A winding structure of a multi-path integrated synchronous coil

Abstract

The application discloses a winding structure of a multi-path integrated synchronous coil. The winding of a transformer is not divided into a primary winding and a secondary winding, the number of turns of all windings is the same, the same name ends are the same and the windings have common ends, all windings share a magnetic core, each single battery in a series battery group is connected in parallel with two windings with the same number of turns, the same first ends, the same last ends and the common ends, and n series battery groups use 2n windings. The number of turns of each winding is consistent, the inductance is consistent, the lead battery balancing precision is high, the voltage difference of the battery balancing is significantly reduced, and the battery balancing requirement can be well met.

Description

Technical Field

[0001] This invention relates to a winding structure for a transformer coil, and more particularly to a winding structure for a multi-channel integrated synchronous coil. Background Technology

[0002] In lithium battery packs, individual cells inevitably exhibit inconsistencies in parameters such as voltage, capacity, or internal resistance during manufacturing and use. This inconsistency is a continuous accumulation process, and the longer the time, the greater the differences between individual cells. In addition, lithium battery packs are also affected by the usage environment, and the inconsistencies between individual cells will be gradually amplified during use, leading to accelerated performance degradation of some individual cells.

[0003] In existing technologies, methods for implementing balancing transformers in n-cell series-connected battery packs include, for example... Figure 1 As shown, the existing multi-channel transformer structure consists of a primary winding L0 and n secondary windings (L1, L2, ..., Ln). The number of turns in each of the n secondary windings is the same, and their sum equals the number of turns in the primary winding L0. During battery balancing, when high-frequency changing currents flow through the various windings of the balancing transformer, induced electromotive forces U1, U2, ... Un are generated at the terminals of each winding, and an induced electromotive force U0 is generated at the terminal of the primary winding. According to Faraday's principle of electromagnetic induction, the induced electromotive force of each winding is positively correlated with the number of turns N, i.e., U1 / N1 = U2 / N2 = ... = Un / Nn = (U1 + U2 + ... Un) / N0. If this induced electromotive force > battery voltage U... B Then the battery will be charged, and current will flow into the battery through the transformer's equalizing winding; if the battery voltage U B The induced voltage is generated by the battery supplying electrical energy to the balancing winding. Current flows out of the battery and into the balancing winding. When N1 = N2 = ... Nn, it ensures that U1 = U2 = ... Un, ultimately achieving battery voltage balancing.

[0004] In existing technologies, multi-channel transformer winding methods employ a split-type asynchronous winding approach. During transformer manufacturing, the primary winding is wound first, followed by separate windings for each secondary winding. One complete turn of the coil on the transformer core constitutes one full turn. Since each winding eventually has a tap to form an independent pin, the position of these taps in the split-type asynchronous winding leads to slight errors in the number of turns between windings. Thus, the actual winding voltage is N1≈N2≈…≈Nn≈N0≈(N1+N2+...Nn). According to Faraday's principle of electromagnetic induction, this slight error in the number of turns (N1, N2,...Nn) results in a difference in the induced voltage across the secondary windings during the operation of the equalizing transformer. This voltage difference manifests as the equalization voltage error of the equalizing transformer, defined as the maximum value of the equalization voltage difference between the individual battery strings. △ U = MAX(Ui -U j (i,j are between 1 and n).

[0005] In existing technology, the split-type asynchronous winding balancing transformer exhibits significant differences in inductance among its n secondary windings, and the sum of the inductances of the n windings also shows a large error compared to the sum of the inductances of the primary windings. In practical balancing applications, it typically achieves a balancing accuracy of only 20mV, making it difficult to further reduce the voltage difference between batteries and thus failing to adequately meet battery balancing requirements. Summary of the Invention

[0006] To address the shortcomings of existing technologies in voltage accuracy, this invention provides a winding structure for a multi-channel integrated synchronous coil, which significantly improves upon the 20mV accuracy of existing technologies. This allows for more efficient and precise fulfillment of battery balancing requirements. The technical solution is as follows:

[0007] A winding structure for a multi-channel integrated synchronous coil is disclosed, wherein the transformer coil windings do not distinguish between primary and secondary windings, all windings have the same number of turns, the same terminal, and a common terminal, each battery in the series battery pack has two windings in parallel with the same number of turns, the same terminal, and a common terminal, and each winding is connected in series with an electronic switch, and the windings are fixed on the transformer frame.

[0008] Preferably, the number of windings with the same number of turns, the same terminal name, and a common terminal is twice the number of battery cells in the series battery pack, and all windings share a single magnetic core.

[0009] Preferably, the magnetic core can be a toroidal, E-type, C-type, U-type, or other type of magnetic core.

[0010] Preferably, the windings with the same number of turns, the same terminal name, and a common terminal are wound in the same direction. All windings are combined into one strand and wound in the same direction for a certain number of turns until they reach the opposite end of the magnetic ring. The winding is not interrupted, and a portion of the length is reserved as an intermediate tap. The same number of turns are wound in the same direction as the aforementioned winding until the starting end of the winding is reached. Then, the starting end of the winding is used as the first end, the intermediate tap as the common end, and the ending end as the last end, and they are separated and connected to the first end lead, the common end lead, and the last end lead of the transformer frame, respectively.

