Energy transfer type single battery voltage management circuit
A battery cell and voltage management technology, applied in battery circuit devices, charge equalization circuits, circuit devices, etc., can solve the problems of poor cycle life and capacity utilization of battery packs, combustion, battery pack performance attenuation, etc.
Pending Publication Date: 2022-01-11
SHANGHAI YUYUAN POWER TECH CO LTD
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AI-Extracted Technical Summary
Problems solved by technology
[0002] The service life of the battery pack is seriously affected by the inconsistency of the battery. According to the "barrel effect", the battery pack is obviously inferior to the performance of the monomer in terms of cycle life and capacity utilization.
With the repeated use of the battery pack, the inconsistency of the cells will intensify, further deteriorati...
Method used
The above-mentioned energy transfer type battery cell voltage management circuit, through the equalization of the transformer, can realize the fast equalization of any single cell in the battery pack, the control method is simple, the equalization current is large, the equalization efficiency is high, the structure is easy to expand, and the primary side of the transformer The number of windings is greatly reduced, which greatly reduces the difficulty of consistent control of the primary winding of the transformer. When the CUK converter equalization circuit balances the battery, the equalization discharge and charge are carried out at the same time, the equalization speed is fast, and the equalization energy transfer efficiency is high. The voltage difference has been increased, which improves the shortcoming that the balance current is very small when the voltage difference of each monomer in the battery pack is small. The switched capacitor method is to manage the active equalization of two adjacent battery cells. The main function is to judge the difference in state of charge between the two adjacent batteries. According to the result of the equalization algorithm, the equalization module uses the switching power supply to The transfer station function of the capacitor transfers the excess power of the high-voltage battery to the low-voltage battery to maximize the battery capacity. This solution only needs switches and capacitors to complete the construction of the equalization circuit. The advantage is that the structure is relatively simple and there is almost no energy loss during the equalization process. Through the combination of the above balancing methods, the inconsistency of the batteries in the battery pack is improved, and the service life of the batteries is prolonged.
When the CUK converter equalization circuit carries out battery equalization, equalization discharge and charge are carried out simultaneously, a...
Abstract
The invention relates to an energy transfer type battery monomer voltage management circuit which is used for managing a battery pack comprising a plurality of battery monomers connected in series, the battery pack is divided into a plurality of battery units, each battery unit comprises a plurality of battery rows connected in series, and each battery row comprises a plurality of battery monomers. The management circuit comprises a transformer, a plurality of inductors, a plurality of energy storage capacitors and a plurality of switching tubes, the transformer is provided with a plurality of primary windings, the two ends of a secondary winding of the transformer are connected with the positive electrode and the negative electrode of the battery pack through the switching tubes respectively, and the primary windings are connected to the two ends of the battery units in parallel through the different switching tubes respectively; and two ends of each battery row are connected in parallel with an inductor through a switch tube, and an energy storage capacitor is connected in series between the adjacent inductors connected in parallel with the battery row in each battery unit. According to the energy transfer type battery monomer voltage management circuit, the inconsistency of the batteries of the battery pack is improved, and the service life of the batteries is prolonged.
Application Domain
Charge equalisation circuitDc-dc conversion +2
Technology Topic
ThermodynamicsControl theory +4
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Examples
- Experimental program(1)
Example Embodiment
[0016] In order to make the objects, technical solutions, and advantages of the present invention more clearly, the technical solutions in the embodiments in the embodiments will be described in contemplation in the embodiment of the present invention, and will be described in connext of the embodiment of the present invention. It is an embodiment of the invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art are in the range of the present invention without making creative labor premise.
