Battery balancing circuit capable of directional energy transfer

Abstract

A battery balancing circuit capable of directional energy transfer includes batteries BA1, BA2...BAN, control units IC1, IC2..., ICN, and also includes a first switch S1 and a second switch K1, a first switch S2 and a second switch K2, a first switch S3 and a second switch K3...a first switch SN, a second switch KN, wherein the first switches S1, S2...SN are sequentially connected in series and connected to the positive end B+ and the negative end B- of the entire string of batteries, the second switch K1 is connected in series with the battery BA1 and then in parallel to both ends of the first switch S1, the second switch K2 is connected in series with the battery BA2 and then in parallel to both ends of the first switch S2, the second switch K3 is connected in series with the battery BA3 and then in parallel to both ends of the first switch S3..., the second switch KN is connected in series with the battery BAN and then in parallel to both ends of the first switch SN. After a battery is fully charged, it can be disconnected from charging, thereby ensuring that the battery is not overcharged; the energy transfer efficiency is greatly improved, and the transfer balance to non-adjacent units is achieved; the capacity of each unit is consistent, thereby improving the discharge capacity and achieving rapid balance.

Description

Technical Field

[0001] The invention relates to a high-speed charge-discharge equalization circuit capable of directionally transferring energy. Background Art

[0002] At present, the battery balancing circuit generally transmits the energy of a unit to the whole string or a small series module through transformer isolation. However, both string forms have the problem of too much efficiency loss. The key is that when one of the cells is full, it must be transmitted as soon as possible to achieve voltage balancing. However, during charging, the actual charging current is much greater than the balancing current, especially during fast charging. It is difficult for a cell that is full first to transmit the excess energy. It is even more difficult to transmit the excess energy when using resistor discharge, which will eventually cause the cell to be overcharged, shorten the life of the cell, or even damage it. The biggest problem with balancing management is that it is impossible to achieve the dynamic separation of redundant design of batteries with degraded performance. That is, if the internal resistance of a cell increases abnormally or even breaks, the whole string cannot be charged and discharged normally. If the capacity of a cell is low, the conventional small current balancing discharge of the cell will not be able to ensure that it is not overcharged. The cell with the lowest capacity will eventually be damaged first or even catch fire due to the degradation of battery charging overvoltage performance. The same is true when the internal resistance of a few cells becomes seriously large during discharge, which directly affects the large current discharge of the whole string. Therefore, it is a blank in current redundant management to automatically separate the problem battery from the system without affecting other batteries. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a battery equalization circuit capable of transmitting energy in a directionally manner.

[0004] The technical solution of the present invention is:

[0005] A battery balancing circuit capable of directional energy transfer includes a whole string of multiple batteries BA1, BA2, BA3...BAN, control units IC1, IC2, IC3..., ICN, and the special feature is that it also includes a first switch S1 and a second switch K1, a first switch S2 and a second switch K2, a first switch S3 and a second switch K3...a first switch SN, a second switch KN, the control unit IC1 is used to control the switch state of the first switch S1 and the second switch K1, the control unit IC2 is used to control the switch state of the first switch S2 and the second switch K2, and the control unit IC3 is used to control the switch state of the first switch S1 and the second switch K1. 3 and the switching state of the second switch K3…The control unit ICN is used to control the switching state of the first switch SN and the second switch KN. The first switches S1, S2, S3…SN are connected in series in sequence and connected to the positive terminal B+ and the negative terminal B- of the whole string of batteries. The second switch K1 is connected in series with the battery BA1 and then connected in parallel at both ends of the first switch S1. The second switch K2 is connected in series with the battery BA2 and then connected in parallel at both ends of the first switch S2. The second switch K3 is connected in series with the battery BA3 and then connected in parallel at both ends of the first switch S3…The second switch KN is connected in series with the battery BAN and then connected in parallel at both ends of the first switch SN.

[0006] Furthermore, Farad capacitors C1, C2, C3, ... CN are connected in series between the positive terminal B+ and the negative terminal B- of the entire battery string.