[0011] Preferably, for the windings with the same number of turns, the same polarities and a common terminal, the winding method is that all windings are wound in the same direction. All the winding wires are combined into one strand and start from the starting end of the magnetic core, and are wound for a certain number of turns in the same winding direction and then return to the starting end of the magnetic core. After that, the winding wires are not interrupted and a part of the wire length is reserved as an intermediate tap. Then, the wires are wound for the same number of turns in the same winding direction as before and return to the starting end position of the magnetic core again. Then, the starting wire end of the winding wire is used as the first end, the intermediate tap is used as the common terminal, and the ending wire end is used as the last end and separated, and are respectively connected to the first-end lead-out pin, the common-terminal lead-out pin and the last-end lead-out pin of the transformer framework.

[0012] Preferably, the transformer framework has a structure in the shape of the Chinese character "Ri", and there are a common-terminal lead-out pin, a first-end lead-out pin and a last-end lead-out pin on its three parallel sides respectively. The number of lead-out pins in each row is not less than the number of single battery cells in the lithium battery pack.

[0013] Preferably, for the structure of the transformer framework in the shape of the Chinese character "Ri", the three parallel sides are arranged at unequal distances, and two rectangular structures of different sizes are formed inside the transformer framework. The completed transformer coil is placed in the larger rectangular structure.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] The applied turn values of each winding on the transformer are highly consistent, the inductance values are highly consistent, the accuracy of the battery balancing is high, and the voltage difference of the balanced voltages of each string of batteries is significantly reduced, which can well meet the battery balancing requirements and significantly extend the service life of the multi-string lithium battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the circuit schematic diagram of the split asynchronous winding method of the existing multi-way transformer;

[0017] Figure 2 It is the circuit schematic diagram of the winding structure of a multi-way integrated synchronous coil according to the present invention;

[0018] Figure 3 It is the schematic diagram of the winding method of the winding structure of a multi-way integrated synchronous coil according to the present invention;

[0019] Figure 4 It is the schematic diagram of the transformer framework structure of the winding structure of a multi-way integrated synchronous coil according to the present invention;

[0020] Figure 5 It is the schematic diagram of the combined structure of the transformer framework and the transformer coil of the winding structure of a multi-way integrated synchronous coil according to the present invention.

[0021] In the diagram: 1. Common terminal; 2. First terminal; 3. Last terminal; 4. Magnetic core; 5. Starting terminal; 6. Opposite terminal; 7. Common terminal lead; 8. First terminal lead; 9. Last terminal lead; 10. Transformer frame; 11. Electronic switch; 12. Transformer coil. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] Figure 2 This is a circuit diagram illustrating an embodiment of the winding method and structure of the multi-channel integrated synchronous coil of the present invention. Figure 2 As shown, the multi-channel integrated synchronous coil of this embodiment is used for a battery pack of four lithium batteries connected in series, including four lithium batteries connected in series (B1, B2, B3 and B4), eight windings with the same number of turns (L11, L12, L21, L22, L31, L32, L41 and L42), eight transistor or MOSFET electronic switches (S11, S12, S21, S22, S31, S32, S41 and S42) and a magnetic core, which is shared by all windings.

[0024] In this embodiment, all eight windings have the same number of turns, the same terminal name, and a common terminal 1. Each pair of windings is connected in series with a switch and then in parallel to a battery. Furthermore, L41 and L42 form a winding pair; L41 is connected in series with switch S41, and L42 is connected in series with switch S42. The circuits of L41 and L42 are connected in parallel to the positive and negative terminals of battery B4. Following the aforementioned connection method, the other three pairs of windings are connected in parallel to batteries B1, B2, and B3, respectively.

[0025] like Figure 3 As shown, the winding method of the multi-channel integrated synchronous coil in this embodiment is as follows: all windings are wound in the same direction, and multiple winding wires with a number not less than the number of individual battery cells are selected. All winding wires are combined into one strand and start from the starting end 5 of the magnetic ring. After winding a certain number of turns in the same winding direction to the opposite end 6 of the magnetic ring, the winding wire is not interrupted and a portion of the wire length is reserved as an intermediate tap. The same number of turns are wound in the same direction as the aforementioned winding to the starting end 5 of the winding wire. Then, the starting wire end is used as the first end 2, the intermediate tap is used as the common end 1, and the ending wire end is used as the last end 3 and separated. They are then connected to the first end lead 8, the common end lead 7, and the last end lead 9 of the transformer frame, respectively.

