Automatic voltage-equalizing and current-equalizing circuit

Abstract

An automatic voltage-equalizing and current-equalizing circuit comprises an input module, N transformer modules and an output module, the primary windings of the N transformer modules are connected in parallel to the output end of the input module, and the secondary windings of the N transformer modules are connected in series to the input end of the output module, or the primary windings of the N transformer modules are connected in series to the output end of the input module, and the secondary windings of the N transformer modules are connected in parallel to the input end of the output module; wherein N is a positive integer greater than or equal to 2, and the turns ratios of the N transformer modules are equal. According to the automatic voltage-equalizing and current-equalizing circuit provided by the utility model, the primary windings of the N transformer modules are connected in parallel or in series with the output end of the input module, the secondary windings are connected in series or in parallel with the input end of the output module, and the turns ratios of the N transformer modules are equal; therefore, the power transmitted by the N transformer modules is equal, and the input end and the output end have self-current-sharing and voltage-sharing capabilities, so that the stability of the system is improved, and the damage risk of the transformer modules is reduced.

Description

Technical Field

[0001] The utility model relates to the field of converters, and more specifically to a self-equalizing voltage and current circuit. Background Art

[0002] LLC resonant converters are often used in renewable energy power conversion applications due to their soft switching and high conversion efficiency. With the expansion of power and the improvement of efficiency targets, resonant converters with a single transformer structure are no longer suitable for high-power applications. To improve the power density and efficiency of the resonant converter and reduce the temperature rise of the transformer under high-power operating conditions, LLC resonant converters with multiple transformers are often used. However, due to factors such as inconsistent manufacturing processes and circuit parasitic parameters of each phase transformer, LLC resonant converters with multiple transformers may have uneven output voltage or current distribution between phases. This leads to uneven power transmission between each phase transformer, increases the instability of the power module, and poses a risk of overheating and burning of transformers with large power transmission. Utility Model Content

[0003] The technical problem to be solved by the present invention is that, in response to the above-mentioned defects of the prior art, a self-equalizing voltage and current circuit is provided, which can enable each transformer module to have the ability of self-equalizing current and voltage, and their transmission power is equal, thereby improving the stability of the system and reducing the risk of damage to the transformer module.

[0004] The technical solution adopted by the utility model to solve the technical problem is: constructing a self-equalizing voltage and current circuit, including an input module, N transformer modules, and an output module;

[0005] The primary windings of the N transformer modules are connected in parallel to the output end of the input module, and the secondary windings are connected in series to the input end of the output module, or the primary windings of the N transformer modules are connected in series to the output end of the input module, and the secondary windings are connected in parallel to the input end of the output module;

[0006] Wherein, N is a positive integer greater than or equal to 2, and the turns ratios of the N transformer modules are equal.

[0007] In the self-equalizing voltage and current circuit described in the present invention, the first end of the primary winding of each transformer module is respectively connected to the first output end of the input module, and the second end is respectively connected to the second output end of the input module; the secondary windings of the N transformer modules are connected in series with each other and then connected between the first input end and the second input end of the output module.

[0008] In the self-equalizing voltage and current balancing circuit described in the present invention, a first switching module is further included; the first end of the first switching module is connected to the first output end of the input module, the second end is connected to the first end of the primary winding of each transformer module, and the third end is connected to the third end of the primary winding of each transformer module; the third end of the primary winding is located between the first end and the second end of the primary winding

[0009] In the self-equalizing voltage and current circuit described in the present invention, the primary windings of each transformer module are connected in series with each other and then connected between the first output terminal and the second output terminal of the input module. The first end of the secondary winding of each transformer module is respectively connected to the first input terminal of the output module, and the second end is respectively connected to the second input terminal of the output module.

[0010] The self-equalizing voltage and current circuit described in the present invention further includes a second switching module; the first end of the second switching module is connected to the first input end of the output module, the second end is connected to the first end of the secondary winding of each transformer module, and the third end is connected to the third end of the secondary winding of each transformer module; the third end of the secondary winding is located between the first end and the second end of the secondary winding.

[0011] In the self-equalizing voltage and current circuit described in the present utility model, the input module includes an input power supply, an inverter unit and a resonance unit;

[0012] The first input end of the inverter unit is connected to the positive pole of the input power supply, the second input end is connected to the negative pole of the input power supply, the first output end is connected to the first output end of the input module via the resonance unit, and the second output end is connected to the second output end of the input module.

[0013] In the self-balanced voltage and current balancing circuit described in the present invention, the inverter unit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube;

[0014] The control ends of the first switching tube, the second switching tube, the third switching tube and the fourth switching tube receive a control signal; the first end of the first switching tube is connected to the second end of the second switching tube to form a first output end of the inverter unit, the second end of the first switching tube is connected to the second end of the third switching tube to form a first input end of the inverter unit, the first end of the third switching tube is connected to the second end of the fourth switching tube to form a second output end of the inverter unit, and the first end of the second switching tube is connected to the first end of the fourth switching tube to form a second input end of the inverter unit.

[0015] In the self-equalizing voltage and current circuit described in the present invention, the resonant unit includes a resonant capacitor and a resonant inductor, and the resonant capacitor and the resonant inductor are connected in series between the first output end of the inverter unit and the first output end of the input module.

[0016] In the self-equalizing voltage and current circuit described in the present utility model, the output module includes an output load, a rectifier unit and a filter unit;

[0017] The first input terminal and the second input terminal of the rectifier unit are connected to the secondary windings of the N transformer modules, the first output terminal is connected to the positive electrode of the output load, and the second output terminal is connected to the negative electrode of the output load;

[0018] The filtering unit is connected between the positive electrode of the output load and the negative electrode of the output load.

[0019] In the self-equalizing voltage and current circuit described in the present utility model, the rectifier unit includes a first diode, a second diode, a third diode and a fourth diode;

[0020] The anode of the first diode is connected to the cathode of the second diode to form a first input terminal of the rectifier unit, the cathode of the first diode is connected to the cathode of the third diode to form a first output terminal of the rectifier unit, the anode of the third diode is connected to the cathode of the fourth diode to form a second input terminal of the rectifier unit, and the anode of the second diode is connected to the anode of the fourth diode to form a second output terminal of the rectifier unit;

[0021] The filtering unit includes at least one filtering capacitor.

[0022] Another technical solution adopted by the present invention to solve the technical problem is to construct a self-equalizing voltage and current circuit, including an inverter unit, a resonance unit, N transformers, a rectifier unit and a filter unit;

[0023] The first input end of the inverter unit is connected to the positive pole of the power supply, the second input end is connected to the negative pole of the power supply, the first output end is connected to the first end of the primary winding of each of the N transformers via the resonance unit, the second output end is connected to the second end of the primary winding of each of the N transformers, and the secondary winding of each of the N transformers is connected in series with each other and then connected between the first input end and the second input end of the rectifier unit; or the first input end of the inverter unit is connected to the positive pole of the power supply, the second input end is connected to the negative pole of the power supply, the primary winding of each of the N transformers is connected in series with each other and then connected between the first output end and the second output end of the inverter unit, the first end of the secondary winding of each of the N transformers is connected to the first input end of the rectifier unit, and the second end of the secondary winding of each of the N transformers is connected to the second input end of the rectifier unit;

[0024] The first output terminal and the second output terminal of the rectifier unit output a load voltage, and the filter unit is connected between the first output terminal and the second output terminal of the rectifier unit; N is a positive integer greater than or equal to 2, and the turns ratios of the N transformer modules are equal;

[0025] The inverter unit includes a first switching tube, a second switching tube, a third switching tube and a fourth switching tube; the control ends of the first switching tube, the second switching tube, the third switching tube and the fourth switching tube receive control signals; the first end of the first switching tube is connected to the second end of the second switching tube to form a first output end of the inverter unit, the second end of the first switching tube is connected to the second end of the third switching tube to form a first input end of the inverter unit, the first end of the third switching tube is connected to the second end of the fourth switching tube to form a second output end of the inverter unit, and the first end of the second switching tube is connected to the first end of the fourth switching tube to form a second input end of the inverter unit.

[0026] The rectifier unit includes a first diode, a second diode, a third diode and a fourth diode; the anode of the first diode is connected to the cathode of the second diode to form a first input end of the rectifier unit, the cathode of the first diode is connected to the cathode of the third diode to form a first output end of the rectifier unit, the anode of the third diode is connected to the cathode of the fourth diode to form a second input end of the rectifier unit, and the anode of the second diode is connected to the anode of the fourth diode to form a second output end of the rectifier unit.

[0027] In implementing the self-equalizing voltage and current circuit of the present invention, since the primary windings of N transformer modules are connected in parallel or in series with the output end of the input module, the secondary windings are connected in series or in parallel with the input end of the output module, and the turns ratios of the N transformer modules are equal, the power transmitted by the N transformer modules is equal, and the input and output ends have self-equalizing current and voltage capabilities, thereby improving the stability of the system and reducing the risk of damage to the transformer modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0029] Figure 1 This is a principle block diagram of the first preferred embodiment of the self-equalizing voltage and current circuit of the utility model;

[0030] Figure 2 This is a principle block diagram of a second preferred embodiment of the self-equalizing voltage and current circuit of the present utility model;

[0031] Figure 3 This is a circuit diagram of a third preferred embodiment of the self-equalizing voltage and current circuit of the present utility model;

[0032] Figure 4 yes Figure 3 The current waveform diagram of the self-equalizing voltage and current circuit shown;

[0033] Figure 5 yes Figure 3 The voltage waveform diagram of the self-equalizing voltage and current circuit shown;

[0034] Figure 6 This is a circuit diagram of a fourth preferred embodiment of the self-equalizing voltage and current circuit of the present utility model;

[0035] Figure 7 This is a circuit diagram of a fifth preferred embodiment of the self-equalizing voltage and current circuit of the present utility model;

[0036] Figure 8 This is a circuit diagram of the sixth preferred embodiment of the self-equalizing voltage and current circuit of the present utility model. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] Figure 1 This is a principle block diagram of the first preferred embodiment of the self-equalizing voltage and current circuit of the present invention. Figure 1As shown, the self-equalizing voltage and current circuit of the present invention includes an input module 10, N transformer modules 1-N, and an output module 20. Figure 1 As shown, the primary windings of the N transformer modules 1-N are connected in parallel to the output end of the input module 10, and the secondary windings are connected in series to the input end of the output module 20. Wherein, N is a positive integer greater than or equal to 2, and the turns ratios of the N transformer modules 1-N are equal.

[0039] In a preferred embodiment of the present invention, the first end of the primary winding of each of the transformer modules 1-N is respectively connected to the first output end of the input module 10, and the second end is respectively connected to the second output end of the input module 10; the secondary windings of the N transformer modules 1-N are connected in series with each other and then connected between the first input end and the second input end of the output module 20.

[0040] exist Figure 1 In the preferred embodiment shown, since the primary windings of the transformer modules 1-N are connected in parallel to the output end of the input module 10, the voltages of their primary windings are equal. Since the secondary windings of the transformer modules 1-N are connected in series to the input end of the output module 20, their secondary currents are equal. The turns ratios of the transformer modules 1-N are equal, so the powers transmitted by the N transformer modules are equal. Therefore, the input and output ends of the transformer modules 1-N have self-current and voltage equalization capabilities, and their transmission powers are equal, thereby improving the stability of the system and reducing the risk of damage to the transformer modules.

[0041] In the present invention, each transformer module may include M transformers, where M is a positive integer greater than or equal to 1. In a preferred embodiment of the present invention, each transformer module may include one transformer. In another preferred embodiment of the present invention, each transformer module may include two or more transformers. The number of transformers may be set according to the actual needs of the self-equalizing voltage and current balancing circuit to accommodate different power output requirements of the self-equalizing voltage and current balancing circuit.

[0042] When multiple transformer modules are used for power transmission, the power level of the converter can be improved; and multiple transformer modules can achieve self-voltage and self-current balancing, and the transmission power is balanced, which can optimize the temperature rise of the system and improve the stability of the system.

[0043] In the present invention, the input module 10 and the output module 20 can be any converter input module or output module known in the art, as long as they can realize the input and output of the converter. For example, they can be LLC resonant input and output modules, or phase-shifted full-bridge or half-bridge input and output modules, all of which fall within the protection scope of the present invention.

[0044] In a preferred embodiment of the present invention, the self-equalizing voltage and current sharing circuit is an LLC resonant converter circuit. Therefore, the input module 10 may include an inverter unit and a resonant unit, and correspondingly, the output module 20 may include a rectifier unit and a filter unit. Those skilled in the art can design the input module 10 and the output module 20 according to actual scenarios to achieve self-equalizing voltage and current sharing for converters with different multi-transformer modules. Therefore, the self-equalizing voltage and current sharing circuit of the present invention has a wide range of application scenarios.

[0045] Figure 2 This is a principle block diagram of the second preferred embodiment of the self-equalizing voltage and current circuit of the present invention. Figure 2 As shown, the self-equalizing voltage and current circuit of the present invention includes an input module 10, N transformer modules 1-N, and an output module 20. Figure 2 As shown, the primary windings of the N transformer modules 1 -N are connected in series to the output end of the input module 10 , and the secondary windings are connected in parallel to the input end of the output module 20 .

[0046] In a preferred embodiment of the present invention, the primary windings of each of the transformer modules 1-N are connected in series with each other and then connected between the first output terminal and the second output terminal of the input module 10, and the first ends of the secondary windings of the N transformer modules 1-N are respectively connected to the first input terminal of the output module 20, and the first ends are respectively connected to the second input terminal of the output module 20.

[0047] Figure 2 The principle of the self-equalizing voltage and current circuit shown is the same as Figure 1 The principle of the self-equalizing voltage and current circuit shown is similar. Because the primary windings of transformer modules 1-N are connected in series to the output end of the input module 10, the currents of their primary windings are equal. Because the secondary windings of transformer modules 1-N are connected in parallel to the input end of the output module 20, their secondary voltages are equal. Since transformer modules 1-N have equal turns ratios, the power transmitted by the N transformer modules is equal. Therefore, the input and output ends of transformer modules 1-N have self-equalizing current and voltage capabilities, and their transmitted power is equal, thereby improving system stability and reducing the risk of transformer module damage.

[0048] Here, the configurations of the input module 10, transformer modules 1-N, and output module 20 can be referred to Figure 1 The embodiments shown will not be described again here.

[0049] Figure 3 This is the third preferred embodiment of the self-equalizing voltage and current circuit of the present invention. Figure 3 In the preferred embodiment shown, the self-balanced voltage and current circuit is an LLC resonant circuit. Figure 1 and3 As can be seen, the self-equalizing voltage and current balancing circuit of the present invention includes an input module 10, two transformer modules, and an output module 20. Each transformer module includes a transformer, that is, the self-equalizing voltage and current balancing circuit of the present invention includes transformers T1 and T2. Transformers T1 and T2 have equal turns ratios, where Lm1 and Lm2 represent the magnetizing inductances of transformers T1 and T2.

