TW202228376A - Redundancy switching power supply - Google Patents

Abstract

The utility model provides a redundant switching power supply comprising a three-phase transformer which comprises a primary winding used for being connected to a three-phase alternating current, and a first secondary winding and a second secondary winding which are used for outputting a first alternating current and a second alternating current which are electrically isolated; the first switching power supply module is used for converting first alternating current output by the first secondary winding into required direct current; and the second switching power supply module is used for converting the second alternating current output by the second secondary winding into the required direct current. The redundancy switching power supply provided by the utility model has relatively low cost.

Description

Redundant switching power supplies

The new model relates to the field of electronic circuits, in particular to a redundant switching power supply.

The switching power supply is a power supply that uses modern power electronics technology to control the on and off time of the switching tube, thereby outputting a stable DC voltage. There are two types of switching power supply, one is DC switching power supply, and the other is AC switching power supply.

FIG. 1 is a circuit diagram of a redundant switching power supply connected to three-phase alternating current in the prior art. As shown in FIG. 1, the redundant switching power supply 1 includes fuses R11, R12 and R13, transformers T11, T12 and T13, and switches The power modules 14 and 15, wherein one end of the primary winding (or primary side) of the transformer T11 is connected to the single-phase alternating current 11 through the fuse R11, the other end is connected to the single-phase alternating current 12, and one end of the primary winding of the transformer T12 passes through The fuse R12 is connected to the single-phase AC power 12 and the other end thereof is connected to the single-phase AC power 13, and one end of the primary winding of the transformer T13 is connected to the single-phase AC power 13 via the fuse R13, and the other end is connected to the single-phase AC power 11. One end of the secondary winding (or secondary side) of the transformers T11, T12 and T13 is connected to the neutral line N, and the other ends of the transformers T11, T12 and T13 are connected to the three-phase input terminal of the switching power supply module 14, and at the same time Connected to the three-phase input terminal of the switching power supply module 15 .

The transformers T11, T12 and T13 respectively step down the AC voltage (for example, 480 volts) of the single-phase AC powers 11, 12 and 13 to 120 volts of AC power, and the three-phase AC input terminal of the switching power supply module 14 receives the 120-volt three-phase AC power , and output the required DC voltage. Similarly, the three-phase AC input end of the switching power supply module 15 receives the three-phase AC power of 120 volts and outputs the required DC voltage. Since the switching power supply module 14 and the switching power supply module 15 are the same, one of the switching power supply modules can be used as a backup of the other switching power supply, thereby providing redundant DC voltage to ensure reliable operation of the electrical device.

However, the existing redundant switching power supply 1 uses three transformers to step down the three-phase AC power to output the step-down three-phase AC power. The cost of the three transformers is relatively high, and the wiring method of the secondary winding is very complicated. Error prone. In addition, each of the switching power supply modules 14 and 15 includes a three-phase rectifier to rectify the three-phase alternating current, and the three-phase rectifier also has a high cost.

In view of the above-mentioned technical problems existing in the prior art, the present invention provides a redundant switching power supply, including: a three-phase transformer including a primary winding for connection to three-phase alternating current, and first and second secondary windings for outputting electrically isolated first and second alternating currents; a first switching power supply module for converting the first alternating current output from the first secondary winding into required direct current; and The second switching power supply module is used for converting the second alternating current output from the second secondary winding into the required direct current.

Preferably, the primary winding includes a first primary winding and a second primary winding, one terminal of the first primary winding is connected to the first-phase alternating current, and the other terminal thereof is connected to the center branch of the second primary winding. A joint, the two terminals of the second primary winding are respectively connected to the second-phase alternating current and the third-phase alternating current.

。 Preferably, the ratio of the number of turns of the second primary winding to the number of turns of the first primary winding is 1:

.

Preferably, the number of turns of the first secondary winding is equal to the number of turns of the second secondary winding.

Preferably, the first primary winding, the second primary winding, the first secondary winding and the second secondary winding are wound on the same magnetic core.

Preferably, the first switching power supply module includes: a first single-phase rectifier whose input end is connected to both ends of the first secondary winding; and a first DC/DC converter whose input end is connected to The output end of the first single-phase rectifier is used for outputting the required direct current.

Preferably, the first switching power supply module further includes an output fuse connected to the output end of the first DC/DC converter.

Preferably, the first DC/DC converter is a step-down chopper circuit.

Preferably, the second switching power supply module comprises: a second single-phase rectifier whose input end is connected to both ends of the second secondary winding; and a second DC/DC converter whose input end is connected to The output end of the second single-phase rectifier is used for outputting the required direct current.

Preferably, the redundant switching power supply includes an input fuse connected between the three-phase alternating current and the primary winding of the three-phase transformer.

The new redundant switching power supply has low cost, simple wiring, and can output stable DC voltage.

