A control method, device and equipment for a photovoltaic grid-connected inverter

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, and in particular, to a control method, device, device and computer-readable storage medium for 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 charged to 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. The photovoltaic grid-connected inverter is the core of the energy conversion and control process. According to the number of stages of power conversion of the grid-connected converter, it can be divided into single-stage and double-stage. The single-stage photovoltaic inverter has simple circuit structure, small number of components, low power consumption and high reliability, and is suitable for high-power ...

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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