Transformer winding switching module in high-frequency isolation converter

Abstract

The utility model relates to the technical field of power electronic products, in particular to a transformer winding switching module in a high-frequency isolation converter, which comprises a transformer, a switch S1 and a plurality of diodes, the number of turns of a primary side winding of the transformer is n1, a secondary side is provided with two windings, and the number of turns is respectively n2 and n3; the switching of the transformer winding is realized by controlling the on and off of the switch S1, when the switch S1 is closed, the secondary winding of the transformer is connected in series for rectification output, and the output gain of the module is increased; when the switch S1 is switched off, the module output gain is reduced, and then dynamic winding switching within the full output voltage range is achieved. According to the utility model, dynamic winding switching can be realized in a full output voltage range, the gain of the transformer can be instantaneously changed, the primary working current can be reduced, the loop loss can be reduced, and constant-power and high-efficiency work of the converter in a wide voltage range can be realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of power electronic products, concretely relates to a transformer winding switching module in high frequency isolation converter. BACKGROUND

[0002] With the rapid development of electric vehicle industry, the efficiency requirement of electric vehicle charger is increasingly stringent. The output voltage range of charging station module is very wide, generally 250V-1000V voltage output. During the charging process, the charger needs to adapt to the wide range of output voltage while maintaining high efficient and stable working state. The traditional transformer has certain limitations in coping with such demand, which cannot effectively meet the dynamic adjustment in the full output voltage range, resulting in large primary working current, increased loop loss, and further affecting the overall working efficiency of the converter.

[0003] The existing patent with the name of "a transformer winding switching method" and the publication number CN109861603A can realize transformer winding switching and improve the efficiency of charging module at low output voltage, but has some deficiencies, such as two switching tubes need to be isolated and driven, which is relatively complex, the switching tube conduction loss is large and the heat dissipation problem needs to be considered, which is not conducive to the further improvement of module efficiency. Therefore, the technical personnel in the art provide a transformer winding switching module in high frequency isolation converter to solve the problems raised in the background technology. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a transformer winding switching module in high frequency isolation converter to solve the problems of low efficiency, complex switching tube driving and large loss of existing technology at wide voltage output, realize dynamic winding switching in the full output voltage range, and improve the efficiency of the converter.

[0005] The purpose of the utility model can be realized by the following technical solutions:

[0006] A transformer winding switching module in high frequency isolation converter, comprising a transformer, a switch S1 and a plurality of diodes, the primary winding turns of the transformer are n1, the secondary side has two windings with turns n2 and n3 respectively;

[0007] By controlling the closing and opening of the switch S1, the switching of the transformer winding is realized. When the switch S1 is closed, the transformer secondary winding is connected in series with the rectifier output, and the module output gain becomes larger;

[0008] When the switch S1 is opened, the module output gain becomes smaller, and the dynamic winding switching in the full output voltage range is realized.

[0009] Further, when the current flows from the transformer 1 pin to the 2 pin, if the switch S1 is closed, the output current of the transformer secondary flows from the 3 pin to the 5 pin, and the diodes D3, D4 are cut off; if the switch S1 is opened, the output current of the transformer secondary flows from the 4 pin to the 5 pin, and the diodes D1, D2 are cut off.

[0010] Further, when the current flows from the transformer 2 pin to the 1 pin, if the switch S1 is closed, the output current of the transformer secondary flows from the 5 pin to the 3 pin, and the diodes D3, D4 are cut off; if the switch is opened, the output current of the transformer secondary flows from the 5 pin to the 4 pin, and the diodes D1, D2 are cut off.

[0011] Further, the switch S1 is composed of two high-frequency switch tubes in series, and the two high-frequency switch tubes are controlled by a driving signal.

[0012] Further, the two high-frequency switch tubes are connected in parallel with a relay, and the high-frequency switch tube is only responsible for instantaneous conduction, and the long-time connection is realized by the relay.