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

FIG. 2 is a circuit diagram of a redundant switching power supply connected to a three-phase alternating current according to a preferred embodiment of the present invention. As shown in FIG. 2 , the redundant switching power supply 2 includes a three-phase transformer T2, and switching power supply modules 24 and 25 connected to the three-phase transformer T2.

，次級繞組27及次級繞組29的匝數相同。 The three-phase transformer T2 includes a primary winding 26 , a secondary winding 27 , a primary winding 28 and a secondary winding 29 . One terminal 261 of the primary winding 26 is connected to the single-phase alternating current 21 , and the other terminal 262 thereof is connected to the center tap 283 of the primary winding 28 . The two terminals 281 and 282 of the primary winding 28 are connected to the single-phase alternating current 22 and the single-phase alternating current 23, respectively. The secondary winding 27 is connected to the switching power supply module 24 , and the secondary winding 29 is connected to the switching power supply module 25 . The ratio of the number of turns of the primary winding 28 to the number of turns of the primary winding 26 is 1

, the number of turns of the secondary winding 27 and the secondary winding 29 are the same.

The switching power supply module 24 includes a single-phase rectifier 241, a DC/DC converter 242 and an output fuse 243, wherein the input end of the single-phase rectifier 241 is connected to both ends of the secondary winding 27 of the three-phase transformer T2, and the DC/DC conversion The input terminal of the rectifier 242 is connected to the output terminal of the single-phase rectifier 241 , and the output fuse 243 is connected to the output terminal of the DC/DC converter 242 .

The switching power supply module 25 is the same as the switching power supply module 24 , and details are not repeated here.

The primary windings 26, 28 of the three-phase transformer T2 are connected to the three-phase alternating currents 21, 22, 23, and the secondary windings 27, 29 of the three-phase transformer T2 output two electrically isolated single-phase alternating currents with a phase difference of 90°. The single-phase rectifier 241 rectifies the alternating current output from the secondary winding 27 into direct current, and the DC/DC converter 242 converts (eg, steps down) the direct current output from the single-phase rectifier 241 into the required direct current.

The magnetic core of the three-phase transformer T2 of the present invention can be formed by a single magnetic core such as EI type and EE type, that is, the primary winding 26, the secondary winding 27, the primary winding 28 and the secondary winding 29 are wound on the same magnetic core. Compared with the transformers T11, T12 and T13 shown in FIG. 1, the cost is reduced. Compared with the switching power supply module 14 shown in FIG. 1 , the switching power supply module 24 has fewer rectifier devices (eg, rectifier diodes) in the single-phase rectifier 241 , and the cost is lower. During the wiring process with the three-phase transformer T2 , the input end of the single-phase rectifier 241 only needs to be connected to both ends of one of the secondary windings of the three-phase transformer T2, and the connection method with the other secondary winding does not need to be considered, so the wiring is simpler.

FIG. 3 is a waveform diagram of the input current, output voltage and output current of the redundant switching power supply shown in FIG. 2 when connected to different loads. The load connected to the output end of the switching power supply module 24 is smaller than the load connected to the output end of the switching power supply module 25, and I1, I2, and I3 are the currents in the alternating currents 21, 22, and 23 respectively (that is, the input of the redundant switching power supply 2). current), V1 and V2 are the output voltages of the secondary windings 27 and 29, respectively, and I4 and I5 are the output currents of the secondary windings 27 and 29.

As shown in Figure 3, the phases of the currents I1, I2 and I3 in the alternating currents 21, 22 and 23 are 120° out of phase, and the current I1 is slightly larger than the current I2 or I3, and the output current I4 is slightly larger than the output current I5. The phase difference between the output voltage V1 and the output voltage V2 is 90°, and the output voltage V1 is equal to the output voltage V2. Even if the loads connected to the switching power supply module 24 and the switching power supply module 25 are different, the three-phase transformer T2 can output two single-phase alternating currents with the same voltage value. Since the voltage values of the single-phase alternating current at the input ends of the switching power supply module 24 and the switching power supply module 25 are the same, after single-phase rectification and DC/DC conversion, the two can output the same DC voltage.

In other embodiments of the invention, the three-phase transformer T2 is replaced by two single-phase transformers, wherein one terminal of the primary winding of one single-phase transformer is connected to the center tap of the primary winding of the other single-phase transformer; or by Replace with other types of transformers capable of converting three-phase alternating current into two-phase alternating current.

In another embodiment of the present invention, the redundant switching power supply further includes an input fuse connected between the three-phase alternating currents 21, 22, 23 and the primary winding of the three-phase transformer T2.

The present invention does not intend to limit the specific circuit structure of the single-phase rectifier 241, which may be a full-wave rectifier circuit or a half-wave rectifier circuit.

