Research On Control Algorithm Of Grid-side Converter Based On PWM

Due to the energy crisis and environmental pollution, wind-electricity as a sustainable clean energy is developing rapidly. The proportion of offshore wind power generation is getting heavier. Offshore system has become an important direction for future development of wind power generation industry. Among all the installed offshore wind turbines, the doubly-fed wind turbines still account for a large part. Along with the applications become more widespread, direct-drive wind power generation system using at offshore is in good prospects. Offshore system generates electricity away from the sea shore, and then transmits the resulting massive high-voltage power to shore to inverter. So the performance of grid-side converter directly affects the efficiency of the whole wind power generation system.This article will take this as a starting point, and expand the study on control algorithm for grid-side converter of direct-drive wind power generation system. The main work of this article is as follows:Firstly, introduces the current development of the wind power industry and analyzes future trends. Then contrast doubly-fed wind power system and direct-drive wind power system and outlines the important role full-scale converter played in wind power generation system. Based on the detailed analysis, ultimately point out the research target:this article’s analysis will focus on the control algorithm of grid-side inverter part of full-scale converter in direct-drive wind power generation system based on offshore wind power generation.Secondly, establish grid-side converter control strategy model. Build the mathematical model of grid-side converter under different coordinate systems. After detailed analyzing grid voltage vector tracing, grid-side current decoupling and reactive power compensation, get the complete control algorithm of grid-side converter based on the mathematical model previously built. Then verify the correctness of the model and control algorithm.Finally, validate the model and algorithm by simulation platform Matlab/Simulink. The first step is to establish a complete simulation model for the direct-drive wind power generation system. Use the comprehensive model of wind conditions to simulate the actual generation environment in real wind farm to confirm the security and stability of the whole system. The second step is to compare the working status of doubly-fed wind power generation system and direct-drive wind power generation system under different working conditions. The purpose of the comparative experiments is to contrast the grid-side control algorithms in different systems. The results prove that the direct-drive wind power generation systems and the grid-side converter control algorithm studied in this article is more practical. And provide a viable model and control strategy of direct-drive offshore wind power generation systems for the further study in the future, which makes this article has a certain theoretical and practical significance.