[0017] like figure 1 As shown, an energy transfer type battery monomer voltage management circuit is used to manage battery cells including a plurality of series. 1 ~ B n The battery pack is divided into a plurality of battery cells 110, each of which includes a plurality of battery rows 112, and the battery row 112 includes a plurality of battery cells. The management circuit includes a transformer T, a plurality of inductance L 1 ~ L n/2 , Multiple energy storage capacitance C L1 ~ C Ln/4 With multiple switch tube s 1-1 ~ S 1-n/2 , S, S N1 ~ S Nn/4 , Transformer T has multiple primary winding n 1-1 ~ N 1-n/4 , The secondary winding N of the transformer T 2 The two ends connect the positive and negative poles of the battery pack by switch pipe S, multiple original winding N, respectively. 1-1 ~ N 1-n/4 Different switch tubes N1 ~ S Nn/4 And connected to both ends of the plurality of battery cells 110. Each battery row 112 passes through a switch tube S 1-1 ~ S 1-n/2 And one inductor is connected, and each battery cell 110 is connected in series between adjacent inductions connected to the battery row 112. L1 ~ C Ln/4.
[0018] In this embodiment, the management circuit also includes a plurality of equalization capacitance C. B1 ~ C Bn/2 Switch with multiple control switches 1 ~ S n , Adjacent battery cells B of the battery row 112 B 1 ~ B n Two control switch s respectively 1 ~ S n And take a balanced capacitor C B1 ~ C Bn/2.
[0019] In this embodiment, the management circuit also includes a plurality of filter capacitance C. 1 ~ C n Each battery unit is connected to each of the battery cells 112 and one filter capacitor c 1 ~ C n. Specifically, the number of battery rows in the plurality of battery cells 110 is equal, and the number of batteries in the plurality of battery rows 112 is equal. The battery unit 110 has two battery rows 112. Neighbor inductance L 1 ~ L n/2 Part of a battery capacitor C L1 ~ C Ln/4 With adjacent inductance L 1 ~ L n/2 Composition CUK converter. Battery row 112 has two battery cells B 1 ~ B n.
[0020] The following combination figure 1 Specific description.
[0021] Taking a series of NOPCCs as an example, one battery unit 110 is formed in accordance with the present invention, and each battery unit 110 is divided into N / 4 units, and each 2 cell monomer is formed. 112, each battery unit 110 consists of two battery rows 112. For example, battery cells B 1 ~ B 4 The first battery unit and battery cells are formed in series B n-3 ~ B n The Nth / 4 battery cells are formed in series. The four battery cells in each battery cell are also divided into two small units (battery rows), each of which consists of two battery monomers, which are shared by 2 Cuk (Care Unite). Skin, Cuk Chopper Circuit) Converter Balance Circuit. Two battery cells in each battery row share 1 capacitance as a balanced capacitor; a battery unit consisting of four battery cells composed of each 2 battery is configured to equalize 1 transformer equalization.
[0022] Among them 1-1 ~ S 1-n/2 , S, S N1 ~ S Nn/4 And control switch s 1 ~ S n For power switch tubes. Filter capacitance C with each battery cell 1 ~ C n For high frequency filtering capacitors for filtering the clutter during the energy transfer process. N 1-1 ~ N 1-n/4 Original windings of the transformer T balanced, N 2 The secondary winding of the transformer equalization. L 1 ~ L n/2 And C L1 ~ C Ln/4 The inductance and capacitance of the multi-CUK converter equalization circuit is respectively. C B1 ~ C Bn/2 Equilibrium capacitance for capacitance equalization.
[0023] The equalization principle of the circuit of the present invention is first, first utilizes a balance between each battery unit 110 and the entire battery pack using a transformer, and then uses the CUK converter equalize the equalization of the balance between adjacent two battery rows, and finally uses the equalization capacitor to complete each Equilibrium between 2 battery cells in the battery row.
[0024] The first battery unit 110 consisting of the first four battery cells B1 to B4 in the battery pack will be described in detail, and the equalization step is as follows:
[0025] In the first step, the equalization of the first battery unit 110 and the entire battery pack is equal to the transformer T equalization. The specific equilibrium process is divided into two cases separately:
[0026] In the first case, it is assumed that the first battery unit is higher than the other battery cells in the battery pack, and the equalization step is as follows:
[0027] Step 1, power switch tube S N1 Tong, turn on the first battery unit and the original edge winding N of the transformer in series 1-1 Part of the battery cell is stored to the original winding N 1-1 middle. Current direction, such as in I 1.
