Multipath output staggered isolation bidirectional Sepic converter

Abstract

The invention belongs to the technical field of converters, and discloses a multiplexed output interleaved 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 port + BUS. 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 invention has the beneficial effects that the multi-path output is realized, the forward and reverse output range can be further increased through series-parallel connection of the output, and the multi-path output circuit can adapt to batteries of various voltage grades.

Description

Technical Field

[0001] The present invention relates to the technical field of converters, and in particular to a multi-channel output interleaved isolation bidirectional Sepic converter. Background Art

[0002] In today's global green energy, energy conservation and emission reduction strategy, State Grid Corporation of China and China Southern Power Grid are vigorously developing new energy power generation technologies such as wind power generation, nuclear power generation and solar home power generation. Distributed power generation, mainly wind and solar power, will bring certain hidden dangers to the safe operation of the power grid due to its volatility, intermittency and unpredictability when connected to the grid. Energy storage technology can largely solve some problems existing in the connection of new energy power generation to the grid, making low-density, random renewable new energy widely used, so energy storage technology has become the object of vigorous development at present.

[0003] Among the small and medium-sized power storage technologies for renewable energy distributed generation, battery energy storage technology is the most widely used, because battery energy storage devices are not only easy to install, but also have flexible capacity adjustment; they can also store valley electricity at night, or store excess electricity at ordinary times, and use it as an emergency power source when the power supply is tight or even interrupted; they are also dispatching experts in peak load shaving and valley filling in power grid operation, and are the key technology for wind and solar grid connection. The grid-connected battery energy storage system mainly realizes energy storage, release and rapid power exchange, and generally consists of two parts: the first is the energy storage part composed of battery modules of different capacities, which is mainly responsible for energy storage and release; the second is the energy conversion system (or charge and discharge converter) composed of power electronic devices, which is a two-way channel for power transmission in the grid-connected battery energy storage system, ensuring the safety and efficiency of battery charging and discharging, and both are indispensable.

[0004] At present, the requirements of battery energy storage systems for charging and discharging converters are getting higher and higher. They are not only required to have traditional charging and discharging functions, but also to meet the wide range of battery voltage. The energy conversion system mainly realizes AC-DC bidirectional conversion and DC-DC bidirectional conversion. At present, Buck-Boost chopper circuits are widely used in DC-DC bidirectional converters. However, in this structure, in order to achieve voltage matching and safe isolation between the battery side and the grid side, it is necessary to add an industrial frequency isolation transformer on the grid side. However, the size, weight and noise of the transformer are relatively large, and the power loss is also high, making it difficult for battery energy storage systems to achieve high charging and discharging efficiency and high power density. Difficult; the bidirectional CUK converter is widely used, but due to the opposite polarity of the input and output of its topology, the voltage stress rating of its power MOS tube and the capacitor voltage rating will be the input voltage plus the output voltage, so it cannot be used in energy storage batteries with wide input and output. The DAB topology uses single-phase fully controlled bridge converters on both sides, which can achieve zero voltage (ZVS) working mode, small power loss, high charging and discharging efficiency, but it requires the application of silicon carbide devices, and the software control is complex, expensive, and low reliability; in addition, the current industry's bidirectional DC-DC converters are almost all single-channel outputs, 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, which is suitable for bidirectional charging piles and various battery energy storage systems, with complete protection functions, high circuit reliability, simple software control and low cost. Summary of the invention

[0006] The invention discloses a multi-channel 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 technology.

[0007] To achieve the above object, the technical solution of the present invention is:

[0008] A multi-channel output interleaved isolation bidirectional Sepic converter, comprising a conversion circuit, wherein the conversion circuit comprises a port +BUS, wherein the port +BUS is connected to one end of a capacitor C210 and one end of an inductor L24, wherein the other end of the inductor L24 is connected to the drain of a MOS tube Q12, the negative end of a diode D49 and one end of a capacitor C214, wherein the other end of the capacitor C214 is connected to one end of an inductor L25 and a pin 1 of a transformer T14, wherein 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 inductor L25 and a pin 2 of the transformer T14 are connected to a port GND; wherein the pin 3 of the transformer T14 is connected to one end of an inductor L27 and one end of a capacitor C223, wherein the other end of the capacitor C223 ..., the other end of the inductor L25 and a pin 2 of the transformer T14 are connected to a port GND; wherein the pin 3 of the transformer T14 is connected to one end of an inductor L27 and one The first end of the transformer T14 is connected to the source of the MOS tube Q21 and one end of the inductor L29, the other end of the inductor L29 is connected to one end of 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, one end of the inductor L26, the drain of the MOS tube Q21, the source of the MOS tube Q20, the other end of the capacitor C229, one end of 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 one end of the capacitor C222, the other end of the capacitor C222 is connected to the drain of the MOS tube Q20 and one end of the inductor L28, and the other end of the inductor L28 is connected to the other end of the capacitor C224 and the port VOUT1.

[0009] A multi-channel output interleaved isolation bidirectional Sepic converter is disclosed, which is suitable for bidirectional charging piles and various types of battery energy storage systems. It includes an isolated bidirectional Sepic conversion circuit, and the interleaved isolation 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 various output capacitors connected in sequence; the interleaved isolation bidirectional Sepic converter has the characteristics of the basic Sepic converter that can buck up and down, and simply realizes the electrical isolation of input and output through a transformer. Due to the left-right symmetrical structure of the circuit, it can also realize bidirectional transmission of energy. It is a new type of 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 output. Its output range can reach 200V-1200V, which can adapt to batteries of various voltage levels. In addition, the use of a transformer to realize input and output electrical isolation makes the entire converter safe and stable, suitable for bidirectional charging piles and various types of battery energy storage systems, with perfect protection functions, high circuit reliability, simple software control, and low cost.

[0010] As a preferred improvement of the present invention: there are multiple conversion circuits, and the ports +BUS of the multiple conversion circuits are connected to each other, and the ports GND are connected to each other.

[0011] As a preferred improvement of the present invention: the number of the conversion circuits is two, and the two conversion circuits work alternately at 180 degrees.

[0012] As a preferred improvement of the present invention: the gate of the MOS tube 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.

[0013] As a preferred improvement of the present invention: the port +BUS is connected to a DC bus.

[0014] As a preferred improvement of the present invention: the port+BUS is connected to an ACDC converter, and the ACDC converter is connected to the mains.

[0015] As a preferred improvement of the present invention: the port VOUT1 and the port VOUT2 are respectively connected to different batteries, or the port VOUT1 and the port VOUT2 are connected in series and then connected to a battery.

[0016] As a preferred improvement of the present invention: the gate of the MOS transistor Q20 and the gate of the MOS transistor Q21 are connected to the port DRV_3, and the port DRV_3 is connected to the controller.

[0017] The beneficial effects of the present invention are as follows:

[0018] It has multiple outputs, and the forward and reverse output range can be further increased by connecting the outputs in series and in parallel. The output range can reach 200V-1200V, which can adapt to batteries of various voltage levels. In addition, the use of a transformer to achieve input and output electrical isolation makes the entire converter safe and stable, suitable for bidirectional charging piles and various battery energy storage systems, with complete protection functions, high circuit reliability, simple software control and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0020] Figure 1 is a schematic diagram of a conversion circuit of the present invention;

