Three-phase power energy storage converter circuit topology

Abstract

The utility model belongs to the technical field of converters, and discloses a three-phase energy storage converter circuit topology, which comprises a port A, a port B and a port C. The port A is connected with one end of an inductor L13, the other end of the inductor L13 is connected with a pin 2 of a switch tube N1 and a pin 1 of a switch tube N2, the port B is connected with one end of an inductor L14, and the other end of the inductor L14 is connected with a pin 2 of a switch tube N1. The port C is connected with one end of the inductor L14, the other end of the inductor L14 is connected with a pin 2 of the switching tube N5 and a pin 1 of the switching tube N3, the port C is connected with one end of the inductor L15, the other end of the inductor L15 is connected with a pin 2 of the switching tube N6 and a pin 1 of the switching tube N4, and a pin 1 of the switching tube N1 is connected with a pin 1 of the switching tube N5, a pin 1 of the switching tube N6, one end of the capacitor C3, one end of the capacitor C1 and one end of the inductor L1. The beneficial effects of the utility model are that better reliability and high efficiency are realized, the cost can be reduced, the size is reduced, and the circuit structure and software control are simplified.

Description

Technical Field

[0001] This utility model relates to the field of converter technology, and in particular to a three-phase energy storage converter circuit topology. Background Technology

[0002] With the rapid development of switching power supply technology, high-power switching power supplies are being used more and more frequently in the market, and energy storage converters are one type of new energy source. In recent years, the power of energy storage power supplies has been increasing. In modern high-power power supply applications, the input voltage is usually a three-phase AC input, which is then rectified by a three-phase Vienna PFC topology and subsequently converted to DC-DC by an LLC circuit to obtain the required DC output voltage.

[0003] In applications such as energy storage inverters, off-grid inverters, and grid-connected inverters, an H-bridge inverter circuit is typically used, along with a boost converter circuit to the MPPT section on the bus. Capable operating modes include charging the battery with solar or AC power, solar inverter output to the grid or off-grid, and battery inverter output to the grid or off-grid. In some low-cost modular applications, LLC (Limited-Low Capacitor) circuits are often used for bidirectional conversion to meet inverter requirements; this LLC+H-bridge circuit mode offers good performance but is relatively expensive. There are also solutions using a single half-bridge LLC or full-bridge LLC for inverter implementation. This mode can also achieve the relevant inverter conversion, but the voltage inverted by the LLC is not stable enough, resulting in voltage fluctuations in the output voltage. This is unacceptable for high-precision instruments and equipment. For applications involving charging within the battery voltage range, parallel output, and grid connection, the inverter's performance is significantly limited, easily leading to various protection failures or even damage.

[0004] Therefore, it is necessary to provide a three-phase energy storage converter circuit topology to achieve better reliability and high efficiency, reduce cost, reduce size, and simplify circuit structure and software control. Utility Model Content

[0005] This utility model discloses a three-phase energy storage converter circuit topology, which relates to the field of power electronics technology. It is mainly used in switching power supplies and is widely used in energy storage inverters, chargers, off-grid inverters and grid-connected inverters. It can effectively solve the technical problems involved in the background art.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows:

