳市科列技术有限公司 Method and circuit for dynamically equalizing battery management system
CN103117577B (en) * 2013-02-04 2015-10-28 杭州高特电子设备有限公司 Energy balance circuit for battery pack of electric vehicle
EP2833531B1 (en) * 2013-07-31 2016-09-21 ABB Schweiz AG Bi-directional battery converter and balancer for an electric energy storage of a power supply system
CN103595092A (en) * 2013-10-30 2014-02-19 广东电网公司电力科学研究院 Controllable current balancing system of electric vehicle battery packs
CN104659877B (en) * 2015-01-28 2017-12-22 杭州高特电子设备股份有限公司 A kind of isolation bidirectional constant maintenance system based on shared device power supply
CN207320901U (en) * 2017-10-25 2018-05-04 杭州科工电子科技有限公司 A kind of family's energy storage Li-ion batteries piles balancer

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109038760A (en) * 2018-02-07 2018-12-18 无锡瓴芯电子科技有限公司 A kind of series-connected cell group modularization active equalization system and method

Also Published As

Publication number Publication date
CN113224816A (en) 2021-08-06

Similar Documents

Publication Publication Date Title
US6917181B2 (en) Power supply unit, distributed power supply system and electric vehicle loaded therewith
CN103199589A (en) Lithium ion battery pack modularization fast equalization circuit and equalizing method
CN107134599B (en) Voltage equalization circuit of series battery pack and working method thereof
Dam et al. Low-frequency selection switch based cell-to-cell battery voltage equalizer with reduced switch count
CN101557105B (en) Device and method for prolonging service life of series direct current power supply unit groups
CN114744698A (en) Parallel battery cluster topology integrating circulating current suppression and charge state equalization circuits
CN115833404A (en) Energy storage system, uninterruptible power supply and battery balancing method
CN113224816B (en) Isolation interface, gating network, protection and equalization circuit and method for series battery pack
CN109617161B (en) Quasi-resonance staggered switch capacitor battery equalization circuit and control method thereof
Liu et al. Design of zero-current parallel-switched-capacitor voltage equalizer for battery strings
Ketzer et al. Evaluating circuit topologies for battery charge equalization
CN110729795B (en) Energy storage power station and battery balance control method thereof
CN218958586U (en) Dual-mode active equalization lithium ion battery circuit
CN111181224A (en) Charging system for multi-section series battery pack and charging method thereof
Nie et al. Fast battery equalization with isolated bidirectional DC-DC converter for PHEV applications
CN106935919B (en) Lithium battery pack energy balancing system
CN208314155U (en) Power battery charge-discharge test instrument
Shen et al. Charge equalization for series connected lithium-ion batteries
CN211701533U (en) Charging system for multi-section series battery pack
CN116505632B (en) Battery charging and discharging circuit and control system and method
CN214380183U (en) Electric signal acquisition circuit for broken grids of storage battery pack
Dam et al. A selection switch based cell-to-cell battery voltage equalizer with reduced switch count
CN216489803U (en) Equalizing circuit
CN115589042A (en) DC-DC converter capable of automatically realizing energy storage monomer equalization
Ding et al. Research on battery management system based on active balance technology

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant