Topological structure of household alternating current and direct current series-parallel multi-port converter

Abstract

The utility model provides a topological structure of a household AC / DC series-parallel multi-port converter. The topological structure comprises a roof photovoltaic device, a distributed energy storage device and a household energy router; the household energy router comprises a photovoltaic input interface, an energy storage bidirectional interface, a direct current power supply interface, an alternating current power supply interface, an alternating current grid-connected interface and a DC-AC bidirectional converter, wherein the DC-AC bidirectional converter is arranged between an alternating current bus and a direct current bus. The household AC / DC hybrid multi-port converter topological structure provided by the utility model can realize multi-scene application, and can realize AC grid-connected power generation.

Description

Technical Field

[0001] The utility model belongs to the technical field of converter topology, and particularly relates to a household AC / DC hybrid multi-port converter topology structure. Background Art

[0002] As an innovative product that combines information technology with power electronics technology, household energy routers achieve efficient and reasonable distribution of electric energy. The device can provide a variety of energy interfaces for AC loads, DC loads, power generation equipment and energy storage equipment, making its access method more flexible and realizing plug-and-play functions. Household energy routers can also adjust the energy flow relationship between distributed power generation interfaces, energy storage interfaces, load interfaces and grid interfaces according to the production capacity of power generation equipment and the energy demand of the load end, realize multi-directional flow of energy, and thus significantly improve energy utilization. Drawing on the role of information routers in the network, it is foreseeable that in future power networks, household energy routers will become key nodes for regulating the energy flow between each subnet and the main grid. At present, there is an urgent need for a topology structure that uses household energy routers in a converter topology structure. Utility Model Content

[0003] The utility model aims to solve the problems in the prior art and proposes a household AC / DC hybrid multi-port converter topology structure.

[0004] The utility model is realized by the following technical scheme. The utility model proposes a household AC / DC hybrid multi-port converter topology structure, which includes rooftop photovoltaic, distributed energy storage device and household energy router;

[0005] The household energy router includes a photovoltaic input interface, an energy storage bidirectional interface, a DC power supply interface, an AC power supply interface, an AC grid connection interface, and a DC-AC bidirectional converter between AC and DC busbars;

[0006] The main topology of the topological structure is a DAB converter, and the distributed energy storage device and the rooftop photovoltaic are located on its low-voltage side, connected to the low-voltage side of the DAB transformer through a DC / DC chopper circuit, and the AC grid-connected interface is connected to the high-voltage side of the DAB converter through an H-bridge; the dual-active bridge circuit DAB realizes the bidirectional flow of energy between the high-voltage DC side and the low-voltage DC side, and improves the DC transformation ratio; the photovoltaic input interface is connected to the low-voltage side DC bus through a Boost DC boost chopper circuit; the energy storage bidirectional interface is connected to the low-voltage side DC bus through a Buck / Boost DC boost circuit; the DC / AC bidirectional converter is composed of a single-phase H-bridge circuit, which can operate in grid-connected inverter and grid-connected rectification modes, the H-bridge DC side is connected to the high-voltage side of the DAB converter, and the H-bridge AC side is connected to the single-phase AC distribution network as an AC power supply interface after passing through a filter; the DC power supply interface is used for DC power supply.

[0007] Furthermore, in the topological structure, the switch tubes Q1, Q2, Q3, and Q4 are switch tubes multiplexed, and the switch tubes Q1, Q2, and the inductor L P The Boost DC boost chopper circuit of the photovoltaic input interface is formed. The switch tube Q3, the switch tube Q4 and the inductor L B A Buck / Boost DC step-up and step-down circuit with a bidirectional energy storage interface is formed. Switch tubes Q1, Q2, Q3, and Q4 also form a DAB converter together with switch tubes Q5, Q6, Q7, Q8, and a transformer.

[0008] Furthermore, in the topology, the switch tube Q L With diode D, capacitor C l A Buck step-down circuit is formed to power the low-voltage DC load in the system.

[0009] Beneficial effects of the utility model:

[0010] The utility model proposes a household AC / DC hybrid multi-port converter topology structure that can be applied in multiple scenarios and can realize AC grid-connected power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a topological diagram of a household AC / DC hybrid multi-port converter. DETAILED DESCRIPTION

[0012] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only part of the embodiments of the present utility model, not all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present utility model.

[0013] Combination Figure 1 , the utility model proposes a household AC / DC hybrid multi-port converter topology structure, the topology structure includes rooftop photovoltaic, distributed energy storage device and household energy router;

[0014] The household energy router includes a photovoltaic input interface, an energy storage bidirectional interface, a DC power supply interface, an AC power supply interface, an AC grid connection interface, and a DC-AC bidirectional converter between AC and DC busbars;

[0015] The main topology of the topological structure is a DAB converter, and the distributed energy storage device and the rooftop photovoltaic are located on its low-voltage side, connected to the low-voltage side of the DAB transformer through a DC / DC chopper circuit, and the AC grid-connected interface is connected to the high-voltage side of the DAB converter through an H-bridge; the dual-active bridge circuit DAB realizes the bidirectional flow of energy between the high-voltage DC side and the low-voltage DC side, and improves the DC transformation ratio; the photovoltaic input interface is connected to the low-voltage side DC bus through a Boost DC boost chopper circuit; the energy storage bidirectional interface is connected to the low-voltage side DC bus through a Buck / Boost DC boost circuit; the DC / AC bidirectional converter is composed of a single-phase H-bridge circuit, which can operate in grid-connected inverter and grid-connected rectification modes, the H-bridge DC side is connected to the high-voltage side of the DAB converter, and the H-bridge AC side is connected to the single-phase AC distribution network as an AC power supply interface after passing through a filter; the DC power supply interface is used for DC power supply.

