Multi-transformer rectifier circuit

Abstract

A multi-transformer rectifier circuit includes at least one output-end current input module, at least one output-end current output module, and at least one current diversion module. These modules work collaboratively to provide power to a DC bus or load, making them suitable for applications with multiple AC input sources. Not only does the circuit offer diverse structures, but the number of inductor and diode series branches in the current diversion module can be varied, enhancing the adjustability of the multi-transformer rectifier circuit.

Description

Technical Field

[0001] The present invention relates to a rectifier circuit, and in particular to a rectifier circuit comprising a plurality of transformers. Background Art

[0002] A rectifier circuit is a circuit that can convert alternating current (AC) into direct current (DC) and is widely used in industries such as electricity, transportation, metallurgy, petroleum, and chemical industry.

[0003] With the development of new energy generation technologies, AC power sources have become more diverse. In addition to traditional thermal, hydropower, and nuclear power generators, they now also include wind, solar thermal, tidal, and hydrogen power generators. Therefore, rectifier circuits also need to be able to utilize multiple AC power sources simultaneously.

[0004] Currently, typical rectifier circuits are typically single-input, single-output. To utilize multiple AC power sources simultaneously, most solutions employ a "single-phase, multiple" strategy to construct a composite rectifier circuit. Specifically, multiple identical and independent sub-rectifier circuits with single input and single output are constructed, with their inputs remaining independent but their outputs connected in parallel. While this "single-phase, multiple" composite rectifier circuit offers a simple structure and easy-to-understand operating principle, overall circuit simplification is not achieved, and utilization of multiple AC power sources is not fully utilized. To address this issue, the present invention proposes a multi-transformer rectifier circuit. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems in the prior art and to provide a multi-transformer rectifier circuit that can simplify the circuit and fully utilize multiple AC power sources.

[0006] To achieve the above objectives, the present invention proposes a multi-transformer rectifier circuit, comprising at least one output-end current input module, at least one output-end current output module, and at least one current diversion module.

[0007] The output current input module includes a transformer:

[0008] The transformer has two ports of its primary winding connected to the AC power supply, and two ports of its secondary winding are intermediate ports, with the intermediate tap of the secondary winding connected to the negative end of the DC bus or one end of the load. The intermediate port can be connected to the current diversion module.

[0009] The output current output module includes a transformer:

[0010] The transformer has two ports of its primary winding connected to the AC power supply, and two ports of its secondary winding are intermediate ports. The intermediate tap of the secondary winding is connected to the positive end of the DC bus or the other end of the load. The intermediate port can be connected to the current diversion module.

[0011] The current diversion module includes at least one inductor and diode series branch. One end of the inductor and diode series branch is connected to any middle port of the output current input module, and the other end of the inductor and diode series branch is connected to any middle port of the output current output module. The current flow direction is from the output current input module to the inductor and diode series branch to the output current output module. The number of inductor and diode series branches in the current diversion module can be variable. The diode in the inductor and diode series branch prevents circulating current.

[0012] Preferably, the output-end current input module has another structure, including a transformer and two diodes:

[0013] The transformer has two ports of its primary winding connected to an AC power source, and two ports of its secondary winding and a middle tap as middle ports;

[0014] The anode of the first diode and the anode of the second diode are both connected to the negative end of the DC bus or one end of the load, the cathode of the first diode is connected to one end of the secondary winding of the transformer, and the cathode of the second diode is connected to the other end of the secondary winding of the transformer.

[0015] Preferably, the output-end current output module further includes another structure, including a transformer and two diodes:

[0016] The transformer has two ports of its primary winding connected to an AC power source, and two ports of its secondary winding and a middle tap as middle ports;

[0017] The cathode of the first diode and the cathode of the second diode are both connected to the positive end of the DC bus or the other end of the load, the anode of the first diode is connected to one end of the secondary winding of the transformer, and the anode of the second diode is connected to the other end of the secondary winding of the transformer.

[0018] The most basic unit of the multi-transformer rectifier circuit is "one output-end current input module + one output-end current output module + one current diversion module." Excluding the current diversion module, the combination of the output-end current input module and the output-end current output module alone presents four basic unit structures. Including the current diversion module further expands the basic unit structure.

