Photovoltaic inverter low voltage ride through detection method and system

Abstract

The invention discloses a photovoltaic inverter low voltage ride through detection method and system. The method comprises a voltage signal acquisition step, a Clarke step of a photovoltaic inverter,a microcontroller detection step of the photovoltaic inverter, specifically, setting PI control parameters of a phase-locked loop of an inverter by adopting a multi-agent chaotic particle swarm optimization algorithm, controlling the phase-locked loop by adopting the PI control parameters and repetitive control when a global optimal point of the system is reached, and detecting low-voltage ride through of the inverter, a step of calculating a symmetrical three-phase voltage drop value, subtracting a reference voltage udref from a d-axis component u'd obtained by Park transformation to obtain acorresponding value, and performing dq / abc inverse transformation of the corresponding value to obtain symmetrical three-phase voltage drop values uac, ubc and ucc, and an output step. The method isadvantaged in that tracking control of the phase-locked loop is carried out by using PI control and repetitive control in the photovoltaic inverter, PI control parameters are set by using an intelligent agent chaotic particle swarm optimization method, so detection accuracy and robustness are improved.

Description

technical field [0001] The invention relates to the field of photovoltaic inverters, in particular to a method and system for detecting low-voltage ride-through of photovoltaic inverters. Background technique [0002] In recent years, the vigorously promoted new energy power generation system has attracted more and more attention from all over the world due to its environmentally friendly, efficient, decentralized and flexible power generation methods. Diversified and clean new energy has become an important solution to the contradiction between energy and the environment. way. In the development of new energy, photovoltaic power generation has developed rapidly, and photovoltaic inverter is an important power equipment for photovoltaic power generation, and many researches have been carried out around photovoltaic inverter. The low-voltage ride-through detection technology of photovoltaic inverter is one of the important research contents. [0003] For example, the test m...

AI Technical Summary

Problems solved by technology

[0004] It is a feasible method to use PI control for low-voltage ride-through detection, but the traditional PI control method is mainly an empirical trial and error method, but it is easy to fall into a local optimum, and the fixed parameters are controlled. When the external environment changes, its dynamic Response performance and adaptability will be reduced, which cannot meet the high-performance and high-precision voltage detection requirements

Therefore, the traditional PI control method is not suitable for the distribution network environment with micro-grid, and it is difficult to give full play to the superior performance of the PI controller.

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