[0007] Furthermore, the control units IC1, IC2, IC3…, ICN simultaneously have positive and negative power supply terminals 1 and 10, a balanced transmission positive terminal +E and a balanced transmission negative terminal -E. The positive and negative power supply terminals 1 and 10 of the control units IC1, IC2, IC3…, ICN are simultaneously voltage signal detection terminals of the batteries BA1, BA2, BA3…BaN and are connected to the corresponding positive and negative poles of the batteries. The balanced transmission positive terminal +E in the same control unit is connected to the positive terminal of the next battery, and the balanced transmission negative terminal -E is connected to the negative terminal of the previous battery. The balanced transmission negative terminal -E of the first battery BANN and the balanced transmission positive terminal +E of the last battery are idle terminals.

[0008] Further, the control units IC1, IC2, IC3 . . . , ICN respectively include a controller uP, a BOOST boost circuit, a communication interface COMM, an inductor or wire I1 and an inductor or wire I2, and switch tubes Z1 and Z2. The communication terminal 9 of the controller uP is connected to the communication interface COMM, one end of the inductor or wire I1 is connected to the corresponding positive electrode of the battery, and the other end is connected to the source of the switch tube Z1. The positive boost feedback control terminal 12 of the BOOST boost circuit is connected to the node of the inductor I1 and the switch tube Z1, one end of the inductor or wire I2 is connected to the corresponding negative electrode of the battery, and the other end is connected to the drain of the switch tube Z2. The negative boost feedback control terminal 13 of the BOOST boost circuit is connected to the node of the inductor or wire I2 and the switch tube Z2. The positive boost detection control terminal 2 of the controller uP is connected to the positive boost control output terminal 11 of the BOOST boost circuit and then connected to the gate of the switch tube Z1. The negative boost detection control terminal 8 of the controller uP is connected to the BOOST The negative boost control output terminal 14 of the boost circuit is connected to the gate of the switch tube Z2, and the enable terminal 15 of the BOOST boost circuit is controlled by the enable output terminal 5 of the controller uP. The switch control terminal 13 of the controller uP is connected to the control terminal of the first switch, and the switch control terminal 27 of the controller uP is connected to the control terminal of the second switch.

[0009] Furthermore, the first switch and the second switch are respectively MOS tubes.

[0010] Furthermore, the first switch and the second switch respectively use a single MOS tube or a dual MOS tube; when a dual MOS tube is used, the corresponding controller uP has two switch control terminals and controls one of the MOS tubes respectively.

[0011] Furthermore, the controller adopts a single chip microcomputer, DSP or PLC.

[0012] Furthermore, the first switches S1, S2...SN and the second switches K1, K2...KN respectively adopt contacts of relays, thyristors or IGBTs controlled by the control unit.

[0013] Furthermore, the positive boost switch tube and the negative boost switch tube of the BOOST boost circuit are MOS tubes M1 and M2 respectively.

[0014] Furthermore, the switch tube Z1 and the switch tube Z2 are synchronous rectification MOS tubes.

[0015] The beneficial effects of the present invention are:

[0016] 1. After a battery is fully charged, it can be disconnected from the charger to ensure that the battery is not overcharged;

[0017] 2. The capacity of the batteries after use is different. The first fully charged battery will be disconnected and the front and rear sections of this battery will be connected, which will not affect the charging and discharging. It can be relayed one level at a time through the directional transmission method, or it can be transmitted in a leapfrog manner through the directional transmission method to make the capacity of each battery equal, so that more energy of the battery group can be released, greatly improving the energy transmission efficiency.

[0018] 3. Each unit independently performs switching control according to battery profit and loss, and fully charges to adjacent or leapfrog units for balance. In addition, ICx can be cascaded for communication, so that feedback will be given to the overall control arbitration to achieve balance transfer to non-adjacent units.

[0019] 4. In any charging and discharging state, one or several cells with insufficient capacity can be transferred through one or several other cells with sufficient capacity, so as to achieve consistency in the capacity of each unit, thereby improving the discharge capacity.

