Double-switch-tube Buck converter based on common mode and differential mode control method

Abstract

The invention relates to a double-switch-tube Buck converter based on a common mode and differential mode control method, and belongs to a converter and a control technology in the field of power electronics. According to the converter, the current difference of positive and negative lines is collected, and the current difference is controlled to be zero through a proportional integral controller,so that the problem of common ground ring current is solved; the average value of positive and negative currents is collected, and then virtual impedance is introduced, so that the problem of power sharing of the converters is solved; and voltage compensation is carried out by increasing an inertia link, so that the problem of voltage drop is solved. According to the converter, the switch tubes are added to the minimum extent, and meanwhile, the control method based on the common mode and differential mode is adopted, and the control method does not need to be switched in a normal operation state and a fault state, so that the anti-fault capability of the system is effectively improved.

Description

technical field [0001] The invention relates to a double switch tube Buck converter based on common mode and differential mode control methods, which belongs to the converter and its control technology in the field of power electronics. Background technique [0002] In recent years, distributed power generation sources have developed on a large scale. They continuously convert renewable energy sources such as solar energy and wind energy into electrical energy, and collect them into microgrids, thereby effectively alleviating the energy crisis. According to data from the China Wind Energy Association, my country's cumulative installed capacity in 2017 reached 188GW; according to statistics from the National Energy Administration, my country's cumulative installed capacity of photovoltaic power generation in 2017 reached 130.25GW. However, distributed power generation sources are generally installed outdoors, and are prone to insulation aging due to factors such as weather an...

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Problems solved by technology

[0003] Aiming at the problem of common ground circulation caused by the negative pole grounding fault on the power supply side in the parallel system of large-scale distributed power generation sources and the problem of voltage drop caused by traditional droop control, the present invention proposes a dual switch tube Buck based on common mode and differential mode control. The converter can effectively suppress the circulating current caused by the negative ground fault of the parallel distributed power generation, and can effectively restore the DC bus voltage, thereby improving the system's anti-fault capability and enhancing the system's stability

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