A residential microgrid based on high-frequency AC bus and its operation method

Abstract

The invention discloses a residential micro-grid based on a high-frequency AC busbar and an operation method thereof, belonging to the field of smart micro-grids. Specifically include: the first full bridge to the fifth full bridge, the full-wave rectifier bridge, the first capacitor to the fourth capacitor and the multi-winding high-frequency transformer T that together constitute the four-port power electronic high-frequency transformer; and the low-voltage DC output unit, AC Busbar unit, first switch to third switch, AC load, power generation unit and energy storage unit. The four-port power electronic high-frequency transformer couples the power generation unit, the energy storage unit, the multi-voltage level low-voltage DC output unit, and the AC busbar unit. With the above structure, the energy can be provided to the local DC load, and the excess energy of the power generation unit can be fed into the grid through the high-frequency transformer. At the same time, it can effectively reduce the voltage conversion stages, scale and cost of the renewable energy system, and isolate the conversion port. The microgrid is capable of operating in multiple grid-connected and islanded modes of operation.

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.

Images