Multipath output staggered isolation bidirectional Sepic converter

Abstract

The utility model belongs to the technical field of converters, and discloses a multi-output staggered isolation bidirectional Sepic converter, which comprises a conversion circuit, the conversion circuit comprises a port + BUS, the port + BUS is connected with one end of a capacitor C210 and one end of an inductor L24, the other end of the inductor L24 is connected with a drain electrode of an MOS tube Q12, a negative end of a diode D49 and one end of a capacitor C214, and the other end of the capacitor C214 is connected with the other end of the MOS tube Q12. The other end of the capacitor C214 is connected with one end of an inductor L25 and a pin 1 of a transformer T14, and the other end of the capacitor C210, a source electrode of the MOS tube Q12, a positive end of the diode D49, the other end of the inductor L25 and a pin 2 of the transformer T14 are connected with a port GND. The beneficial effects of the utility model are that the multi-path output is provided, the forward and reverse output range can be further increased through the series-parallel connection of the output, and the multi-path output circuit can be suitable for batteries of various voltage levels.

Description

TECHNICAL FIELD

[0001] The utility model relates to inverter technical field especially relates to a kind of multi-output staggered isolation bidirectional Sepic converter. BACKGROUND

[0002] In today's global green energy, energy-saving emission reduction strategy, State Grid Corporation and Southern Power Grid are developing wind power generation, nuclear power generation and solar home power generation and other new energy generation technologies.Energy storage technology can largely solve some problems existing when new energy generation is connected to grid, so that low-density, random renewable new energy is widely used, so energy storage technology becomes the object of current vigorous development.

[0003] At present, in small and medium-sized power energy storage technology for new energy distributed generation, battery energy storage technology is the most widely used, because battery energy storage device is not only easy to install, capacity can be flexibly adjusted;It can also store off-peak electricity at night, or store excess electricity at ordinary times, and use it as emergency power when power supply is tight or even interrupted;And it is also a peak load shifting and valley filling dispatching expert of power grid operation, and is a key technology of wind and solar power grid connection.Grid-connected battery energy storage system mainly realizes energy storage, release and fast power exchange, and is generally composed of two parts: first, the energy storage part composed of different capacity battery modules, mainly responsible for energy storage and release;Second, the energy conversion system (or called charging and discharging converter) composed of power electronic devices, which is a two-way channel for power transmission in grid-connected battery energy storage system, ensures the safety and efficiency of battery charging and discharging, and is indispensable.

[0004] Currently, battery energy storage systems place increasingly higher demands on charge / discharge converters. These converters not only need traditional charge / discharge functions but also must support a wide range of battery voltages. Energy conversion systems primarily implement AC-DC bidirectional converters and DC-DC bidirectional converters. Buck-Boost chopper circuits are widely used in DC-DC bidirectional converters. However, to achieve voltage matching and safety isolation between the battery side and the grid side, a power frequency isolation transformer needs to be added to the grid side. This transformer is large, heavy, and noisy, and has high power loss, making it difficult for battery energy storage systems to achieve high charge / discharge efficiency and high power density. It's difficult; bidirectional CUK converters are widely used, but because their topology has opposite input and output polarities, the voltage stress rating of their power MOSFETs and the capacitor voltage rating are the sum of the input and output voltages. Therefore, they cannot be used in energy storage batteries with wide input and output ranges. On the other hand, DAB topologies use single-phase fully controlled bridge converters on both sides, which can achieve zero-voltage (ZVS) operation, with low power loss and high charging and discharging efficiency. However, they require silicon carbide devices, and the software control is complex, expensive, and has low reliability. In addition, most bidirectional DC-DC converters in the industry are currently single-output, which cannot meet the needs of simultaneous charging and discharging of different battery voltages.

[0005] Therefore, it is necessary to provide a multi-output interleaved isolated bidirectional Sepic converter, suitable for bidirectional charging piles and various battery energy storage systems, with comprehensive protection functions, high circuit reliability, simple software control, and low cost. Utility Model Content

[0006] This utility model discloses a multi-output interleaved isolation bidirectional Sepic converter, which relates to the field of bidirectional DC-DC converters and can effectively solve the technical problems involved in the background art.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows:

