Transformer winding current-sharing power supply and electric equipment
By setting a common-mode inductor between the secondary circuits of the transformer, the problem of uneven current distribution in the transformer windings is solved, current balance is achieved, and the service life of the transformer is extended.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN INCREASE TECH CO LTD
- Filing Date
- 2025-04-07
- Publication Date
- 2026-04-21
AI Technical Summary
When the two windings of a transformer are connected in parallel, the output current is uneven, causing one winding to work under overload and the other to work under light load. Long-term use will lead to overheating of the windings and shorten the product life.
A common-mode inductor is placed between the first and second secondary circuits of the transformer. The voltage balance characteristics of the common-mode inductor are used to achieve current sharing.
By setting a common-mode inductor, the current in the transformer windings is balanced, which avoids overheating of the windings and extends the service life of the transformer.
Smart Images
Figure CN224154139U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of power supply design, and in particular to a power supply and electrical equipment with transformer winding current sharing. Background Technology
[0002] Transformers are common and essential components in power supply products. When the impedance of the transformer windings and their circuitry is not consistent, and the two windings operate in parallel, an uneven output current will occur. In this situation, one winding may be overloaded while the other is lightly loaded. Prolonged use of the transformer windings in this manner will lead to overheating and a rapid decrease in product lifespan.
[0003] Therefore, how to design a power supply and electrical equipment that can share current in transformer windings and avoid the aforementioned problem of uneven current distribution in transformer windings is a technical problem that the industry urgently needs to solve. Utility Model Content
[0004] In view of the problem of uneven current distribution in transformer windings in the prior art, this utility model proposes a power supply and electrical equipment for equalizing current distribution in transformer windings.
[0005] The technical solution of this utility model is to propose a power supply for current sharing of transformer windings, including a transformer. The transformer has a primary winding connected to the primary circuit, a first secondary winding connected to a first secondary circuit, and a second secondary winding connected to a second secondary circuit. The first secondary circuit and the second secondary circuit are connected to the same load output. The power supply also includes a current sharing circuit connected between the first secondary circuit and the second secondary circuit. The current sharing circuit is used to balance the current on the first secondary circuit and the second secondary circuit.
[0006] Furthermore, the current sharing circuit is a common-mode inductor composed of a third coil winding disposed in the first secondary circuit and a fourth coil winding disposed in the second secondary circuit.
[0007] Furthermore, the first secondary circuit includes winding internal resistance Ro1, wiring resistance Rc1, diode D1, diode D2, diode D3, and diode D4;
[0008] The diodes D1, D2, D3, and D4 constitute a full-bridge circuit, with diodes D1 and D3 forming the first bridge arm and diodes D2 and D4 forming the second bridge arm.
[0009] The opposite-named end of the first secondary winding is connected in series with the winding internal resistance Ro1 and then connected to the midpoint of the first bridge arm. The same-named end of the first secondary winding is connected to the midpoint of the second bridge arm. The negative terminals of diodes D1 and D2 are connected in series with the trace resistance Rc1 and then connected to one end of the load. The positive terminals of diodes D3 and D4 are connected in series and then connected to the other end of the load.
[0010] Furthermore, the second secondary circuit includes winding internal resistance Ro2, trace resistance Rc2, diode D5, diode D6, diode D7, and diode D8;
[0011] Diodes D5, D6, D7, and D8 form a full-bridge circuit, with D5 and D7 forming the third bridge arm and D6 and D8 forming the fourth bridge arm.
[0012] The opposite-named end of the second secondary winding is connected in series with the winding internal resistance Ro2 and then connected to the midpoint of the third bridge arm. The same-named end of the second secondary winding is connected to the midpoint of the fourth bridge arm. The negative terminals of diodes D5 and D6 are connected in series with the trace resistance Rc2 and then connected to one end of the load. The positive terminals of diodes D7 and D8 are connected in series and then connected to the other end of the load.
[0013] Furthermore, the third coil winding is connected in series between the same-name end of the first secondary winding and the midpoint of the second bridge arm, and the same-name end of the third coil winding is connected to the same-name end of the first secondary winding.
[0014] The fourth coil winding is connected in series between the opposite end of the second secondary winding and the winding internal resistance Ro2, and the same end of the fourth coil winding is connected to the opposite end of the second secondary winding.
[0015] Furthermore, the first secondary circuit includes winding internal resistance Ro1, wiring resistance Rc1, diode D1, diode D2, diode D3, and diode D4;
[0016] The diodes D1, D2, D3, and D4 constitute a full-bridge circuit, with diodes D1 and D3 forming the first bridge arm and diodes D2 and D4 forming the second bridge arm.