[0016] The converter topology also includes local AC and DC loads, a grid-connected part, a metering display unit and a communication unit, which will not be described in detail here.

[0017] In the topological structure, the switch tubes Q1, Q2, Q3, and Q4 are multiplexed. The switch tubes Q1, Q2, and the inductor L P The Boost DC boost chopper circuit of the photovoltaic input interface is formed. The switch tube Q3, the switch tube Q4 and the inductor L B The Buck / Boost DC step-up / step-down circuit with a bidirectional energy storage interface is formed. The switch tubes Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8 and the transformer form a DAB converter. The reuse of the switch tubes can reduce the number of switch tubes used in the converter, thereby improving the converter integration and reducing the cost and volume.

[0018] In the topology, the switch tube Q L With diode D, capacitor C l The Buck step-down circuit is formed to power the low-voltage DC load (such as DC LED lighting) in the system. The actual circuit of this topology also includes sampling, protection, drive circuits, controllers, interface circuits and human-machine interfaces. Its technical indicators are as follows: the photovoltaic input interface voltage on the low-voltage side is 50-90V, the bidirectional interface voltage of the energy storage on the low-voltage side is 48V, the DC power supply on the low-voltage side is 48V, the DC voltage on the high-voltage side is 375V, and the AC grid-connected interface is AC single-phase 220V.

[0019] The designed household AC / DC hybrid multi-port converter topology operation scenarios include:

[0020] Photovoltaic input interface: It mainly operates in maximum power tracking mode, and its output energy is used to charge local DC loads, AC loads and energy storage. When the photovoltaic output energy meets the local load and energy storage and there is still excess energy, the excess energy is connected to the AC grid for power generation through the grid-connected port;

[0021] Energy storage bidirectional interface: Under the premise of meeting the state of charge (SoC) constraints, high storage and low generation are carried out according to the time-of-use electricity price to achieve arbitrage. When discharging, the supply objects include DC loads or grid-connected power generation, and the charging energy can be provided by photovoltaic and grid-connected ports;

[0022] DC power supply interface: mainly realizes 48V DC power supply, which is used for DC LED lighting, notebook and mobile phone charging scenarios;

[0023] AC grid-connected interface: When photovoltaic power generation is in surplus and energy storage is discharged at low electricity prices, it works in grid-connected inverter mode and the excess power is supplied to the grid; when photovoltaic power generation and energy storage are insufficient, it works in grid-connected rectification mode and the insufficient energy required by the DC load is supplemented by the AC grid.

[0024] The above is a detailed introduction to a household AC / DC hybrid multi-port converter topology structure proposed in the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for general technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A household AC / DC hybrid multi-port converter topology structure, characterized in that: The topology includes rooftop photovoltaics, distributed energy storage devices and household energy routers; The household energy router includes a photovoltaic input interface, an energy storage bidirectional interface, a DC power supply interface, an AC power supply interface, an AC grid connection interface, and a DC-AC bidirectional converter between AC and DC busbars; The main topology of the topological structure is a DAB converter, and the distributed energy storage device and the rooftop photovoltaic are located on its low-voltage side, connected to the low-voltage side of the DAB transformer through a DC / DC chopper circuit, and the AC grid-connected interface is connected to the high-voltage side of the DAB converter through an H-bridge; the dual-active bridge circuit DAB realizes the bidirectional flow of energy between the high-voltage DC side and the low-voltage DC side, and improves the DC transformation ratio; the photovoltaic input interface is connected to the low-voltage side DC bus through a Boost DC boost chopper circuit; the energy storage bidirectional interface is connected to the low-voltage side DC bus through a Buck / Boost DC boost circuit; the DC / AC bidirectional converter is composed of a single-phase H-bridge circuit, which can operate in grid-connected inverter and grid-connected rectification modes, the H-bridge DC side is connected to the high-voltage side of the DAB converter, and the H-bridge AC side is connected to the single-phase AC distribution network as an AC power supply interface after passing through a filter; the DC power supply interface is used for DC power supply.

2. The topological structure according to claim 1, characterized in that: In the topological structure, the switch tubes Q1, Q2, Q3, and Q4 are multiplexed. The switch tubes Q1, Q2, and the inductor L P The Boost DC boost chopper circuit of the photovoltaic input interface is formed. The switch tube Q3, the switch tube Q4 and the inductor L B A Buck / Boost DC step-up and step-down circuit with a bidirectional energy storage interface is formed. Switch tubes Q1, Q2, Q3, and Q4 also form a DAB converter together with switch tubes Q5, Q6, Q7, Q8, and a transformer.

3. The topological structure according to claim 1, characterized in that: In the topology, the switch tube Q L With diode D, capacitor C l A Buck step-down circuit is formed to power the low-voltage DC load in the system.

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