Method and device for controlling photovoltaic grid-connected inverter, and apparatus

Abstract

The invention discloses a method for controlling a photovoltaic grid-connected inverter. The method comprises: obtaining output voltage and output power of a photovoltaic cell at preset moment; according to variation trends of the output voltage and output power, performing iterative computation on an output current set value, until an output current reference value of a maximum power point tracking (MPPT) control module at a maximum power point of the photovoltaic cell is obtained; according to the output current reference value, calculating to obtain a current set value of a current inner loop, finally, based on a proportional resonance (PR) control strategy, realizing maximum power point tracking and photovoltaic inverter grid connected. Through the variation trends of the output voltage and output power of the photovoltaic cell, iterative computation is directly performed on the output current set value, and finally the current set value of the current inner loop is obtained. Compared with the prior art, voltage outer loop control is not needed, the method can track the maximum power point more rapidly and accurately, and simplifies a photovoltaic grid-connected inverter control system, and photovoltaic grid-connected fault through capability is improved, so as to ensure safe operation of a power grid.

Description

technical field [0001] The present invention relates to the field of electric power technology, in particular to a control method, device, equipment and computer-readable storage medium of a photovoltaic grid-connected inverter. Background technique [0002] my country's photovoltaic power generation system is mainly a DC system, that is, the electric energy generated by the solar cell is used to charge the battery, and the battery directly supplies power to the load. In the middle, a photovoltaic grid-connected inverter is required to convert the DC power into AC power. Photovoltaic grid-connected inverters are the core of energy conversion and control processes. According to the number of power conversion stages of grid-connected converters, they can be divided into single-stage and double-stage. The single-stage photovoltaic inverter circuit structure is simple, the number of components is small, the power consumption is low and the reliability is high, and it is suitable...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, the PV grid-connected fault ride-through strategy generally adopts the AC current limiting strategy based on the improved feed-forward control low-voltage ride-through strategy and the traditional dual-vector control, but these control methods have the problem of slow tracking speed, and gradually able to adapt to needs

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