[0017] The same-name terminal of the first secondary winding is connected in series with the winding internal resistance Ro1 and then connected to the midpoint of the first bridge arm. The opposite-name terminal of the first secondary winding is connected to the midpoint of the second bridge arm. The negative terminals of diodes D1 and D2 are connected in series with the trace resistance Rc1 and then connected to one end of the load. The positive terminals of diodes D3 and D4 are connected in series and then connected to the other end of the load.
[0018] Furthermore, the second secondary circuit includes winding internal resistance Ro2, trace resistance Rc2, diode D5, diode D6, diode D7, and diode D8;
[0019] Diodes D5, D6, D7, and D8 form a full-bridge circuit, with D5 and D7 forming the third bridge arm and D6 and D8 forming the fourth bridge arm.
[0020] The same-name terminal of the second secondary winding is connected in series with the winding internal resistance Ro2 and then connected to the midpoint of the third bridge arm. The opposite-name terminal of the second secondary winding is connected to the midpoint of the fourth bridge arm. The negative terminals of diodes D5 and D6 are connected in series with the trace resistance Rc2 and then connected to one end of the load. The positive terminals of diodes D7 and D8 are connected in series and then connected to the other end of the load.
[0021] Furthermore, the third coil winding is connected in series between the opposite end of the first secondary winding and the midpoint of the second bridge arm, and the opposite end of the third coil winding is connected to the opposite end of the first secondary winding.
[0022] The fourth coil winding is connected in series between the same-name end of the second secondary winding and the winding internal resistance Ro2, and the opposite-name end of the fourth coil winding is connected to the same-name end of the second secondary winding.
[0023] This utility model also proposes an electrical device having a power supply with the aforementioned transformer winding current sharing.
[0024] Compared with the prior art, the present invention has at least the following beneficial effects:
[0025] This invention adds a common-mode inductor between the first and second secondary circuits of the transformer. Utilizing the inherent characteristics of the common-mode inductor, the current in the first and second secondary circuits is balanced, thereby avoiding the problem of uneven current distribution in the transformer windings. Compared to traditional designs, this invention uses fewer components and can solve the problem of uneven current distribution in transformer windings simply and efficiently. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a schematic diagram of the power supply principle for current sharing in the transformer windings in this utility model.
[0028] Figure 2 This is a connection diagram of a two-winding transformer in the prior art.
[0029] Figure 3 for Figure 2 A schematic diagram of the voltage and current waveforms in the embodiment;
[0030] Figure 4 This is a schematic diagram of the specific circuit connection of the power supply for current sharing of the transformer windings in this utility model.
[0031] Figure 5 for Figure 4 A schematic diagram of the voltage and current waveforms in the embodiment. Detailed Implementation
[0032] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0033] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the present invention, and does not imply that every embodiment of the present invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.
[0034] The principle and structure of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.
[0035] Please see Figure 2This is a schematic diagram of a transformer used in a power supply circuit in the prior art. The transformer has a primary winding Lp, a first secondary winding Ls1, and a second secondary winding Ls2. The circuit connected to the rear end of the first secondary winding Ls1 is the first secondary circuit, and its opposite-name terminal is connected to a winding internal resistance Ro1, the resistance of which is 0.1 ohms. The circuit connected to the rear end of the second secondary winding Ls2 is the second secondary circuit, and its opposite-name terminal is connected to a winding internal resistance Ro2, the resistance of which is 10 ohms. The outputs of the first secondary circuit and the second secondary circuit are connected to the same load Load.
[0036] Here, the impedance on the first secondary winding Ls1 line is 0.1 ohms, and the impedance on the second secondary winding Ls2 line is 10 ohms. The first secondary winding Ls1 and the second secondary winding Ls2 are connected to the load Load after full-wave rectification. Because the impedances on the first secondary winding Ls1 line and the second secondary winding Ls2 line differ significantly, please refer to [link to relevant documentation]. Figure 3 At this time, the average current I(Rc1) after rectification of the first secondary winding Ls1 is about 3A, and the average current I(Rc2) after rectification of the second secondary winding Ls2 is about 0A. At this time, the current on the first secondary winding Ls1 and the second secondary winding Ls2 is severely uneven, which may cause the transformer windings to overheat, thereby shortening its lifespan.
[0037] Based on the above problems, the design concept of this utility model is to set a current sharing circuit between the first secondary circuit and the second secondary circuit. This current sharing circuit is composed of a common-mode inductor and utilizes the voltage balance characteristic of the common-mode inductor itself to achieve the effect of current sharing.