[0019] On the basis of the basic structure, a composite structure of "multiple output-end current input modules + multiple output-end current output modules + multiple diversion modules" can be further realized, including one output-end current input module connected to multiple diversion modules, one output-end current output module connected to multiple diversion modules, and a combination of different basic structures.

[0020] Any of the above diodes can be replaced by a controllable switching device (such as a synchronous rectification MOSFET).

[0021] The AC power source may be a multi-level AC power source with two or more levels, including a sinusoidal AC power source; and may be from the same source or different sources.

[0022] The beneficial effects of the present invention are mainly manifested in that, compared with the existing "single-phase multiple" composite rectifier circuit, the output-end current input type module and the output-end current output type module of the multi-transformer rectifier circuit of the present invention cannot work independently. They both need to work in conjunction with the current diversion module to jointly convert the electrical energy of multiple AC power sources. The basic structure and composite structure that can be formed are diverse, especially the number of inductor and diode series branches in the current diversion module is variable, which can improve the adjustability of the entire circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a circuit diagram of embodiment 1 of the present invention.

[0024] Figure 2 2 is an output power characteristic diagram of Example 1 of the present invention.

[0025] Figure 3 This is a circuit diagram of embodiment 2 of the present invention.

[0026] Figure 4 2 is an output power characteristic diagram of Example 2 of the present invention.

[0027] Figure 5 2 is a graph showing the output voltage ripple characteristics of Example 2 of the present invention.

[0028] Figure 6 This is a circuit diagram of embodiment 3 of the present invention.

[0029] Figure 7 2 is an output power characteristic diagram of Example 3 of the present invention.

[0030] Figure 8 3 is an output voltage ripple characteristic diagram of embodiment 3 of the present invention.

[0031] Figure 9 This is a circuit diagram of embodiment 4 of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the accompanying drawings. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. In the following description, numerous specific details are set forth to facilitate a thorough understanding of the present invention. However, those skilled in the art will appreciate that these specific details are not necessary for practicing the present invention. In addition, in some embodiments, to avoid obscuring the present invention, well-known circuits, materials, or methods are not described in detail.

[0033] Throughout this specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combinations and / or subcombinations in one or more embodiments or examples. Furthermore, it will be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes only and that like reference numerals indicate like elements. It will be understood that when an element is referred to as being "connected to" or "coupled to" another element, it may be directly connected or coupled to the other element, or there may be intervening elements.

[0034] Example 1

[0035] Reference Figure 1 A multi-transformer rectifier circuit includes at least one output-end current input module, at least one output-end current output module, and at least one current diversion module. The output-end current input module, the output-end current output module, and the current diversion module have the same structure.

[0036] Among them, one output-end current input type module is A1, one output-end current output type module is a1, and one current diversion module is J1.

[0037] The output current input module A1 includes a transformer T 1A . Transformer T 1A The two terminals of the primary winding are connected to the AC power supply V AC1 The two ports 1_A and 1_B of the secondary winding are the middle ports, and the middle tap of the secondary winding is connected to the negative terminal V o - Or one end of the load, the middle ports 1_A and 1_B are connected to the diversion module J1.

[0038] The output current output module a1 includes a transformer T 1a . Transformer T 1aThe two terminals of the primary winding are connected to the AC power supply V ac1 The two ports 1_a and 1_b of the secondary winding are the middle ports, and the middle tap of the secondary winding is connected to the positive terminal V o + Or the other end of the load, the middle ports 1_a and 1_b are connected to the flow guide module J1.

[0039] The flow guide module J1 includes four inductor and diode series branches: the first inductor and diode series branch is an inductor L a1 and diode D a1 In series, the inductor L a1 One end of the inductor is connected to the middle port 1_A of A1, and the inductor L a1 The other end of the diode D a1 The anode of diode D a1 The cathode of a1 is connected to the middle port 1_a; the second inductor and diode series branch is connected to the inductor L b1 and diode D b1 In series, the inductor L b1 One end of the inductor is connected to the middle port 1_A of A1, and the inductor L b1 The other end of the diode D b1 The anode of diode D b1 The cathode of is connected to the middle port 1_b of a1; the third inductor and diode series branch is connected to the inductor L c1 and diode D c1 In series, the inductor L c1 One end of the inductor is connected to the middle port 1_B of A1, and the inductor L c1 The other end of the diode D c1 The anode of diode D c1 The cathode of a1 is connected to the middle port 1_a; the fourth inductor and diode series branch is connected to the inductor L d1 and diode D d1 In series, the inductor L d1 One end of the inductor is connected to the middle port 1_B of A1, and the inductor L d1 The other end of the diode D d1 The anode of diode D d1 The cathode of the inductor is connected to the middle port 1_b of a1. In addition to limiting the direction of current flow, the diodes in the inductor and diode series branches also prevent circulating current when the number of inductor and diode series branches is greater than one. The number of inductor and diode series branches in the current diversion module J1 is variable, ranging from 0 to 4.