[0050] The input module 10 includes an input power supply Vin, an inverter unit, and a resonant unit. The output module includes an output load Ro, a rectifier unit, and a filter unit. The inverter unit's first input is connected to the positive electrode Vin+ of the input power supply, its second input is connected to the negative electrode Vin of the input power supply, its first output is connected to the first output of the input module via the resonant unit, and its second output is connected to the second output of the input module. The primary windings of transformers T1 and T2 are connected in parallel to the first and second output terminals of the input module, respectively. The rectifier unit's first input is connected to the first input of the output module 20, its second input is connected to the second input of the output module 20, its first output is connected to the positive electrode Ro+ of the output load, and its second output is connected to the negative electrode Ro- of the output load. The filter unit is connected between the positive electrode Ro+ and the negative electrode Ro- of the output load. The secondary windings of transformers T1 and T2 are connected in series between the first input and second input / output terminals of the output module, respectively.

[0051] Further Figure 3 As shown, the inverter unit includes switches S1, S2, S3, and S4. The resonant unit includes a resonant capacitor Cr1 and a resonant inductor Lr1. The rectifier unit includes a diode D1, a diode D2, a diode D3, and a diode D4. The filter unit includes a filter capacitor Co. The control ends of the switches S1, S2, S3, and S4 receive control signals. The first end of the switch S1 is connected to the second end of the switch S2 to form a first output end of the inverter unit. The second end of the switch S1 is connected to the second end of the switch S3 to form a first input end of the inverter unit. The first end of the switch S3 is connected to the second end of the switch S4 to form a second output end of the inverter unit. The first end of the switch S2 is connected to the first end of the switch S4 to form a second input end of the inverter unit. The resonant capacitor Cr1 and the resonant inductor Lr1 are connected in series between the first output terminal of the inverter unit and the primary windings of the transformer T1 and the primary windings of the transformer T2.

[0052] Specifically, if Figure 3As shown, the first end of the resonant capacitor Cr1 is connected to the first end of the switching transistor S1 and the second end of the switching transistor S2. The second end of the resonant capacitor Cr1 is connected to the first end of the primary winding of the transformer T1 and the first end of the primary winding of the transformer T2 via the resonant inductor Lr1. The second end of the primary winding of the transformer T1 and the second end of the primary winding of the transformer T2 are connected to the first end of the switching transistor S3 and the second end of the switching transistor S4, respectively. Here, the positions of the resonant capacitor Cr1 and the resonant inductor Lr1 can be interchanged.

[0053] The anode of diode D1 is connected to the cathode of diode D2 to form the first input terminal of the rectifier unit. The cathode of diode D1 is connected to the cathode of diode D3 to form the first output terminal of the rectifier unit. The anode of diode D3 is connected to the cathode of diode D4 to form the second input terminal of the rectifier unit. The anode of diode D2 is connected to the anode of diode D4 to form the second output terminal of the rectifier unit. The first end of the secondary winding of transformer T1 is connected to the anode of diode D1 and the cathode of diode D2. The second end of the secondary winding of transformer T1 is connected to the first end of the secondary winding of transformer T2. The second end of the secondary winding of transformer T2 is connected to the anode of diode D3 and the cathode of diode D4. In other words, the secondary windings of transformers T1 and T2 are connected in series between the first and second input terminals of the rectifier unit. The filter capacitor Co is connected between the positive electrode Ro+ of the output load and the negative electrode Ro- of the output load.

[0054] In a preferred embodiment of the present invention, the switch transistors S1-S4 can be MOS transistors, IGBT transistors, or triodes. The diodes D1-D4 can also be implemented by switch transistors.

