A method for controlling the DC component of photovoltaic grid-connected current

Abstract

The present invention relates to a method for controlling a DC component of a photovoltaic grid-connected current, and belongs to the field of electric power and photovoltaic new energy power generation. The DC component in the inductor current is filtered, averaged, and controlled, and then added with the inductor current after the DC component is amplified to obtain a suppressed inductor current, and then the ABC coordinate is transformed to DQZ. After passing through a controller and a compensator, the DC coordinate is transformed to ABC three-phase after being added with the grid voltage feedforward, and then the DQZ coordinate is transformed to ABC three-phase. After SPWM modulation, a current with a three-phase duty ratio that meets the requirements is emitted. The present invention changes the feedback system of current control in the control of the DC component of the three-phase independent inductor current, thus avoiding the disturbance effect on the main control current, and will not cause problems such as resonance that have a greater impact on performance. At the same time, the outer loop limit is controlled in real time, and the control effect of the DC component of the inductor current is accurately limited, and the control effect is good.

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