[0020] 5. When charging and discharging online, a unit with poor profit or loss status can be disconnected without affecting the function of the entire string. Disconnecting a unit will only make the total voltage of the entire string slightly lower. This solves the problem of sudden increase or even damage of the internal group due to low capacity of one or several units, and a relatively good charging and discharging environment can be provided.

[0021] 6. Because the synchronous rectification MOS in ICx is in the on state and the attached inductor is a large current path and the internal resistance can be made very small, it can transmit several amperes or even tens of amperes of current for rapid balancing.

[0022] 7. The synchronous rectification MOS tube Zx and the attached inductor Ix in ICx can not only work in the open state during transfer balancing, but also work in the switching state of pulse width current limiting and positive and negative boost with the participation of inductance. Pulse width current limiting is used for crossing transfer balancing, and positive and negative boost is used for adjacent transfer balancing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the circuit principle diagram of the present invention (battery BA3 transfers energy to BA1 across BA2);

[0024] Figure 2 It is a schematic diagram of the circuit structure of the control unit of the present invention;

[0025] Figure 3 It is a schematic diagram of the connection of the positive boost output switch and the negative boost output switch MOS of the BOOST boost circuit of the present invention;

[0026] Figure 4 It is a schematic diagram of battery BA1 transferring energy to BA3 across BA2;

[0027] Figure 5 is a circuit schematic diagram of the second switch of the present invention using dual MOS tubes;

[0028] Figure 6 It is a single unit control schematic diagram of the switch using relay contacts;

[0029] Figure 7 It is a single unit control schematic diagram of a switch using a thyristor;

[0030] Figure 8 This is a single unit control schematic diagram using MOS tubes for switches

[0031] Fig. 9 It is a circuit principle diagram of the present invention using a farad capacitor. DETAILED DESCRIPTION

[0032] Example 1

[0033] like Figure 1 As shown, a battery balancing circuit capable of directional energy transfer includes batteries BA1, BA2, BA3...BaN, first switches S1, S2, S3,...SN, second switches K1, K2, K3...KN, and a control unit IC1 for controlling the first switch S1 and the second switch K1, a control unit IC2 for controlling the first switch S2 and the second switch K2, a control unit IC3 for controlling the first switch S3 and the second switch K3...and a control unit ICN for controlling the first switch SN and the second switch KN, wherein the first switches S1, S2, S3...SN are connected in series in sequence, the second switch K1 is connected in series with the battery BA1 and then in parallel with both ends of the first switch S1, the second switch K2 is connected in series with the battery BA2 and then in parallel with both ends of the first switch S2, the second switch K3 is connected in series with the battery BA3 and then in parallel with both ends of the first switch S3..., the second switch KN is connected in series with the battery BAN and then in parallel with both ends of the first switch SN.

[0034] like Figure 2As shown, the first switch and the second switch simultaneously use dual MOS tubes and are respectively the first switches S-1 and S-2 and the second switches K-1 and K-2, the control units IC1, IC2, IC3 ..., ICN have the same structure, the control unit IC1 has positive and negative power supply terminals 1 and 10, a balanced transmission positive terminal +E and a balanced transmission negative terminal -E, the power supply terminal of the control unit IC1 is also a battery voltage signal detection terminal and is connected to the corresponding positive and negative electrodes of the battery, the control unit IC1 includes a controller uP, a BOOST boost circuit, a communication interface COMM, inductors I1 and I2, and switch tubes Z1 and Z2, the communication terminal 9 of the controller uP is connected to the communication interface COMM, one end of the inductor I1 is connected to the corresponding positive electrode of the battery, and the other end is connected to the source of the switch tube Z1, the BOOST The positive boost feedback control terminal 12 of the boost circuit is connected to the node of the inductor I1 and the switch tube Z1, one end of the inductor I2 is connected to the corresponding negative electrode of the battery, and the other end is connected to the drain of the switch tube Z2, the negative boost feedback control terminal 13 of the BOOST boost circuit is connected to the node of the inductor I2 and the switch tube Z2, the positive boost detection control terminal 2 of the controller uP is connected to the positive boost control output terminal 11 of the BOOST boost circuit and then connected to the gate of the switch tube Z1, the negative boost detection control terminal 8 of the controller uP is connected to the negative boost control output terminal 14 of the BOOST boost circuit and then connected to the gate of the switch tube Z2, the enable terminal 15 of the BOOST boost circuit is controlled by the enable output terminal 5 of the controller uP, the balanced transmission positive terminal +E is connected to the positive terminal of the previous battery, the balanced transmission negative terminal -E is connected to the negative terminal of the next battery, the switch control terminal 13 and the switch control terminal 34 of the controller uP are respectively connected to the control terminals of the first switch S-1 and S-2, The switch control terminal 2 7 and the switch control terminal 4 6 of the controller uP are connected to the control terminals of the second switches K-1 and K-2 respectively.