[0008] A multi-output interleaved isolated bidirectional Sepic converter, comprising a conversion circuit, the conversion circuit comprising a port +BUS, one end of the port +BUS being connected with one end of an inductor L24, the other end of the inductor L24 being connected with a drain of a MOS tube Q12, a negative end of a diode D49 and one end of a capacitor C214, the other end of the capacitor C214 being connected with one end of an inductor L25 and a pin 1 of a transformer T14, the other end of the capacitor C210, a source of the MOS tube Q12, a positive end of the diode D49, the other end of the inductor L25 and a pin 2 of the transformer T14 being connected with a port GND; a pin 3 of the transformer T14 being connected with one end of an inductor L27 and one end of a capacitor C223, the other end of the capacitor C223 being connected with a source of a MOS tube Q21 and one end of an inductor L29, the other end of the inductor L29 being connected with one end of a capacitor C229 and a port VOUT2, a pin 4 of the transformer T14 being connected with a pin 5 of the transformer T14, the other end of the inductor L27, one end of an inductor L26, a drain of the MOS tube Q21, a source of a MOS tube Q20, the other end of the capacitor C229, one end of a capacitor C224 and a port AGND1, a pin 6 of the transformer T14 being connected with the other end of the inductor L26 and one end of a capacitor C222, the other end of the capacitor C222 being connected with a drain of the MOS tube Q20 and one end of an inductor L28, the other end of the inductor L28 being connected with the other end of the capacitor C224 and a port VOUT1.

[0009] Disclosed is a multi-output interleaved isolated bidirectional Sepic converter, which is suitable for bidirectional charging piles and various battery energy storage systems. The converter comprises an isolated bidirectional Sepic conversion circuit, which comprises an input capacitor, a primary energy storage inductor, a primary MOS tube, a primary energy storage capacitor, a transformer, a secondary energy storage capacitor, a secondary MOS tube, a secondary energy storage inductor and various output capacitors connected in sequence. The interleaved isolated bidirectional Sepic converter has the characteristics of a basic Sepic converter that can step up and step down voltage, and can achieve electrical isolation between input and output through a transformer. Due to the left-right symmetrical structure of the circuit, bidirectional energy transmission can also be achieved. The converter is a novel bidirectional isolated DC-DC converter, which has multiple outputs and can further increase the forward and reverse output range through the series and parallel connection of the outputs. The output range can reach 200V-1200V, and the converter can be adapted to batteries of various voltage levels. In addition, the input and output electrical isolation is achieved by using a transformer, so that the entire converter becomes safe and stable, and is suitable for bidirectional charging piles and various battery energy storage systems. The converter has perfect protection function, high circuit reliability, simple software control and low cost.

[0010] As a preferred improvement of the utility model: the quantity of the conversion circuit is multiple, the port +BUS of multiple the conversion circuit is connected with each other, the port GND is connected with each other.

[0011] As a preferred improvement of the utility model: the quantity of the conversion circuit is two, two the conversion circuit staggered 180 degrees work.

[0012] As a preferred improvement of the utility model: the gate of MOS tube Q12 is connected with one end of resistance R146 and port DRV_1, the other end of resistance R146 is connected with port GND, and the port DRV_1 is connected with a controller.

[0013] As a preferred improvement of the utility model: the port +BUS is connected with a DC bus.

[0014] As a preferred improvement of the utility model: the port +BUS is connected with an ACDC converter, and the ACDC converter is connected with commercial power.

[0015] As a preferred improvement of the utility model: the port VOUT1 and the port VOUT2 are connected with different batteries respectively, or the port VOUT1 and the port VOUT2 are connected with a battery in series.

[0016] As a preferred improvement of the utility model: the gate of MOS tube Q20 and the gate of MOS tube Q21 are connected with port DRV_3, and the port DRV_3 is connected with a controller.

[0017] The utility model has the advantages of the following:

[0018] It has multiple output, can further increase the positive and negative output range through the output series and parallel connection, the output range can reach 200V-1200V, can adapt to various voltage grade batteries, plus the input and output electrical isolation realized by using transformer, makes the whole converter become safe, stable, is suitable for bidirectional charging pile and various battery energy storage systems, the protection function is perfect, the circuit reliability is high, the software control is simple, and the cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed in the embodiment description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can obtain other drawings according to these drawings without creating creative labor.

[0020] Figure 1 It is the schematic diagram of the conversion circuit of the utility model;

[0021] Figure 2 Figure 1 is a structural schematic diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0023] It should be noted that all directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directionality indications also change accordingly.

[0024] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0025] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In addition, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the scope of protection required by the present application.

[0027] Please refer to Figure 1As shown, the utility model provides a kind of multi-output staggered isolation bidirectional Sepic converter, including conversion circuit, the conversion circuit includes port +BUS, one end of the port +BUS connection capacitor C210 and inductance L24 one end, the other end of the inductance L24 connects the drain of MOS tube Q12, the negative end of diode D49 and the one end of capacitor C214, the other end of the capacitor C214 connects the one end of inductance L25 and the pin 1 of transformer T14, the other end of the capacitor C210, the source of the MOS tube Q12, the positive end of the diode D49, the other end of the inductance L25 and the pin 2 of the transformer T14 connect port GND;The pin 3 of the transformer T14 connects the one end of inductance L27 and the one end of capacitor C223, the other end of the capacitor C223 connects the source of MOS tube Q21 and the one end of inductance L29, the other end of the inductance L29 connects the one end of capacitor C229 and port VOUT2, the pin 4 of the transformer T14 connects the pin 5 of the transformer T14, the other end of the inductance L27, the one end of the inductance L26, the drain of the MOS tube Q21, the source of MOS tube Q20, the other end of the capacitor C229, the one end of capacitor C224 and port AGND1, the pin 6 of the transformer T14 connects the other end of the inductance L26 and the one end of capacitor C222, the other end of the capacitor C222 connects the drain of the MOS tube Q20 and the one end of inductance L28, the other end of the inductance L28 connects the other end of the capacitor C224 and port VOUT1.The gate of the MOS tube Q12 connects the one end of resistance R146 and port DRV_1, the other end of the resistance R146 connects port GND, and the port DRV_1 is connected to controller.The port +BUS connects DC bus, or the port +BUS connects ACDC converter, and ACDC converter is connected to mains.The port VOUT1 and the port VOUT2 can be connected to different devices respectively, or be connected to the same device after being connected in series (or parallel), in the embodiment, the port VOUT1 and the port VOUT2 are connected to different batteries respectively, or the port VOUT1 and the port VOUT2 are connected to battery after being connected in series.The gate of the MOS tube Q20 and the gate of the MOS tube Q21 are connected to port DRV_3, and port DRV_3 is connected to controller.The pin 12 of transformer T14 shares a coil, the pin 34 shares a coil, and the pin 56 shares a coil.Preferably, the number of the conversion circuit is multiple, the port +BUS of multiple the conversion circuit is connected to each other, and the port GND is connected to each other.It has multi-output, can further increase the positive and negative output range by the series-parallel connection of output, and the output range can reach 200V-1200V, can adapt to batteries of various voltage grades, plus using transformer to realize input and output electrical isolation, so that the whole converter becomes safe and stable.

[0028] Embodiment one

[0029] See Figure 2 As shown in the figure, a multi-output interleaved isolated bidirectional Sepic converter includes two conversion circuits.

[0030] A multi-output interleaved isolated bidirectional Sepic converter is suitable for bidirectional charging piles and various battery energy storage systems, including an isolated first bidirectional Sepic conversion circuit and an isolated second bidirectional Sepic conversion circuit. The interleaved isolated bidirectional Sepic converter circuit includes an input capacitor, a primary energy storage inductor, a primary MOS tube, a primary energy storage capacitor, a transformer, a secondary energy storage capacitor, a secondary MOS tube, a secondary energy storage inductor, and an output capacitor. The interleaved isolated bidirectional Sepic converter has the characteristics of a basic Sepic converter that can step up and step down, and can achieve simple input and output electrical isolation through a transformer. Due to the left-right symmetrical structure of the circuit, bidirectional energy transmission can also be achieved.

[0031] The first primary side of the multi-output interleaved isolated bidirectional Sepic converter includes a first energy storage inductor L24, a first MOS tube Q12, a first diode D49, a first energy storage capacitor C214, a second energy storage inductor L25, and a first transformer primary side T14-A (pin 1). The energy storage inductor L24 is connected to the input +BUS and the cathode of the first MOS tube Q12 and the first diode D49 and the first energy storage capacitor C214. The source of the first MOS tube Q12 is connected to the anode of the first diode D49 and GND, and the first energy storage capacitor C214 is connected to the second energy storage inductor L25. The first transformer primary side T14-A is connected to the second energy storage inductor L25. The first transformer primary side T14-A and the second energy storage inductor L25 are connected to GND at the other end.

