Battery pack online capacity detection system and method based on reverse side-by-side topology

Abstract

The invention discloses a reverse side-by-side topology-based battery pack online capacity detection system and method, and the method comprises the steps: connecting a battery spacing switch in series in a battery pack, and symmetrically connecting the battery spacing switch to buses at two sides in a left-right side-by-side manner through a bus switch to form a reverse side-by-side topology shaped like a Chinese character'fei '; the bus switch paths are respectively connected to two leads of the bus on the same side at adjacent or spaced positions; the controller switches the controllable switch, the batteries are automatically selected to form a discharge loop, and constant-current discharge is carried out through the DC / DC converter to a termination condition; when a battery pack commissioning instruction arrives, the controllable switch is switched again, the standby battery replaces the test battery, and a full-capacity battery whole string is formed for power supply. According to the invention, full-automatic control of on-line capacity detection is realized, and waste of electric energy is avoided; a buck-boost converter or only boost converter is adopted, various reverse side-by-side topologies are achieved through deformation of the relative position of a bus switch path, the flexibility of test and power supply circuit construction is greatly improved, and the robustness and reliability of system power supply are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of direct current power supply systems with battery packs as primary or backup power sources, and in particular to an online capacity detection controller, system and method based on reverse parallel topology. BACKGROUND

[0002] With the development of new energy technology, direct current battery packs have become the cornerstone of energy storage in the fields of communication, data, transportation, emergency, and medical treatment. However, their capacity may decay over time and with environmental factors, directly affecting the ability of the system to cope with extreme situations. Precise detection is crucial for ensuring stable power supply, avoiding safety accidents, and economic losses.

[0003] Communication base stations need to operate 24 hours a day to avoid signal interruption and additional maintenance costs. Data center UPS systems rely on battery packs to ensure millisecond-level power supply switching to prevent data loss and business paralysis. The energy storage module of a new energy vehicle is centered on a direct current lithium battery pack, whose capacity directly determines the vehicle's range and is a key factor affecting driving safety and user experience. In public spaces such as shopping malls, office buildings, underground garages, tunnels, and emergency disaster sites such as earthquakes and fires, emergency lighting equipment relies on direct current battery packs for power supply, and their capacity directly affects the safety and order of personnel evacuation. In medical devices such as electrocardiogram monitors and surgical shadowless lamps, direct current battery packs are the last line of defense for patient safety, especially in intensive care units and operating rooms. Even a few seconds of power outage can endanger patient lives.

[0004] Traditional capacity detection requires disconnecting the battery pack from the load, such as offline full discharge testing. However, communication base stations, medical equipment, and other scenarios cannot be shut down, so they often use a temporary backup battery to replace the working battery pack, resulting in longer detection cycles and some battery packs being undetected for a long time.

[0005] Recently, some new technologies for battery pack capacity testing have emerged. For example, Chinese invention patent application number 202411707669.4 discloses an offline battery capacity testing method, system, and device for energy cycle testing. This method collects load current data, voltage data, and battery temperature data, divides a sliding window, and obtains the current anomaly coefficient, current fluctuation coefficient, load electrical parameter anomaly coefficient, and temperature confidence coefficient at each data collection moment. The usable capacity of the battery pack in each energy cycle is obtained by acquiring the battery capacity correction factor at each data collection moment. However, this method, based on the process characteristics of the load current, can only perform battery capacity testing offline. Chinese invention patent application No. 202211450309.1 provides a battery discharge testing device and method. The device includes a power supply panel, a discharge tester, a DC ammeter, and a load port. The discharge tester is used to provide a constant current load, and the DC ammeter is used to detect the discharge current of the battery pack and is communicatively connected to the discharge tester. This invention can meet the requirements of power regulations for battery discharge for constant current discharge of a single battery pack, and the battery is always online during the discharge process. During the test, if an emergency occurs in the DC system such as DC bus grounding, DC bus undervoltage, battery open circuit, battery undervoltage, battery overheating, or battery pack outlet open circuit, the discharge tester automatically stops the discharge test.

[0006] Among the above technical solutions, traditional offline testing methods require disconnecting the battery pack from the system, rendering the battery unusable during testing; moreover, the testing process is time-consuming and energy-intensive. Offline discharge testing requires consuming electrical energy through dummy loads such as resistors, potentially wasting tens to hundreds of kilowatt-hours of energy per charge-discharge cycle, and necessitates additional air conditioning for cooling, further exacerbating energy waste. While online testing methods such as coulomb integration can monitor in real time, they are susceptible to temperature, load changes, and battery aging, resulting in insufficient accuracy; furthermore, when used as a backup power source, they do not have the opportunity to operate online, meaning their capacity status needs to be periodically monitored during standby when not in use.

[0007] To control costs, most DC battery pack systems are generally configured with a single power supply. The current conventional method of verifying capacity by discharging a dummy load and then discharging each battery individually can lead to insufficient backup capacity if a power outage or other abnormal situation occurs. This directly affects the normal operation of the system.

[0008] Therefore, a new online capacity control system and method are needed to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide an online capacity detection controller, system, and method for battery packs that does not waste electrical energy, can automatically and comprehensively detect the battery pack, and can ensure that the power supply capacity is not lost during the detection process.

[0010] One of the technical solutions of the present application is to provide a battery pack online capacity detection system based on reverse side-by-side topology, which comprises: a DC / DC converter for voltage adaptation and current control of the discharge circuit; a backup battery for replacing the test battery pair to supply power to the battery string; a common bus used as a common channel for communication between the single battery, the backup battery and the converter; a switch array integrated by controllable switches for switching selection of the battery and the path when the discharge circuit and the battery string are constructed; wherein the bus switch and the battery string formed at both ends of the battery string and the battery interval switch arranged between any two adjacent single batteries form a reverse side-by-side topology, and the same side end of the interval switch between the two adjacent batteries is connected to different root conductors of any one of the two test buses in the common bus through the bus switch; a controller for obtaining electrical parameters, instructions and controlling the controllable switches in the switch array, which is configured to:

[0011] On the one hand, in response to the capacity detection instruction, a full battery to be tested and a chargeable battery are selected to form a discharge test battery pair; the controllable switch is controlled to connect the two batteries in the battery pair to the discharge end and the charging end of the DC / DC converter through the two test buses respectively to form a discharge circuit; feedback control is performed based on the electrical parameters in the discharge circuit to make the discharge battery discharge at a preset current to a cutoff condition, and the discharge capacity is calculated cumulatively; the just discharged battery is used as a new charged battery, a new full battery is selected as a discharge battery, a new battery pair is iteratively formed and discharged, and the capacity detection of each single battery in the battery pack is completed,

[0012] Meanwhile, the battery pack power supply demand is monitored, when there is a demand, the controllable switch is controlled to disconnect the current discharge circuit, the batteries in the battery pack except the current discharge test battery pair are connected in series to form a battery sub-string, and the backup battery is connected to the battery sub-string after replacing the batteries in the current test battery pair to form a battery string to supply power to the DC bus.

[0013] In another embodiment of the application, there is also provided a battery pack online capacity detection controller based on reverse side-by-side topology, which internally comprises a processor, and a memory and an interface module connected to the processor; the memory is used to store data and programs running on the processor, and the interface module is used to process data and signals exchanged between the processor and external units such as electrical parameter sensors, controllable switches in the switch array, and output display units; the processor is configured to: on one hand, in response to a capacity detection instruction, select a full battery as a discharge battery and a charged battery as a charging battery to form a discharge test battery pair; control the controllable switches to connect the two batteries in the discharge test battery pair to the discharge end and the charging end of the DC / DC converter through two test buses respectively; based on the feedback control of electrical parameters in the discharge circuit, make the discharge battery discharge at a preset current to a cutoff condition, and cumulatively calculate the capacity of the discharge battery; take the just discharged battery as a new charging battery, select a new full battery as a discharge battery, iteratively form a new battery pair and perform discharge test until each single battery in the battery pack completes capacity detection; on the other hand, monitor power supply demand, and if the demand is reached, control the controllable switches to disconnect the current discharge circuit, connect all the batteries in the battery pack except the current discharge test battery pair in a segmented string, and replace each battery in the current test battery pair with a standby battery to form a battery whole string, and then connect the battery whole string to the DC bus through controllable switches to supply power to the DC bus.

[0014] As a preference, the electrical parameter sensors can also be integrated into the battery pack online capacity detection controller based on reverse side-by-side topology, and the sensors are used to detect electrical parameters in the discharge circuit and the voltage of the DC bus. Alternatively, the switch array can also be integrated into the controller. Meanwhile, the controller can also integrate a user interface, which includes a display module and an operation interface. Preferably, any pole of each port of the DC / DC converter can be connected to any wire of the test bus through controllable switches.

[0015] As a preference, the system also has a high-power load and a charging module converted from AC / DC; in the discharge test, the discharge battery that has not completed discharging the charged battery is also discharged to a termination condition by the high-power load. In the discharge test, the charged battery that receives discharging is also charged to a full state by the charging module.

[0016] After the first discharge capacity test of all batteries in the battery pack, only part of the capacity-lagging batteries can be discharged at full capacity in the next round of discharge tests, and other batteries with capacity exceeding the preset value can only be subjected to shallow discharge capacity tests.

[0017] As a preferred, the controller is further configured to, when forming the discharge loop: each of the test batteries takes a different test bus as the test target bus, and closes the bus switch and the battery interval switch between the two ends to build a respective path; and the DC / DC converter in the reverse pressure output state can discharge the battery with the adjacent electrode as the negative electrode to the adjacent battery; and the DC / DC converter in the reverse pressure or positive pressure output state can discharge between the non-adjacent test batteries, and at this time, at least one battery interval switch in the path built between the two test batteries is opened.

[0018] As a preferred, the controller is further configured to, when replacing the current test battery pair with the standby battery: use two standby batteries with single voltage and capacity, and the two batteries in the battery pair can optionally take different buses as bypass target buses, replace the standby battery on the corresponding bypass target bus, and close the bus switch between each of the test battery and the standby battery replacing it and the corresponding bypass target bus to form two bypass replacement segments; and open and close the battery interval switch inside and outside the loop formed by the test battery in each of the two segments, respectively, to form a full-capacity string to the DC bus without circulating current.

[0019] As a preferred, the reverse parallel topology is simplified, and every N single battery is taken as a group, and each single battery in the group is connected to one side bus through a bus switch; another N single battery is also taken as a group, and adjacent groups are directly connected to the other side, i.e., different buses, through bus switches, and a large group of 2N single batteries is repeated and connected as a period.

[0020] As a preferred, in the formed reverse parallel topology, the other side end of the battery interval switch is also connected to the same wire of the two side test buses through a bus switch; so that the wires of any test bus connected by the bus switch on both sides of each single battery are different roots.

[0021] As a preferred, the controller is further configured to, when forming the discharge loop: any two test batteries adjacent to or not adjacent to each other can form a discharge loop for discharge test; wherein the bus switch directly connected between each of the two test batteries and the different test bus without passing through the battery interval switch is closed, and at least one battery interval switch between the two test batteries is opened in the discharge loop.

[0022] As preferred, the controller is further configured to replace the current test battery pair with the spare battery: adopt 2 single-voltage and capacity spare batteries; if the adjacent two batteries form a battery pair, the two batteries can optionally be different buses as bypass target buses, replace the spare battery on the corresponding bypass target bus, select and close the bus switch between each of the test battery and the spare battery connected by the bypass target bus to form two bypass replacement segments, i.e. sub-strings; each of the two bypass replacement segments is spaced apart from at least one battery interval switch in the loop formed by the test battery; wherein if the two loops each include two battery interval switches in their respective ranges, the battery interval switches between the two test batteries and on both sides are respectively closed and opened; otherwise, the two loops cannot have a common circuit segment, and each battery interval switch in the two loops is opened; and after connecting other batteries to form a full-capacity battery string to supply power to the DC bus. That is, after closing other battery interval switches, connect non-test batteries in the battery pack; if the non-adjacent batteries form a test battery pair, the two batteries can optionally be different buses as bypass target buses, replace the spare battery on the corresponding bypass target bus, close the bus switch between each of the test battery and the spare battery connected by the bypass target bus to form a battery segment, i.e. a sub-string, wherein each segment includes at least one battery interval switch inside; at the same time, the battery interval switches inside and between each segment are respectively opened and closed to form a full-capacity string without circulating current.

[0023] As preferred, in the formed reverse side-by-side topology, the other side end of the battery interval switch is also connected to another wire of the two test buses through a bus switch; so that the wire of any test bus directly connected to each monomer battery on both sides through the bus switch is the same; the controller is further configured to form a discharge loop: connect to the test bus in the second and first connection modes by passing through the bus switch after the electrode passes through the battery interval switch, and directly passing through the bus switch without passing through the battery interval switch, respectively; the two test batteries each take a different test bus as a test target bus, and their two poles are each connected to a different wire of the test target bus; when the two test batteries are adjacent, their facing poles and back poles are each connected to the test target bus in the first and second connection modes, respectively; when the two test batteries are spaced apart by 1 battery, the facing pole of at least one of the batteries is connected in the first connection mode, and the other pole is connected in the second connection mode; when the two test batteries are spaced apart by 2 or more batteries, any electrode of them is respectively connected to the test target bus in the first and second connection modes; at the same time, the bus switch and the battery interval switch in the first and second connection modes are closed to form a connection path, and at least one battery interval switch between the two test batteries that is not in the connection path is opened.