[0055] The following will be combined Figure 3-5 The principle of the self-equalizing voltage and current circuit of the present invention is described as follows. Figure 3 The self-equalizing voltage and current circuit shown has two transformers T1 and T2, whose primary and secondary winding turn ratios are n1 and n2 respectively. In order to make transformers T1 and T2 transmit the same power, the primary and secondary winding ratios of transformers T1 and T2 are equal, that is: n1 = n2. The primary windings of the transformers T1 and T2 are connected in parallel to the output end of the resonant unit, and the secondary windings of the transformers T1 and T2 are connected in series to the input end of the rectifier unit. Based on the parallel connection relationship of the primary windings of the transformers T1 and T2, the voltages of the primary and secondary windings of the transformers T1 and T2 are equal, that is: V Tp1 =V Tp2 , V Ts1 =V Ts2 ; Among them, V Tp1 、V Tp2are the voltages across the primary windings of transformers T1 and T2, V Ts1 、V Ts2 are the voltages across the secondary windings of transformers T1 and T2 respectively. Figure 5 As shown, since the primary windings of the two transformers T1 and T2 are connected in parallel, the voltages across the primary windings of the transformers T1 and T2 are equal, and the voltages across the secondary windings of the transformers T1 and T2 are also equal, and the effective values ​​are: V TS1 =V TS2 =12.752V, there is no voltage deviation problem at the output end of the secondary winding of transformers T1 and T2.

[0056] Based on the relationship that the secondary windings of transformers T1 and T2 are connected in series, the currents flowing through the primary and secondary windings of transformers T1 and T2 are equal, that is: i Tp1 =i Tp2 ,i Ts1 =i Ts2 ; Among them, i Tp1 、i Tp2 are the currents flowing through the primary windings of transformers T1 and T2, i Ts1 、i Ts2 are the currents flowing through the secondary windings of transformers T1 and T2 respectively. Figure 4 As shown, since the secondary windings of the two transformers T1 and T2 are connected in series, the current flowing through the secondary windings of transformers T1 and T2 is the same. At this time, the effective value of the secondary current flowing through the two transformers is: i TS1 =i TS2 =169.2A, no current deviation problem.

[0057] Therefore, the input and output ends of transformers T1 and T2 have the ability to self-balance current and voltage, and the power transmitted by transformers T1 and T2 remains equal, which improves the stability of the system.

[0058] Figure 6 This is the fourth preferred embodiment of the self-equalizing voltage and current circuit of the present invention. Figure 6 The embodiment shown is Figure 3 The embodiment shown is similar, the only difference is that n transformers are provided, where n is a positive integer less than N. Figure 6 As shown, the voltage and current balancing circuit has n transformers T1, T2, T3...Tn, whose primary and secondary winding turn ratios are n1, n2, n3... respectively. In order to make each transformer transmit the same power, the primary and secondary winding turn ratios of each transformer are equal, that is: n1=n2=n3=...nn. Figure 3 Similar to the embodiment shown, the primary windings of the transformers are connected in parallel to the output end of the resonant cavity, and the secondary windings of the transformers are connected in series to the input end of the rectifier circuit.

[0059] Based on the parallel connection relationship of the primary windings of each transformer T1, T2, T3, etc., the voltage of the primary and secondary windings of each transformer is equal, that is: V Tp1 =V Tp2 =V Tp3 =..., V Ts1 =V Ts2 =V Ts3 =...; where V Tp1 、V Tp2 、V Tp3。。。 are the voltages at both ends of the primary winding of each transformer, V Ts1 、V Ts2 、V Ts3。。。 are the voltages at both ends of the secondary windings of each transformer. Based on the relationship that the secondary windings of each transformer T1, T2, T3... are connected in series, the currents flowing through the primary and secondary windings of each transformer are equal, that is: i Tp1 =i Tp2 =i Tp3 =..., i Ts1 =i Ts2 =i Ts3＝。。。 ; Among them, i Tp1 、i Tp2 、i Tp3 ...are the currents flowing through the primary windings of each transformer, i Ts1 、i Ts2 、i Ts3 ...are the currents flowing through the secondary windings of the transformers. Therefore, the input and output terminals of each transformer T1, T2, T3... have self-current and voltage balancing capabilities, maintaining the same power transmission across each transformer, improving system stability.

