Research On The Control Of Vertical-Axis Tidal Generation System

With the increasing population and rapid development of kinds of industries, the demand for sources is dramatically rising day by day. As the mostly consumed and regular fossil sources, such as coal, crude oil and natural gas, are running out of storage and the great amount of CO2and other waste from their burning leads to serious pollution problems to our living environment and brings damages to the eco-system of the planet. Thus, it is especially crucial to exploit renewable energy for answering the solution to the huge need of energy and improving the living condition for people’s health. Since the ocean covers over70percent of the surface of the earth, it contains inestimable and tremendous energy so that tidal power generation as one kind of renewable energies has a considerably bright future of exploitation with much less pollution, attracting more and more attention and related research.This thesis mainly focused on the study and analysis of the structure and control system for tidal power generation. Combined with a renewable energy project, the operation and output characteristics of the vertical-axis hydraulic turbine were deeply studied while the operating principles and processes of energy conversion were also specifically analyzed. Based on those discussions, the structure of the tidal power generation had been designed.According to the features of tidal velocity and power generation, the thesis designed a energy control strategy for the generation system and the control methods for the DC/DC converter and DC/AC inverter were devised with the digital PI and SVPWM (Space Vector Pulse Width Modulation) technologies to effectively regulate the power output from the system to the grid or the consumers in the form of three phases AC with a stable frequency and voltage.A model of the tidal power generation system then was built based on the platform of Matlab/Simulink software and the simulation results in terms with control methods and low-voltage-ride-through problem verified their correctness. On that basis, a physical and experimental prototype had been set up, of which the hardware of the main and control circuit for the generation system was designed with the core controller DSP2812and power switch IPM (Intelligent Power Module) and the control methods proposed above were realized by writing algorithm programs. The practical experimental results demonstrated a good performance and justified the control strategy.The research studied in this paper is supported and subsidized by the renewable energy special fund of State Oceanic Administration (GHME2011CL01).