[0013] The beneficial effects of the utility model are:

[0014] 1. The transformer winding switching module of the high-frequency isolation converter, a new transformer switching topology is provided, dynamic winding switching can be realized in the full output voltage range, the gain of the transformer is changed instantaneously, the primary working current is reduced, the loop loss is reduced, and constant power and high efficiency work in a wide voltage range of the converter are realized.

[0015] 2. The transformer winding switching module of the high-frequency isolation converter, the high-frequency switch tube is controlled by a driving signal, and isolation driving is not needed, the structure is simpler, the relay is used to reduce the conduction loss of the switch device, the high-frequency switch tube is only responsible for instantaneous conduction, the conduction time is very short, the loss is very small, and the heat dissipation of the switch tube does not need to be considered, and the long-time connection relies on the relay. DRAWINGS

[0016] The utility model will be further described below in combination with the drawings.

[0017] Figure 1 It is the switching principle diagram of the transformer winding switching module of the high-frequency isolation converter provided by the utility model;

[0018] Figure 2 It is the circuit principle diagram of the switch S1 in the transformer winding switching module of the high-frequency isolation converter provided by the utility model. CONCRETE IMPLEMENTATION

[0019] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present utility model.

[0020] Embodiment 1

[0021] Please refer to the drawings Figure 1 The transformer winding switching module in the high-frequency isolation transformer in the embodiment of the present utility model comprises a transformer, a switch S1 and a plurality of diodes (D1-D6), the primary winding of the transformer has a number of turns n1, the secondary winding has two windings, and the numbers of turns are n2 and n3 respectively.

[0022] Wherein, C1 is a filter capacitor, and R1 is a load.

[0023] The switching of the transformer winding is realized by controlling the closing and opening of the switch S1. When the switch S1 is closed, the secondary winding of the transformer is connected in series with a rectifier output, and the output gain of the module is increased.

[0024] Suppose that the output voltage of the transformer is Uo, the primary winding voltage of the transformer is Up, the primary winding current is Ip, and the secondary winding current is Is.

[0025] Specifically, when S1 is closed, the secondary winding of the transformer is connected in series with a rectifier output, the output voltage of the transformer is The output gain of the transformer is increased. When the current in the high-frequency transformer flows from the 1 pin of the transformer to the 2 pin and then flows out, the output current of the secondary winding of the transformer flows out from the 5 pin and then flows into the 3 pin, at this time, the secondary winding potential of the transformer is 3 pin>4 pin>5 pin, so the diodes D3 and D4 are cut off, and the diodes D1 and D2 are turned on. When the current in the high-frequency transformer flows from the 2 pin of the transformer to the 1 pin and then flows out, the output current of the secondary winding of the transformer flows out from the 3 pin and then flows into the 5 pin, at this time, the secondary winding potential of the transformer is 5 pin>4 pin>3 pin, so the diodes D3 and D4 are cut off, and the diodes D1 and D2 are turned on.

[0026] When the switch S1 is opened, the output gain of the module is decreased, and dynamic winding switching in the full output voltage range is realized.

[0027] Specifically, when S1 is opened, the output voltage of the transformer is The transformer output gain becomes smaller. When the current in the high-frequency converter flows from the 1 pin of the transformer to the 2 pin, the output current of the secondary side of the transformer flows from the 4 pin to the 5 pin, at this time, the potential of the secondary side of the transformer is 3 pin>4 pin>5 pin, since S1 is disconnected, the current of the 3 pin of the transformer has no loop, so the diodes D1 and D2 are cut off; when the current in the high-frequency converter flows from the 2 pin of the transformer to the 1 pin, the output current of the secondary side of the transformer flows from the 5 pin to the 4 pin, at this time, the potential of the secondary side of the transformer is 5 pin>4 pin>3 pin, similarly, the diodes D1 and D2 are cut off.

