Photovoltaic grid connected inverter control method based on active power backup

Abstract

The invention discloses a photovoltaic grid connected inverter control method based on active power backup. According to the method, a traditional photovoltaic inverter is improved, a power ring is added between a voltage ring and a current ring, and seamless switching between maximum power tracking and active power backup state can be achieved through direct-current voltage ring and direct powerring control. By combining a fitting peak value judging method and a maximum power tracking control method, the maximum power point is determined, maximum power tracking is rapidly and seamlessly switched into the active backup state, and a traditional photovoltaic inverter achieves the active power backup function.

Description

technical field [0001] The invention belongs to the field of photovoltaic inverter grid-connected control, and in particular relates to a photovoltaic grid-connected inverter control method based on active power backup. Background technique [0002] With the deterioration of the environment, the aggravation of the energy crisis, technological progress, and the reduction of device production costs, new energy generation technologies such as photovoltaics and wind power have developed rapidly and become research hotspots at home and abroad. [0003] At present, photovoltaic power generation systems mostly adopt the method of maximum power tracking (MPPT) to connect to the grid. Compared with traditional synchronous generators, photovoltaic power generation systems have fast response speed, simple and flexible control, and can maximize the use of light energy. However, the photovoltaic power generation system "just generates power, regardless of the grid", resulting in excess g...

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Problems solved by technology

[0011] The purpose of the present invention is to provide a photovoltaic grid-connected inverter control method based on active power backup in view of the problem that traditional photovoltaic inverters can only output power in the manner of maximum power tracking, resulting in excess power in the grid. A power loop is added between the current loops, and seamless switching between maximum power tracking and power control is realized. The switching conditions are determined by the fitting peak judgment method, and the active power backup of the traditional photovoltaic inverter is realized.

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