[0024] As preferred, the controller is further configured to, in replacing the current test battery pair with the spare battery pair: adopt 2 single-voltage and capacity spare batteries; if the two batteries in the battery pair are adjacent, the two batteries in the battery pair can optionally have different buses as bypass target buses, replace the spare batteries on the corresponding bypass target buses, select and close the bus switches between the test battery and the spare battery replacing it and each corresponding bypass target bus to form two bypass replacement segments; the two segments each include a battery interval switch in the loop formed by the test battery, and the two loops formed cannot have a common circuit segment; open and close the battery interval switches inside and outside the two loops to connect the non-test batteries in the battery pack and form a full-capacity string of DC buses without circulating current; and if the two batteries in the battery pair are not adjacent, the two batteries in the battery pair can optionally have different buses as bypass target buses, replace the spare batteries on the corresponding bypass target buses, select and close the bus switches between the test battery and the spare battery replacing it and each corresponding bypass target bus to form two bypass replacement segments; the two segments each form a loop with the test battery, and the battery interval switches inside and outside the two loops are opened and closed to form a full-capacity battery string.

[0025] As preferred, in the reverse parallel topology formed, one side end of the battery interval switch is also connected to another wire of the two test buses through a bus switch to form a fully symmetric periodic topology; and the battery interval switches are arranged every 1 single battery in the battery pack.

[0026] As preferred, in the system, multiple DC / DC converters including reverse pressure output and positive pressure output can be arranged, and one of them can be used to build a discharge circuit by switching the bus switch as needed. Among them, for non-adjacent batteries, if neither of the bus switch paths connected to the test buses on their two sides contains a battery interval switch, a positive pressure or reverse pressure output converter can be used, and at least one battery interval switch between them is opened to avoid short circuit.

[0027] As preferred, the reverse parallel topology is replaced by: a battery interval switch is connected in series between the two ends of the battery string formed by the battery pack and between any two adjacent single batteries inside it, and the two side ends of the battery interval switch are connected to different wires of the two test buses through a bus switch; and the same side ends of the two adjacent battery interval switches are connected to the same wire of the test bus on either side through a bus switch; and each single battery is also connected to any test bus on its two sides through a bus switch without passing through the wire connected by the battery interval switch.

[0028] Correspondingly, the controller is further configured to replace the standby battery for the current test battery pair: adopt 2 single-voltage and capacity standby batteries; if the adjacent two batteries form a battery pair, each of the two test batteries is bypassed and replaced by the standby battery connected by the test bus, one of the two test batteries is connected to one of the test buses through the bus switch after passing through the battery interval switch, the corresponding test battery and the bus switch between the test battery and the test bus are closed; the other test battery is connected to the other test bus through the bus switch after passing through the battery interval switch, the corresponding test battery and the bus switch between the other test battery and the test bus are closed; at the same time, the battery interval switches adjacent to and in the middle of the two test batteries on both sides are opened and closed respectively to avoid circulating current and connecting the two standby batteries, and to form a full-capacity battery string after connecting other batteries to supply power to the DC bus; and if the non-adjacent batteries form a test battery pair, the two batteries in the battery pair can optionally select different buses as bypass target buses, and are replaced by the standby battery on the corresponding bypass target bus, the bus switches between the test battery and the standby battery connected by the corresponding bypass target bus are closed to form a battery segment; at the same time, the battery interval switches inside and outside each segment are opened and closed respectively to form a full-capacity battery string without circulating current.

[0029] As a preferred, the controller is further configured to replace the standby battery for the current test battery pair: adopt 2 single-voltage and capacity standby batteries, introduce a bypass bus BP in the circuit, which is connected to the same positive electrode or the same negative electrode of each single battery through a bus switch, and is extended to both sides of the battery string in cycles; the two batteries in the battery pair can optionally select different buses as bypass target buses, and are replaced by the standby battery on the corresponding bypass target bus; close the bus switch directly connected between the inner side electrodes of one of the batteries and the two side buses in the opposite direction, close the bus switch between the outer side of the battery interval switch JKL connected to the outer side electrode of the battery and BP, close the jumper switch between BP and a wire on the bypass target bus of the battery in the stringing direction, and close the bus switch between the two ends of the corresponding standby battery and the bypass target bus; close the bus switch between the two ends of the other standby battery and the other test bus, and close the bus switch between a wire on the other test bus and the outer side of the battery interval switch JKR connected to the outer side electrode of the other battery in the stringing direction; at the same time, the battery interval switches between and outside JKL and JKR are opened and closed respectively to form a full-capacity battery string.

[0030] As a preference, the backup battery adopts a single battery with double voltage and capacity; the controller is further configured to replace the current test battery pair with the backup battery at a time when the replacement structure adopts two backup batteries, one of which is replaced with a single backup battery with double voltage and capacity, and the other of which adopts a jumper mode.

[0031] As a preference, the DC / DC converter adopts a single-mode Boost converter, two empty single batteries in the battery pack are connected in series through a bus to form a charging battery as a whole, and two ends of the charging battery are connected to two wires of one of the test buses.

[0032] Preferably, a single-capacity backup battery or a double-capacity backup battery can be connected to any test bus through a bus switch.

[0033] In another embodiment of the application, a battery pack online capacity detection method based on a reverse parallel topology is also provided, comprising the following steps:

[0034] S1, initialization, a controllable pre-connection topology between the battery and the bus is built by a switch array composed of various controllable switches, wherein a battery interval switch is connected in series between two ends of a battery string formed by the battery pack and between any two adjacent single batteries inside the battery string, one side end of the battery interval switch is connected to one wire of a test bus through a bus switch and forms a reverse parallel topology, and the same side end of the adjacent two battery interval switches is connected to different wires of the test bus through the bus switch;

[0035] S2, detecting a demand event of the battery pack to supply power to the DC bus, if the event does not occur, turning to S6, otherwise turning to S3;

[0036] S3, stopping the capacity test and disconnecting the current discharge test circuit;

[0037] S4, controlling the controllable switch, replacing the test battery string with a backup battery with a capacity equivalent to the total capacity of the current test battery pair through the common bus to supply power to the DC bus with the formed battery string;

[0038] S5, waiting until the battery pack supply demand is removed, charging each single battery to a full state, and turning to S2;

[0039] S6, judging whether the current battery capacity detection test is being performed, if yes, turning to S12, otherwise turning to S7;

[0040] S7, judging whether there is a capacity detection instruction, if yes, turning to S8, otherwise turning to S2;

[0041] S8, select one of the to-be-tested full battery as a discharging battery, form a charging battery with the available battery, and form a test battery pair with the two batteries;

[0042] S9, control the controllable switch to connect the discharging battery and the charging battery to two ends of the DC / DC converter through the common two test buses, and form a discharging loop;

[0043] S10, detect the voltage ratio at the two ends of the converter and the discharging current, switch the controllable switch, and discharge the discharging loop at a preset current through negative feedback control;

[0044] S11, collect and record the discharging parameters, and go to S2;

[0045] S12, determine whether the discharging termination condition is reached, if yes, calculate the discharging capacity of the current discharging battery according to the recorded discharging parameters, and go to S13, otherwise go to S10;

[0046] S13, determine whether all the batteries have completed the capacity detection, if yes, go to S14, otherwise use the discharging battery just discharged as a new available battery and go to S9;

[0047] S14, output the discharging capacity values of each single battery in the battery pack, end the current capacity test, and go to S2.

[0048] Compared with the prior art, the battery pack online capacity detection system, method and device / controller of the application has the following advantages: the battery pack online capacity detection controller and method based on the reverse parallel topology of the application connect the battery interval switch in the battery pack to the two side buses symmetrically through the bus switch to form a reverse parallel topology similar to a non-alphabet, and the connected bus switch paths on the same bus side are connected to different root conductors at positions adjacent to or spaced by one path.

[0049] On this basis, the DC / DC converter is also connected to the common two test buses through controllable switches, so that a full battery in the battery pack can be flexibly selected, and a discharge circuit is constructed between the full battery and the just emptied battery to perform a discharge test, and the voltage matching between the two end batteries is realized through the converter to realize constant current discharge, so that the capacity of the battery to be tested is detected. The flow of electrical energy between the batteries avoids the waste of electrical energy; the time-sharing multiplexing of the common components such as the bus and the converter reduces the complexity of the system and simplifies the structure of the system. When the battery pack needs to be put into use due to some reasons, the standby battery can replace the test battery in the current discharge circuit whose capacity has been reduced due to discharge, so that the overall capacity of the battery pack caused by the individual lagging battery in the battery pack can be avoided, the power supply capacity and working time of the direct current load of the system are ensured, and the power supply reliability is improved. The switching of the controllable switch in the discharge circuit and the bypass replacement circuit enables both of them to be automatically constructed, and the full-automatic control of the on-line capacity detection is realized. In addition, the detection time can be shortened through consistent shallow discharge, so that the test frequency can be improved, and the capacity state of the battery pack can be grasped more timely.

[0050] In the present application, the converter in the single or bidirectional step-up and step-down, and single step-up mode is adopted, and flexible and various discharge test circuit construction modes are provided; in the circuit topology in which the test battery is replaced by the standby battery, the full battery string construction of the battery pack is realized through the introduction of the bypass bus, the short-circuit switch between different wires in the bus, and the cross-over switch between the buses, and the robustness and system reliability of the power supply circuit are further improved.

[0051] It should be understood that all combinations of the aforementioned concepts and additional concepts discussed in greater detail below can be contemplated as part of the inventive subject matter disclosed herein. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 Structure diagram of the battery pack on-line capacity detection system based on the reverse parallel topology;

[0053] Figure 2 Polarity diagram of the two end batteries of the DC / DC converter;

[0054] Figure 3A 、 Figure 3B SEPIC and Zeta converters with positive voltage output, Figure 3C 、 Figure 3D Buck k-Boost and CUK converters with reverse voltage output, Figure 3E 、 Figure 3F Bidirectional Buck / Boost and Buck-Boost converters:

[0055] Figure 4 Structure diagram of the reverse parallel prototype topology in the battery pack string connection;

[0056] Figure 5A 、 Figure 5B are respectively discharge circuit schematic diagram under reverse parallel prototype topology; Figure 5C is reverse parallel topology schematic diagram formed by each battery and two side buses of the present application; Figure 5D is another reverse parallel topology schematic diagram;

[0057] Figure 6A 、 Figure 6B are respectively discharge circuit schematic diagram between adjacent and non-adjacent batteries;

[0058] Figure 7A and Figure 7B 、 Figure 7C and Figure 7D are respectively circuit structure diagram of test batteries replaced by spare battery bypass under two reverse parallel topologies;

[0059] Figure 8A 、 Figure 8B are respectively circuit topology diagram and discharge circuit topology diagram of adjacent test batteries replaced by spare battery bypass under another mode reverse parallel topology;

[0060] Figure 9 is another topology diagram of adjacent test batteries replaced by bypass bus under another reverse parallel topology;

[0061] Figure 10A 、 Figure 10B are respectively another reverse parallel topology single spare battery bypass replacement topology diagram;

[0062] Figure 11A 、 Figure 11B is simplified reverse parallel topology schematic diagram formed by each battery and two side buses of the present application;

[0063] Figure 12 is discharge circuit schematic diagram between batteries under simplified reverse parallel topology; Figure 13A 、 Figure 13B are respectively circuit structure diagram of non-adjacent and adjacent test batteries replaced by spare battery bypass;

[0064] Figure 14A 、 Figure 14B is circuit structure diagram of test batteries replaced by single spare battery bypass in another embodiment;

[0065] Figure 15A 、 Figure 15B 、 Figure 15C are respectively circuit structure diagram of 2, 3 and 1 spare battery bypass replacing 3 test batteries under boost conversion mode;

[0066] Figure 16The application discloses a battery group on-line capacity detection controller, system and method based on a reverse parallel topology.

[0067] Figure 17A 、 Figure 17B The application discloses a battery group on-line capacity detection controller, system and method based on a reverse parallel topology. DETAILED DESCRIPTION

[0068] The preferred embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application is not limited to these embodiments. The present application covers any alternatives, modifications, equivalent methods and solutions within the spirit and scope of the present application.

[0069] The application is described in more detail below with reference to the accompanying drawings. It should be noted that the drawings are in a simplified form and are only used to facilitate, clarify and assist in the description of the embodiments of the present application. For ease of description, terms such as "first", "second", "third" and "upper", "lower" and the like are only used to distinguish one part from another part with the same name, and do not necessarily require or imply any such actual relationship or order between the parts.

[0070] Embodiment 1

[0071] The battery group composed of lithium batteries, lead-acid batteries and the like needs to be intermittently detected during use to master the discharge capacity of each single battery in the battery group, so that aging or faulty batteries can be found and handled in time. During the discharge process for capacity detection, once the battery group needs to be put into use, the capacity of the entire battery group will be greatly reduced due to the consumption of part of the capacity of the battery under test, and the overall capacity is subject to only the single battery with the least capacity.

