Coupling inductor battery equalization circuit
By using a coupled inductor battery equalization circuit in the battery module, and using a coupled inductor to realize the energy transfer between single cells, the problems of low equalization rate and large number of energy storage components in the prior art are solved, and more efficient battery equalization is achieved.
Patent Information
- Application Number
- CN202422556862.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2034-10-22
AI Technical Summary
The existing battery module equalization technology has the problem of low equalization rate and large number of equalization units required, especially when the number of inductors increases with the number of single cells, resulting in an increase in the number of energy storage components.
A coupled inductor battery equalization circuit is adopted, which includes an equalization switch unit, an active equalization unit and a battery module connected in series. The energy transfer between the single cells is realized through the coupled inductor, thereby reducing the use of energy storage elements.
The energy transfer between any single cell is achieved through magnetic coupling, which improves the battery equalization rate and reduces the number of energy storage elements.
Smart Images
Figure CN222981276U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of battery module balancing, and more specifically, to a coupled inductor battery balancing circuit. Background Technique
[0002] To meet the power supply voltage requirements, single cells generally work in the form of a battery module. However, the inconsistencies in parameters such as the capacity and voltage of each single cell in the battery module will gradually increase with the number of charge and discharge cycles, affecting the safety of the battery module. Existing battery module balancing technologies have problems such as low balancing speed and a large number of required balancing units.
[0003] Some studies use an inductor, an energy storage element, as the hub for energy transfer to improve the balancing speed, but the number of inductors increases significantly as the number of single cells increases. Therefore, we need a coupled inductor battery balancing circuit that can reduce the number of energy storage elements and increase the battery balancing speed. Summary of the Utility Model
[0004] The utility model aims to solve at least one of the technical problems existing in the prior art or related technologies.
[0005] For this reason, the purpose of the present utility model is to propose a coupled inductor battery balancing circuit.
[0006] To achieve the above purpose, the technical solution of the present utility model provides a coupled inductor battery balancing circuit, which includes: a first balancing switch unit, a second balancing switch unit,..., a (2n - 1)-th balancing switch unit, and a 2n-th balancing switch unit connected in series with each other, an active balancing unit, and a battery module; wherein, each balancing switch unit is composed of a first switch S d and a second switch S c connected in series; the active balancing unit is composed of a coupled inductor with n windings; the battery module is composed of 2n single cells B 1 , B 2 ,..., B 2n-1 and B 2n connected in series; the positive pole of the first switch S d of each balancing switch unit is connected to the positive pole of the second switch S c ; the negative pole of the first switch S d of the (2m - 1)-th balancing switch unit is connected to the positive pole of the single cell B 2m-1 through a wire, and the negative pole of the second switch S c of the (2m - 1)-th balancing switch unit is connected to the single cell B m through a winding L 2m-1 of the coupled inductor and the positive pole of the single cell Bis connected to the negative electrode; the first switch S of the 2m-th equalization switch unit d The negative electrode is connected through a winding L of a coupled inductor m to the single cell B 2m is connected to the positive electrode, and the second switch S of the 2m-th equalization switch unit c The negative electrode is connected to the negative electrode of the single cell B through a wire 2m is connected; where n represents the total number of windings of the coupled inductor, and n is a positive integer; m represents the serial number of a certain winding of the coupled inductor, and m ∈ [1, n].
[0007] Preferably, the coupled inductor battery equalization circuit further includes: a switch control unit; the switch control unit is connected to each equalization switch unit; the switch control unit is configured to send control instructions to each equalization switch unit to control the on / off of the first switch and the second switch of each equalization switch unit.
[0008] Preferably, the first switch and the second switch of each equalization switch unit are both composed of a MOSFET tube and an anti-reverse diode connected in parallel across its two ends; each equalization switch unit is configured to control the energy transfer and exchange between the single cell and the active equalization unit.
[0009] Preferably, the positive electrode of the anti-reverse diode connected in parallel with the first switch is connected to the positive electrode of the first switch, and the positive electrode of the anti-reverse diode connected in parallel with the second switch is connected to the positive electrode of the second switch.
[0010] Preferably, one end of the m-th winding of the coupled inductor in the active equalization unit is connected to the common pole of the 2m-th single cell and the (2m - 1)-th single cell, and the other end of the m-th winding of the coupled inductor in the active equalization unit and the first switch S of the 2m-th equalization switch unit d2m and the second switch S of the (2m - 1)-th equalization switch unit c2m-1 are connected to the common end.
[0011] Preferably, the ends of the windings of the coupled inductor connected to the common poles of the single cells are the same-name ends.
[0012] Preferably, the common pole of the 2m-th single cell and the (2m + 1)-th single cell and the second switch S of the 2m-th equalization switch unit c2m and the first switch S of the (2m + 1)-th equalization switch unit d2m+1 are connected to the common end.