[0038] Please see Figure 4 The present invention provides a power supply for transformer winding current sharing, which includes a transformer having a primary winding Lp connected to the primary circuit, a first secondary winding Ls1 connected to the first secondary circuit, and a second secondary winding Ls2 connected to the second secondary circuit, wherein the first secondary circuit and the second secondary circuit are connected to the same load output.
[0039] The above configuration also includes a current sharing circuit connected between the first secondary circuit and the second secondary circuit, which is used to balance the current on the first secondary circuit and the second secondary circuit.
[0040] The current sharing circuit specifically includes a third coil winding L3 and a fourth coil winding L4, wherein the third coil winding L3 is located in the first secondary circuit and the fourth coil winding L4 is located in the second secondary circuit, and the third coil winding L3 and the fourth coil winding L4 form a common mode inductor.
[0041] In a common-mode inductor, there is generally only one loop in the working circuit, allowing current to flow through two coil windings simultaneously, forming mutually canceling magnetic fields. Its current is mainly affected by the coil's own resistance and the damping effect of leakage inductance at a negligible operating frequency. Since the resistance of the third coil winding L3 and the fourth coil winding L4 is basically the same, by setting the above-mentioned common-mode inductor in the first secondary circuit and the second secondary circuit, the current sharing of the first secondary winding Ls1 and the second secondary winding Ls2 of the transformer can be achieved.
[0042] Figure 1 The schematic diagram for the common-mode inductor design of this utility model shows that, for the first secondary winding Ls1, the current flows in from the opposite-named terminal. Therefore, for the third winding L3, the current enters from the same-named terminal and exits from its opposite-named terminal. Similarly, for the second secondary winding Ls2, the current flows out from its same-named terminal. Therefore, for the fourth winding L4, the current enters from its opposite-named terminal and exits from its same-named terminal. After the third winding L3 and the fourth winding L4 form a common-mode inductor, the current can enter from the same-named terminal of the third winding L3 and exit from the same-named terminal of the fourth winding L4, thus forming a loop to achieve the aforementioned current sharing effect.
[0043] The above Figure 1 This is a preferred embodiment of the present invention. In other embodiments of the present invention, the connection of the first secondary winding Ls1, the second secondary winding Ls2, the third coil winding L3, and the fourth coil winding L4 can be adjusted so that the same-name end of the third coil winding L3 is connected to the same-name end of the first secondary winding Ls1, and the same-name end of the fourth coil winding L4 is connected to the opposite-name end of the second secondary winding Ls2. At this time, the current can also enter from the same-name end of the third coil winding L3 and exit from the same-name end of the fourth coil winding L4, thereby forming a loop to achieve the above-mentioned current sharing effect.
[0044] Specifically, based on the above approach, please refer to... Figure 4 In this utility model, the first secondary circuit can be designed as follows:
[0045] The first secondary circuit includes winding internal resistance Ro1, trace resistance Rc1, diode D1, diode D2, diode D3, and diode D4;
[0046] In this circuit, diodes D1, D2, D3, and D4 form a full-bridge circuit, with diodes D1 and D3 forming the first bridge arm and diodes D2 and D4 forming the second bridge arm.
[0047] The opposite-named end of the first secondary winding is connected to the midpoint of the first bridge arm after being connected in series with the winding internal resistance Ro1. The same-named end of the first secondary winding is connected to the midpoint of the second bridge arm. The negative terminals of diodes D1 and D2 are connected in series with the trace resistance Rc1 and then connected to one end of the load. The positive terminals of diodes D3 and D4 are connected in series and then connected to the other end of the load.
[0048] The second secondary circuit can be designed as follows:
[0049] The second secondary circuit includes the winding internal resistance Ro2, the routing resistance Rc2, diode D5, diode D6, diode D7, and diode D8;
[0050] Among them, diodes D5, D6, D7, and D8 form a full-bridge circuit, with diodes D5 and D7 forming the third bridge arm and diodes D6 and D8 forming the fourth bridge arm.
[0051] The opposite-named end of the second secondary winding is connected in series with the winding internal resistance Ro2 and then connected to the midpoint of the third bridge arm. The same-named end of the second secondary winding is connected to the midpoint of the fourth bridge arm. The negative terminals of diodes D5 and D6 are connected in series with the trace resistance Rc2 and then connected to one end of the load. The positive terminals of diodes D7 and D8 are connected in series and then connected to the other end of the load.