[0026] In another embodiment, the winding method of the multi-channel integrated synchronous coil is as follows: all windings are wound in the same direction, and multiple winding wires with a quantity not less than the number of single battery cells are selected. All the winding wires are combined into one strand and simultaneously start from the starting end 5 of the magnetic core and are wound for a certain number of turns in the same winding direction and return to the starting end 5 of the magnetic ring. After that, the winding wires are not interrupted and a part of the wire length is reserved as the middle tap. Then, the winding wires are wound for the same number of turns in the same winding direction as before and return to the position of the starting end 5 of the magnetic ring again. Then, the starting end of the winding wire is used as the first end 2, the middle tap is used as the common end 1, and the ending wire head is used as the last end 3 and separated, and are respectively connected to the first-end lead-out pin 8, the common-end lead-out pin 7, and the last-end lead-out pin 9 of the transformer frame.

[0027] Each winding wire forms two windings according to the first end, the last end, and the common end, and the total number of all windings is twice the number of single battery cells. Further, in the actual winding process, in order to ensure the winding efficiency and improve the efficiency of subsequent processes, different colors of winding wires are used for each group of windings corresponding to different single batteries to distinguish them.

[0028] As Figure 4 shown, the transformer frame 10 used in this embodiment is of a "day" - shaped structure. On its three parallel sides, each side has a row of lead - out pins respectively, with a total of three rows. After excluding the reserved pin positions and duplicate pin positions, the number of lead - out pins in each row is the same as the number of single battery cells in the lithium - battery pack. Its three rows of lead - out pins are the common - end lead - out pin 7, the first - end lead - out pin 8, and the last - end lead - out pin 9. As Figure 5 shown, the wound transformer coil 12 is placed in the frame between the common - end lead - out pin 7 and the first - end lead - out pin 8 of the transformer frame 10. The common end 1 of the transformer coil 12 is connected to the common - end lead - out pin 7 of the transformer frame 10, the first end 2 of the transformer coil 12 is connected to the first - end lead - out pin 8 of the transformer frame 10, and the last end 3 of the transformer coil 12 is connected to the last - end lead - out pin 9 of the transformer frame 10.

[0029] When the transformer frame 10 is connected to the transformer coil 12, the common - end lead - out pin 7, the first - end lead - out pin 8, and the last - end lead - out pin 9 on the transformer frame 10 are numbered respectively in the same direction. The common end 1, the first end 2, and the last end 3 of the winding wires of the same color in the transformer coil 12 are respectively connected to the lead - out pins with the same number among the common - end lead - out pin 7, the first - end lead - out pin 8, and the last - end lead - out pin 9.

[0030] When the transformer frame 10 is connected to the battery pack, each row of lead - out pins on the transformer frame 10 is numbered respectively in the same direction. Each group of common - end lead - out pins 7 with the same number is connected to the positive electrode of the single battery, and the first - end lead - out pin 8 and the last - end lead - out pin 9 are connected together to the negative electrode of the single battery.

[0031] In another embodiment of the present invention, the pin at the first end lead-out pin 8 of the transformer frame 10 can also be used as the end lead-out pin, while the pin at the end lead-out pin 9 serves as the first end lead-out pin.

[0032] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A winding structure for a multi-channel integrated synchronous coil, characterized in that, The transformer coil windings do not distinguish between primary and secondary windings. All windings have the same number of turns, the same terminal and a common terminal (1). Each battery in the series battery pack has two windings with the same number of turns, the same terminal and a common terminal (1) connected in parallel. Each winding is connected in series with an electronic switch (11). All windings are fixed on the transformer frame (10). The number of windings with the same number of turns, the same terminal and a common terminal is twice the number of battery cells in the series battery pack. Among them, the windings with the same number of turns, the same name terminals and a common terminal (1) are wound in the same direction. All windings are combined into one strand and start from the beginning end (5) of the magnetic ring. After winding a certain number of turns in the same direction to the opposite end (6) of the magnetic ring, the winding is not interrupted and a portion of the length is reserved as an intermediate tap. The same number of turns are wound again in the same direction to the beginning end (5) of the winding. Then the starting end of the winding is used as the first end (2), the intermediate tap is used as the common terminal (1), and the ending end is used as the end end (3) and separated. They are then connected to the first end lead (8), the common end lead (7) and the end lead (9) of the transformer frame (10) respectively.

2. The winding structure of a multi-channel integrated synchronous coil according to claim 1, characterized in that, All windings of the winding structure share a single magnetic core (4).

3. The winding structure of a multi-channel integrated synchronous coil according to claim 2, characterized in that, The magnetic core (4) is a toroidal, E-type, C-type, or U-type magnetic core.

4. The winding structure of a multi-channel integrated synchronous coil according to claim 1, characterized in that, The transformer frame (10) has a s-shaped structure with a common end lead (7), a first end lead (8) and a last end lead (9) on its three parallel sides. The number of leads in each row is no less than the number of individual battery cells in the lithium battery pack.

5. The winding structure of a multi-channel integrated synchronous coil according to claim 1, characterized in that, The transformer frame (10) has a scalloped structure with three parallel sides that are not equidistant. The transformer frame (10) has two rectangular structures of different sizes inside, with the larger rectangular structure containing the wound transformer coil (12).

Images