[0028] Step 2, power switch tube S N1Turn off, power switch tube S is turned on, turn on the entire battery pack and the sub-winding N of the equilibrium of the transformer in series 2 , The last step is stored to the original winding n 1-1 The power is coupled to the secondary winding n 2 Medium, side winding n 2 The amount of electricity is then flowed to the entire battery pack. Current direction, such as in I 2.
[0029] In the second case, it is assumed that the first battery unit is lower than the other battery cells in the battery pack, and the equalization step is as follows:
[0030] Step 1, the power switch pipe S is turned on, turn on the entire battery module and the sub-winding N of the transformer equal to it. 2 Part of the entire battery module stores to the secondary winding n 2 middle. The direction of the current is as shown in the figure. 3.
[0031] Step 2, power switch pipe S is turned off, power switch tube S N1 Tong, turn on the first battery unit and the original edge winding N of the transformer in series 1-1 Previous stored side winding n 2 The power is coupled to the original winding n 1-1 Medium, original edge winding N 1-1 The amount of electricity is then transferred to the first battery cell. The direction of the current is as shown in the figure. 4.
[0032] In the second step, after several cycles of the first step, the balance of the first battery unit and the battery pack has been completed. Now turn off the transformer equalization, and turn on the equalization of the two battery rows within the battery cell. .
[0033] It is now assumed that 2 battery monomers in the first battery 1 ~ B 2 2 battery cells compared to the second small battery unit B 3 ~ B 4 The battery cell voltage is high, the equalization step is as follows: see figure 1.
[0034] Step 1, power switch tube S 1-1 MOS tube Q 1-1 Tong, close the input and output loop. Power switch tube S 1-2 Medium diode D 1-2 Reverse off. 2 battery monomers in the first battery are included 1 ~ B 2 Above current I 1 Induct 1 Independent storage capacitor C L1 Discharge current I 2 Induct 2 Independent, 2 battery monomers row to the second battery 3 ~ B 4 Battery charging transfer power. The discharge of the first battery row and the charging of the second battery row are carried out simultaneously, and the energy is bidirectional flow.
[0035] Step 2, power switch tube S 1-1 MOS tube Q 1-1 Undefined, power switch tube S 1-2 Medium diode D 1-2 Positive and turned on, close the input and output loop. 2 battery monomers in the first battery are included 1 ~ B 2 Inspiration L 1-1 Induction electromotive force plus energy storage capacitor C L1 Charging, charging current I 3 Independent capacitor C L1 Industrial storage, inductance L 2 Release energy, its discharge current I 4 2 battery monomers row to the second battery 3 ~ B 4 Battery charging transfer power. The discharge of the first battery row and the charging of the second battery row are carried out simultaneously, and the energy is bidirectional flow.
[0036] It is known from steps 1 and 2 of the above, regardless of the power switch tube S 1-1 MOS tube Q 1-1 During the turn-on, the first battery row can transfer energy to the second battery, and the energy storage capacitor C. L1 In the circuit is an energy storage element. Power switch tube s 1-1 MOS tube Q 1-1 During the deadline, the first battery row of current I 3 Make energy capacitance C L1 Charging storage energy; in power switch tube s 1-1 MOS tube Q 1-1 Bottom capacitor C during conduction L1 The discharge releases energy to the second battery.
[0037] If the 2 battery monomer B in the first battery is 1 ~ B 2 2 battery monomers in the second battery 3 ~ B 4 The battery cell voltage is low, and the equalization step is similar to the above steps 1 and step 2.
[0038] In the third step, after several cycles of the second step, the balance between the first battery row and the second small battery row has been completed. Now turn off the CUK converter equalization to open the equalization capacitance in each battery. To complete the balance between the internal 2 battery cells.
[0039] Now use the equalization of the first battery row as an example. The specific equilibrium process is as follows:
[0040] First battery-ranging battery cells B 1 ~ B 2 One of the cells must have relatively high voltage, and now the battery monomer B is now 1 Compared to battery monomer B 2 High voltage is high. Order power switch tube S 1 Tongtong, turn on battery cells B 1 Equilibrium capacitor C B1 Part of the battery unit stores to equalization capacitance C B1 middle. The direction of the current is as shown in the figure. 5.