[0072] Therefore, the application provides a battery group on-line capacity detection controller, system and method based on a reverse parallel topology. Specifically, the battery group on-line capacity detection method based on a reverse parallel topology comprises the following steps:

[0073] S1, initialization, a controllable pre-connection topology between a battery and a bus is built by a switch array composed of various controllable switches, wherein a battery group forms a battery string, and a battery interval switch is connected in series between both ends of the battery string and between any two adjacent single batteries in the battery group; one side end of the battery interval switch is connected to one wire of a test bus through a bus switch and forms a reverse parallel topology, and the same side end of the adjacent two battery interval switches is connected to different wires of the test bus through the bus switch;

[0074] S2, detecting the demand event of the battery pack supplying power to the DC bus, if the event does not occur, turning to S6, otherwise turning to S3;

[0075] S3, stopping the capacity test, disconnecting the current discharge test loop;

[0076] S4, controlling the controllable switch, replacing the test battery string with a standby battery whose capacity is equivalent to the current test battery to the total full capacity through the common bus, and supplying power to the DC bus with the formed battery string;

[0077] S5, waiting until the battery pack power supply demand is removed, charging each single battery to a full state, and turning to S2;

[0078] S6, determining whether the current battery capacity detection test is being performed, if yes, turning to S12, otherwise turning to S7;

[0079] S7, determining whether there is a capacity detection instruction, if yes, turning to S8, otherwise turning to S2;

[0080] S8, selecting a full battery to be tested as a discharge battery, forming a charge battery with a receivable battery, and forming a test battery pair;

[0081] S9, controlling the controllable switch to connect the discharge battery and the charge battery to the two ends of the DC / DC converter through the common test bus, forming a discharge loop;

[0082] S10, detecting the voltage ratio at the two ends of the converter and the discharge current, switching the controllable switch, and discharging the discharge loop at a preset current through negative feedback control;

[0083] S11, collecting and recording the discharge parameters, and turning to S2;

[0084] S12, determining whether the discharge termination condition is reached, if yes, calculating the discharge capacity of the current discharge battery according to the recorded discharge parameters, and turning to S13, otherwise turning to S10;

[0085] S13, determining whether all batteries have completed capacity detection, if yes, turning to S14, otherwise taking the just discharged discharge battery as a new receivable battery and turning to S9;

[0086] S14, outputting the discharge capacity values of each single battery in the battery pack, ending the current capacity test, and turning to S2.

[0087] The present application takes into account the contradiction between the need for discharge in online capacity detection and the need for full capacity in DC power supply, such as Figure 1As shown, for the battery pack of n single batteries connected in series, the two ends thereof can be connected to the DC load bus through controllable switches, so that the whole string of batteries can supply power to the DC load through the DC bus Bd when needed.

[0088] In order to realize the on-line capacity detection of each single battery in the battery pack, a first bus and a second bus are introduced as common buses to be connected to the DC / DC converter which is also a common component. Figure 1 As shown, in the on-line capacity detection system of the battery pack based on the reverse parallel topology using the method of the application, the system comprises an on-line capacity detection controller of the battery pack based on the reverse parallel topology, a switch array, common buses, a DC / DC converter and a backup battery. The DC / DC converter is used to adapt the voltage between the selected discharge battery and the charge battery in the battery pack, and to make the discharge battery discharge the charge battery at a preset current through the PWM control of the controllable switch. The common buses include a first bus and a second bus, which are used as common channels for the connection between different single batteries in the battery pack and the two ends of the DC / DC converter. The backup battery is used to replace the discharge battery and the charge battery in the discharge circuit and to form a whole string of batteries together with other single batteries in the battery pack when the DC bus Bd needs to be powered by the battery pack. The switch array is used to change the connection topology of the batteries and the buses through switching control, so as to variably build the discharge circuit and to form a full-capacity whole string of batteries to supply power to the bus Bd.

[0089] The working current control of the DC / DC converter during the capacity detection in the discharge circuit can match the voltage of the two-end batteries and make the discharge circuit discharge at a preset current under the action of the controller. For example, in a case where the discharge battery and the charge battery are both composed of a single battery, the DC / DC converter needs to be used to control the discharge current on the basis of the reduced voltage at the initial stage of the discharge, and to control the discharge current on the basis of the increased voltage in the later stage of the test due to the continuously reduced voltage of the discharge battery and the continuously increased voltage of the charge battery. Therefore, in combination with the above-mentioned Figures 1-3E As shown, the DC / DC converter capable of reducing and increasing voltage is selected and connected between the selected discharge battery and the charge battery through the common first bus and the second bus.

[0090] The on-line capacity detection controller of the battery pack based on the reverse parallel topology comprises a processor, a memory connected to the processor and an interface module. The memory is used to store data and programs running on the processor, the interface module is used to interact data and signals between the processor and external units such as the electrical parameter sensor, the controllable switch in the switch array and the output display unit, and the processor is configured to:

[0091] In one aspect, in response to a capacity detection instruction, a full battery and a chargeable battery are selected to form a discharge test battery pair; controllable switches in a switch array are controlled to connect the two batteries in the discharge test battery pair to a discharge end and a charge end of a DC / DC converter via a first bus and a second bus respectively; feedback control is performed based on the collected electrical parameters in the discharge circuit to make the discharge battery discharge at a preset current until a cutoff condition is reached, and the discharge capacity of the discharge battery is calculated according to the electrical parameters in the discharge process; the just discharged battery is formed into a new chargeable battery, a new full battery is selected as a discharge battery, and a new battery pair is iteratively formed for discharge testing until each single battery in the battery pack is subjected to capacity detection. In another aspect, the power supply demand of the battery pack is monitored simultaneously, and if the demand is reached, the controllable switches in the current discharge circuit are disconnected to form a battery sub-string by connecting all the batteries in the battery pack except the current discharge test battery pair in the battery pack in series, and the battery sub-string is connected to the DC bus via controllable switches to replace the batteries in the current test battery pair with spare batteries to form a battery string to supply power to the DC bus; among the controllable switches controlled by the controller, there is a battery interval switch between the two ends of the battery string formed by the battery pack and between any two adjacent single batteries in the battery string, one side of each battery interval switch is connected to one wire of the two test buses via a bus switch to form a reverse side-by-side topology, and the same side of the two adjacent battery interval switches is connected to different wires of the test bus via bus switches.

[0092] In combination Figure 1 As shown in the drawings, the electrical parameter sensor can also be integrated into the battery pack online capacity detection controller based on the reverse side-by-side topology, and the sensor is used to detect the electrical parameters in the discharge circuit and the voltage of the DC bus. Alternatively, the switch array can also be integrated into the controller. Meanwhile, the controller can also integrate a user interface including a display module and an operation interface; the display module is used to display the capacity detection process and results, and the operation interface includes keys and parameter input modules for user operation and parameter setting, wherein the display module and the operation interface can also be combined in a human-computer interaction module, such as a touch screen for display and operation interaction.

[0093] The conventional battery capacity detection system often uses a discharge instrument, which uses a high-power resistor as a load to perform discharge testing, and the electrical energy is wasted in the test. To overcome this shortcoming, the present application realizes the recycling of electrical energy by discharging a full battery to one or more discharged batteries in the battery pack. To overcome the problem of capacity loss in the battery pack caused by the conventional capacity detection method, the present application ensures the full capacity state of the battery pack by controllably replacing the common full-capacity spare battery.

[0094] Specifically, in combination Figure 1 ,Figure 2 As shown, each individual battery cell (BAi) connected in series in the battery pack has its positive and negative terminals connected to two common test buses, a first bus and a second bus, respectively, via controllable bus switches in the switch array. Each test bus includes two wires, and the two wires of each bus are then connected to the two ends of the DC / DC converter via bus switches.

[0095] A step-down / step-up DC / DC converter, also known as a buck-boost DC / DC converter, can be... Figures 3A-3F One of the converters shown. Figure 3A , Figure 3B These are SEPIC and Zeta converters, respectively, both of which have positive voltage outputs. Figure 2 Vd and Vc1 are shown on the right; and the discharge battery Vd at the input terminal on the left and the charging battery Vc at the output terminal on the right are grounded together. The voltage ratio of Vc to Vd is M(D)=D / 1-D, where D is the percentage of the controllable switch's on-time in the control cycle of the converter current, i.e., the duty cycle. Figure 3C , Figure 3D These are Buck-Boost converters and CUK converters, which use one and two inductors respectively. Unlike the previous two converters, they both provide reverse voltage output. Figure 2 As shown on the right, Vd and Vc2; that is, the physical negative terminal of the discharge battery Vd is directly connected to the physical positive terminal of the rechargeable battery Vc on the right, and the voltage ratio of Vc to Vd is M(D) = -D / 1-D.

[0096] Figure 3E It is a bidirectional Buck / Boost converter that can realize bidirectional power transmission. When transmitting from left to right, it is in buck mode, and the voltage ratio between the output and input terminals is M(D)=U2 / U1=D1; when transmitting from right to left, it is in boost mode, and the voltage ratio between the output and input terminals is M′(D)=U1 / U2=1 / 1-D2; where D1 and D2 are the duty cycles of the control pulses S1 and S2, respectively. Figure 3F Bidirectional / Bi Buck-Boost circuit from Figure 3CThe DC / DC converter can realize bidirectional energy transmission, and the output voltage is lower or higher than the input voltage. When energy is transmitted from V1 to V2, the switch tubes Q2 and Q3 do not work, and there are two working modes: a step-down mode and a step-up mode. In the step-down mode, Q4 is cut off, and Q1 is in pulse width modulation (PWM) working mode, so that the voltage ratio of the output terminal to the input terminal is D1. In the step-up mode, Q1 is turned on, and Q4 is in PWM working mode, so that the voltage ratio is 1 / (1-D4'), wherein D1 and D4 are the duty cycles of Q1 and Q4 respectively. When energy flows in the opposite direction, the switch tubes Q1 and Q4 do not work, and the step-down and step-up working modes of V2 to V1 are controlled by changing the duty cycles of Q2 and Q3 respectively.

[0097] As shown in Figure 1 In order to flexibly switch the connection between the single battery in the battery pack and the port of the converter, any pole of each port of the DC / DC converter can be connected to any wire of the test bus through a controllable switch.

[0098] In each discharge test, the working voltage and discharge current of the test battery connected to the step-up and step-down DC / DC converter are detected in real time. As shown in Figure 1 After the voltage and current sensors detect these electrical parameters, the electrical parameters are sent to the controller, and the duty cycle D of the controllable switch in the step-up and step-down DC / DC converter is adjusted by the closed-loop control unit in the controller according to the control law, so that the controlled quantities of the current and voltage tend to be consistent with the target values and are digitally controlled according to the periodic and timing control of the pre-set curve; so as to discharge the measured battery from the full charge state to the empty state.

[0099] During the discharge test of each single battery, the processor calculates the SOC change value of the discharge battery by using the collected electrical parameters, so as to estimate the discharge capacity of each single battery from the full charge state to the empty state, and to estimate the discharge capacity of the battery pack, thereby achieving the purpose of battery capacity detection. The state of charge (SOC) is used to reflect the remaining capacity of the battery, and the change value is iteratively calculated from the initial state. The SOC change value calculation formula of the discharge battery at time t is: Alternatively, the calculated value can be divided by the rated capacity Cr of the battery.

[0100] As shown in Figure 1 , Figure 2As shown, in the battery capacity detection system, all controllable switches including bus switches, battery interval switches and switch tubes in the converter are integrated into a switch array. The controller controls the controllable switches to realize the discharge test of the selected and dynamically changed battery interval through the converter, and the overall full-capacity lossless series connection of the battery pack after bypassing and standby replacement of the test battery when power is supplied on demand.

[0101] As shown in Figure 1 , in the natural series connection of the battery pack, the opposite electrodes between adjacent batteries are connected to each other. In order to enable any single electrode to be connected to the DC / DC converter through the first bus and the second bus, as shown in Figure 4 , the present application designs a reverse side-by-side prototype topology for the connection between the battery and the bus. In the reverse side-by-side prototype topology, the positive and negative electrodes of each single battery are each connected to two wires of the first bus B1 through a bus switch, and are each connected to two wires of the second bus B2 through a bus switch; thereby, one of the batteries can be selected and connected to one of the test buses through the on-off control of the bus switch. Since the adjacent electrodes are connected to each other, the adjacent batteries share the bus switch paths of the opposite / adjacent electrodes to the buses on both sides. In combination with Figure 1 , Figure 4 , a full battery and an empty battery can be selected to form a test battery pair, and the test battery pair can be connected to the discharge end and the charging end / power receiving end of the DC / DC converter through the two test buses.

[0102] As shown in Figure 5A , Figure 5B , without loss of generality, a full battery BA4 discharging to an empty battery BA3 is taken as an example to illustrate the construction of the discharge circuit; wherein, the DC / DC converter selects a Buck-Boost converter with reverse voltage output and a Zeta converter with positive voltage output in Figure 5A , Figure 5B .

[0103] In Figure 5A , the physical negative electrode of the discharge end Vd of the reverse voltage output converter is collinear with the physical positive electrode of the charging end Vc; correspondingly, as shown by the dotted circle in the figure, the negative electrode of BA4 is directly connected to the positive electrode of BA3 through the collinear line. As shown by the dotted curve in the figure, since the two electrode ends are originally adjacent in the reverse side-by-side prototype topology, the DC / DC converter with reverse voltage output can be used to construct the discharge circuit between the adjacent batteries. Further analysis shows that, due to the collinear feature of the reverse voltage output DC / DC converter, the discharge circuit will cause the overall short circuit of the two batteries if the direction is reversed, i.e., BA3 discharges to BA4.

