Residence microgrid based on high-frequency alternating-current bus and operation method

Abstract

The invention discloses a residence microgrid based on a high-frequency alternating-current bus and an operation method, and belongs to the field of intelligent microgrids. The microgrid comprises first to fifth full bridges, a full-wave rectifier bridge, first to fourth capacitors and a multi-winding high-frequency transformer T jointly form a four-port power electronic high-frequency transformer; as well as a low-voltage DC output unit, an AC bus unit, first to third switches, an AC load, a power generation unit, and an energy storage unit. The four-port power electronic high-frequency transformer couples the power generation unit, the energy storage unit, a multi-voltage-stage low-voltage direct-current output unit and the alternating-current bus unit. By the adoption of the structure,energy can be provided for a local direct-current load, surplus energy of the power generation unit can also be fed into the power grid through the high-frequency transformer, meanwhile, the voltage conversion stage number, scale and cost of a renewable energy system can be effectively reduced, and a conversion port is isolated. The microgrid can operate in various grid-connected and island operation modes.

Description

technical field [0001] The invention relates to the field of household smart microgrids, in particular to a residential microgrid based on a high-frequency AC busbar and an operating method thereof. Background technique [0002] Micro-Grid, also known as micro-grid, is a small power generation and distribution system composed of distributed power sources, energy storage devices, energy conversion devices, loads, monitoring and protection devices. The purpose of the microgrid is to realize the flexible and efficient application of distributed power and solve the problem of grid connection of distributed power with a large number and various forms. [0003] The micro-grid acts as an intermediate link to connect the power grid and distributed sources. Connecting distributed sources to the micro-grid and then connecting the micro-grid to the power grid can reduce the impact of some distributed sources with poor power quality on the power grid. The micro-grid can work in the gri...

AI Technical Summary

Problems solved by technology

[0005] The traditional microgrid structure is as attached figure 1 As shown, multiple distributed sources and energy storage devices all use independent converters and branches, resulting in many voltage conversion stages, high cost, large scale, large energy loss, and it is difficult to control the whole

[0006] The traditional home microgrid structure is as follows figure 2 As shown, among household appliances, refrigerators, washing machines, and microwave ovens are household high-power equipment, and they all get power directly from the grid, while commonly used mobile phones, laptops, desk lamps, etc., all need to convert AC power into DC power, and then supply power. , the voltage level change is also accompanied by energy consumption, and it cannot work in an island state

[0007] The home microgrid structure with distributed sources is attached image 3 As shown, the introduction of distributed sources makes it possible for the home microgrid to work in an isolated state, but the microgrid structure with multiple distributed sources has intermittent energy due to the inconsistent quality of power generated by multiple distributed sources. Fluctuations, if directly fed into the power grid, will impact the power grid and threaten the stability of the entire power grid. Generally, energy storage units will be added to the micro-grid. Energy storage units can generally be divided into two categories, one is with high power density Supercapacitor, good dynamic response, high charging and discharging power in a short time

The other is the battery with high energy density, which is widely used at present. It is often used for long-term charging and discharging. The power density is low, and the rapid change of load will affect the life of the battery.

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