[0035] like Figure 3 As shown, the positive boost switch tube M1 and the negative boost switch tube M2 of the BOOST boost circuit are MOS tubes respectively, and the switch tubes Z1 and Z2 are synchronous rectifier tubes corresponding to each other.

[0036] When the battery BA3 transfers power to the battery BA1 across the battery BA2, the second switches K1, K2, K3 and the first switch S1 are disconnected, and the first switches S2 and S3 are turned on. At the same time, the BOOST boost circuits of the control units IC2 and IC3 are switched from the boost state to the corresponding switch tube Z2 being always turned on. The switch tubes Z1, Z2 and Z3 of the control units IC1, IC2 and IC3 and all the boost switch tubes M1 and M2 are turned off. The inductor is regarded as a path in the DC state, such as Figure 1 As shown by the thick line, the battery BA3 is connected in parallel with the battery BA1 to achieve energy transfer.

[0037] like Figure 4 As shown, when the battery BA1 transfers power to the battery BA3 across the battery BA2, the second switches K1, K2, K3 and the first switches S1, S2 are disconnected, and the first switch S3 is turned on. At the same time, the BOOST boost circuits of the control units IC2 and IC3 are switched from the boost state to the corresponding switch tube Z2 being always turned on, the switch tube Z2 of the control unit IC1 is turned off, the switch tubes and the boost switch tube M1 of IC2 and IC3 are all turned off, and the boost switch tube M1 of the control unit IC1 is turned on. The inductor is regarded as a path in the DC state, as shown in FIG. Figure 1 As shown by the thick line, the battery BA1 and the battery BA3 are connected in parallel to achieve energy transfer.

[0038] like Figure 5 As shown, taking the Nth unit as an example, the first switch SN adopts a single MOS tube, and the second switch adopts a dual MOS tube and they are KN-1 and KN-2 respectively.

[0039] like Figure 6 As shown, the first switch SN and the second switch KN respectively use normally open contacts of relays controlled by the control unit.

[0040] like Figure 7 As shown, the first switch SN and the second switch KN respectively use normally open contacts of relays controlled by the control unit.

[0041] like Figure 8 As shown, the first switch SN and the second switch KN are respectively single MOS tubes.

[0042] The controller can realize communication control by using digital logic chip, single chip microcomputer, DSP, FPGA, ASIC, PC or PLC.

[0043] When only energy transfer is required, the inductor can be replaced by a wire.

[0044] Example 2

[0045] like Fig. 9 As shown, Farad capacitors C1, C2, C3...CN are connected in series between the positive terminal B+ and the negative terminal B- of the entire string of batteries, and the rest is the same as in Example 1 to solve the current discontinuity problem when the switch is switched and improve the instantaneous large current performance.