[0060] Figure 7 This is a circuit diagram of the fifth preferred embodiment of the self-equalizing voltage and current circuit of the present utility model. Figure 8 This is a circuit diagram of the sixth preferred embodiment of the self-equalizing voltage and current circuit of the present utility model. Figure 7 The embodiment shown is Figure 3 The embodiment shown is similar, Figure 8 The embodiment shown is Figure 6 The embodiment shown is similar, and each transformer has primary windings connected in parallel and secondary windings connected in series. The difference is that Figure 7-8 In the preferred embodiment shown, the self-equalizing voltage and current circuit further includes a first switching module. The first end of the first switching module is connected to the first output end of the input module, the second end is connected to the first end of the primary winding of each transformer module, and the third end is connected to the third end of the primary winding of each transformer module; the third end of the primary winding is located between the first end and the second end of the primary winding. Specifically, Figure 7 In the preferred embodiment shown, the first switching module is a single-pole double-throw relay K. Of course, in other preferred embodiments of the present invention, other devices may also be used, such as a double-pole double-throw relay, a switch tube, etc. Figure 7 As shown, the fixed end of the moving contact of the single-pole double-throw relay K is connected to the first output terminal of the inverter unit formed by switching transistors S1-S4 via the resonant capacitor Cr1 and the resonant inductor Lr1. The first static contact A of the single-pole double-throw relay K is connected to the first ends of the primary windings of transformers T1 and T2, respectively. The second static contact B is connected to the center tap (i.e., the third end) of the primary windings of transformers T1 and T2, respectively. The second ends of the primary windings of transformers T1 and T2 are connected to the second output terminal of the inverter unit formed by switching transistors S1-S4. When the moving contact contacts the first static contact A, the entire primary windings of transformers T1 and T2 are connected to the circuit. When the moving contact contacts the first static contact B, part of the primary windings of transformers T1 and T2 are connected to the circuit. Therefore, by switching the single-pole double-throw relay K between the two static contacts A and B, the turns ratio of the transformer module connected to the circuit can be changed, thereby adapting to a wide range of different applications. Of course, in other preferred embodiments of the present invention, the third end of the primary winding is not limited to the middle tap, and it only needs to be located between the first end and the second end. Figure 8 The preferred embodiment shown, which Figure 7 The embodiment shown is similar, that is, the SPDT relay K is used to switch N transformers T1 to TN. Those skilled in the art will appreciate that the SPDT relay K can also be provided on the secondary side of the transformer.

[0061] Furthermore, for the embodiment of the primary side in series and the secondary side in parallel of the present invention, the first end of the single-pole double-throw relay K (the fixed end of the moving contact) can be connected to the first input end of the output module, the first static contact is connected to the first end of the secondary winding of each transformer module, and the second static contact is connected to the third end of the secondary winding of each transformer module; the third end of the secondary winding is located between the first end and the second end of the secondary winding, and its principle is the same as Figure 7-8 Similar to the embodiment shown, the turns ratio of the transformer module connected to the circuit can also be changed to adapt to a wide range of different applications.

[0062] In implementing the self-equalizing voltage and current circuit of the present invention, since the primary windings of the transformer modules 1-N are connected in parallel or in series with the output end of the input module, the secondary windings are connected in series or in parallel with the input end of the output module, and the turns ratios of the transformer modules 1-N are equal, the power transmitted by the N transformer modules is equal, and the input and output ends have the ability to self-equalize current and voltage, thereby improving the stability of the system and reducing the risk of damage to the transformer modules. Furthermore, it can be applied to converters with multiple transformer modules of various types, and the output power can be increased by increasing the number of transformer modules and the number of transformers in the transformer modules. Furthermore, the turns ratio of the transformer module access circuit can be changed by adding a switching module, thereby adapting to a wide range of different applications.

[0063] Although the present invention is described through specific embodiments, those skilled in the art will appreciate that various modifications and equivalent substitutions may be made to the present invention without departing from the scope of the present invention. Furthermore, various modifications may be made to the present invention to address specific circumstances or materials without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but rather encompasses all embodiments falling within the scope of the claims of the present invention.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A self-equalizing voltage and current circuit, characterized in that: It includes an input module, N transformer modules, and an output module; The primary windings of the N transformer modules are connected in parallel to the output end of the input module, and the secondary windings are connected in series to the input end of the output module, or the primary windings of the N transformer modules are connected in series to the output end of the input module, and the secondary windings are connected in parallel to the input end of the output module; Wherein, N is a positive integer greater than or equal to 2, and the turns ratios of the N transformer modules are equal.