[0021] Figure 2This is a structural diagram of Embodiment 1 of the present invention. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] See also Figure 1As shown, the present invention provides a multi-channel output interleaved isolation bidirectional Sepic converter, including a conversion circuit, the conversion circuit including a port +BUS, the port +BUS is connected to one end of a capacitor C210 and one end of an inductor L24, the other end of the inductor L24 is connected to the drain of a MOS tube Q12, the negative end of a diode D49 and one end of a capacitor C214, the other end of the capacitor C214 is connected to one end of an inductor L25 and a pin 1 of a 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 inductor L25 and a pin 2 of the transformer T14 are connected to a port GND; the pin 3 of the transformer T14 is connected to one end of an inductor L27 and one end of a capacitor C223, the capacitor C22 The other end of the MOS transistor Q21 is connected to the source of the MOS transistor Q21 and one end of the inductor L29, the other end of the inductor L29 is connected to one end of 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, one end of the inductor L26, the drain of the MOS transistor Q21, the source of the MOS transistor Q20, the other end of the capacitor C229, one end of 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 one end of the capacitor C222, the other end of the capacitor C222 is connected to the drain of the MOS transistor Q20 and one end of 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 gate of the MOS transistor 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, or 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 can be connected to different devices respectively, or the two can be connected in series (or in parallel) and then connected to the same device. In this embodiment, the port VOUT1 and the port VOUT2 are connected to different batteries respectively, or the port VOUT1 and the port VOUT2 are connected in series and then connected to the battery. The gate of the MOS tube Q20 and the gate of the MOS tube Q21 are connected to the port DRV_3, and the port DRV_3 is connected to the controller. The pin 12 of the transformer T14 shares a coil, the pin 34 shares a coil, and the pin 56 shares a coil. Preferably, the number of the conversion circuits is multiple, and the ports +BUS of the multiple conversion circuits are connected to each other, and the ports GND are connected to each other. It has multiple outputs, and the forward and reverse output range can be further increased by connecting the outputs in series and parallel. The output range can reach 200V-1200V, which can adapt to batteries of various voltage levels. In addition, the use of transformers to achieve input and output electrical isolation makes the entire converter safe and stable.

[0028] Embodiment 1

[0029] See also Figure 2 As shown, a multi-output interleaved isolation bidirectional Sepic converter includes two conversion circuits.

[0030] A multi-channel 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 output capacitors of each channel. The interleaved isolated bidirectional Sepic converter has the characteristics of a basic Sepic converter that can step up or down the voltage, and can simply realize the electrical isolation of input and output through a transformer. Due to the left-right symmetrical structure of the circuit, it can also realize bidirectional transmission of energy.

[0031] The first primary side of the multi-channel output interleaved isolation 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 drain of the first MOS tube Q12 and the cathode of the first diode D49 and the first energy storage capacitor C214. The source of the first MOS tube Q12 and the anode of the first diode D49 and GND, the first energy storage capacitor C214, are 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 other end of the first transformer primary side T14-A and the second energy storage inductor L25 are connected to GND.

[0032] The first secondary side of the multi-channel output interleaved isolation bidirectional Sepic converter includes the first transformer secondary side T14-C (pin 56), T14-D (pin 34), the third energy storage inductor L26, the second energy storage capacitor C222, the second MOS tube Q20, the fourth energy storage inductor L28, the fifth energy storage inductor L27, the third energy storage capacitor C223, the third MOS tube Q21, the sixth energy storage inductor L29, the first transformer secondary side T14-C is connected to the third energy storage inductor L26 and the second energy storage capacitor C222, and the drain of the second MOS tube Q20 is connected to the second energy storage capacitor C22 2 and the fourth energy storage inductor L28, the source of the second MOS tube Q20 is connected to the source of the third MOS tube Q21 and to AGND; the fourth energy storage inductor L28 is connected to the output VOUT1, the secondary side T14-D of the first transformer is connected to the fifth energy storage inductor L27 and the third energy storage capacitor C223, the drain of the third MOS tube Q21 is connected to the third energy storage capacitor C223 and the sixth energy storage inductor L29, the source of the third MOS tube Q21 is connected to the center tap of the secondary side of the first transformer and the third energy storage inductor L26, the connection point of the fifth energy storage inductor L27, and the sixth energy storage inductor L29 is connected to the output VOUT2.

