Multi-winding transformer for battery equalizer

Abstract

A battery active equalizer generally uses a multi-winding transformer and is generally composed of a plurality of enameled wire windings. Due to the problems that the labor cost is high in the winding process and the phase is easy to mistake when the outgoing line is connected, the utility model provides a scheme that the copper foil line on the circuit board is used for replacing an enameled wire and the winding is directly manufactured on the circuit board. A transformer magnetic core is generally realized by forming a closed-loop magnetic core by two half magnetic cores; in order to enable the routing of the winding to be shortest and the conductive resistance to be reduced, the central column of the magnetic core is cylindrical. By using the scheme of the utility model, the manpower manufacturing cost is reduced, the outgoing line phase is fixed, and the design is convenient for batch production; and meanwhile, the magnetic coupling between the coils is also greatly improved. In order to further make full use of copper foil on a circuit board to manufacture a winding coil, the utility model provides a specific routing method of copper foil lines.

Description

Technical Field

[0001] This patent relates to the field of battery application protection, specifically a multi-winding transformer for a battery equalizer. Background Art

[0002] Multi-winding transformers are currently the main choice for active equalizers for batteries. Usually, many windings are wound on a magnetic ring. Because of the voltage phase problem when the wires are output, the two lead heads must be correctly distinguished. Only when they are connected correctly can the normal operation of the whole machine be ensured. Due to human error, it is easy to have phase lead errors, resulting in an increase in defective products during the production process; there are also multi-winding transformers implemented with enameled wires. Since the enameled wires are wound together, each enameled wire winding has the same potential as the corresponding battery string. In this way, since the potential of the battery string gradually increases, some of the enameled wires wound together maintain the highest potential of the battery pack, and some maintain the lowest potential of the battery pack. In this way, the voltage between the enameled wires will be very high. In order to operate safely, it is inevitable that high requirements are placed on the insulation of the enameled wires, otherwise the enameled wires are prone to creepage and breakdown, causing the equalizer to fail and damage the battery pack. Summary of the invention

[0003] Technical issues to be solved:

[0004] How to solve the problems encountered in the process of winding multi-winding transformers with enameled wire and solve the problem of easy mismatch of the lead wire phase.

[0005] Solution:

[0006] In response to this problem, this patent proposes to use the ring-shaped lines etched on the printed circuit board to replace the traditional enameled wire winding; the specific content is: a multi-winding transformer for a battery equalizer, composed of a magnetic core and a winding, characterized in that: the magnetic core is two half pieces that are combined into a closed complete magnetic core; the winding is obtained by etching a spiral ring-shaped line on a large piece of copper foil on a printed circuit board, which is referred to as a PCB board, and the printed circuit board can be a double-layer or multi-layer copper foil board; the two lead wires of each winding eventually extend to a dedicated output corresponding wiring hole; if one PCB board is not enough to complete the required number of windings, multiple PCB boards can be stacked to complete it. The lead wires of the winding eventually reach the fixed output wiring hole, so that the voltage phase relationship of the two lead wires of the winding is fixed from then on, which facilitates the subsequent direct design of the whole machine and directly obtains the final required machine; this solution solves the problem of easy misconnection of the winding output wire once and for all. On the other hand, since the windings of the multi-winding transformer are made of multiple copper foil plates stacked together, the high creepage voltage problem caused by the traditional enameled wire windings is completely avoided, which greatly reduces the voltage between directly adjacent windings, thus reducing the requirements for insulation and improving the safety and reliability of the entire machine.