[0041] Step 2, power switch tube S 1 Close, power switch tube s 2 MOS tube is closed and body diode is turned on, turn on battery monomer B 2 Equilibrium capacitor C with B1 , Equalization capacitor C B1 The power stored in the previous step is transferred to the battery cell B 2 middle. The direction of the current is as shown in the figure. 6.
[0042] After several cycles of the third step, the equalization of the two battery cells between the first battery is completed, and finally the capacitor actively balanced, and the equalization completion of the entire series battery pack ends.
[0043] The total equilibrium strategy is to first utilize the transformer equalization to complete the power transfer active equalization between each battery unit and the entire battery pack, and then use the CUK converter equalization to complete the power transfer active balance between adjacent two battery rows, and finally The power transfer equalization active balance between 2 battery cells in each battery row is completed by equalization capacitance.
[0044] The transformer balance can achieve equalization of multiple battery cells at the same time, so that all end voltages of all battery cells are finally close to the average voltage level. The topology has the advantages of simple operation, easy to control, but when the number of battery monomers is large, the multi-winding transformer is difficult to ensure the consistency of each winding in one side, there is a disadvantage that is not easy to expand. The present invention is divided into a plurality of battery cells throughout the battery unit, and the battery unit is connected to the primary winding of the transformer. After the packet transformer is balanced, the number of transformer main edge windings is greatly reduced, with four battery orders in each battery unit. As an example, the number of primary windings of the transformer is 1/4 of the original number, so that the consistency control difficulty of the primary side winding of the transformer is greatly reduced.
[0045] The CUK converter equalization circuit performs battery equilibrium and charging simultaneously, the equalization speed is fast, and the equalization energy transfer efficiency is high, but it is usually only equal to 2 battery monomers, and the equalization principle is between the unit cells. The voltage difference is balanced, so that the equalization current is small when the monomer voltage difference is small, and the equalization efficiency is low. The present invention packets the series monomer battery, and the inductance in each CuK converter is equal to the voltage of the battery row in series of the plurality of monomer batteries, and has two battery cells in each battery area as an example, inductance equalization. The voltage is twice the voltage of each unit cell, which is equivalent to 2 times the pressure difference between the monomer battery, thereby improving the pressure difference, and improves the individual voltages in the battery pack. When it is small, the equalization of a small amount of current is small.
[0046] The above energy transfer battery monomer voltage management circuit, through the transformer equalization, the rapid equalization of any monomer battery in the battery pack, simple control mode, high equilibrium current, high equilibrium efficiency, easy to expand, the number of main edge windings of the transformer A large decrease is reduced, making the consistency control difficulty of the transformer maintenance. The CUK converter equalization circuit performs battery equilibrium and charging simultaneously, the equalization speed is fast, the equalization energy transfer efficiency is high, and the inductance in each Cuk converter is equal to the voltage of the battery row of the plurality of unit cells. The pressure difference has been increased, and the equalization current is small when each monomer voltage difference is small in the battery pack. The switching capacitor method is to manage the active balance between the neighboring battery cells. The main function is to determine the difference in pttal state difference between the adjacent two batteries. According to the result of the equalization algorithm, the equalization module is used to switch the power supply. The transfer station of the capacitor transfers the voltage height of the battery to the battery low to the battery, and maximizes the battery capacity. This program only requires switching and capacitance to complete the construction of equalization circuits, and the advantage is that there is almost no energy loss during the balanced process. Through the combination of the above equilibrium, the inconsistency of the battery pack battery is improved, and the battery life is extended.
[0047] The above embodiments are merely expressed in several embodiments of the invention, which are more specific and detailed, but is not to be construed as limiting the patent scope of the invention. It should be noted that in terms of one of ordinary skill in the art, several deformations and improvements can be made without departing from the concept of the present invention, which belongs to the scope of the present invention. Thus, the scope of the scope of the invention should be taken in the appended claims.
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