[0104] In Figure 5B which the positive voltage output converter discharging terminal Vd's physical negative pole is the same physical pole as the charging terminal Vc's, i.e. co-linear; correspondingly, referring to the oval circle shown in the figure, the negative pole of BA4 is directly connected to the negative pole of BA3 through the co-linear line. As shown by the dotted curve in the figure, since in the reverse parallel prototype topology, the two electrode terminals are connected in the middle by BA3; therefore, once the positive voltage output converter is turned on, the BA3 battery will be short-circuited, thus damaging the battery.

[0105] Therefore, based on the reverse parallel prototype topology, not only cannot the positive voltage output converter be used, but even if the reverse voltage output converter is used, the discharging can only be performed in one direction, greatly limiting the flexibility of the discharging loop construction. Further analysis shows that based on the reverse parallel prototype topology, if an attempt is made to bypass replace the test battery with a standby battery, a parallel circuit will be formed between the standby battery and the test battery to be replaced, causing a circulating current, which not only will form a large current to affect the battery life but also will reduce the overall discharging capacity of the battery pack.

[0106] Based on repeated tests and research, on the basis of the reverse parallel prototype topology, the defects thereof are improved, and a reverse parallel topology structure as shown in Figure 5C is designed. Among them, the key lies in the introduction of the battery inter-battery switch between the battery electrodes and the orientation feature design of its path with the bus switch.

[0107] Referring to 5C, the present application has a battery inter-battery switch between the two ends of the battery string formed by the battery pack and between any two adjacent monomer batteries inside it. One side of the battery inter-battery switch JK, such as the end connected to the negative pole in the figure, is connected to one of the two test bus wires through one bus switch ZK and forms a reverse parallel topology, and the same side of the adjacent two battery inter-battery switches JK, i.e. the end connected to the negative pole, is connected to different wires of any one side test bus through the bus switch. For example, the right side JK of BA1 and BA2 is connected to L3 and L4 of the first bus and L1 and L2 of the second bus through bus switches ZK. At the same time, in order to form a direct connection loop between the monomer battery and the test bus, Figure 5C two bus switch paths are used in the middle, i.e. on the basis of the above, the other side of the battery inter-battery switch JK is also connected to the same wire of the two test buses through one bus switch ZK; so that the wires of any test bus connected by the bus switch on both sides of each monomer battery are different roots. Further, as shown by the dotted curve in the figure, based on this reverse parallel topology, any monomer battery can be connected to the two wires of the two test buses on both sides through the bus switch, so that any battery can be connected to the common DC / DC converter port through the bus.

[0108] Based on the designed reverse-parallel topology, the construction method of its discharge circuit is analyzed. For example... Figure 5C As shown, in this topology, L1 of B1 is directly connected to the positive terminal of the odd-numbered battery via bus switch ZK, and L2 is directly connected to its negative terminal; in B2, L3 and L4 are also directly connected to the positive and negative terminals of the odd-numbered batteries, respectively. Figure 6A The diagram illustrates the discharge circuit from the left battery BA2 to the right battery BA3, as shown by the segmented dashed lines. Although the reverse voltage output converter structure causes the negative terminal of BA2 and the positive terminal of BA3 to be collinearly connected, as shown by the arrows in the diagram, the problem of the two test batteries being short-circuited as a whole can be avoided by disconnecting the battery separator switch JK23. This is understandable. Figure 6A Based on a reverse-voltage output DC / DC converter, when battery BA3 (with the adjacent electrode being the negative terminal) discharges to the adjacent BA2, the intermediate JK23 can remain either open or closed. See also... Figure 6B As shown, when non-adjacent batteries, such as BA1 and BA3, are discharging, regardless of the discharge direction, a short circuit can be avoided by disconnecting at least one battery separator switch between them, thus forming a discharge loop.

[0109] This invention enables capacity detection and on-demand power supply. On one hand, in the reverse parallel topology circuit of this invention, when battery pairs formed by discharging and charging batteries at different locations need to form a discharge circuit, different discharge circuit topologies need to be constructed in step S9. Extending to a general case, the discharge circuit construction strategy can be summarized as follows: For DC / DC converters with reverse or positive voltage output, under this dual-bus switch path topology, any two adjacent / non-adjacent test batteries can form a discharge circuit for discharge testing; wherein, in the discharge circuit, the bus switches that directly connect the two test batteries to different test buses (i.e., without passing through battery spacer switches) are closed, and at least one battery spacer switch between the two test batteries is opened.

[0110] for Figure 3EThe bidirectional Buck / Boost converter, when the voltage of the charging battery and the discharging battery is close to each other, if the hard connection control between the voltage reduction mode and the voltage increase mode is performed according to the voltage size, the multiple back-and-forth switching of the whole circuit will be caused, and voltage spikes will be caused. Therefore, the pass-through mode is introduced between the voltage reduction mode and the voltage increase mode. Specifically, the controller is further configured to: in the voltage reduction mode, when the ratio of the voltage at the charging battery end to the voltage at the discharging battery end is greater than a preset first voltage multiple threshold, the jump connection controllable switch between the positive electrodes at the two ends of the converter is switched to the closed state, so that the converter works in the pass-through mode; in the pass-through mode, the controllable switch connected in series between the positive electrodes at the input and output ends of the converter is controlled by the PWM pulse, so that the discharging battery discharges the charging battery at a preset current; then, when the duty cycle of the PWM pulse in the pass-through mode is greater than a preset second voltage multiple threshold, the jump connection controllable switch is disconnected, and the voltage increase mode is entered by switching. Correspondingly, the controllable bus switch paths are arranged between any port of the bidirectional Buck / Boost converter and the two test buses, so that the discharging battery can be connected to the two ports of the voltage reduction input end and the voltage increase input end of the bidirectional Buck / Boost converter respectively, so that the discharging circuit can be switched in the mode while keeping the discharging direction.

[0111] On the other hand, when the battery pair formed by different batteries is replaced by the standby battery, the step S4 also needs to design a different bypass replacement topology. In the embodiment, two single batteries are used as standby batteries, and the voltage and capacity of each standby battery are equal to those of a single battery in the battery pack.

[0112] As Figure 7A , the test battery pair is composed of two adjacent batteries, such as BA1 and BA2. The two standby batteries are BAbm1 connected to the first bus B1 through the bus switch and BAbm2 connected to the second bus B2. In the figure, BAbm1 and BAbm2 are used to replace test batteries BA1 and BA2 respectively. As can be seen from the figure, along the segmented dashed line on the left side of BA1 and through BAbm1, because there are two bus switch paths in parallel and connected to the same two conductors at the right side of BA1, it is necessary to analyze whether one of them needs to be selected. If the left path is selected, it is found that parallel connection between BA1 and BAbm1 will be formed at this time, and battery parallel connection will cause circulating current, which will affect the battery life and reduce the discharge capacity. Therefore, the right path as shown by the segmented dashed line must be selected. Similarly, for BA2, because the left bus switch path has been determined, the right bus switch path of BA2 must also use the same right path shown in the figure. At the same time, by disconnecting the battery interval switch on the right side of the selected path of the two test batteries, parallel circulating current is avoided.

[0113] It can be understood that, after the battery interval switches on the left side of BA1 are opened at the left end and the bus switch paths from the left end to the buses on both sides are connected to the wires different from the wires connected to the right end, the test battery pair composed of BA1 and BA2 can also bypass the test battery of the spare battery pair through the left bus switch paths of the battery interval switches on the left side of each battery; at the same time, the battery interval switches on the left side of the two test batteries are disconnected to form a test battery bypass replacement section. After closing the other battery interval switches, connecting the section with other batteries, and forming a full-capacity battery string to supply power to the DC bus in the backward direction.

[0114] By closing the bus switches between the test batteries and the spare batteries replacing them and the same test bus, a test battery bypass replacement section is formed. Since there are three battery interval switches on both sides and in the middle of two adjacent batteries, the two test battery bypass replacement sections formed by the two test batteries and the loop formed by the test batteries may include one or two battery interval switches. If the two loops include a common circuit section and each include only one battery interval switch, the battery interval switch between the two test batteries in the common circuit section must be closed to connect the two sections, which will inevitably form a parallel loop current. When the two loops each include one battery interval switch, if they are in contact through a common point, the battery interval switches of the two are on the left side or the right side; if they are not in contact, the battery interval switches of the two are on the outside of the two test batteries, in which case the battery interval switch in the middle of the loop needs to be closed. When the two loops each include one, two battery interval switches and have no common circuit section, they are in contact through a common point, and the battery interval switches of the two are the three on both sides and in the middle of the two test batteries, in which case the battery switch in the middle can be disconnected, but if it is closed, it will not affect. When the two loops each include two battery interval switches and the common circuit section is the battery interval switch between the two test batteries, the battery interval switches in the range of the two are the three on both sides and in the middle of the two test batteries, in which case the battery switch in the middle can be disconnected, and if it is closed, it will not affect.

[0115] Thus, the bypass replacement topology construction strategy of adjacent battery pairs forming discharge test battery pairs can be summarized: two batteries in a battery pair can optionally differ in the bus as the bypass target bus, by replacing the spare battery on the corresponding bypass target bus, selecting and closing the bus switch between the test battery and the spare battery connected to the bus, and the bus switch between the spare battery and the bus, to form two bypass replacement segments, i.e., sub-strings; the two bypass replacement segments are each separated from at least one battery interval switch in the loop formed by the test battery; wherein if the two loops each include two battery interval switches in their respective ranges, the battery interval switches between the two test batteries and on both sides are respectively closed and opened; otherwise, the two loops cannot have a common circuit segment, and each battery interval switch in the two loops is opened; and after connecting other batteries to form a full-capacity battery string to supply power to the DC bus. That is, after closing the other battery interval switches, the non-test batteries in the battery pack are connected.

[0116] Further, the spare bypass replacement circuit construction of test battery pairs composed of non-adjacent batteries is analyzed. Referring to Figure 7B As shown, when the discharge and charge batteries are not adjacent, at least one monomer battery is spaced therebetween, and at least two battery interval switches are also spaced therebetween. Without loss of generality, taking BA1 and BA3, which are spaced by only one battery, as an example, each of the two is surrounded by a corresponding target bus, i.e., a bypass target bus, and a bus switch, to form a loop with the corresponding spare replacement battery. The two loops formed by the two test batteries will not have a common circuit segment, so one or two battery interval switches on both sides of the two test batteries can be opened to avoid parallel loop current. As shown in Figure 7B The arrows on the left and right sides of the battery interval switch of BA3 and the hook symbol in the same row indicate that for the segment or loop surrounded by the bus switch path between BA3 and its spare replacement battery BAbmd and B1, the battery interval switch on either side or both sides can be opened to avoid parallel loop current between them. Among them, the dashed line of the segment shows that BA1 and BA3 both achieve spare battery bypass replacement jump by opening the right side JK.

[0117] As shown in Figure 7B and Figure 7A , in the two circuits, the spare batteries connected to the upper test bus B2 are used to replace the odd-numbered battery BA1 and the even-numbered battery BA2, respectively. Since the electrodes of adjacent batteries on the same side are connected to different root conductors on the test bus, in order to adapt to the polarity, as shown in Figure 7B , each pole of the spare battery is connected to any root conductor on the test bus through a bus switch.

[0118] Thus, the general rule of constructing the topology of the standby replacement of the test battery pair by the non-adjacent batteries is summarized: the optional different bus of the two batteries in the battery pair is the bypass target bus, and the standby battery on the corresponding bypass target bus is replaced, and the bus switch between the test battery and the standby battery connected to the bus is closed, to form a battery section, i.e., a sub-string, wherein each section internally includes at least one battery interval switch; at the same time, the battery interval switches inside and between each section are respectively opened and closed to form a full-capacity string without circulating current.

[0119] In the discharge test for capacity detection, as a preferred, the preset discharge current value can be taken as I 10 It can also be adjusted according to the service length of the battery, such as the battery unit within two years of service, which can be taken as k*I 10 discharge, wherein k can be taken as 1.2-1.5, and the coefficient k is gradually reduced as the service length increases.

[0120] Generally, the full discharge cutoff voltage of a 2V lead-acid single battery is 1.8V, and the full discharge cutoff voltage of a 12V battery is 10.8V. As a preferred, the discharge termination condition is set as the discharge battery voltage falling to k1 times of the full discharge cutoff voltage during discharge; as a preferred, k1 is taken as 1.035-1.12 times. Actual test experiments show that when this cutoff voltage is used, the single battery discharge time will be reduced from 0.1C or 0.1I 10 The corresponding 10-hour shortening is 2-8 hours.

[0121] For a 50% capacity shallow discharge, the discharge cutoff voltage of the single battery can be taken as 2V. As a preferred, for a more shallow discharge test, the discharge termination condition is that the discharge battery voltage falls to k2 times of the 50% capacity shallow discharge cutoff voltage; as a preferred, k2 is taken as 1.01-1.025 times. Actual test experiments show that when this cutoff voltage is used, the single battery discharge time will be further shortened to about 1-2 hours.

[0122] As a preferred, a high-power load or a DC / AC converter and a charging module converted by AC / DC are also provided in the system; the discharge battery that has not completed discharge in the discharge test of the charged battery is also discharged to the termination condition by the high-power load. And, the charged battery that receives discharge in the discharge test is also charged to the full capacity state by the charging module. Wherein, the initially empty battery can be obtained by discharging to the high-power load or DC / AC converter.