[0040] For ease of understanding, Figure 1 Only a portion of the entire multi-transformer rectifier circuit is shown—A1, a1, and J1. Figure 1 Taking the displayed part as an example, the focus is on the steady-state working process of the output-end current input type module, the output-end current output type module, and the diversion module working in coordination.

[0041] For simplicity, it is assumed that A1 and a1 use the same components, transformer T 1A The first port of the primary winding and the secondary winding port 1_A are the same-name terminals. 1a The first port of the primary winding and the secondary winding port 1_a are the same-name terminals. 1A and T 1a The middle tap is taken as the center tap; the AC power supply v connected to A1 AC1 For a two-level AC power supply (+V AC1 、-V AC1 ), the AC power supply v connected to a1 ac1 Also a two-level AC power supply (+A·V AC1 、-A·V AC1 ), A is a constant. Take A>1 as an example to illustrate. Figure 1 A working cycle T1 of the circuit shown can be divided into two stages. A typical working condition is as follows:

[0042] (1) Phase 1: v AC1 =+V AC1 , v ac1 =+A·V AC1

[0043] J1: D b1 conduction, D a1 and D d1 Cut-off, (a)v AC1 T 1A 、v ac1 T 1a With L b1 、D b1 , DC bus or load forms the first loop, flowing through L b1 and D b1 The current in the series branch i b1 increase; (b)v AC1 T 1A 、v ac1 T 1a With L c1 、D c1 , DC bus or load forms the second circuit, D c1 conduction until the current flows through L c1 and D c1 The current in the series branch i c1 Decrease to 0.

[0044] (2) Phase 2: vAC1 =-V AC1 , v ac1 =-A·V AC1

[0045] J1: D c1 conduction, D a1 and D d1 Cut-off, (a)v AC1 T 1A 、v ac1 T 1a With L c1 、D c1 , DC bus or load forms the first loop, flowing through L c1 and D c1 The current in the series branch i c1 increase; (b)v AC1 T 1A 、v ac1 T 1a With L b1 、D b1 , DC bus or load forms the second circuit, D b1 conduction until the current flows through L b1 and D b1 The current in the series branch i b1 Decrease to 0.

[0046] From the above working process, we can see that v AC1 T 1A 、v ac1 T 1a Power the DC bus or load in series.

[0047] The working process of the inductor and diode series branches in J1 with the number of 1 to 3 is similar to the above and will not be repeated here. In order to understand the influence of J1 on the adjustability of the entire circuit, further assume that V AC1 =20V,v AC1 The period T1=20μs, v AC1 +V AC1 The pulse width is T1 / 2, v AC1 -V AC1 The pulse width is also T1 / 2, T 1A and T 1a The primary and secondary turns ratios are both 1:4, the coupling coefficients are both 0.999, and the load is R = 25Ω / / C o =1μF. Three cases are described below: Case 1: A = 1.25; Case 2: A = 1; Case 3: A = 0.8.

[0048] Take L a1 =L b1 =L c1=L d1 =300μH, Figure 2 The output power performance of the embodiment 1 of the present invention under the above three conditions is given. Figure 2 It can be seen that the number of inductor and diode series branches inside J1 affects the output power of Example 1. Making the number of inductor and diode series branches variable can increase the flexibility of controlling Example 1.

[0049] Example 2

[0050] Reference Figure 3 A multi-transformer rectifier circuit includes at least one output-end current input module, at least one output-end current output module, and at least one current diversion module. The output-end current input module, the output-end current output module, and the current diversion module have the same structure.

[0051] Among them, one output-end current input type module is A1, one output-end current output type module is a1, and one current diversion module is J1.