[0007] A three-phase energy storage converter circuit topology includes ports A, B, and C. Port A is connected to one end of inductor L13, and the other end of inductor L13 is connected to pin 2 of switch N1 and pin 1 of switch N2. Port B is connected to one end of inductor L14, and the other end of inductor L14 is connected to pin 2 of switch N5 and pin 1 of switch N3. Port C is connected to one end of inductor L15, and the other end of inductor L15 is connected to pin 2 of switch N6 and pin 1 of switch N4. Pin 1; Pin 1 of the switching transistor N1 is connected to pin 1 of the switching transistor N5, pin 1 of the switching transistor N6, one end of capacitor C3, one end of capacitor C1, and one end of inductor L1. The other end of inductor L1 is connected to pin 1 of the switching transistor Q108 and one end of capacitor C14. The other end of capacitor C15 is connected to pin 1 of transformer T1. Pin 2 of transformer T1 is connected to pin 2 of the switching transistor Q108 and port GND. The other end of capacitor C3 is connected to the other end of capacitor C1. One end of capacitor C4, one end of capacitor C5, and one end of inductor L2 are connected. The other end of inductor L2 is connected to pin 1 of switch transistor Q109 and one end of capacitor C17. The other end of capacitor C17 is connected to pin 1 of transformer T2. Pin 2 of transformer T2 is connected to pin 2 of switch transistor Q109, the other end of capacitor C5, the other end of capacitor C4, pin 2 of switch transistor N4, pin 2 of switch transistor N3, pin 2 of switch transistor N2, and port GND. Pin 4 of transformer T1 is connected to pin 1 of switch transistor Q128. Pin 2 of switch transistor Q128 is connected to one end of capacitor C59 and port OUT1. Pin 3 of transformer T1 is connected to the other end of capacitor C59 and port AGND1. Pin 4 of transformer T2 is connected to pin 1 of switch transistor Q129. Pin 2 of switch transistor Q129 is connected to one end of capacitor C22 and port OUT2. Pin 3 of transformer T2 is connected to the other end of capacitor C22 and port AGND2.

[0008] A novel three-phase energy storage converter topology is proposed to replace the traditional bidirectional inverter converter circuit or the complex input inverter H-bridge circuit and LLC approach. Without reducing efficiency, it can achieve a wide battery voltage range and bus voltage range, thereby meeting the requirements of high reliability, small size, and low cost for applications such as energy storage inverters, off-grid inverters, and grid-connected inverters. The circuit consists of inductors, isolation capacitors, transformers, and power switching transistors.

[0009] As a preferred improvement of this utility model: port A is connected to one end of inductor L13 through fuse F7, port B is connected to one end of inductor L14 through fuse F8, and port C is connected to one end of inductor L15 through fuse F9.

[0010] As a preferred improvement of this utility model: the converter circuit topology includes a controller, which is connected to the control terminals of switching transistors N1, N2, N3, N4, N5, N6, Q108, and Q109.

[0011] As a preferred improvement of this utility model: one end of capacitor C15 is connected to one end of capacitor C446, the other end of capacitor C15 is connected to the other end of capacitor C446, one end of capacitor C17 is connected to one end of capacitor C18, and the other end of capacitor C17 is connected to the other end of capacitor C18.

[0012] As a preferred improvement of this utility model: port A, port B and port C are connected to three-phase power, and port OUT1 and port OUT2 are connected to a battery.

[0013] As a preferred improvement of this utility model: the port OUT1 and the port OUT2 are connected, and the port AGND1 and the port AGND2 are connected.

[0014] As a preferred improvement of this utility model: the switching transistors Q128 and Q129 are diodes, with pin 1 being the positive terminal and pin 2 being the negative terminal.

[0015] As a preferred improvement of this utility model, the types of the switching transistors N1, N2, N3, N4, N5, N6, Q108, Q109, Q128, and Q129 include, but are not limited to, IGBTs, bipolar transistors, silicon carbide, gallium nitride, and MOSFETs.

[0016] As a preferred improvement of this utility model: the switching transistors N1, N2, N3, N4, N5, N6, Q108, Q109, Q128 and Q129 are MOSFETs, wherein pin 1 is the drain and pin 2 is the source.

[0017] The beneficial effects of this utility model are as follows:

[0018] It can achieve stable bus voltage control, meeting the performance requirements of various energy storage converters. In particular, it uses a single-stage circuit instead of a bridge circuit and high-voltage silicon carbide devices, which can achieve better reliability and higher efficiency, reduce costs and size, and has the advantages of simplified circuit structure and software control. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0020] Figure 1 This is a schematic diagram of the circuit topology of a three-phase energy storage converter according to the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0023] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0026] In some energy storage inverters, off-grid inverters, and grid-connected inverters, the operating mode typically involves drawing power from the grid to achieve the bus voltage when the mains power is available, and then charging the battery through bidirectional DC-DC conversion. In LLC+H bridge circuit applications, due to the two-stage conversion, control and regulation can be easily achieved, and the bus voltage can be stabilized. This is beneficial for inverter output parallel connection and MPPT applications, but the application cost is high and it is not easy to control. In applications using single-stage LLC bidirectional conversion, the bus voltage is unstable in order to achieve soft-start control. This greatly limits the inverter performance in situations such as charging within the battery voltage range, output parallel connection, and grid-connected applications, and is prone to various protection failures, leading to malfunctions or application problems. Based on the above description, a three-phase energy storage converter circuit is used to replace the single-stage LLC or LLC+H bridge circuit, which can achieve stable bus voltage control and meet the performance requirements of various energy storage converters. In particular, by using a single-stage circuit instead of a bridge circuit and using high-voltage silicon carbide devices, better reliability and higher efficiency can be achieved, while reducing costs, size, and simplifying circuit structure and software control.

[0027] Please see Figure 1As shown, this utility model provides a three-phase energy storage converter circuit topology, including port A, port B, and port C. Port A is connected to one end of inductor L13, and the other end of inductor L13 is connected to pin 2 of switch N1 and pin 1 of switch N2. Port B is connected to one end of inductor L14, and the other end of inductor L14 is connected to pin 2 of switch N5 and pin 1 of switch N3. Port C is connected to one end of inductor L15, and the other end of inductor L15 is connected to pin 1 of switch N6. 2. Pin 1 of switch N1 and switch N4; pin 1 of switch N1 is connected to pin 1 of switch N5, pin 1 of switch N6, one end of capacitor C3, one end of capacitor C1, and one end of inductor L1. The other end of inductor L1 is connected to pin 1 of switch Q108 and one end of capacitor C14. The other end of capacitor C15 is connected to pin 1 of transformer T1. Pin 2 of transformer T1 is connected to pin 2 of switch Q108 and port GND. The other end of capacitor C3 is connected to capacitor C... The other end of capacitor C109, one end of capacitor C4, one end of capacitor C5, and one end of inductor L2 are connected. The other end of inductor L2 is connected to pin 1 of switching transistor Q109 and one end of capacitor C17. The other end of capacitor C17 is connected to pin 1 of transformer T2. Pin 2 of transformer T2 is connected to pin 2 of switching transistor Q109, the other end of capacitor C5, the other end of capacitor C4, pin 2 of switching transistor N4, pin 2 of switching transistor N3, pin 2 of switching transistor N2, and port GND. Pin 4 of transformer T1 is connected to pin 1 of switching transistor Q128. Pin 2 of switching transistor Q128 is connected to one end of capacitor C59 and port OUT1. Pin 3 of transformer T1 is connected to the other end of capacitor C59 and port AGND1. Pin 4 of transformer T2 is connected to pin 1 of switching transistor Q129. Pin 2 of switching transistor Q129 is connected to one end of capacitor C22 and port OUT2. Pin 3 of transformer T2 is connected to the other end of capacitor C22 and port AGND2. Ports OUT1 and OUT2 can be connected to different devices, or they can be connected to the same device in series or parallel. In this embodiment, port A is connected to one end of inductor L13 through fuse F7, port B is connected to one end of inductor L14 through fuse F8, and port C is connected to one end of inductor L15 through fuse F9. The converter circuit topology includes a controller, which is connected to the control terminals of switches N1, N2, N3, N4, N5, N6, Q108, and Q109. One end of capacitor C15 is connected to one end of capacitor C446, and the other end of capacitor C15 is connected to the other end of capacitor C446. One end of capacitor C17 is connected to one end of capacitor C18, and the other end of capacitor C17 is connected to the other end of capacitor C18.With a simple topology, few components, and low cost, it can replace expensive traditional inverter circuit structures and complete bidirectional conversion of energy storage inverters.