[0123] After the first time the discharge capacity of all batteries of the battery pack is detected, in the next round of discharge test, only part of the capacity lag battery can be discharged at full capacity, and other capacity exceeds the preset value of single battery can only be tested by the above shallow discharge capacity test. Since the constant current discharge is adopted, the present application can significantly shorten the core capacity test time by adopting the method of combining short-time shallow discharge and partial battery complete discharge test.

[0124] The results and intermediate data obtained by each capacity detection can be stored in the server, wherein the server can communicate with one or more systems of the present application through a cloud platform.

[0125] Embodiment 2:

[0126] Unlike the previous embodiment, in this embodiment, another double bus switch topology is provided based on the reverse side-by-side structure. In the basic reverse side-by-side structure, the same side end of the battery interval switch, such as the right end, is connected to different root conductors of any side test bus through the bus switch. In order to form a direct loop between the single battery and the test bus, as shown in Figure 8A , this embodiment also adopts a double bus switch path, that is, on the basis of the above, the other side end of the battery interval switch JK, that is, the left end, is also connected to another root conductor of the two-side test bus through a bus switch ZK; so that the two sides of each single battery are connected to the same root conductor of any test bus through the bus switch without passing through the battery interval switch. Further, as shown by the segmented dashed line in Figure 8B , based on this reverse side-by-side topology, the two sides of any single battery are connected to another same root conductor of any test bus after passing through a battery interval switch; so that when constructing the discharge loop, one end of any single battery is directly connected to two different root conductors of one test bus through the bus switch, and the other end is connected to the same test bus through the battery interval switch and then through the bus switch, and then connected to one end of the DC / DC converter through the test bus.

[0127] Referring to Figure 8BAs shown, when discharging test is performed between two adjacent batteries such as BA1 and BA2, the facing electrodes of the two adjacent batteries are directly connected to different test buses through bus switches, and the back electrodes of the two adjacent batteries are connected to another wire of the corresponding test bus through a cell interval switch and a bus switch. For two test batteries such as BA1 and BA3 which are separated by one cell, at least one of the two test batteries has its adjacent electrode directly connected to a test bus through a bus switch. For two test batteries which are separated by two or more cells, at least one of the two test batteries has its electrode on either side directly connected to a test bus through a bus switch, i.e., the two electrodes on either side of the two test batteries are respectively connected to their test target buses through bus switches with or without passing through cell interval switches. After the cells are connected to their test target buses, at least one cell interval switch which is not in the connection path is disconnected. If the DC / DC converter adopts reverse pressure output, the last connection mode can be adopted for adjacent / non-adjacent test batteries, i.e., the two electrodes on either side of the two test batteries are respectively connected to their test target buses through bus switches with or without passing through cell interval switches.

[0128] Based on the characteristics of the topology, the discharge loop construction strategy can be summarized as follows: in the other double bus switch connection path topology, a discharge loop is formed between two test batteries for discharging test; the two test batteries are respectively connected to test buses in the second connection mode and the first connection mode, i.e., the two electrodes on either side of the two test batteries are respectively connected to different wires of their test target buses; when the two test batteries are adjacent, the facing electrodes and the back electrodes of the two test batteries are respectively connected to their test target buses in the first connection mode and the second connection mode; when the two test batteries are separated by one cell, the facing electrodes of at least one of the two test batteries are connected in the first connection mode, and the other electrodes are connected in the second connection mode; when the two test batteries are separated by two or more cells, any electrode of the two test batteries is respectively connected to its test target bus in the first connection mode and the second connection mode; at the same time, the bus switches and the cell interval switches in the first connection mode and the second connection mode are closed to form a connection path, and at least one cell interval switch which is not in the connection path is disconnected.

[0129] On the other hand, bypass replacement topologies in different situations are designed. In the topology of the embodiment, when any single cell is connected to different wires of the buses on both sides, it must pass through one of the cell interval switches on both sides. Referring to Figure 8AIn the middle, respectively, with the connection to B1, B2 BAbm1, BAbm2 to replace the test battery BA1, BA2; reference to the dotted line shown in the figure, BAbm1 and the test battery BA1 replaced by both through the bus switch and B1 by bus switch connected to the loop, including BA1 and BA2 JK between the JK; and BA2 and its spare replacement battery and B1 connected to the loop does not include this JK, two loops exist only common point is BA2 left point also JK right point. At this time, by opening the two loop battery interval switch to avoid parallel circulation, and closed after the other JK to form a full capacity battery string.

[0130] In Figure 8A In the middle, if the BA2 loop as a whole left to make the loop also includes its left JK, in order to connect the two spare batteries, you must close this JK, at this time will form parallel circulation. Another structure, if the BA1 loop as a whole left to make the loop does not include its right JK, in order to connect the two spare batteries, you must close this JK, but this time can be avoided by opening the BA1 left JK parallel circulation.

[0131] For non-adjacent battery, no matter how the two test battery selection of its loop through the battery interval switch, two loops will not exist common circuit segment. Therefore, there is no need to limit the construction direction of its bypass replacement topology.

[0132] Thus, the bypass replacement topology construction strategy of adjacent test battery pair under this embodiment can be summarized as follows: the two batteries in the battery pair can optionally select different buses as bypass target buses, and replace the spare batteries on the corresponding bypass target buses. The bus switches between the test battery and the spare battery replacing it are selected and closed to form two bypass replacement segments. Each of the two segments includes a battery interval switch in the loop formed by the test battery. The two loops cannot have a common circuit segment. The battery interval switches inside and outside the two loops are opened and closed to connect the non-test batteries in the battery pack and form a full capacity string without circulating current.

[0133] In addition, the bypass replacement topology construction strategy of non-adjacent test battery pair can be summarized as follows: the two batteries in the battery pair can optionally select different buses as bypass target buses, and replace the spare batteries on the corresponding bypass target buses. The bus switches between the test battery and the spare battery replacing it are selected and closed to form two bypass replacement segments. Each of the two segments forms a loop with the test battery. The battery interval switches inside and outside the two loops are opened and closed to form a full capacity battery string.

[0134] This embodiment designs another reverse parallel topology, so that the connection loop between each single battery and the test bus includes and only includes one battery interval switch, thereby facilitating the design of the discharge test loop and the standby battery bypass replacement topology.

[0135] Embodiment 3:

[0136] Unlike the above embodiments, in this embodiment, the double bus switch topology is simplified. As shown in Figure 11A , a battery interval switch is connected in series between the two ends of the battery string formed by the battery pack and between any two adjacent single batteries inside the battery string. One side of the battery interval switch is connected to one wire of the two test buses through a bus switch to form a reverse parallel topology, and the same side of the adjacent two battery interval switches is connected to different wires of any one test bus through a bus switch. As shown in Figure 11A , the two adjacent JKs on the right side of BA1 and BA2 are connected to L1 / L3 and L2 / L4 respectively through bus switches.

[0137] As shown by the segmented dashed line above BA1, similar to the previous embodiment, in this topology, only one of the two paths of the single battery connected to the test bus passes through the battery interval switch JK. As shown by the segmented dotted line below BA2 and the segmented dashed line below BA3, adjacent batteries share a bus switch path in the loop formed by each of them and the test bus, thereby saving bus switches compared to the double bus switch structure. In another way, as shown in Figure 11B , only the bus switch connected to the two buses is arranged on the left side of the battery interval switch JK, not on the right side.

[0138] Taking the Figure 11A topology as an example, in Figure 12 , the discharge circuit of BA3 and the adjacent battery BA2 under reverse pressure output DC / DC conversion is shown. As can be seen, when BA3 with adjacent positive electrode discharges to BA2, it can work normally. However, unlike Figure 6A , under this topology structure, when BA2 with adjacent positive electrode discharges to BA3, the negative electrode of BA2 will be collinear with the positive electrode of BA3, as shown by the segmented dotted line in the figure, which will cause a short circuit between the two. Since the single battery must include a battery interval switch in the loop with the test bus, the switch must be closed to form a path, i.e. JK on the right side of BA1 must be closed, which makes it different from Figure 6A , where the short circuit can be avoided by disconnecting the switch.

[0139] From Figure 12As can be seen, the bus switch path of each single battery connected with the test bus is unique, and thus, on the one hand, based on the characteristics of the topology, the discharge loop construction strategy under the single bus switch path topology can be summarized: each test battery takes different test buses as the test target bus, and closes the bus switch and the battery interval switch between the two ends and the corresponding test target bus to construct the respective path; under the reverse pressure output DC / DC conversion, the battery with the adjacent electrode as the negative electrode discharges to the adjacent battery; between the non-adjacent test batteries, the discharge can be carried out through the DC / DC converter with reverse pressure or positive pressure output, and at this time, at least one battery interval switch in the non-constructed path between the two test batteries is opened.

[0140] On the other hand, the bypass replacement topology structure under different situations is designed. In the topology of the present embodiment, since the bus switch path passed by any single battery when connected to different wires on both sides of the bus is determined, the bypass replacement topology thereof is also only two. Figure 13A 、 Figure 13B The standby bypass replacement topologies of the test battery pairs composed of non-adjacent and adjacent batteries are respectively shown, Figure 13A In the two batteries, BA1 and BA3 are replaced by standby batteries connected to B2 and B1 respectively; Figure 13B In the two batteries, BA2 and BA3 are replaced by standby batteries connected to B1 and B2 respectively. As shown by the segmented dashed lines or dotted circles in the two figures, the bus switches between the test battery and the corresponding standby battery and the corresponding bus are closed to form battery segments, and the battery interval switches between the bus switch paths passed by the respective segments are opened to avoid parallel circulating current. Figure 13B In the two battery segments, there is a common point to achieve the natural connection of the two segments, and Figure 13A In the two battery segments, there is no common point, and the connection of the two segments with BA2 is achieved by closing JK on the right side of BA2.

[0141] Thus, the bypass replacement topology construction strategy of the test battery pair under the present embodiment can be summarized: the two batteries in the battery pair can optionally take different buses as the bypass target bus, and the standby battery on the corresponding bypass target bus is replaced, the bus switches between the test battery and the replaced standby battery and the corresponding bypass target bus are closed to form two bypass replacement segments; the battery interval switches inside and outside the loop formed by the test battery are respectively opened and closed to form a full-capacity string to the DC bus without circulating current.

[0142] The present embodiment simplifies the reverse side-by-side topology, so that each single battery has a determined connection loop with the test bus, thereby simplifying the circuit structure and saving controllable switches while quickly constructing the discharge test loop and the standby battery bypass replacement circuit.

[0143] Embodiment 4:

[0144] Different from the embodiment 1, this embodiment provides another structure of double bus switch reverse side-by-side topology. Referring to Figure 5D the figure, there is a cell interval switch JK between the two ends of the battery string formed by the battery pack and between any two adjacent single cells inside the battery pack. One end of the cell interval switch JK connected to the negative electrode is connected to one wire of the two-side test bus through a bus switch ZK and forms a reverse side-by-side topology, and the same end of the adjacent two cell interval switches JK, i.e., the end connected to the negative electrode, is connected to the same wire of the any-side test bus through the bus switch; at the same time, the other end of the cell interval switch JK is also connected to the other wire of the two-side test bus through a bus switch ZK. Figure 5D

[0145] In Figure 5D , the left end and the right end of each JK are connected to L1 and L2 of the first bus and L3 and L4 of the second bus through bus switches ZK. Through this double bus switch path, a direct connection loop between each single cell and the test bus is formed, as shown by the dashed line in the figure. Based on this reverse side-by-side topology, the two sides of any single cell can be directly connected to the two wires of the two-side test bus through bus switches, or connected to the two wires of the two-side test bus through a cell interval switch and then through a bus switch, and then connected to the common DC / DC converter port through the bus.

[0146] In comparison Figure 5C with Figure 5D the structure, the difference between the two is that in the former topology, the single cell can pass through 0 or 1 or 2 cell interval switches in the loop formed by the controllable switch and the test bus; while in the latter topology, the single cell can only pass through 0 or 2 cell interval switches in the loop formed by the controllable switch and the test bus.

[0147] Based on the reverse side-by-side topology, the construction method of the discharge loop is analyzed. As Figure 5D shown, L1 of B1 is directly connected to the positive electrode of the battery through the bus switch ZK, and L2 is directly connected to the negative electrode; in B2, L3 and L4 are directly connected to the positive electrode and the negative electrode of the battery, respectively. Since the two sides of each single cell are directly connected to the test bus through the bus switch, i.e., the discharge path between the battery and the test bus does not need to pass through JK; therefore, even the discharge between adjacent batteries can be avoided by disconnecting the cell interval switch between them.

[0148] ​Thus, the discharge loop construction strategy under the topology of the present embodiment can be summarized as follows: for a DC / DC converter with reverse or forward voltage output, a discharge loop can be formed between any two adjacent / non-adjacent test batteries in the topology of the double bus switch path topology to perform discharge test; in the discharge loop, the bus switches directly connected between each of the two test batteries and the different test buses are closed, and at least one battery interval switch between the two test batteries is opened.