2. The self-voltage and current balancing circuit according to claim 1, characterized in that: The first end of the primary winding of each transformer module is respectively connected to the first output end of the input module, and the second end is respectively connected to the second output end of the input module; the secondary windings of the N transformer modules are connected in series with each other and then connected between the first input end and the second input end of the output module.

3. The self-voltage and current balancing circuit according to claim 2, characterized in that: It further includes a first switching module; the first end of the first switching module is connected to the first output end of the input module, the second end is connected to the first end of the primary winding of each transformer module, and the third end is connected to the third end of the primary winding of each transformer module; the third end of the primary winding is located between the first end and the second end of the primary winding.

4. The self-voltage and current balancing circuit according to claim 1, wherein: The primary windings of each transformer module are connected in series with each other and then connected between the first output terminal and the second output terminal of the input module. The first end of the secondary winding of each transformer module is respectively connected to the first input terminal of the output module, and the second end is respectively connected to the second input terminal of the output module.

5. The self-voltage and current balancing circuit according to claim 4, characterized in that: It further includes a second switching module; the first end of the second switching module is connected to the first input end of the output module, the second end is connected to the first end of the secondary winding of each transformer module, and the third end is connected to the third end of the secondary winding of each transformer module; the third end of the secondary winding is located between the first end and the second end of the secondary winding.

6. The self-voltage and current balancing circuit according to any one of claims 2 to 4, characterized in that: The input module includes an input power supply, an inverter unit and a resonance unit; The first input end of the inverter unit is connected to the positive pole of the input power supply, the second input end is connected to the negative pole of the input power supply, the first output end is connected to the first output end of the input module via the resonance unit, and the second output end is connected to the second output end of the input module.

7. The self-voltage and current balancing circuit according to claim 6, characterized in that: The inverter unit includes a first switching tube, a second switching tube, a third switching tube and a fourth switching tube; The control ends of the first switching tube, the second switching tube, the third switching tube and the fourth switching tube receive a control signal; the first end of the first switching tube is connected to the second end of the second switching tube to form a first output end of the inverter unit, the second end of the first switching tube is connected to the second end of the third switching tube to form a first input end of the inverter unit, the first end of the third switching tube is connected to the second end of the fourth switching tube to form a second output end of the inverter unit, and the first end of the second switching tube is connected to the first end of the fourth switching tube to form a second input end of the inverter unit.

8. The self-voltage and current balancing circuit according to claim 7, characterized in that: The resonance unit includes a resonance capacitor and a resonance inductor, and the resonance capacitor and the resonance inductor are connected in series between the first output end of the inverter unit and the first output end of the input module.

9. The self-voltage and current balancing circuit according to any one of claims 2 to 4, characterized in that: The output module includes an output load, a rectifier unit and a filter unit; The first input terminal and the second input terminal of the rectifier unit are connected to the secondary windings of the N transformer modules, the first output terminal is connected to the positive electrode of the output load, and the second output terminal is connected to the negative electrode of the output load; The filtering unit is connected between the positive electrode of the output load and the negative electrode of the output load.

10. The self-voltage and current balancing circuit according to claim 9, characterized in that: The rectifier unit includes a first diode, a second diode, a third diode and a fourth diode; The anode of the first diode is connected to the cathode of the second diode to form a first input terminal of the rectifier unit, the cathode of the first diode is connected to the cathode of the third diode to form a first output terminal of the rectifier unit, the anode of the third diode is connected to the cathode of the fourth diode to form a second input terminal of the rectifier unit, and the anode of the second diode is connected to the anode of the fourth diode to form a second output terminal of the rectifier unit; The filtering unit includes at least one filtering capacitor.

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