[0032] The first secondary side of the multi-output interleaved isolated bidirectional Sepic converter includes a first transformer secondary side T14-C (pin 56), T14-D (pin 34), a third energy storage inductor L26, a second energy storage capacitor C222, a second MOS tube Q20, a fourth energy storage inductor L28, a fifth energy storage inductor L27, a third energy storage capacitor C223, a third MOS tube Q21, a sixth energy storage inductor L29, the first transformer secondary side T14-C is connected with the third energy storage inductor L26 and the second energy storage capacitor C222, the drain electrode of the second MOS tube Q20 is connected with the second energy storage capacitor C222 and the fourth energy storage inductor L28, the source electrode of the second MOS tube Q20 is connected with the source electrode of the third MOS tube Q21 and AGND; the fourth energy storage inductor L28 is connected with the output VOUT1, the first transformer secondary side T14-D is connected with the fifth energy storage inductor L27, the third energy storage capacitor C223, the drain electrode of the third MOS tube Q21 is connected with the third energy storage capacitor C223 and the sixth energy storage inductor L29, the source electrode of the third MOS tube Q21 is connected with the center tap of the first transformer secondary side and the fifth energy storage inductor L27, the connection point of the fifth energy storage inductor L27, and the sixth energy storage inductor L29 is connected with the output VOUT2.

[0033] The second primary side of the multi-output interleaved isolated bidirectional Sepic converter includes a seventh energy storage inductor L32, a fourth MOS tube Q13, a second diode D42, a fourth energy storage capacitor C218, an eighth energy storage inductor L33, a second transformer primary side T7-A (pin 12), the energy storage inductor L32 is connected with the input +BUS and the cathode of the fourth MOS tube Q13 and the second diode D42 and the fourth energy storage capacitor C218, the anode of the fourth MOS tube Q13 and the anode of the second diode D42 and GND, the fourth energy storage capacitor C218 is connected with the eighth energy storage inductor L33, the second transformer primary side T7-A is connected with the eighth energy storage inductor L33, and the other end of the second transformer primary side T7-A and the eighth energy storage inductor L33 is connected with GND.

[0034] The second path secondary side of the multi-output staggered isolation bidirectional Sepic converter includes a second transformer secondary side T7-C (pin 56), T7-D (pin 34), a ninth energy storage inductor L36, a fifth energy storage capacitor C230, a fifth MOS tube Q22, a tenth energy storage inductor L34, an eleventh energy storage inductor L37, a sixth energy storage capacitor C231, a sixth MOS tube Q23, a twelfth energy storage inductor L35, the second transformer secondary side T7-C is connected with the ninth energy storage inductor L36 and the fifth energy storage capacitor C230, the drain electrode of the fifth MOS tube Q22 is connected with the fifth energy storage capacitor C230 and the tenth energy storage inductor L34, the source electrode of the fifth MOS tube Q22 is connected with the source electrode of the sixth MOS tube Q23 and AGND2; the tenth energy storage inductor L34 is connected with the output VOUT3, the second transformer secondary side T17-D is connected with the eleventh energy storage inductor L37, the sixth energy storage capacitor C231, the drain electrode of the twelfth MOS tube Q23 is connected with the sixth energy storage capacitor C231 and the twelfth energy storage inductor L35, the source electrode of the sixth MOS tube Q23 is connected with the center tap of the second transformer and the ninth energy storage inductor L36, the connection point of the eleventh energy storage inductor L37, and the twelfth energy storage inductor L35 is connected with the output VOUT4.

[0035] When running forward, the converter Q12 is turned on, the +BUS-L24-Q12-GND loop and the C214-Q12-L25 loop are simultaneously turned on, the L24 and the L25 are energy-stored, when the MOS tube driving DRV_1 is low, the +BUS-L24-C214-T14-A-GND loop and the L25-T14-A loop are simultaneously turned on, at this time, the input and the L24 supply power to the load, and at the same time, the C214 is also charged, the energy stored in the C214 is transferred to the L24 when the DRV_1 is high, at this time, the secondary side transformer T14-C-C222-L28-VOUT1-AGND discharges to the load, and at the same time, the load is also discharged through the T14-D-C223-L29-VOUT2-AGND, the L28 and the L29 are energy-stored, when the driving DRV_1 is low, the L28-VOUT1-AGND-Q20 loop and the L29-VOUT2-AGND-Q21 loop are simultaneously turned on, the energy stored in the L28 and the L29 is released to the load.