[0046] The above are only specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery balancing circuit capable of directional energy transfer, comprising a whole string of multiple batteries BA1, BA2, BA3 ... BAN, and control units IC1, IC2, IC3 ..., ICN, characterized in that: The first switch S1 and the second switch K1, the first switch S2 and the second switch K2, the first switch S3 and the second switch K3…the first switch SN and the second switch KN are also included. The control unit IC1 is used to control the switch states of the first switch S1 and the second switch K1, the control unit IC2 is used to control the switch states of the first switch S2 and the second switch K2, the control unit IC3 is used to control the switch states of the first switch S3 and the second switch K3…the control unit ICN is used to control the switch states of the first switch SN and the second switch KN. The first switches S1, S2, S3…SN are sequentially connected in series and connected to the positive terminal B+ and the negative terminal B- of the whole string of batteries. The second switch K1 is connected in series with the battery BA1 and then connected in parallel at both ends of the first switch S1. The second switch K2 is connected in series with the battery BA2 and then connected in parallel with the first switch S 2, the second switch K3 is connected in series with the battery BA3 and then in parallel with the first switch S3, the second switch KN is connected in series with the battery BAN and then in parallel with the first switch SN; the control units IC1, IC2, IC3 ..., ICN have positive and negative power supply terminals (1 and 10), a balanced transmission positive terminal +E and a balanced transmission negative terminal -E at the same time, the positive and negative power supply terminals (1 and 10) of the control units IC1, IC2, IC3 ..., ICN are also voltage signal detection terminals of the batteries BA1, BA2, BA3 ... BaN and are connected to the positive and negative electrodes of the corresponding batteries, the balanced transmission positive terminal +E in the same control unit is connected to the positive terminal of the next battery, the balanced transmission negative terminal -E is connected to the negative terminal of the previous battery, the balanced transmission negative terminal -E of the first battery BANN and the balanced transmission positive terminal +E of the last battery are idle terminals;The control units IC1, IC2, IC3, ..., ICN respectively include a controller uP, a BOOST boost circuit, a communication interface COMM, an inductor or wire I1 and an inductor or wire I2, and switch tubes Z1 and Z2. The communication terminal (9) of the controller uP is connected to the communication interface COMM. One end of the inductor or wire I1 is connected to the corresponding positive electrode of the battery and the other end is connected to the source of the switch tube Z1. The positive boost feedback control terminal (12) of the BOOST boost circuit is connected to the node of the inductor I1 and the switch tube Z1. One end of the inductor or wire I2 is connected to the corresponding negative electrode of the battery and the other end is connected to the drain of the switch tube Z2. The negative boost feedback control terminal (13) of the BOOST boost circuit is connected to the junction of the inductor or wire I2 and the switch tube Z2. The positive boost detection control terminal 2 of the controller uP is connected to the positive boost control output terminal 11 of the BOOST boost circuit and then connected to the gate of the switch tube Z1. The negative boost detection control terminal (8) of the controller uP is connected to the negative boost control output terminal (14) of the BOOST boost circuit and then connected to the gate of the switch tube Z2. The enable terminal (15) of the BOOST boost circuit is controlled by the enable output terminal (5) of the controller uP. The switch control terminal 1 (3) of the controller uP is connected to the control terminal of the first switch. The switch control terminal 2 (7) of the controller uP is connected to the control terminal of the second switch. ; 2. The battery equalization circuit capable of directional energy transfer according to claim 1, characterized in that: Farad capacitors C1, C2, C3...CN are connected in series between the positive terminal B+ and the negative terminal B- of the entire battery string.

3. The battery equalization circuit capable of directional energy transfer according to claim 1, characterized in that: The first switch and the second switch are MOS tubes respectively.

4. The battery equalization circuit capable of directional energy transfer according to claim 3 is characterized in that: The first switch and the second switch respectively use a single MOS tube or a dual MOS tube. When a dual MOS tube is used, the corresponding controller uP has two switch control terminals, each of which controls one of the MOS tubes.

5. The battery equalization circuit capable of directional energy transfer according to claim 1, characterized in that: The controller adopts a single chip microcomputer, a DSP or a PLC.

6. The battery equalization circuit capable of directional energy transfer according to claim 1, characterized in that: The first switches S1, S2...SN and the second switches K1, K2...KN respectively use contacts of relays, thyristors or IGBTs controlled by the control unit.

7. The battery equalization circuit capable of directional energy transfer according to claim 1, characterized in that: The positive boost switch tube and the negative boost switch tube of the BOOST boost circuit are MOS tubes M1 and M2 respectively.

8. The battery equalization circuit capable of directional energy transfer according to claim 1, characterized in that: The switch tube Z1 and the switch tube Z2 are synchronous rectification MOS tubes.

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