[0028] In this application, the high-voltage side of the circuit is connected to three-phase power, and the low-voltage side is connected to a battery. The three-phase power can also be replaced with other sources / loads. In this embodiment, ports A, B, and C are connected to three-phase power, and ports OUT1 and OUT2 are connected to the battery. Preferably, ports OUT1 and OUT2 are connected, ports AGND1 and AGND2 are connected, and ports OUT1 and OUT2 are connected in series with the battery. It should be further noted that any other components used to achieve the above effects should fall within the inventive concept of this utility model and should be protected within its scope.

[0029] The circuit shown in the diagram is a bidirectional energy storage inverter. When the circuit is used for unidirectional operation, the primary or secondary MOSFETs can be replaced with diodes. In this embodiment, the switching transistors Q128 and Q129 are diodes, with pin 1 being the positive terminal and pin 2 being the negative terminal. It should be further noted that any other components used to achieve the above effects should fall within the inventive concept of this utility model and should be protected within its scope.

[0030] The switching device in the diagram is a MOSFET. Other switching devices can also achieve the function, including but not limited to IGBTs, bipolar transistors, silicon carbide, and gallium nitride. Specifically, the types of switching transistors N1, N2, N3, N4, N5, N6, Q108, Q109, Q128, and Q129 include, but are not limited to, IGBTs, bipolar transistors, silicon carbide, gallium nitride, and MOSFETs. In this embodiment, switching transistors N1, N2, N3, N4, N5, N6, Q108, Q109, Q128, and Q129 are MOSFETs, where pin 1 is the drain and pin 2 is the source. It should be further noted that using other components to achieve the above effect should fall within the inventive concept of this utility model and should be within the protection scope of this utility model.

[0031] Working principle:

[0032] During forward operation (three-phase input, output charges the battery).

[0033] The input three-phase voltage (A, B, C) is boosted through a three-phase six-switch circuit structure. Each phase is staggered by 120°, and the boosted voltage is stored in large capacitors C1, C3, C4, and C5.

[0034] Complementary switches Q108 and Q128, Q109 and Q129.

[0035] When Q108 is on, Q128 is off; when Q109 is on, Q129 is off. Inductor L1 stores energy through Q108, and inductor L2 stores energy through Q129. During this time period, transformers T1 and T2, as well as capacitors C15, C446, C17, and C18 are reset.

[0036] When Q108 is turned off, Q128 is turned on, and the energy of inductor L1 is transferred to the battery side through capacitors C15 and C446 and transformer T1.

[0037] When Q109 is turned off, Q129 is turned on, and the energy of inductor L2 is transferred to the battery side through capacitors C17 and C18 and transformer T2.

[0038] When operating in reverse (the battery discharges at the output terminal, and three-phase levels are output at the positive input three-phase port), the battery outputs a three-phase level.

[0039] When Q128 is turned on, Q108 is turned off, and the battery energy is transferred to the bus side through C446, C15 and L1, with L1 storing the energy.

[0040] When Q129 is turned on, Q109 is turned off, and the battery energy is transferred to the bus side through C17, C18 and L2, with L2 storing the energy.

[0041] When Q128 is turned off, Q108 is turned on, inductor L1 freewheels, energy is released to the bus side, and C446, C15 and T1 are reset.

[0042] When Q129 is turned off, Q109 is turned on, inductor L2 freewheels, energy is released to the bus side, and C17, C18 and T2 are reset.

[0043] During this period, the energy from the secondary winding is stored in the large capacitors C1, C3, C4, and C5. By controlling the operation based on the three-phase six-switch, the energy from the large capacitors is output to the terminals.

[0044] A three-phase energy storage converter circuit is adopted to replace the single-stage LLC or LLC+H bridge circuit, which can achieve stable bus voltage control and meet the performance requirements of various energy storage converters. In particular, the use of a single-stage circuit instead of a bridge circuit and the use of high-voltage silicon carbide devices can achieve better reliability and higher efficiency, reduce costs, reduce size, and simplify circuit structure and software control.

