Analysis And Suppression Method For Broadband Resonances In Large Scale Distributed Power Station

Vigorously develop new energy power generation technology is to seize the strategic point of international competition,the strategic means to optimize the energy structure of our country is to protect energy security and the only way to deal with climate change.Therefore,to actively promote the new energy-based large-scale distributed power plant construction is the development of China's energy structure and improve the inevitable choice.However,large-scale distributed power plant large-scale access to the power quality of the power grid will bring serious challenges.In this paper,the wide-frequency resonance analysis and suppression of large distributed power stations are studied as follows:(1)Derive the equivalent circuit of the distributed power generation unit,transmission line and transformer in the broadband domain,and according to these equivalent circuits to build a single distributed power plant circuit model and a number of distributed power plant circuit model.Then according to these two models,the following six current expressions are obtained:1)a single distributed power plant when the power generation unit output current,power plant input to the main transformer side of the current and the total current into the public grid;2)a distributed power plant composed of a number of large-scale distributed power plant input to its main transformer side of the original side of the current,a distributed power plant input to the public grid current and the entire system input the total power grid;(2)According to the actual situation of the project to set the simulation parameters,from a single distributed power plant and a number of different types of distributed power plant calculated by the six current coefficient of MATLAB simulation and analysis of the possibility of occurrence of wide frequency domain resonance,finally,the generation mechanism of each resonance zone is analyzed according to the simulation results and multiple simulation experiments;(3)Design the hybrid active filter device,set the parameters according to the actual situation of the project;a single distributed power station circuit model with HAPF and a plurality of distributed power station circuit models are built,and find the following three current expression:1)with a single distributed power plant with HAPF input to the primary side of the main transformer current;2)with HAPF when a single distributed power plant output to the public grid of the total current;3)total current output from a number of large distributed generation systems to the utility grid when HAPF is included.Then,the potentials of the three kinds of current coefficients are simulated and analyzed.The potentials of the harmonic resonance in the wide frequency domain are analyzed.At the same time,the theoretical analysis shows that HAPF can effectively attenuate the wide frequency domain resonance,and finally,a low-voltage experimental platform was designed to verify the effect of HAPF on the wide-band resonant suppression.