[0149] On the other hand, a bypass replacement topology for the test battery is designed. In the present embodiment, two standby batteries are also used. As shown in Figure 7C , the test battery pair is composed of two adjacent batteries, such as BA1 and BA2. The two standby batteries are BAbm1 connected to the first bus B1 through a bus switch and BAbm2 connected to the second bus B2; in the figure, BAbm1 and BAbm2 are used to replace test batteries BA1 and BA2, respectively. Since BAbm1 and BAbm2 need to be connected in series with other batteries in the battery pack, such as BA3, and Bd on the left side, the battery interval switches on the left side of BA1, between BA1 and BA2, and on the right side of BA2 are all closed. As shown by the curved arrows in Figure 7C , this will cause parallel circulating current between BAbm1 and BA1 and between BAbm2 and BA2.

[0150] Therefore, by observing the topology characteristics, a feasible replacement topology is constructed in Figure 7D . On both sides of the battery interval switch on the left side of BA1, similar to the battery interval switch between the same batteries, the path between the left side of the battery interval switch and the other wire of the two test buses connected by the bus switch is completed, so that each battery interval switch is connected to any wire of any test bus through the bus switch. Accordingly, the bypass replacement topology construction strategy when the adjacent batteries form a test battery pair can be summarized as follows: each of the two test batteries is bypassed and replaced by a standby battery connected by a bus switch; one of the test batteries, such as BA1, is connected to one of the test buses, such as B1, through the bus switch after passing through the battery interval switch; the corresponding test battery, i.e., BAbmd, and the bus switch between the test battery, i.e., BA1, and the test bus are closed; the other test battery, i.e., BA2, is connected to the other test bus, i.e., B2, through the bus switch after passing through the battery interval switch; the corresponding test battery, i.e., BAbmu, and the bus switch between the other test battery, i.e., BA2, and the test bus are closed; at the same time, the battery interval switches on both sides of the two test batteries are opened and closed, respectively, to avoid circulating current and connect the two standby batteries, and to form a full-capacity battery string after connecting other batteries to supply power to the DC bus. Figure 7D Compared with Figure 7CFor each backup battery, two bus switch paths are provided, i.e. for each electrode of the backup battery, a path is provided through the bus switch to any one of the two wires of the test bus to which it is connected.

[0151] Further, the backup replacement circuit construction when the test battery pair is composed of non-adjacent batteries is analyzed. Referring to Figure 7D When the two batteries are not adjacent, at least one monobloc battery is interposed therebetween, and at least two battery interval switches are interposed, without loss of generality, taking BA1 and BA3 which are separated by only one battery as an example, each of which forms a loop with the corresponding backup replacement battery and the corresponding bypass target bus through the bus switch; the two loops formed thereby can be disconnected from one or two battery interval switches on both sides of the two test batteries to avoid parallel loop current, since there is no common point circuit section.

[0152] Thus, the general rule of backup replacement topology construction when the test battery pair is composed of non-adjacent batteries is summarized: the two batteries in the battery pair can optionally have different buses as bypass target buses, and replacement is performed through the backup battery on the corresponding bypass target bus, and the bus switch between the test battery and the backup battery connected to the bus is closed to form a battery section; at the same time, the battery interval switches inside and outside each section are respectively disconnected and closed to form a full-capacity string without loop current. Among them, at least one of the battery interval switches inside each section, i.e. on both sides of the test battery, can be disconnected.

[0153] Embodiment 5:

[0154] In view of the problem that adjacent test batteries in the last embodiment Figure 7C cannot construct a bypass replacement circuit through the direct connection of the bus switch path in the middle, this embodiment solves the problem by introducing a bypass bus BP and a bus cross-over switch BPK.

[0155] As Figure 9 shown, the bypass bus BP introduced is a single wire, which is connected to the same positive electrode or the same negative electrode of each monobloc battery through the bus switch, and is extended to both sides of the battery string in a cycle. Figure 9 In this embodiment, BP is connected to the positive electrode of each monobloc battery, and is also connected to the left side of JK1 on the left side in a cycle in a repetitive manner, and a controllable cross-over switch BPK is provided between BP and the wires of each test bus.

[0156] Referring to Figure 9The middle circle point, black point and segmented point line show that the bus switch on the left side of closed JK1 is closed to BP, and is connected to one of the wires L4 of B2 through BPK, and is connected to another wire L3 of B2 after closing the bus switch between the standby battery BAbmu and B2, and is connected to L1 through the bus switch between the wire L3 and another wire L1 on the bus B1 respectively, and is connected to another wire L2 of B1 after closing the bus switch between the standby battery BAbmd and B1, and is connected to the right end of JK on the right side of BA2 through the bus switch from L2. Among them, the parallel ring current is avoided by opening the battery interval switch on the left side of BA1 and the right side of BA2.

[0157] The key is the bypass bus, which will replace the battery to be bypassed, such as BA1, with one of the buses, such as B2, to move one battery interval switch distance laterally, i.e. to the left side of the battery interval switch JK1, so that the bypass of BA1 can be realized by opening the switch JK1. And the series connection path is connected to the starting point of the translated bus path, i.e. the wire L4 connected to the test bus at the negative electrode of BA1, through the bus cross-over switch BPK. At the same time, the wire L1 connected to another test battery BA2 at the right end electrode, i.e. the right end electrode, is different from the wire L2 connected to another test battery BA2 at the right end electrode, i.e. the right end electrode, so that the standby battery connected to B1 can replace BA2.

[0158] Thus, the following conclusions are drawn Figure 5D In the structure shown, when the adjacent batteries form a test battery pair, another topology of the standby replacement topology is constructed: a bypass bus BP is introduced in the circuit, which is connected to the same positive electrode or the same negative electrode of each single battery through a bus switch, and is extended to both sides of the battery string in cycles; the two batteries in the battery pair can optionally select different buses as bypass target buses, and replace them with standby batteries on the corresponding bypass target buses; close the bus switch between the inner side electrodes of the two batteries and the two side buses, close the bus switch between the outer side of the battery interval switch JKL connected to the outer side electrode of the battery and BP, close the cross-over switch between BP and one of the wires on the bypass target bus of the battery in the series direction, and close the bus switch between the corresponding standby battery and the bypass target bus; close the bus switch between the other standby battery and the other test bus, and close the bus switch between the other test bus and the other battery interval switch JKR connected to the outer side electrode of the battery in the series direction; at the same time, open and close the battery interval switches between and outside JKL and JKR to form a full-capacity battery string.

[0159] The bypass replacement topology of the embodiment is constructed by introducing bypass bus and bus cross-over switch, which increases the diversity and flexibility of the system test control circuit construction.

[0160] Embodiment 6:

[0161] Different from the previous embodiment, in the embodiment, the backup battery is a single backup battery. A single backup battery is used to bypass and replace the current discharge test battery pair. The discharge capacity of the backup battery is the sum of the capacities of two single batteries, and the voltage is the sum of the voltages of the two single batteries. For example, two single batteries can be connected in series.

[0162] For example, as shown in 7A, based on the bypass replacement topology circuit constructed in embodiment 1, one of the test battery pairs is replaced by a single backup battery with double capacity, and the other is bypassed. Without loss of generality, the backup battery BAbm1 on B1 is selected from the two backup batteries, that is, BAbm1 is still used to replace the test battery BA1, and for BA2, the bus shorting switch BK is used for bypassing.

[0163] As shown by the dotted lines and the circle points in the figure, the bus switches on both sides of BA2 and between B2 are closed, and by closing the shorting switch BK, a section of wire is used to replace BA2 to access to the battery string circuit. It can be understood that BA1 can also be bypassed by closing the shorting switch BK on B1, and a backup battery with double voltage and capacity is used to replace BA2.

[0164] Comparison Figure 7B , Figure 7A It can be understood that Figure 7B one of the backup batteries can also be replaced by a battery with double voltage and capacity; the other backup battery position segment is replaced by a section of wire by closing the shorting switch BK on the bus connected to it to realize the bypassing of the corresponding test battery.

[0165] Thus, the bypass replacement topology construction strategy for adjacent battery pairs in the discharge test battery pair can be summarized as follows: two batteries in a battery pair can optionally select different buses as bypass target buses, one battery is replaced by a spare battery on its corresponding bypass target bus, and the other is connected by another bus, the bus switches between the test battery and the spare battery and the corresponding bus are selected and closed, and the short circuit switch between the two wires on the other bus is closed to form two bypass replacement segments; each of the two segments is separated from at least one battery interval switch in the loop formed by the test battery; if the two loops each include two battery interval switches, the battery interval switches between the two test batteries and on both sides are closed and opened respectively; otherwise, the two loops cannot have a common circuit segment, and all battery interval switches in the two loops are opened; and after connecting other batteries to form a full-capacity battery string, the battery string supplies power to the DC bus.

[0166] The general rule for constructing a spare replacement topology for a test battery pair of non-adjacent batteries is also summarized as follows: two batteries in a battery pair can optionally select different buses as bypass target buses, one battery is replaced by a spare battery on its corresponding bypass target bus, and the other is connected by another bus, the bus switches between the test battery and the spare battery and the corresponding bus are closed, and the short circuit switch between the two wires on the other bus is closed to form two bypass replacement segments, each of which includes at least one battery interval switch inside; at the same time, the battery interval switches inside and outside each segment are opened and closed respectively to form a full-capacity battery string without circulating current.

[0167] In addition, referring to FIG. 2, Figure 8A The bypass replacement topology can also be constructed in a similar manner for the topology in Example 2. Similarly, the bypass replacement topology construction strategy for adjacent test battery pairs in the double switch topology can be summarized as follows: two batteries in a battery pair can optionally select different buses as bypass target buses, one battery is replaced by a spare battery on its corresponding bypass target bus, and the other is connected by another bus, the bus switches between the test battery and the spare battery and the corresponding bus are selected and closed, and the short circuit switch between the two wires on the other bus is closed to form two bypass replacement segments; each of the two bypass replacement segments includes one battery interval switch in the loop formed by the test battery, and the two loops formed cannot have a common circuit segment; the battery interval switches inside and outside the two loops are opened and closed respectively to connect the non-test batteries in the battery group and form a full-capacity battery string without circulating current.

[0168] And, the bypass replacement topology construction strategy of non-adjacent test battery pair: the optional different bus of two batteries in the battery pair is the bypass target bus, one battery is replaced by the spare battery on the corresponding bypass target bus, and the other is jumpered by another bus; the bus switches between the test battery and the spare battery and the corresponding bus are closed, and the short circuit switch between the two wires on the other bus is closed to form two bypass replacement segments; each of the two segments forms a loop with the test battery, and the battery interval switches inside and outside the two loops are opened and closed respectively to form a full capacity string without circulating current.

[0169] In addition, referring to Figure 14A , Figure 14B , the single bus switch topology shown in Figure 11A of embodiment 3 can also be constructed in a similar manner to form a bypass replacement topology.

[0170] Figure 14A , Figure 14B respectively show the spare bypass replacement topology of test battery pairs composed of non-adjacent and adjacent batteries, Figure 14A , BA1 and BA3 are replaced / jumpered by the spare battery connected to B2 and the B1 wire segment respectively; Figure 14B , BA2 and BA3 are replaced / jumpered by the spare battery connected to B1 and the B2 wire segment respectively. Referring to the segment dotted line or circle point shown in the two figures, the bus switches between the test battery and the corresponding spare battery and the corresponding bus are closed, or the short circuit switch BK on the other bus is closed to form the battery segment, and the battery interval switches between the paths of the respective bus switches are opened to avoid parallel circulating current. Figure 14B Two battery segments in have a common point to achieve the natural connection of the two segments, and Figure 14A has no common point, which realizes the connection of the two segments and BA2 by closing JK on the right side of BA2.

[0171] Therefore, the bypass replacement topology construction strategy of the test battery pair under this embodiment can be summarized as follows: the optional different bus of two batteries in the battery pair is the bypass target bus, one battery is replaced by the spare battery on the corresponding bypass target bus, and the other is jumpered by another bus; the bus switches between the test battery and the spare battery and the corresponding bus are closed, and the short circuit switch between the two wires on the other bus is closed to form two bypass replacement segments; the battery interval switches inside and outside the loop formed by each of the two segments and the test battery are opened and closed respectively to form a full capacity string without circulating current to supply power to the DC bus.

[0172] In addition, referring to Figure 7D , the single bus switch topology shown in Figure 5DThe double bus switch reverse side-by-side topology of the other structure shown can also be constructed in a similar way to build the single spare battery bypass replacement topology.

[0173] Similarly, the single spare battery bypass replacement topology construction strategy of the adjacent battery pair to form a discharge test battery pair can be summarized as follows: the two batteries in the battery pair can optionally select different buses as bypass target buses, one of which is replaced by the spare battery on its corresponding bypass target bus, and the other is jumpered through another bus; select and close the bus switches between the test battery and the spare battery and the corresponding bus, and close the short circuit switch between the two wires on the other bus to form two bypass replacement segments, wherein each segment includes two battery interval switches; open and close the battery interval switches adjacent to and in the middle of the two test battery whole sides, respectively, and form a full capacity battery string with no circulating current after connecting other battery segments in series.

[0174] In addition, the general rule for constructing a single spare battery replacement topology when non-adjacent batteries form a test battery pair is as follows: the two batteries in the battery pair can optionally select different buses as bypass target buses, one of which is replaced by the spare battery on its corresponding bypass target bus, and the other is jumpered through another bus; close the bus switches between the test battery and the spare battery and the corresponding bus, and close the short circuit switch between the two wires on the other bus to form two bypass replacement segments; open and close the battery interval switches inside and outside each segment, respectively, to form a full capacity string with no circulating current.