According to the turns ratio of the primary winding and the secondary winding of the three-phase transformer T2 and the required DC voltage, the DC/DC converter 242 of the present invention can be a step-up or step-down DC/DC converter, such as It is a boost chopper circuit (or Boost circuit) or a step-down chopper circuit (or Buck circuit). For example, when the alternating currents 21 , 22 , and 23 provide 480 volts of alternating current, and the switching power supply modules 24 and 25 output 12 volts or 24 volts of direct current, the DC/DC converter is preferably a Buck circuit.

In other embodiments of the present invention, the secondary winding 27 and the secondary winding 29 have different turns, and the switching power supply module 24 and the switching power supply module 25 output the same or different DC voltages.

Although the present invention has been described through the preferred embodiments, the present invention is not limited to the embodiments described herein, and further includes various changes and changes made without departing from the scope of the present invention.

1: Redundant switching power supply 2: Redundant switching power supply 11: Single-phase AC 12: single-phase alternating current 13: single-phase alternating current 14: Switching power supply module 15: Switching power supply module 21: single-phase alternating current; three-phase alternating current 22: single-phase alternating current; three-phase alternating current 23: single-phase alternating current; three-phase alternating current 24: Switching power supply module 25: Switching power supply module 26: Primary winding 27: Secondary winding 28: Primary winding 29: Secondary winding 241: Single-phase rectifier 242: DC/DC Converter 243: Output fuse 261: Terminal 262: Terminal 281: Terminal 282: Terminal 283: Center tap I1: Current I2: Current I3: Current I4: output current I5: output current N: Neutral R11: Fuse R12: Fuse R13: Fuse T2: Three-phase transformer T11: Transformer T12: Transformer T13: Transformer V1: output voltage V2: output voltage

Embodiments of the present invention will be further described below with reference to the accompanying drawings, wherein: [FIG. 1] is a circuit diagram of a redundant switching power supply in the prior art connected with three-phase alternating current. [FIG. 2] is a circuit diagram of a redundant switching power supply connected to a three-phase alternating current according to a preferred embodiment of the present invention. [Fig. 3] is a waveform diagram of input current, output voltage and output current when the redundant switching power supply shown in Fig. 2 is connected to different loads.

2: Redundant switching power supply

21: single-phase alternating current; three-phase alternating current

22: single-phase alternating current; three-phase alternating current

23: single-phase alternating current; three-phase alternating current

24: Switching power supply module

25: Switching power supply module

26: Primary winding

27: Secondary winding

28: Primary winding

29: Secondary winding

241: Single-phase rectifier

242: DC/DC Converter

243: Output fuse

261: Terminal

262: Terminal

281: Terminal

282: Terminal

283: Center tap

T2: Three-phase transformer

Claims (10)

A redundant switching power supply, comprising: a three-phase transformer including a primary winding for connection to three-phase alternating current, and first and second secondary windings for outputting electrically isolated first and second alternating currents; a first switching power supply module for converting the first alternating current output from the first secondary winding into required direct current; and The second switching power supply module is used for converting the second alternating current output from the second secondary winding into the required direct current. The redundant switching power supply of claim 1, wherein the primary winding includes a first primary winding and a second primary winding, one terminal of the first primary winding is connected to the first-phase alternating current, and the other terminal thereof is connected to the The center tap of the second primary winding is connected, and the two terminals of the second primary winding are respectively connected to the second-phase alternating current and the third-phase alternating current. The redundant switching power supply of claim 2, wherein the ratio of the number of turns of the second primary winding to the number of turns of the first primary winding is 1:

. The redundant switching power supply of claim 2, wherein the number of turns of the first secondary winding is equal to the number of turns of the second secondary winding. The redundant switching power supply of claim 2, wherein the first primary winding, the second primary winding, the first secondary winding and the second secondary winding are wound on the same magnetic core. The redundant switching power supply according to any one of claims 1 to 5, wherein the first switching power supply module comprises: a first single-phase rectifier having an input connected to both ends of the first secondary winding; and The input end of the first DC/DC converter is connected to the output end of the first single-phase rectifier, and the output end thereof is used for outputting the required direct current. The redundant switching power supply of claim 6, wherein the first switching power supply module further comprises an output fuse connected to the output end of the first DC/DC converter. The redundant switching power supply of claim 6, wherein the first DC/DC converter is a step-down chopper circuit. The redundant switching power supply according to any one of claims 1 to 5, wherein the second switching power supply module comprises: a second single-phase rectifier having an input connected to both ends of the second secondary winding; and The input terminal of the second DC/DC converter is connected to the output terminal of the second single-phase rectifier, and the output terminal is used for outputting the required direct current. The redundant switching power supply of claim 1, wherein the redundant switching power supply comprises an input fuse connected between the three-phase alternating current and the primary winding of the three-phase transformer.

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