[0052] The output current input module A1 includes a transformer T 2A , diode D 2A and diode D 2B . T 2A The two terminals of the primary winding are connected to the AC power supply V AC1 The two ports 1_A and 1_B of the secondary winding and the middle tap 1_C are the middle ports, and the middle port 1_C is connected to the diversion module J1. 2A The anode and diode D 2B The anodes are connected to the negative terminal of the DC bus V o - Or one end of the load is connected, diode D 2A The cathode of diode D is connected to the middle port 1_A. 2B The cathode of is connected to the middle port 1_B.

[0053] The flow guide module J1 includes two inductor and diode series branches: the first inductor and diode series branch is an inductor L a2 and diode D a2 In series, the inductor L a2 One end of the inductor is connected to the middle port 1_C of A1, and the inductor L a2 The other end of the diode D a2 The anode of diode D a2 The cathode of a1 is connected to the middle port 1_a; the second inductor and diode series branch is connected to the inductor L b2 and diode D b2 In series, the inductor L b2One end of the inductor is connected to the middle port 1_C of A1, and the inductor L b2 The other end of the diode D b2 The anode of diode D b2 The cathode of the inductor is connected to the middle port 1_b of a1. In addition to limiting the direction of current flow, the diodes in the inductor and diode series branches also prevent circulating current when the number of inductor and diode series branches is greater than one. The number of inductor and diode series branches in the current diversion module J1 is variable, ranging from 0 to 2.

[0054] The rest of the structure is the same as that of Example 1.

[0055] For ease of understanding, Figure 3 Only a portion of Example 2—A1, a1, and J1—is shown. Figure 3 Taking the displayed part as an example, the focus is on the steady-state working process of the output-end current input type module, the output-end current output type module, and the diversion module working in coordination.

[0056] For simplicity, it is assumed that A1 and a1 use the same components, transformer T 2A The first port of the primary winding and the secondary winding port 1_A are the same-name terminals. 1a The first port of the primary winding and the secondary winding port 1_a are the same-name terminals. 2A and T 1a The middle tap is taken as the center tap; the AC power supply v connected to A1 AC1 For a two-level AC power supply (+V AC1 、-V AC1 ), the period is T1, the AC power supply v connected to a1 ac1 (t) = v AC1 (tB*T1), that is, v AC1 and v ac1 The amplitude or level value and frequency are the same, but the initial phase is different. Take B = 0.5 as an example to illustrate. Figure 3 A working cycle T1 of the circuit shown can be divided into two stages. A typical working condition is as follows:

[0057] (1) Phase 1: v AC1 =+V AC1 &v ac1 =-V AC1

[0058] In A1: D 2B conduction, D 2A Cut-off;

[0059] J1: D a2 conduction, (a)v AC1 T2A 、v ac1 T 1a With L a2 、D a2 , DC bus or load, D 2B Forming the first loop, flowing through L a2 and D a2 The current in the series branch i a2 increase; (b)v AC1 T 2A 、v ac1 T 1a With L b2 、D b2 , DC bus or load, D 2B Forming the second loop, D b2 conduction until the current flows through L b2 and D b2 The current in the series branch i b2 Decrease to 0.

[0060] (2) Phase 2: v AC1 =-V AC1 &v ac1 =+V AC1

[0061] In A1: D 2A conduction, D 2B Cut-off;

[0062] J1: D b2 conduction, (a)v AC1 T 2A 、v ac1 T 1a With L b2 、D b2 , DC bus or load, D 2A Forming the first loop, flowing through L b2 and D b2 The current in the series branch i b2 increase; (b)v AC1 T 2A 、v ac1 T 1a With L a2 、D a2 , DC bus or load, D 2A Forming the second loop, D a2 conduction until the current flows through L a2 and D a2 The current in the series branch i a2 Decrease to 0.

[0063] From the above working process, we can see that v AC1 T 2A、v ac1 T 1a Power the DC bus or load in series.

[0064] The working process of the inductor and diode series branch in J1 is similar to the above and will not be repeated here. To facilitate understanding of the influence of J1 on the adjustability of the entire circuit, further assume that V AC1 =20V,v AC1 The period T1=20μs, v AC1 +V AC1 The pulse width is T1 / 2, v AC1 -V AC1 The pulse width is also T1 / 2, T 2A and T 1a The primary and secondary turns ratios are both 1:4, the coupling coefficients are both 0.999, and the load is R = 25Ω / / C o =1μF. Three cases are described below: Case 1: B = 0.5; Case 2: B = 0.25; Case 3: B = 0.