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

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

[0035] During forward operation, converter Q12 is turned on, the +BUS-L24-Q12-GND loop and the C214-Q12-L25 loop are turned on at the same time, L24 and L25 store energy, and when the MOS tube drives DRV_1 to a low position, the +BUS-L24-C214-T14-A-GND loop and the L25-T14-A loop are turned on at the same time. At this time, the input and L24 supply power to the load and charge C214 at the same time. The energy stored in C214 is charged to L24 when DRV_1 is set high. 24 transfer, at this time the secondary transformer T14-C-C222-L28-VOUT1-AGND discharges to the load, and also discharges to the load through T14-D-C223-L29-VOUT2-AGND, L28 and L29 store energy, when driving DRV_1 to low, L28-VOUT1-AGND-Q20 loop and L29-VOUT2-AGND-Q21 loop are turned on at the same time, and the energy stored in L28 and L29 is released to the load.

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

[0037] When the second path of this converter is running, it only works 180 degrees staggered with the first path, and the principle is exactly the same.

[0038] A multi-channel output interleaved isolation bidirectional Sepic converter has multiple outputs. The forward and reverse output ranges can be further increased by connecting the outputs in series and in parallel. The output range can reach 200V-1200V and can adapt to batteries of various voltage levels. In addition, a transformer is used to achieve input and output electrical isolation, making the entire converter safe and stable. It is suitable for bidirectional charging piles and various battery energy storage systems, with complete protection functions, high circuit reliability, simple software control and low cost.

[0039] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A multi-output interleaved isolation bidirectional Sepic converter, characterized in that: The conversion circuit includes a conversion circuit, wherein the conversion circuit includes a port +BUS, wherein the port +BUS is connected to one end of a capacitor C210 and one end of an inductor L24, wherein the other end of the inductor L24 is connected to the drain of a MOS tube Q12, the negative end of a diode D49 and one end of a capacitor C214, wherein the other end of the capacitor C214 is connected to one end of an inductor L25 and a pin 1 of a transformer T14, and 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 inductor L25 and a pin 2 of the transformer T14 are connected to a port GND; Pin 3 of the transformer T14 is connected to one end of the inductor L27 and one end of the capacitor C223, the other end of the capacitor C223 is connected to the source of the MOS tube Q21 and one end of the inductor L29, the other end of the inductor L29 is connected to one end of the capacitor C229 and the port VOUT2, pin 4 of the transformer T14 is connected to pin 5 of the transformer T14, the other end of the inductor L27, one end of the inductor L26, the drain of the MOS tube Q21, the source of the MOS tube Q20, the other end of the capacitor C229, one end of the capacitor C224 and the port AGND1, pin 6 of the transformer T14 is connected to the other end of the inductor L26 and one end of the capacitor C222, the other end of the capacitor C222 is connected to the drain of the MOS tube Q20 and one end of the inductor L28, and the other end of the inductor L28 is connected to the other end of the capacitor C224 and the port VOUT1.

2. The multi-output interleaved isolation bidirectional Sepic converter according to claim 1, characterized in that: There are multiple conversion circuits, and the ports +BUS of the multiple conversion circuits are connected to each other, and the ports GND are connected to each other.

3. The multi-output interleaved isolation bidirectional Sepic converter according to claim 2, characterized in that: There are two conversion circuits, and the two conversion circuits work alternately at 180 degrees.

4. The multi-output interleaved isolation bidirectional Sepic converter according to claim 1, characterized in that: The gate of the MOS transistor 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.

5. The multi-output interleaved isolation bidirectional Sepic converter according to claim 1, characterized in that: The port +BUS is connected to a DC bus.

6. The multi-output interleaved isolation bidirectional Sepic converter according to claim 1, characterized in that: The port+BUS is connected to the ACDC converter, and the ACDC converter is connected to the mains.

7. The multi-output interleaved isolation bidirectional Sepic converter according to claim 1, characterized in that: The port VOUT1 and the port VOUT2 are respectively connected to different batteries, or the port VOUT1 and the port VOUT2 are connected in series to connect batteries.

8. The multi-output interleaved isolation bidirectional Sepic converter according to claim 1, characterized in that: The gate of the MOS transistor Q20 and the gate of the MOS transistor Q21 are connected to the port DRV_3, and the port DRV_3 is connected to the controller.

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