[0045] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A three-phase energy storage inverter circuit topology, characterized by: Port A connects one end of inductor L13, the other end of inductor L13 connects pin 2 of switch tube N1 and pin 1 of switch tube N2, port B connects one end of inductor L14, the other end of inductor L14 connects pin 2 of switch tube N5 and pin 1 of switch tube N3, port C connects one end of inductor L15, the other end of inductor L15 connects pin 2 of switch tube N6 and pin 1 of switch tube N4; Pin 1 of switch tube N1 connects pin 1 of switch tube N5, pin 1 of switch tube N6, one end of capacitor C3, one end of capacitor C1 and one end of inductor L1, the other end of inductor L1 connects pin 1 of switch tube Q108 and one end of capacitor C14, the other end of capacitor C15 connects pin 1 of transformer T1, pin 2 of transformer T1 connects pin 2 of switch tube Q108 and port GND, the other end of capacitor C3 connects the other end of capacitor C1, one end of capacitor C4, one end of capacitor C5 and one end of inductor L2, the other end of inductor L2 connects pin 1 of switch tube Q109 and one end of capacitor C17, the other end of capacitor C17 connects pin 1 of transformer T2, pin 2 of transformer T2 connects pin 2 of switch tube Q109, the other end of capacitor C5, the other end of capacitor C4, pin 2 of switch tube N4, pin 2 of switch tube N3, pin 2 of switch tube N2 and port GND; Pin 4 of transformer T1 connects pin 1 of switch tube Q128, pin 2 of switch tube Q128 connects one end of capacitor C59 and port OUT1, pin 3 of transformer T1 connects the other end of capacitor C59 and port AGND1, pin 4 of transformer T2 connects pin 1 of switch tube Q129, pin 2 of switch tube Q129 connects one end of capacitor C22 and port OUT2, pin 3 of transformer T2 connects the other end of capacitor C22 and port AGND2.

2. A three-phase energy storage converter circuit topology according to claim 1, characterized in that: One end of inductor L13 is connected to port A through fuse F7, one end of inductor L14 is connected to port B through fuse F8, one end of inductor L15 is connected to port C through fuse F9.

3. A three-phase energy storage inverter circuit topology according to claim 1, characterized in that: The converter circuit topology comprises a controller connected to the control terminals of switch tube N1, switch tube N2, switch tube N3, switch tube N4, switch tube N5, switch tube N6, switch tube Q108 and switch tube Q109.

4. A three-phase energy storage converter circuit topology according to claim 1, characterized in that: One end of capacitor C15 is connected to one end of capacitor C446, the other end of capacitor C15 is connected to the other end of capacitor C446, one end of capacitor C17 is connected to one end of capacitor C18, the other end of capacitor C17 is connected to the other end of capacitor C18.

5. A three-phase electrical energy storage inverter circuit topology according to claim 1, characterized in that: Port A, port B and port C are connected to three-phase power, port OUT1 and port OUT2 are connected to a battery.

6. A three-phase energy storage converter circuit topology according to claim 1, characterized by: The port OUT1 and the port OUT2 are connected, and the port AGND1 and the port AGND2 are connected.

7. A three-phase energy storage converter circuit topology according to claim 1, characterized by: The switch tube Q128 and the switch tube Q129 are diodes, the pin 1 of both is the positive terminal, and the pin 2 is the negative terminal.

8. A three-phase electrical energy storage inverter circuit topology according to claim 1, characterized in that: The types of the switch tube N1, the switch tube N2, the switch tube N3, the switch tube N4, the switch tube N5, the switch tube N6, the switch tube Q108, the switch tube Q109, the switch tube Q128 and the switch tube Q129 include but are not limited to IGBT, bipolar triode, silicon carbide, gallium nitride and MOS tube.

9. A three-phase electrical energy storage inverter circuit topology according to claim 1, characterized in that: The switch tube N1, the switch tube N2, the switch tube N3, the switch tube N4, the switch tube N5, the switch tube N6, the switch tube Q108, the switch tube Q109, the switch tube Q128 and the switch tube Q129 are MOS tubes, wherein the pin 1 is the drain, and the pin 2 is the source.

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