[0065] Take L a2 =L b2 =100μH, Figure 4 The output power performance of the embodiment 2 of the present invention under the above three conditions is given. Figure 5 The output voltage ripple performance of the embodiment 2 of the present invention under the above three conditions is given. Figure 4 and Figure 5 It can be seen that the number of inductor and diode series branches inside J1 affects both the output power and output voltage ripple of Example 2. Making the number of inductor and diode series branches variable can increase the flexibility of controlling Example 2.

[0066] Apart from Figure 3 The circuit shown in Example 2 also has other possible structures. An inductor and diode series branch can exist between any intermediate port (1_A, 1_B, and 1_C) of A1 and any intermediate port (1_a and 1_b) of a1. The operating principles of other structures of Example 2 are similar to those disclosed in Example 2 above and are not further described.

[0067] Example 3

[0068] Reference Figure 6 A multi-transformer rectifier circuit includes at least one output-end current input module, at least one output-end current output module, and at least one current diversion module. The output-end current input module, the output-end current output module, and the current diversion module have the same structure.

[0069] Among them, one output-end current input type module is A1, one output-end current output type module is a1, and one current diversion module is J1.

[0070] The output current output module a1 includes a transformer T 2a , diode D 2a and diode D 2b The transformer T 2a The two terminals of the primary winding are connected to the AC power supply V AC1 The two ports 1_a and 1_b of the secondary winding and the middle tap 1_c are the middle ports, and the middle port 1_c is connected to the diversion module J1. 2a The cathode and diode D 2b The cathode of each is connected to the positive terminal of the DC bus V o + Or the other end of the load is connected; diode D 2a The anode of the transformer T 2a The secondary winding port 1_a is connected to the diode D 2b The anode of the transformer T 2a The secondary winding port 1_b is connected.

[0071] The diversion module J1 includes an inductor and a diode in series. a3 and diode D a3 In series, the inductor L a3 One end of the inductor is connected to the middle port 1_C of A1, and the inductor L a3 The other end of the diode D a3 The anode of diode D a3 The cathode of a1 is connected to the middle port 1_c of a1. In addition to limiting the direction of current flow, the diode in the series inductor-diode branch also prevents circulating current when the number of current diversion modules is greater than one. The number of series inductor-diode branches in the current diversion module J1 is variable, ranging from 0 to 1.

[0072] The rest of the structure is the same as that of Example 2.

[0073] For ease of understanding, Figure 6 Only a portion of Example 3 - A1, a1 and J1 - is shown. Figure 6 Taking the displayed part as an example, the focus is on the steady-state working process of the output-end current input type module, the output-end current output type module, and the diversion module working in coordination.

[0074] For simplicity, it is assumed that A1 and a1 use the same components, transformer T 2A The first port of the primary winding and the secondary winding port 1_A are the same-name terminals. 2aThe first port of the primary winding and the secondary winding port 1_a are the same-name terminals. 2A and T 2a The middle tap is taken as the center tap; the AC power supply v connected to A1 AC1 For a two-level AC power supply (+V AC1 、-V AC1 ), the period is T1, the AC power supply v connected to a1 ac1 (t) = v AC1 (a*t), that is, v AC1 and v ac1 The amplitude or level value and initial phase are the same, but the frequency and period are different. This is explained by taking a=2 as an example. Figure 6 A working cycle T1 of the circuit shown can be divided into four stages. A typical working condition is as follows:

[0075] (1) Phase 1: v AC1 =+V AC1 &v ac1 =+V AC1

[0076] In A1: D 2B conduction, D 2A Cut-off; a1: D 2a conduction, D 2b Cut-off;

[0077] J1: D a3 conduction, v AC1 T 2A 、v ac1 T 2a With L a3 、D a3 、D 2a , DC bus or load, D 2B This forms a loop.

[0078] (2) Phase 2: v AC1 =+V AC1 &v ac1 =-V AC1

[0079] In A1: D 2B conduction, D 2A Cut-off; a1: D 2b conduction, D 2a Cut-off;

[0080] J1: D a3 conduction, v AC1 T 2A 、v ac1 T 2a With L a3 、Da3 、D 2b , DC bus or load, D 2B This forms a loop.