[0007] Beneficial effects of the invention:

[0008] This patent solves the problem of troublesome manual winding of multi-winding transformers. The creepage voltage between the coils is relatively greatly reduced, and the winding lead wires no longer have phase errors. Production is simpler, the overall cost is low, and the coupling between windings is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 , Multi-winding transformer outline

[0010] Figure 2 , Typical core appearance (the core model in the figure is PQ3220)

[0011] Figure 3 , the appearance of the PCB after etching the circular copper foil lines (finally covered with insulating paint)

[0012] Figure 4 , multi-winding transformer assembly diagram

[0013] Figure 5 , Schematic diagram of the wiring of the three windings DETAILED DESCRIPTION

[0014] A multi-winding transformer for a battery balancer is mainly composed of a magnetic core and a winding. The magnetic core is composed of two half pieces combined into a closed complete magnetic core; the winding is obtained by etching a circular line on a large piece of copper foil on a printed circuit board. This printed circuit board (with circular copper foil lines etched on it) is hereinafter referred to as a PCB board. Figure 3 As shown; the PCB board can be a single-layer, double-layer or multi-layer copper foil board, and the upper and lower layers of the outermost layer of the board are covered with insulating paint; the two lead wires of each winding are finally extended to the dedicated output corresponding wiring holes, Figure 3 The "25" in the figure indicates the winding output wiring hole. When one PCB board cannot meet the number of required windings, multiple PCB boards can be stacked together to solve the problem.

[0015] In order to reduce the total length of the copper foil used in the winding and reduce the resistance of the winding, the magnetic column located in the center of the magnetic core adopts a cylindrical shape, such as Figure 2 As shown; the area where the PCB board matches the center part of the magnetic core is in a circular shape, such as Figure 3 As shown; the assembly diagram of the PCB board and the magnetic core assembled into a multi-winding transformer is shown in Figure 4 The typical appearance of a finished multi-winding transformer is shown in Figure 1 shown.

[0016] In order to make full use of the large copper foil on the printed circuit board to make winding lines, this patent provides a routing method for multiple winding copper foil lines, such as Figure 5 As shown, in Figure 5 The wiring method of the three windings is shown in FIG. 1 , specifically: one end of each of the three windings starts from the respective wiring holes of the outermost part of the circular PCB board and enters the entrance of the circular PCB board (at Figure 5 After reaching the position marked with "Incoming Line", continue to follow the solid line counterclockwise around the edge. When you reach the innermost part of the circular PCB board (where you will not be able to continue routing), remove the wires in a nearly smooth manner to the circumference closest to the edge of the inner ring, and then pass through the metallized vias ( Figure 5 The three small holes pointed by the arrows in the middle) reach the other side of the PCB board, and then continue to route along the circular PCB board from the inside to the outside in the same routing direction ( Figure 5 The routing is still in a spiral ring. When it reaches the outermost circle of the circular PCB board (as shown in the dotted line in the middle), the wiring is still in a spiral ring. Figure 5 The three wires marked with "outgoing wires" in the middle) then reach the corresponding winding output wiring holes directly or through metallized vias using the conductive lines on the front and back PCB boards to form three complete winding coils.

[0017] The routing principle of the N windings is exactly the same as that of the above three windings, specifically: one end of each of the N windings starts from the corresponding wiring hole of the outermost part of the annular PCB board, and is routed in a spiral from the outside to the inside along the annular PCB board. When reaching the innermost edge of the annular PCB board, it is routed to a circle closest to the inner ring edge in an approximately smooth manner, and then each passes through the metallized via to reach the other side of the PCB board, and then continues to route from the inside to the outside along the annular PCB board in the same routing direction. The routing method is still a spiral ring. When reaching the outermost circle of the annular PCB board, it finally reaches the corresponding winding output wiring hole directly or through the metallized via using the conductive lines on the front and back PCB boards to form N complete winding coils.

Claims

1. A multi-winding transformer for a battery equalizer, comprising a magnetic core and windings, characterized in that: The magnetic core is composed of two halves combined into a closed complete magnetic core; the winding is obtained by etching spiral ring lines on a large piece of copper foil on a printed circuit board. This printed circuit board is referred to as a PCB board. The printed circuit board can be a multi-layer copper foil board; the two lead wires of each winding eventually extend to the dedicated output corresponding wiring holes; If one PCB board is not enough to complete the required number of windings, multiple PCB boards can be stacked to complete it.

2. The multi-winding transformer for a battery equalizer according to claim 1, characterized in that: The central column of the magnetic core is cylindrical; the PCB board used is in a ring shape in the area matching the central part of the magnetic core.

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