[0052] Then the third coil winding is connected in series between the same-name end of the first secondary winding and the midpoint of the second bridge arm, and the same-name end of the third coil winding is connected to the same-name end of the first secondary winding.
[0053] The fourth coil winding is connected in series between the opposite end of the second secondary winding and the winding internal resistance Ro2, and the same end of the fourth coil winding is connected to the opposite end of the second secondary winding.
[0054] At this time, the same-name terminal of the third coil winding L3 is connected to the same-name terminal of the first secondary winding Ls1, and the same-name terminal of the fourth coil winding L4 is connected to the opposite-name terminal of the second secondary winding Ls2. The current enters from the same-name terminal of the third coil winding L3 and exits from the same-name terminal of the fourth coil winding L4, thus forming a loop to achieve the above-mentioned current sharing effect.
[0055] In another embodiment of this utility model, the first secondary circuit can be designed as follows:
[0056] The first secondary circuit includes winding internal resistance Ro1, trace resistance Rc1, diode D1, diode D2, diode D3, and diode D4;
[0057] In this circuit, diodes D1, D2, D3, and D4 form a full-bridge circuit, with diodes D1 and D3 forming the first bridge arm and diodes D2 and D4 forming the second bridge arm.
[0058] The same-named end of the first secondary winding is connected to the midpoint of the first bridge arm after being connected in series with the winding internal resistance Ro1. The opposite-named end of the first secondary winding is connected to the midpoint of the second bridge arm. The negative terminals of diodes D1 and D2 are connected in series with the trace resistance Rc1 and then connected to one end of the load. The positive terminals of diodes D3 and D4 are connected in series and then connected to the other end of the load.
[0059] The second secondary circuit can be designed as follows:
[0060] The second secondary circuit includes the winding internal resistance Ro2, the routing resistance Rc2, diode D5, diode D6, diode D7, and diode D8;
[0061] Among them, diodes D5, D6, D7, and D8 form a full-bridge circuit, with diodes D5 and D7 forming the third bridge arm and diodes D6 and D8 forming the fourth bridge arm.
[0062] The same-named end of the second secondary winding is connected in series with the winding internal resistance Ro2 and then connected to the midpoint of the third bridge arm. The opposite-named end of the second secondary winding is connected to the midpoint of the fourth bridge arm. The negative terminals of diodes D5 and D6 are connected in series with the trace resistance Rc2 and then connected to one end of the load. The positive terminals of diodes D7 and D8 are connected in series and then connected to the other end of the load.
[0063] Then, the third coil winding is connected in series between the opposite end of the first secondary winding and the midpoint of the second bridge arm, and the opposite end of the third coil winding is connected to the opposite end of the first secondary winding.
[0064] The fourth coil winding is connected in series between the same-name terminal of the second secondary winding and the winding internal resistance Ro2, and the opposite-name terminal of the fourth coil winding is connected to the same-name terminal of the second secondary winding.
[0065] At this time, the opposite-named end of the third coil winding L3 is connected to the opposite-named end of the first secondary winding Ls1, and the opposite-named end of the fourth coil winding L4 is connected to the same-named end of the second secondary winding Ls2. The current can enter from the same-named end of the third coil winding L3 and exit from the same-named end of the fourth coil winding L4, thus forming a loop to achieve the above-mentioned current sharing effect.
[0066] Please see Figure 5 Based on the above settings, the average current I(Rc1) after rectification of the first secondary winding Ls1 is about 1.5A, and the average current I(Rc2) after rectification of the second secondary winding Ls2 is about 1.5A. At this time, the current on the first secondary winding Ls1 and the second secondary winding Ls2 is very balanced, avoiding the problem of winding life reduction caused by uneven current in the prior art.
[0067] This utility model also proposes an electrical device having a power supply with the aforementioned transformer winding current sharing.
[0068] In summary, compared with the prior art, the present invention has at least the following beneficial effects:
[0069] This invention adds a common-mode inductor between the first and second secondary circuits of the transformer. Utilizing the inherent characteristics of the common-mode inductor, the current in the first and second secondary circuits is balanced, thereby avoiding the problem of uneven current distribution in the transformer windings. Compared to traditional designs, this invention uses fewer components and can solve the problem of uneven current distribution in transformer windings simply and efficiently.
[0070] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A power supply for transformer winding current sharing, comprising a transformer having a primary winding connected to a primary circuit, a first secondary winding connected to a first secondary circuit, and a second secondary winding connected to a second secondary circuit, wherein the first secondary circuit and the second secondary circuit are connected to the same load output, characterized in that, It also includes a current sharing circuit connected between the first secondary circuit and the second secondary circuit, the current sharing circuit being used to balance the current on the first secondary circuit and the second secondary circuit.