[0013] Advantages of the present utility model:
[0014] The coupled inductor battery equalization circuit provided by the present utility model enables energy transfer between any single battery through magnetic coupling when battery equalization is required, reducing the use of energy storage components and increasing the equalization rate.
[0015] The additional aspects and advantages of the present utility model will become apparent in the following description or be understood through the practice of the present utility model. Brief Description of the Drawings
[0016] Figure 1 The module schematic diagram of the coupled inductor battery equalization circuit showing an embodiment of the present utility model is presented. Detailed Description of the Embodiments
[0017] To more clearly understand the above-mentioned objects, features, and advantages of the present utility model, the present utility model will be further described in detail below in conjunction with the drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.
[0018] Many specific details are set forth in the following description to facilitate a thorough understanding of the present utility model. However, the present utility model may be implemented in other ways different from those described herein. Therefore, the protection scope of the present utility model is not limited to the limitations of the specific embodiments disclosed below.
[0019] As Figure 1 shown, the coupled inductor battery equalization circuit includes: a first equalization switch unit, a second equalization switch unit,..., a (2n - 1)th equalization switch unit, a 2nth equalization switch unit connected in series with each other, an active equalization unit, and a battery module; wherein, each equalization switch unit is composed of a first switch S d and a second switch S c connected in series; the active equalization unit is composed of a coupled inductor with n windings; the battery module is composed of 2n single cells B 1 , B 2 ,..., B 2n-1 and B 2n connected in series; the positive poles of the first switch S d of each equalization switch unit are connected to the positive poles of the second switch S c ; the negative pole of the first switch S d of the (2m - 1)th equalization switch unit is connected to the positive pole of the single cell B 2m-1 through a wire, and the negative pole of the second switch S c of the (2m - 1)th equalization switch unit is connected to the single cell B m through a winding L 2m-1 of the coupled inductor and the positive pole of the single cell Bis connected to the negative electrode; the first switch S of the 2m-th equalization switch unit d The negative electrode is connected to a winding L of the coupling inductor through m a monomer battery B 2m is connected to the positive electrode, and the second switch S of the 2m-th equalization switch unit c The negative electrode is connected to the negative electrode of the monomer battery B through a wire 2m ; where n represents the total number of windings of the coupling inductor, and n is a positive integer; m represents the serial number of a certain winding of the coupling inductor, and m ∈ [1, n].
[0020] The coupling inductor battery equalization circuit further includes: a switch control unit; the switch control unit is connected to each equalization switch unit; the switch control unit is used to send control instructions to each equalization switch unit to control the on-off of the first switch and the second switch of each equalization switch unit.
[0021] Preferably, the first switch and the second switch of each equalization switch unit are both composed of a MOSFET tube and an anti-reverse diode connected in parallel at both ends thereof; each equalization switch unit is used to control the energy transfer and exchange between the monomer battery and the active equalization unit.
[0022] The positive electrode of the anti-reverse diode connected in parallel with the first switch is connected to the positive electrode of the first switch, and the positive electrode of the anti-reverse diode connected in parallel with the second switch is connected to the positive electrode of the second switch.
[0023] One end of the m-th winding of the coupling inductor in the active equalization unit is connected to the common pole of the 2m-th monomer battery and the (2m - 1)-th monomer battery, and the other end of the m-th winding of the coupling inductor in the active equalization unit and the first switch S of the 2m-th equalization switch unit d2m and the second switch S of the (2m - 1)-th equalization switch unit c2m-1 are connected to the common end.
[0024] One end of each winding of the coupling inductor connected to the common pole of the monomer battery is the same-named end.
[0025] The common pole of the 2m-th monomer battery and the (2m + 1)-th monomer battery and the second switch S of the 2m-th equalization switch unit c2m and the first switch S of the (2m + 1)-th equalization switch unit d2m+1 are connected to the common end.
[0026] As Figure 1 shown, the following is a specific description of the working mode of the coupling inductor battery equalization circuit of the present invention.
[0027] If the difference Δ between the state of charge (SOC) of the cell with the lowest SOC in the battery module and the SOC of the cell with the lowest SOC among other cells whose SOC has a different parity from its number is within a specific range, that is, when the difference Δ < β, where β is a certain value, then the first switch S of the cell with the highest charge is turned on d , and the active equalization unit is charged, and the energy is stored in the active equalization unit. When the switch control unit Fcn gives a low-level signal, the first switch S d is turned off, and at the same time, the switch control unit Fcn turns on the second switch S of the cell with the minimum SOC c , and the active equalization unit charges the cell with the minimum SOC in the reverse direction. When the current in the coupled inductor is 0, the second switch S c is turned off to complete a single equalization.