[0028] The output voltage of the charging station module has a wide range, generally 250V-1000V voltage output, and the module is required to maintain constant power output in the output voltage range, the relationship between the transformer voltage and the number of turns can be well utilized by the winding switching mode to meet the output wide voltage range, and the relationship between the transformer current and the number of turns can also be utilized to reduce the current of the primary side and the high-frequency chopping circuit when the output voltage is low voltage and large current, thereby reducing the loss of the primary side and improving the efficiency of the module.

[0029] The relationship between the transformer primary and secondary currents and the number of turns of the transformer is that when the switch S1 is closed, the primary current of the transformer is At this time, the output voltage of the charging module is high, and the output current is small; when the switch S1 is disconnected, the primary current of the transformer is At this time, the output voltage of the charging module is low, and the output current is large, and the number of secondary turns is reduced, and the increase of the primary current when S1 is attracted will not be large.

[0030] Embodiment 2

[0031] Please refer to Figure 1 and Figure 2 Based on the embodiment 1, the switch S1 is composed of two high-frequency switch tubes in series, and the two high-frequency switch tubes are controlled by one driving signal, without isolation driving, and the structure is simpler.

[0032] The high-frequency switch tube can be a semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT).

[0033] In addition, in the embodiment, the two high-frequency switch tubes are connected in parallel with a relay, and the high-frequency switch tube is only responsible for instantaneous conduction, and the long-time connection is realized by the relay. Thus, the relay is used to reduce the conduction loss of the switch device, and the high-frequency switch tube is only responsible for instantaneous conduction, and the conduction time is very short, and the loss is very small, and the heat dissipation of the switch tube does not need to be considered, and the long-time connection is realized by the relay.

[0034] The above has carried out the detailed description to one embodiment of the utility model, but the content described is only the preferred embodiment of the utility model, cannot be considered for limiting the implementation scope of the utility model. All equal changes and improvements etc. that are made in the utility model application scope should still belong to the patent coverage scope of the utility model.

Claims

1. A transformer winding switching module in a high frequency isolated converter comprising a transformer, a switch SI and a plurality of diodes, characterized in that: The primary winding of the transformer has n1 turns, and the secondary winding has two windings with n2 and n3 turns respectively; By controlling the closing and opening of the switch S1, the switching of the transformer winding is realized. When the switch S1 is closed, the output of the secondary winding of the transformer is in series with the rectifier, and the gain of the module output is increased. When the switch S1 is opened, the gain of the module output is decreased, and the dynamic winding switching in the full output voltage range is realized.

2. The transformer winding switching module in a high frequency isolated converter of claim 1, wherein: When the current flows from the 1 pin to the 2 pin of the transformer, if the switch S1 is closed, the output current of the secondary winding of the transformer flows from the 3 pin to the 5 pin, and the diodes D3 and D4 are cut off; if the switch S1 is opened, the output current of the secondary winding of the transformer flows from the 4 pin to the 5 pin, and the diodes D1 and D2 are cut off.

3. The transformer winding switching module in a high frequency isolated converter of claim 1, wherein: When the current flows from the 2 pin to the 1 pin of the transformer, if the switch S1 is closed, the output current of the secondary winding of the transformer flows from the 5 pin to the 3 pin, and the diodes D3 and D4 are cut off; if the switch S1 is opened, the output current of the secondary winding of the transformer flows from the 5 pin to the 4 pin, and the diodes D1 and D2 are cut off. The switch S1 is composed of two high-frequency switch tubes in series, and the two high-frequency switch tubes are controlled by a driving signal.

4. The transformer winding switching module in a high frequency isolated converter of claim 1, wherein: The two high-frequency switch tubes are connected in parallel with a relay, and the high-frequency switch tubes are only responsible for instantaneous conduction, and the long-time connection is realized by the relay.

5. A transformer winding switching module in a high frequency isolated converter according to claim 4, characterized in that: ​

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