[0036] When the reverse operation; MOS Q20, Q21 is turned on, VOUT1-L28-Q20-AGND loop and C222-Q20-L26 loop are turned on at the same time, L28, L26 stores energy, the second road VOUT2-L29-Q21-AGND loop and C223-Q21-L27 loop are turned on at the same time, L27, L29 stores energy, when MOS Q20, Q21 is turned off, VOUT1-L28-C222-T14-C-AGND loop and L26-T14-C loop are turned on at the same time, the second road VOUT2-L29-C223-T14-D-AGND loop and L27-T14-D loop are turned on at the same time, at this time VOUT1 and VOUT2 and L28, L29 supply power to the load, at the same time also charge C222, C223, C222, C223 stored energy is transferred to L26, L27 when MOS Q20, Q21 is turned on, at this time the primary side transformer T14-A-C214-L24-+BUS-GND discharges to the load, L24 stores energy, when MOS Q20, Q21 is turned on, L24-+BUS-Q12(D49) loop is turned on, L24 stored energy is released to the load.

[0037] The second road of the transformer operates, only and the first road stagger 180 degrees, and its principle is completely consistent.

[0038] A multi-output interleaved isolation bidirectional Sepic converter has multiple outputs, and the output can be connected in series and parallel to further increase the forward and reverse output range, the output range can reach 200V-1200V, and the converter can be adapted to batteries of various voltage grades; in addition, the input and output are electrically isolated by using a transformer, so that the entire converter is safe, stable, suitable for bidirectional charging piles and various battery energy storage systems, has perfect protection function, high circuit reliability, simple software control and low cost.

[0039] Although the embodiments of the utility model have been disclosed as above, it is not limited to the application listed in the specification and embodiments, and it can be fully applied to various fields suitable for the utility model. For those skilled in the art, other modifications can be easily realized, therefore, the utility model is not limited to specific details and the figures shown and described herein without departing from the general concept defined by the claims and equivalent scope.

Claims

1. A multi-output interleaved isolated bidirectional Sepic converter characterized by: The transformer T14 is connected to the inductor L27 and the capacitor C223, the other end of the capacitor C223 is connected to the source of the MOS Q21 and the inductor L29, the other end of the inductor L29 is connected to the capacitor C229 and the port VOUT2, the pin 4 of the transformer T14 is connected to the pin 5 of the transformer T14, the other end of the inductor L27, the inductor L26, the drain of the MOS Q21, the source of the MOS Q20, the other end of the capacitor C229, the capacitor C224 and the port AGND1, the pin 6 of the transformer T14 is connected to the other end of the inductor L26 and the capacitor C222, the other end of the capacitor C222 is connected to the drain of the MOS Q20 and the inductor L28, the other end of the inductor L28 is connected to the other end of the capacitor C224 and the port VOUT1. The number of the transformer circuit is multiple, the port +BUS of multiple transformer circuits are connected to each other, and the port GND is connected to each other.

2. The multi-output interleaved isolated bidirectional Sepic converter of claim 1, wherein: The number of the transformer circuit is two, and the two transformer circuits work staggered by 180 degrees.

3. The multi-output interleaved isolated bidirectional Sepic converter of claim 2, wherein: The gate of the MOS Q12 is connected to one end of the resistor R146 and the port DRV_1, the other end of the resistor R146 is connected to the port GND, and the port DRV_1 is connected to the controller.

4. The multi-output interleaved isolated bidirectional Sepic converter of claim 1, wherein: The port +BUS is connected to the DC bus.

5. The multi-output interleaved isolated bidirectional Sepic converter of claim 1, wherein: The port +BUS is connected to the ACDC converter, and the ACDC converter is connected to the mains.

6. The multi-output interleaved isolated bidirectional Sepic converter of claim 1, wherein: The port VOUT1 and the port VOUT2 are respectively connected to different batteries, or the port VOUT1 and the port VOUT2 are connected to the battery in series.

7. The multi-output interleaved isolated bidirectional Sepic converter of claim 1, wherein: The gate of the MOS Q20 and the gate of the MOS Q21 are connected to the port DRV_3, and the port DRV_3 is connected to the controller.

8. The multi-output interleaved isolated bidirectional Sepic converter of claim 1, wherein: The gate of the MOS Q12 is connected to one end of the resistor R146 and the port DRV_1, the other end of the resistor R146 is connected to the port GND, and the port DRV_1 is connected to the controller. The port +BUS is connected to the DC bus. The port +BUS is connected to the ACDC converter, and the ACDC converter is connected to the mains. The port VOUT1 and the port VOUT2 are respectively connected to different batteries, or the port VOUT1 and the port VOUT2 are connected to the battery in series. The gate of the MOS Q20 and the gate of the MOS Q21 are connected to the port DRV_3, and the port DRV_3 is connected to the controller.

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