2. The power supply for transformer winding current sharing of claim 1, wherein, The current sharing circuit is a common-mode inductor composed of a third coil winding disposed in the first secondary circuit and a fourth coil winding disposed in the second secondary circuit.
3. The transformer winding current sharing power supply of claim 2, wherein, The first secondary circuit includes winding internal resistance Ro1, trace resistance Rc1, diode D1, diode D2, diode D3, and diode D4; The diodes D1, D2, D3, and D4 constitute a full-bridge circuit, with diodes D1 and D3 forming the first bridge arm and diodes D2 and D4 forming the second bridge arm. The opposite-named end of the first secondary winding is connected in series with the winding internal resistance Ro1 and then connected to the midpoint of the first bridge arm. The same-named end of the first secondary winding is connected to the midpoint of the second bridge arm. The negative terminals of diodes D1 and D2 are connected in series with the trace resistance Rc1 and then connected to one end of the load. The positive terminals of diodes D3 and D4 are connected in series and then connected to the other end of the load.
4. The transformer winding current sharing power supply of claim 3, wherein, The second secondary circuit includes winding internal resistance Ro2, trace resistance Rc2, diode D5, diode D6, diode D7, and diode D8; Diodes D5, D6, D7, and D8 form a full-bridge circuit, with D5 and D7 forming the third bridge arm and D6 and D8 forming the fourth bridge arm. The opposite-named end of the second secondary winding is connected in series with the winding internal resistance Ro2 and then connected to the midpoint of the third bridge arm. The same-named end of the second secondary winding is connected to the midpoint of the fourth bridge arm. The negative terminals of diodes D5 and D6 are connected in series with the trace resistance Rc2 and then connected to one end of the load. The positive terminals of diodes D7 and D8 are connected in series and then connected to the other end of the load.
5. The transformer winding current sharing power supply of claim 4, wherein, The third coil winding is connected in series between the same-name end of the first secondary winding and the midpoint of the second bridge arm, and the same-name end of the third coil winding is connected to the same-name end of the first secondary winding. The fourth coil winding is connected in series between the opposite end of the second secondary winding and the winding internal resistance Ro2, and the same end of the fourth coil winding is connected to the opposite end of the second secondary winding.
6. The transformer winding current sharing power supply of claim 2, wherein, The first secondary circuit includes winding internal resistance Ro1, trace resistance Rc1, diode D1, diode D2, diode D3, and diode D4; The diodes D1, D2, D3, and D4 constitute a full-bridge circuit, with diodes D1 and D3 forming the first bridge arm and diodes D2 and D4 forming the second bridge arm. The same-name terminal of the first secondary winding is connected in series with the winding internal resistance Ro1 and then connected to the midpoint of the first bridge arm. The opposite-name terminal of the first secondary winding is connected to the midpoint of the second bridge arm. The negative terminals of diodes D1 and D2 are connected in series with the trace resistance Rc1 and then connected to one end of the load. The positive terminals of diodes D3 and D4 are connected in series and then connected to the other end of the load.
7. The transformer winding current sharing power supply of claim 6, wherein, The second secondary circuit includes winding internal resistance Ro2, trace resistance Rc2, diode D5, diode D6, diode D7, and diode D8; Diodes D5, D6, D7, and D8 form a full-bridge circuit, with D5 and D7 forming the third bridge arm and D6 and D8 forming the fourth bridge arm. The same-name terminal of the second secondary winding is connected in series with the winding internal resistance Ro2 and then connected to the midpoint of the third bridge arm. The opposite-name terminal of the second secondary winding is connected to the midpoint of the fourth bridge arm. The negative terminals of diodes D5 and D6 are connected in series with the trace resistance Rc2 and then connected to one end of the load. The positive terminals of diodes D7 and D8 are connected in series and then connected to the other end of the load.
8. The transformer winding current sharing power supply of claim 7, wherein, The third coil winding is connected in series between the opposite end of the first secondary winding and the midpoint of the second bridge arm, and the opposite end of the third coil winding is connected to the opposite end of the first secondary winding. The fourth coil winding is connected in series between the same-name end of the second secondary winding and the winding internal resistance Ro2, and the opposite-name end of the fourth coil winding is connected to the same-name end of the second secondary winding.
9. An electric device, characterized by A power supply having transformer winding current sharing as described in any one of claims 1 to 8.