[0081] (3) Phase 3: v AC1 =-V AC1 &v ac1 =+V AC1

[0082] In A1: D 2A conduction, D 2B Cut-off; a1: D 2a conduction, D 2b Cut-off;

[0083] J1: D a3 conduction, v AC1 T 2A 、v ac1 T 2a With L a3 、D a3 、D 2a , DC bus or load, D 2A This forms a loop.

[0084] (4) Stage 4: v AC1 =-V AC1 &v ac1 =-V AC1

[0085] In A1: D 2A conduction, D 2B Cut-off; a1: D 2b conduction, D 2a Cut-off;

[0086] J1: D a3 conduction, v AC1 T 2A 、v ac1 T 2a With L a3 、D a3 、D 2b , DC bus or load, D 2A This forms a loop.

[0087] From the above working process, we can see that v AC1 T 2A 、v ac1 T 2a Power the DC bus or load in series.

[0088] To understand the effect of J1 on the adjustability of the entire circuit, further assume that V AC1 =20V,vAC1 The period T1=20μs, v AC1 +V AC1 The pulse width is T1 / 2, v AC1 -V AC1 The pulse width is also T1 / 2, T 2A and T 2a The primary and secondary turns ratios are both 1:4, the coupling coefficients are both 0.999, and the load is R = 25Ω / / C o =1μF. Three cases are described below: Case 1: a = 2; Case 2: a = 1; Case 3: a = 0.5.

[0089] Take L a3 =300μH, Figure 7 The output power performance of the third embodiment of the present invention under the above three conditions is given. Figure 8 The output voltage ripple performance of the embodiment 3 of the present invention under the above three conditions is given. Figure 7 and Figure 8 It can be seen that the number of inductor and diode series branches inside J1 affects both the output power and output voltage ripple of Example 3. Making the number of inductor and diode series branches variable can increase the flexibility of controlling Example 3.

[0090] Apart from Figure 6 The circuit shown in Example 3 also has other possible structures. An inductor and diode series branch can exist between any intermediate port (1_A, 1_B, and 1_C) of A1 and any intermediate port (1_a, 1_b, and 1_c) of a1. The operating principles of other structures in Example 3 are similar to those disclosed in Example 3 above and are not further described.

[0091] Example 4

[0092] Reference Figure 9 A multi-transformer rectifier circuit includes at least one output-end current input module, at least one output-end current output module, and at least one current diversion module. The output-end current input module, the output-end current output module, and the current diversion module have the same structure.

[0093] Among them, one output-end current input type module is A1, one output-end current output type module is a1, and one current diversion module is J1.

[0094] The output end current input type module A1 is the same as that in embodiment 1.

[0095] The output terminal current output type module a1 is the same as that in embodiment 3.

[0096] The flow guide module J1 includes two inductor and diode series branches: the first inductor and diode series branch is an inductor L a4 and diode D a4 In series, the inductor L a4 One end of the inductor is connected to the middle port 1_A of A1, and the inductor L a4 The other end of the diode D a4 The anode of diode D a4 The cathode of is connected to the middle port 1_c of a1; the second inductor and diode series branch is connected to the inductor L b4 and diode D b4 In series, the inductor L b4 One end of the inductor is connected to the middle port 1_B of A1, and the inductor L b4 The other end of the diode D b4 The anode of diode D b4 The cathode of the inductor is connected to the middle port 1_c of a1. In addition to limiting the direction of current flow, the diodes in the inductor and diode series branches also prevent circulating current when the number of inductor and diode series branches is greater than one. The number of inductor and diode series branches in the current diversion module J1 is variable, ranging from 0 to 2.

[0097] Similar to Example 2, except Figure 9 For the circuit shown in Example 4, there are other possible structures. An inductor and a diode series branch can exist between any middle port (1_A and 1_B) of A1 and any middle port (1_a, 1_b and 1_c) of a1.

[0098] In terms of structure, embodiment 4 and embodiment 2 can be regarded as a reciprocal relationship. Since the working processes of the two are similar, they will not be described in detail.

[0099] As described above, both the output-side current input module and the output-side current output module have two different configurations, and the current diversion module also has multiple configurations. Simple permutations and combinations can create numerous embodiments. Typical embodiments 1 through 4 are selected for illustration and explanation. The remaining embodiments, as their operating principles are generally similar, are omitted for elaboration.