[0175] In addition, referring to Figure 9 , Figure 10A , Figure 10B The double bus switch reverse side-by-side topology of the structure shown in Example 5 Figure 5D after introducing a bypass bus can also be constructed in a similar way to build a single spare battery bypass replacement topology.

[0176] As shown in Figure 10A , take the test battery pair composed of non-adjacent BA1 and BA3 as an example. Among them, BA1 is replaced by BAbmu and BA3 is jumpered. Referring to the circle point shown, the replacement of BA1 is similar to the circuit in Figure 9 . Referring to the lower circle point and segment dashed line shown in the figure, BA3 can be jumpered by closing the bus switches between its two sides to the same wire on B1, and opening the battery interval switches between the two bus switch paths.

[0177] In another way, BA3 can also be jumpered by closing the bus switches on the outside of the BA3 two-side battery interval switches JK to B1, and opening the two-side JK, while closing the short circuit switch BK on B1.

[0178] And, referring toFigure 9 As shown in the middle, for the adjacent BA1 and BA2 to form a test battery pair, BA1 is replaced by a single spare battery on the same side bus, and the battery interval switch in the middle is opened to avoid parallel current flow. Figure 9 As shown in the middle, for the adjacent BA1 and BA2 to form a test battery pair, BA1 is replaced by a single spare battery on the same side bus, and the battery interval switch in the middle is opened to avoid parallel current flow. Figure 10A As shown in the middle, for the adjacent BA1 and BA2 to form a test battery pair, BA1 is replaced by a single spare battery on the same side bus, and the battery interval switch in the middle is opened to avoid parallel current flow.

[0179] Thus, another topology for constructing a single spare battery replacement topology when two batteries form a test battery pair in the structure shown in FIG. 8 is summarized as follows: Figure 5D As shown in the middle, for the adjacent BA1 and BA2 to form a test battery pair, BA1 is replaced by a single spare battery on the same side bus, and the battery interval switch in the middle is opened to avoid parallel current flow.

[0180] As shown in FIG. 10, for the adjacent BA1 and BA2 to form a test battery pair, the two monoblock batteries can also be regarded as a whole, and the two ends of the whole are directly connected to one side bus through bus switches, and the single spare battery connected on the bus is replaced, and parallel current flow is avoided by opening the battery interval switch in the middle of the whole, Figure 10B As shown in FIG. 10, for the adjacent BA1 and BA2 to form a test battery pair, the two monoblock batteries can also be regarded as a whole, and the two ends of the whole are directly connected to one side bus through bus switches, and the single spare battery connected on the bus is replaced, and parallel current flow is avoided by opening the battery interval switch in the middle of the whole, Figure 10B As shown in FIG. 10, for the adjacent BA1 and BA2 to form a test battery pair, the two monoblock batteries can also be regarded as a whole, and the two ends of the whole are directly connected to one side bus through bus switches, and the single spare battery connected on the bus is replaced, and parallel current flow is avoided by opening the battery interval switch in the middle of the whole,

[0181] Thus, another topology for constructing a single spare battery replacement topology when two batteries form a test battery pair in the structure shown in FIG. 8 is summarized as follows: Figure 5D As shown in the middle, for the adjacent BA1 and BA2 to form a test battery pair, BA1 is replaced by a single spare battery on the same side bus, and the battery interval switch in the middle is opened to avoid parallel current flow.

[0182] In this embodiment, for various reverse parallel topologies, the test battery is bypassed and replaced by a single backup battery, which increases the construction method of backup replacement topology and increases the diversity and flexibility of the test circuit. Among them, any test bus can be respectively connected to a single capacity, double capacity backup battery through the bus switch, so that when the backup battery line fails, other backup batteries can still be used for backup replacement, greatly improving the reliability and robustness of the system test.

[0183] Embodiment 7:

[0184] In the discharge test circuit, the boost and buck DC / DC converter needs to switch between boost and buck modes. For this purpose, the DC / DC converter can use a single mode Boost converter. Thus, the discharge battery voltage is lower than the charge battery during the entire discharge process, and there is no need to switch the voltage mode. At this time, the test battery is composed of N single batteries greater than 2.

[0185] For a battery pair composed of N single batteries, the backup battery can be combined in various ways: for example, a single backup battery with N times voltage and capacity; or a backup battery with N-1 times voltage and capacity, a backup battery with 1 times voltage and capacity; or N backup batteries with 1 times voltage and capacity, and other series combinations equivalent to N single batteries.

[0186] In the Boost boost mode, to form a charge battery, as shown in Figure 9 This embodiment introduces a series bus similar to a bypass bus. Without loss of generality, take N=3 as an example. Two empty single batteries in the battery group are connected to two wires of one of the test buses through the series bus.

[0187] Correspondingly, a bypass replacement topology of a test battery pair composed of 3 single batteries needs to be constructed. Figure 15A 、 Figure 15B and Figure 15C respectively show the bypass replacement topology design of the test battery pair composed of three adjacent and non-adjacent batteries under the single bus switch structure shown in Figure 11A

[0188] Figure 15A ​In this case, three adjacent single cells form a cell pair, and an attempt is made to replace BA1 with BAbm2 connected to B2, and BAbm11, BAbm12 connected to B1 to replace BA2, BA3 respectively. Here, BA2, BA3 are regarded as a whole, and their two ends are directly connected to the wire L on B1 through the bus switch. Then, BAbm11, BAbm12 are connected in series through the same wire L2 on B1, and their two ends are connected to the replaced cell whole at the junction of the whole and L1. However, analysis shows that this will cause a short circuit of the spare battery series whole. In order to

[0189] Here, the topology is modified with the help of the series bus BP. As shown by the lower segmented dotted line and the circle point in the figure, the spare battery BAbm11 adopts double capacity, and its right side is connected to BP through the closed jumper switch BPK between L2 and BP, and is connected to other cells through the bus switch between BP and the negative electrode of BA4; at the same time, by opening the cell interval switch between BA1 and BA4 shown by the arrow in the figure, parallel circulation is avoided. That is, Figure 15A In this case, one single spare battery and one double capacity spare battery are used to test the bypass replacement of the battery, and due to parity, the capacities of the two spare batteries in the figure can be interchanged. In order to simplify the figure, only the part of the bus switch connected to BP is shown in the figure.

[0190] More generally, Figure 15B In this case, after the introduction of the Nth, i.e. the third test bus, each bus replaces the test battery with one spare battery connected to it. Among them, the spare batteries BAbm2, BAbm1, BAbm3 connected to B2, B1, B3 replace BA1, BA2, BA4 respectively. Three test batteries each take a different bus as the bypass target bus, and the bus switch between the two ends of each spare battery and the corresponding bypass target bus is closed to form a spare replacement circuit segment, and the cell interval switch inside and outside each segment is opened and closed to form a full capacity cell string.

[0191] Figure 15C Then a single spare battery replacement topology is shown, in which a single spare battery BAbmu of 3 times capacity replaces BA1, and adjacent BA3 and BA4 are short-circuited by the same wire on B1 and disconnected JK34 to realize the jump. It can be understood that, referring to Figure 9 、 Figure 15A As shown, similar to the discharge circuit construction, for two non-adjacent single cells, they can be connected in series or bypassed through a test bus and a series or bypass bus respectively.

[0192] The construction rule of the bypass replacement topology under the Boost conversion can be summarized as follows: when two adjacent cells in the middle of the battery are regarded as a whole; a single cell and a 2x capacity backup cell are used to test the bypass replacement of the cell; the bus switch between one side of the whole and one wire on the bus is closed, the bus switches between the corresponding backup cell and the bus on both sides in the series connection direction are closed, and the bus switches between the series bus and the other wire on the bus and the cell connected to the other side of the whole are closed; the bus switches between the other cell and the corresponding backup cell and the other test bus are connected, the cell interval switches between the whole and the other cell are disconnected, and the other cell interval switches are closed to form a full capacity cell string; or, a 3x capacity single backup cell and the corresponding test cell are connected to two wires on one test bus, and the cell interval switches between the test cell bus switch paths are disconnected; the bus switches between the whole and the other test bus are closed, and the cell interval switches in the whole are disconnected to form a full capacity cell string.

[0193] Alternatively, three single capacity cells are respectively used as bypass target buses with different test buses, the bus switches between each backup cell and the corresponding test cell and the corresponding bypass target bus are closed to form a cell segment, and the cell interval switches inside and outside each cell segment are respectively disconnected and closed to form a full capacity cell string.

[0194] Alternatively, a 3x capacity single backup cell and the corresponding test cell are connected to two wires on one test bus, and the cell interval switches between the test cell bus switch paths are disconnected; the bus switches between the other cell and the other test bus are closed, the short circuit switch between the two wires on the other test bus is closed, and the cell interval switches between the other test cell bus switch paths are disconnected; the bus switches between the third cell and the single wire on the series bus are closed, and the cell interval switches between the third cell bus switch paths are disconnected; after the other cell interval switches are closed, a full capacity cell string is formed.

[0195] This embodiment introduces a series bus for Boost conversion circuit to series connect single cells to form a multiple voltage charging cell whole. The series bus is also used as a bypass bus to bypass and replace the test cell with the test bus.

[0196] Embodiment 8:

[0197] Different from the above embodiments, this embodiment simplifies the double bus switch topology and reduces the cell interval switches. As shown in FIG. 8, the bus switches between the two ends of the test cell and the two wires on the test bus are connected, and the cell interval switches between the test cell bus switch paths are disconnected. Figure 16As shown, the embodiment simplifies the structure and forms the following reverse parallel topology: the same pole of each single battery is connected to any one wire of the two test buses through the bus switch, and the battery string formed by the battery pack is arranged with the battery interval switch every 1 single battery inside and at both ends. In the figure, the bus is directly connected to the negative pole of the battery, which can also be replaced by being directly connected to the positive pole.

[0198] The reverse parallel topology formed by the double bus switch saves one battery interval switch in each group of two batteries. For the reverse pressure output DC / DC converter, the discharge test can be performed between adjacent batteries. Based on the reverse pressure output converter, the battery with the adjacent electrode as the negative pole in the battery pack is used as the discharge battery to discharge the other adjacent battery; for example, BA3 can discharge BA2, BA4 can discharge BA3, and so on.

[0199] As a preferred, multiple DC / DC converters including reverse pressure output and positive pressure output can be arranged in the system, and one of them can be used to build the discharge circuit by switching through the bus switch as needed.

[0200] For non-adjacent batteries, if neither of the bus switch paths connected to the test bus on both sides of the battery contains a battery interval switch, the converter with positive pressure or reverse pressure output can be used to avoid short circuit by disconnecting at least one battery interval switch between them. For example, BA3 can discharge BA1 by disconnecting JK on the right side of BA2. It is this feature that makes it only need one battery interval switch between non-adjacent batteries, i.e., at least 1 or more batteries apart.

[0201] Correspondingly, the backup battery is used in multiple combinations, and 1 times and 2 times capacity backup batteries are respectively connected to the two test buses. For example, Figure 16 As shown by the middle segmented dashed line, when the battery pack is put into use during the discharge of BA2 to BA1, the current capacity detection test is stopped, and the 2 times capacity single backup battery connected to B1 is used to bypass and replace the two test batteries, and the loop current can be avoided by disconnecting JK23 to form a full capacity battery string.

[0202] When BA3 discharges BA2 to form a test battery pair, the bypass replacement circuit can be built according to the upper segmented dotted line. In this case, the 2 times capacity single backup battery connected to B2 is used to bypass and replace the two test batteries, and the loop current can also be avoided by disconnecting JK23 to form a full capacity battery string. It can be understood that the method of retaining only one battery interval switch in each group of two batteries in the embodiment is also applicable to the other topologies mentioned above.

[0203] The double bus switch topology is simplified in the embodiment, the number of battery interval switches is saved, the diversity of the test circuit topology is increased, and the flexibility of circuit building is improved.

[0204] Embodiment 9:

[0205] This embodiment simplifies the basic anti-parallel topology by reducing bus switches. Specifically, take every N cells as a group, and connect each cell in the group to one side bus through a bus switch as a whole; take another N cells as a group, and connect the group to the other side bus through a bus switch; repeat the arrangement in a cycle of a group of 2N cells.

[0206] As shown in Figure 17A , without loss of generality, take N=2 as an example to show the circuit structure. Among them, BA1 and BA2 form a group and are connected to the lower bus B1; BA3 and BA4 form a group and are connected to the upper bus B2; the group where BA5 is located is connected to the lower bus B1. In the figure, the reduced bus switches are shown in dashed ovals.

[0207] Analysis of this simplified topology shows that N cells form a group, and the outermost cells in the group are connected to the two side buses through bus switches as a whole, and the other N-1 intermediate cells are only connected to the upper / lower bus. Without considering the boundary effect, in a cycle consisting of a group, compared with the original two groups of 2N*2=4N bus switches, 2*(N-1) bus switches at the non-group edge position can be reduced. Taking N=2 as an example, 2 / 8=25% of the bus switches can be reduced. When N=3, the reduction is 2*2 / 12=1 / 3.