[0028] For example: At time k, the SOC of cell B 1 in the battery module is the largest, and the SOC of cell B 2 is the smallest. Then the first switch S of cell B 1 is closed, and cell B d1 transfers energy to the coupled inductor. After charging is completed, the first switch S 1 is disconnected and the second switch S d1 is closed, and the energy in the coupled inductor is transferred to cell B c2 . 2 .
[0029] If the difference Δ between the SOC of the cell with the lowest SOC in the battery module and the SOC of the cell with the lowest SOC among other cells whose SOC has a different parity from its number exceeds a specific range, that is, when the difference Δ ≥ β, where β is a certain value, then the first switches S of all cells whose parity is different from that of the cell with the minimum SOC are turned on d , and the active equalization unit is charged. When the switch control unit Fcn gives a low-level signal, the first switch S d is turned off, and at the same time, the switch control unit Fcn turns on the second switch S of the cell with the minimum SOC c , and the active equalization unit charges the cell with the minimum SOC in the reverse direction. When the current in the coupled inductor is 0, the second switch S c2 is turned off to complete a single equalization.
[0030] For example: At time k, the SOC of cell B 1 in the battery module is the smallest, then the first switches S of all cells whose parity is different from that of cell B 1 are closed d2 、Sd4 ……S d2n , the single cell B 2 、B 4 ……B 2n transfers energy to the coupled inductor. After the charging is completed, the first switch S d2 、S d4 ……Sd 2n is disconnected and the second switch S c1 is closed to transfer the energy in the coupled inductor to the single cell B 1 .
[0031] It has been proved that the coupled inductor battery equalization circuit provided by the present utility model has technical advantages that cannot be surpassed in the existing battery module equalization technologies.
[0032] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, various changes and modifications can be made to the present utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.
Claims
1. A coupled inductor battery balancing circuit, characterized in that: include: A first balancing switch unit, a second balancing switch unit, ..., a (2n-1)th balancing switch unit, a 2nth balancing switch unit, an active balancing unit and a battery module are connected in series; wherein each balancing switch unit is composed of a first switch S connected in series. d and the second switch S c The active balancing unit is composed of a coupled inductor with n windings; the battery module is composed of 2n single cells B1, B2, ..., B connected in series 2n-1 and B 2n constitute; The first switch S of each balancing switch unit d The positive electrode of the second switch S c The positive electrode is connected; the first switch S of the (2m-1)th balancing switch unit d The negative electrode is connected to the single battery B through a wire 2m-1 The positive electrode of the second switch S of the (2m-1)th balancing switch unit is connected. c The negative pole of the coupled inductor is connected through a winding L m With single battery B 2m-1 The first switch S of the 2mth balancing switch unit is connected to the negative electrode; d The negative pole of the coupled inductor is connected through a winding L m With single battery B 2m The positive electrode of the second switch S of the 2mth balancing switch unit is connected. c The negative electrode is connected to the single battery B through a wire 2m The negative pole is connected; Wherein, n represents the total number of windings of the coupled inductor, and n is a positive integer; m represents the serial number of a winding of the coupled inductor, and m∈[1,n].
2. The coupled inductor battery equalization circuit according to claim 1, characterized in that: Also includes: a switch control unit; The switch control unit is connected to each balancing switch unit; The switch control unit is used to send a control instruction to each balancing switch unit to control the on and off of the first switch and the second switch of each balancing switch unit.
3. The coupled inductor battery equalization circuit according to claim 1, characterized in that: The first switch and the second switch of each balancing switch unit are composed of a MOSFET tube and an anti-reverse diode connected in parallel at both ends; each balancing switch unit is used to control the energy transfer and exchange between the single battery and the active balancing unit.
4. The coupled inductor battery equalization circuit according to claim 3, characterized in that: The anode of the anti-reverse diode connected in parallel with the first switch is connected to the anode of the first switch, and the anode of the anti-reverse diode connected in parallel with the second switch is connected to the anode of the second switch.
5. The coupled inductor battery equalization circuit according to claim 1, characterized in that: One end of the mth winding of the coupling inductor in the active balancing unit is connected to the common electrode of the 2mth single battery and the (2m-1)th single battery, and the other end of the mth winding of the coupling inductor in the active balancing unit is connected to the first switch S of the 2mth balancing switch unit. d2m and the second switch S of the (2m-1)th balancing switch unit c2m-1 The common end is connected.
6. The coupled inductor battery equalization circuit according to claim 1, characterized in that: One end of each winding of the coupled inductor connected to the common pole of the single battery is a same-name end.
7. The coupled inductor battery equalization circuit according to claim 1, characterized in that: The common pole of the 2mth single cell and the (2m+1)th single cell and the second switch S of the 2mth balancing switch unit c2m and the first switch S of the (2m+1)th balancing switch unit d2m+1 The common end is connected.