D-q axis parameter identification method for grid-connected inverter of photovoltaic power generation system

Abstract

The invention provides a d-q axis parameter identification method for a grid-connected inverter of a photovoltaic power generation system. The d-q axis parameter identification method includes: an inverter control reference value Udc-ref and Qref jump are arranged on the grid-connected inverter of the photovoltaic power generation system, or a three-phase short circuit fault is manufactured on the side of a power grid so as to collect disturbance data required by parameter identification; d axis parameters of the grid-connected converter are calculated according to the collected data, and the d axis parameters comprise filter inductance, d axis inner ring current control ring proportionality coefficients, inner ring current control ring integral coefficients, outer ring active power control ring proportionality coefficients and outer ring active power control ring integral coefficients; and a filter inductance parameter is fixed to be a d axis identification result, q axis parameters of the grid-connected inverter are calculated according to the collected data, and the q axis parameters comprise q axis inner ring current control ring proportionality coefficients, inner ring current control ring integral coefficients, outer ring reactive power control ring proportionality coefficients and outer ring active power control ring integral coefficients. The d-q axis parameter identification method for the grid-connected inverter of the photovoltaic power generation system reduces order and identification difficulty of a model to be recognized and improves identification accuracy.

Description

technical field [0001] The invention relates to the field of grid analysis and calculation, in particular to a d-q axis parameter identification method of a grid-connected inverter of a photovoltaic power generation system. Background technique [0002] In recent years, photovoltaic power generation, as a clean and renewable energy source, has been widely applied and promoted. The "Twelfth Five-Year Plan" for the development of renewable energy sets the domestic photovoltaic installed capacity at 15GW in 2015. The grid connection of large-scale photovoltaic power generation is one of the development trends of its application. The design of grid-connected large-scale photovoltaic power generation system and the transient characteristics after grid-connected are current research hotspots. [0003] As a key component of the photovoltaic power generation system, the inverter of the photovoltaic power generation grid-connected system plays a decisive role in its transient chara...

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Problems solved by technology

In addition, some domestic scholars have studied the impact on the comprehensive load model after the distribution network side is connected to the photovoltaic power generation system, and derived the overall external characteristic equation of the photovoltaic system, but the photovoltaic power generation system model used ignores the current inner loop control link, and The identification results of the parameters of the inverter outer loop control link have different parameters in multiple disturbance identifications, and the consistency of the identification results is not good

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