[0100] Although diodes are used in the aforementioned embodiments to carry out freewheeling and energy transfer on the secondary side of each transformer, those skilled in the art will appreciate that the above-mentioned diodes can also be replaced by controllable switching devices (such as synchronous rectifier MOSFETs). In addition, the AC power supply in the aforementioned embodiments can be an AC-AC, DC-AC, or other power (electronic) device with AC output, and the AC form can be multi-level or sinusoidal with two or more levels; the transformer parameters (such as: the number of turns of the primary and secondary sides, the excitation inductance, the relationship between the same and opposite terminals, the position of the intermediate tap, etc.) in the output-end current input type module and the output-end current output type module can be the same or different; an output-end current input type module can be connected to multiple diversion modules, and an output-end current output type module can also be connected to multiple diversion modules. The embodiment can also include any combination of the aforementioned embodiments 1 to 4. The contents described in the embodiments of this specification are merely an enumeration of the implementation forms of the inventive concept. The scope of protection of the present invention should not be regarded as limited to the specific forms described in the embodiments. The scope of protection of the present invention also extends to equivalent technical means that can be thought of by those skilled in the art based on the inventive concept.

Claims

1. A multi-transformer rectifier circuit, characterized in that: The multi-transformer rectifier circuit includes at least one output-end current input module, at least one output-end current output module, and at least one current diversion module; The output current input module includes a transformer: The transformer has two ports of its primary winding connected to an AC power source, two ports of its secondary winding are intermediate ports, and an intermediate tap of its secondary winding is connected to the negative end of a DC bus or one end of a load; The output current output module includes a transformer: The transformer has two ports of its primary winding connected to the AC power supply, two ports of its secondary winding are middle ports, and the middle tap of its secondary winding is connected to the positive end of the DC bus or the other end of the load; The current diversion module includes at least one inductor and diode series branch, one end of the inductor and diode series branch is connected to any middle port of the output end current input type module, and the other end of the inductor and diode series branch is connected to any middle port of the output end current output type module. The current direction is the output end current input type module → the inductor and diode series branch → the output end current output type module.

2. The multi-transformer rectifier circuit according to claim 1, wherein: The output current input module has another structure, including 1 transformer and 2 diodes: The transformer has two ports of its primary winding connected to an AC power source, and two ports of its secondary winding and a middle tap as middle ports; The anode of the first diode and the anode of the second diode are both connected to the negative end of the DC bus or one end of the load, the cathode of the first diode is connected to one end of the secondary winding of the transformer, and the cathode of the second diode is connected to the other end of the secondary winding of the transformer.

3. The multi-transformer rectifier circuit according to claim 1 or 2, characterized in that: The output current output module also includes another structure, including a transformer and two diodes: The transformer has two ports of its primary winding connected to an AC power source, and two ports of its secondary winding and a middle tap as middle ports; The cathode of the first diode and the cathode of the second diode are both connected to the positive end of the DC bus or the other end of the load, the anode of the first diode is connected to one end of the secondary winding of the transformer, and the anode of the second diode is connected to the other end of the secondary winding of the transformer.

4. The multi-transformer rectifier circuit according to claim 3, wherein: The number of the series branches of inductors and diodes in the current guidance module is variable.

5. The multi-transformer rectifier circuit according to claim 3, wherein: One output-end current input module is connected to at least one current guide module.

6. The multi-transformer rectifier circuit according to claim 3, wherein: One output-end current output module is connected to at least one current guide module.

7. The multi-transformer rectifier circuit according to claim 3, wherein: Some or all of the diodes are replaced by unidirectional conductive controllable switching devices.

8. The multi-transformer rectifier circuit according to claim 3, wherein: Some or all of the transformer parameters are the same or different; some or all of the AC power sources are the same or different.

9. The multi-transformer rectifier circuit according to claim 3, wherein: Part or all of the AC power supply is a multi-level AC power supply with two levels or more, including a sinusoidal AC power supply.

10. The multi-transformer rectifier circuit according to claim 3, wherein: Some or all of the output-end current input modules and / or some or all of the output-end current output modules and / or some or all of the current guiding modules may have the same structure or different structures.

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