[0208] Under this simplified topology, since the cells in the same group are connected to the same side test bus, when discharging test is performed, the discharging cells must be selected in different groups. For example, when discharging test is performed between BA3 and BA1 in two groups, JK between BA2 and BA3 can be disconnected to avoid short circuit.

[0209] Correspondingly, in order to make the same cell serve as a discharging cell or a charging cell in different test stages, a bidirectional DC / DC converter is needed to cooperate; or, two ports of the DC / DC converter are connected to two test buses through bus switches.

[0210] Further, when the capacity difference of the cells in a group is within a preset range, 2 to N cells in a group can be selected to form a discharging cell and a charging cell as a whole, and discharging test can be performed between the two wholes. For example, BA3 and BA4 can form a first virtual cell whole, BA1 and BA2 can form a second virtual cell whole, and the capacity of the first virtual cell whole can be tested by discharging from the second virtual cell whole to the first virtual cell whole.

[0211] Further, as shown inFigure 17B As shown, the simplified topology is also modified by adding inter-battery isolation switches and staggering the bus switch paths on both sides. In 17B, the bus switch path connected to the upper test bus is shifted to the right, and inter-battery isolation switches are added between the start points of the disengaged bus switch paths, as shown by the dashed line rectangle JK232, etc.

[0212] In combination with the description in Embodiment 1, it can be understood that, as shown by the dashed line in FIG. 1A, because inter-battery isolation switches are added between the bus switch paths of the two groups of bus switch paths connected to different test buses, a DC / DC converter with reverse output or forward output can be used between the two adjacent groups of single batteries or virtual batteries, and the discharge direction can be arbitrarily selected. Figure 17B

[0213] In this embodiment, the bus switch is simplified, further increasing the diversity of the test circuit topology.

[0214] Embodiment 10:

[0215] In another embodiment of the present application, a battery pack online capacity detection method based on the reverse side-by-side topology is also provided, characterized in that it comprises the following steps:

[0216] S0, initialization, building a system pre-connection circuit, forming a discharge circuit between the single batteries through a controllable switch array and a common bus and a DC / DC converter;

[0217] S1, synchronously starting a high-priority first sub-process S12-S15 and a second sub-process S22-S28;

[0218] S12, detecting a demand event of the battery pack to supply power to the DC bus, if not, assigning a discharge test permission flag as 1 and turning to S12, otherwise turning to S13;

[0219] S13, assigning the discharge test permission flag as 0, stopping the capacity test and turning to S14;

[0220] S14, controlling the controllable switch to replace the test battery string with a standby battery whose capacity is equivalent to the total capacity of the current test battery in the battery pack through the common bus to supply power to the DC bus;

[0221] S15, waiting until the battery pack power supply demand is removed, charging each single battery to a full state, and turning to S12;

[0222] S22, judging whether there is a capacity detection instruction, if yes and the discharge test permission flag is 1, turning to S23, otherwise turning to

[0223] S22; ​

[0224] S23, select one of the to-be-tested full batteries as a discharging battery to form a charging battery with the available battery and to form a test battery pair;

[0225] S24, control the controllable switch to connect the discharging battery and the charging battery to the two ends of the DC / DC converter through the common test bus to form a discharging loop;

[0226] S25, detect the voltage ratio at the two ends of the converter and the discharging current to switch the controllable switch and to discharge the discharging loop at a preset current through negative feedback control, and collect and record the discharging parameters;

[0227] S26, judge whether the discharging termination condition is reached, if yes, calculate the discharging capacity of the current discharging battery and turn to S27, otherwise, turn to S25;

[0228] S27, judge whether all the batteries have completed the capacity detection, if yes, turn to S28, otherwise, take the just-discharged battery as a new available battery and turn to S23;

[0229] S28, output the discharging capacity value of each single battery in the battery pack, end the current capacity test and turn to S22.

[0230] Since the priority of the first sub-process is higher than that of the second sub-process, once the discharging test permission flag is assigned as 0 during the running of the first sub-process, the running of the second sub-process is stopped.

[0231] The embodiment realizes the on-line capacity detection of the battery pack through the multi-thread method. The two threads communicate through the flag bit as a semaphore, so that the on-line capacity detection is realized through two relatively independent sub-threads, and the reliability of the on-demand power supply is ensured while the on-line detection is performed.

[0232] It can be understood that the controllable switch connected with the DC bus in the switch array can be a programmable switching switch realized through an intermediate relay and a high-power contactor. The switching control of the circuit in the above various scenarios can form a table of the action state of the switch, and the on-line application is quickly responded and executed by looking up the table.

[0233] The above describes several embodiments of the application, but these embodiments are prompted as examples and do not limit the scope of the application.

Claims

1. An online capacity testing system for battery packs based on a reverse side-by-side topology, comprising: DC / DC converters are used for voltage adaptation and current control in discharge circuits. A spare battery is used to replace the test battery and power the entire series of batteries. The common bus serves as a shared channel for connecting individual batteries, backup batteries, and converters. The switch array, composed of integrated controllable switches, is used for switching between batteries and pathways when a discharge circuit or battery string is constructed. The bus switches and battery spacer switches, located at both ends of the battery string and between any two adjacent individual cells, form a reverse-parallel topology. This allows the same side of adjacent battery spacer switches to be connected via the bus switches to different wires on either of the two test buses in the common bus. The controller, used to acquire electrical parameters, commands, and control the controllable switches in the switch array, is configured as follows: On one hand, in response to the capacity detection command, a fully charged discharge battery and a rechargeable battery to be tested are selected to form a discharge test battery pair; a controllable switch is controlled so that the two batteries in the battery pair are connected to the discharge terminal and the charging terminal of the DC / DC converter respectively through two test buses to form a discharge circuit; feedback control is performed based on the electrical parameters in the discharge circuit to make the discharge battery discharge to the cutoff condition according to the preset current, and the discharge capacity is calculated cumulatively; the newly discharged battery is used as the new rechargeable battery, and a new fully charged battery is selected as the discharge battery, and new battery pairs are iteratively formed and discharged tests are performed until the capacity detection of each individual cell in the battery pack is completed. Simultaneously, the power supply demand of the battery pack is monitored. When there is a demand, the controllable switch is controlled to disconnect the current discharge circuit. The battery segments other than the current discharge test battery pair in the battery pack are connected in series to form a battery sub-string. The spare battery replaces each battery in the current test battery pair through the common bus and is then connected to the battery sub-string to form a complete battery string, which then supplies power to the DC bus.

2. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 1, characterized in that, The controller is also configured to, when forming a discharge circuit: each of the two test batteries uses a different test bus as the test target bus, closes the bus switch and battery spacer switch between its two ends and the corresponding test target bus to construct its own path; under reverse voltage output DC / DC conversion, a battery with an adjacent electrode as the negative electrode can discharge to an adjacent battery; between non-adjacent test batteries, discharge can be carried out through a DC / DC converter with reverse voltage or positive voltage output, at which time, at least one battery spacer switch between the two test batteries that is not in the constructed path is disconnected.

3. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 1, characterized in that, The controller is also configured to, when replacing the current test battery pair with a backup battery: use two backup batteries with the same voltage and capacity, in which the two batteries in the battery pair can be selected to use different buses as bypass target buses, and replace them through the backup battery on their corresponding bypass target bus, close the bus switch between the test battery and the backup battery that replaces it and their respective bypass target buses to form two bypass replacement segments. The battery spacer switches inside and outside the loop formed by the two segments and the test battery are respectively disconnected and closed to form a full-capacity string without circulating current supplying power to the DC bus.

4. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 1, characterized in that, The reverse side-by-side topology is simplified by taking N individual cells as a group, and each group as a whole, the individual cells are connected to one side of the bus through a bus switch. The adjacent N individual cells are also grouped together. The adjacent groups are directly connected to the other side via a bus switch, i.e., a different bus. The connection is repeated in a large group consisting of 2N individual cells as a cycle.

5. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 1, characterized in that, In the resulting reverse side-by-side topology, the other side of the battery spacer switch is also connected to the same wire of the test bus on both sides through a bus switch; so that the wires of each individual battery that are directly connected to the test bus through the bus switch, i.e., without passing through any test bus connected by the battery spacer switch, are of different roots.

6. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 5, characterized in that, The controller is also configured to, when forming a discharge circuit: any two adjacent / non-adjacent test batteries can form a discharge circuit for discharge testing; wherein, in the discharge circuit, the bus switch that directly connects each of the two test batteries to the different test buses, i.e., without passing through the battery spacer switch, is closed, and at least one battery spacer switch between the two test batteries is opened.

7. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 5, characterized in that, The controller is also configured to, when replacing the current test battery pair with a backup battery, use two backup batteries with the same voltage and capacity. If two adjacent batteries form a battery pair, the two batteries can choose different buses as bypass target buses and replace them with spare batteries on their corresponding bypass target buses. Select and close the bus switches between the test battery and the spare battery connected to its corresponding bypass target bus and the bus to form two bypass replacement segments, i.e., serialization. Each of the two bypass replacement sections and the test battery forms a loop that includes at least one battery spacer switch. If each of the two loops includes two battery spacer switches, then the battery spacer switches between the two test batteries and on both sides are closed and opened respectively. Otherwise, the two loops cannot have a common circuit segment, and all battery spacer switches within the two loops are opened. After connecting other batteries in series to form a full-capacity battery string, power is supplied to the DC bus. That is, after closing other battery spacer switches, non-test batteries in the battery pack are connected. If the test battery pair is not composed of adjacent batteries, the two batteries can be selected from different buses as bypass target buses. The battery is replaced by a spare battery on its corresponding bypass target bus. The bus switches between the test battery and the spare battery connected to its corresponding bypass target bus are closed to form battery segments, i.e., strings. Each segment includes at least one battery interval switch. At the same time, the battery interval switches within and between each segment are opened and closed to form a full-capacity string without circulating current.

8. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 1, characterized in that, In the resulting reverse side-by-side topology, the other end of the battery spacer switch is also connected to another wire of the test bus on both sides through a bus switch; so that the wires of each individual battery directly connected to any test bus through the bus switch are the same. The controller is also configured to, when forming a discharge circuit, connect to the test bus via the second and first connection modes respectively, with the electrodes passing through the battery spacer switch and then through the bus switch, and without passing through the battery spacer switch but directly through the bus switch; the two test batteries each use a different test bus as the test target bus, and their two poles are each connected to different wires of their test target bus. When two test batteries are adjacent, their opposing electrodes and back electrodes are connected to their target test bus in the first and second connection modes, respectively. When there is one battery between the two test batteries, the opposing electrodes of at least one battery are connected in the first connection mode, and the other electrodes are connected in the second connection mode. When there are two or more batteries between the two test batteries, each of their electrodes is connected to their target test bus in the first and second connection modes, respectively. At the same time, the bus switch and battery spacing switch in the first and second connection modes are closed to form a connection path, and at least one battery spacing switch between the two test batteries that is not in the connection path is disconnected.

9. The online capacity testing system for battery packs based on reverse side-by-side topology according to claim 1, characterized in that, In the resulting reverse side-by-side topology, one side of the battery spacer switch is connected to another wire of the test bus on both sides via a bus switch to form a fully symmetrical periodic topology; within the battery pack, one battery spacer switch is provided for every single cell.

10. A method for online capacity detection of battery packs based on reverse side-by-side topology, comprising the following steps: S1. Initialization: A controllable pre-connection topology between the battery and the bus is built by a switch array composed of various controllable switches. A battery spacer switch is connected in series between the two ends of the battery string formed by the battery pack and between any two adjacent individual cells inside it. One side of each battery spacer switch is connected to one of the wires of the test bus on both sides through a bus switch to form a reverse side-by-side topology. The same side of two adjacent battery spacers is connected to different wires of the test bus on either side through a bus switch. S2. Detect the event that the battery pack needs to supply power to the DC bus. If the event does not occur, go to S6; otherwise, go to S3. S3. Stop capacity test and disconnect the current discharge test circuit; S4. Control the controllable switch and, through the common bus, replace the test battery with a spare battery whose capacity is equivalent to the current test battery to the total full capacity of the battery pack, and put the formed battery string into the DC bus to supply power to the DC bus. S5. Wait until the power demand of the battery pack is released, then charge each individual battery to full charge, and then proceed to S2. S6. Determine if a battery capacity test is currently in progress. If yes, proceed to S12; otherwise, proceed to S7. S7. Determine if a capacity detection command has arrived. If so, proceed to S8; otherwise, proceed to S2. S8. Select a fully charged battery to be tested as the discharge battery, and form a rechargeable battery with the acceptable battery and combine the two into a test battery pair; S9. Control the controllable switch to connect the discharge battery and the rechargeable battery to the two ends of the DC / DC converter via a common two-test bus to form a discharge circuit; S10. Detect the voltage ratio and discharge current across the converter to switch the controllable switch, and use negative feedback control to make the discharge circuit discharge at a preset current. S11. Collect and record discharge parameters, then proceed to S2; S12. Determine whether the discharge termination condition has been met. If so, calculate the current discharge capacity of the battery based on the recorded discharge parameters and proceed to S13. Otherwise, proceed to S10. S13. Determine whether all batteries have completed capacity detection. If yes, proceed to S14; otherwise, use the discharged battery that has just finished discharging as the new rechargeable battery and proceed to S9. S14: Output the discharge capacity value of each individual cell in the battery pack, end the capacity test and proceed to S2.

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