Study On Grid-connected Technology Of Large-capacity Off-shore Wind Turbine

With the growth of China’s new energy technology, wind power technology is developing rapidly. Due to the none occupation land area and less noise pollution and so on, offshore wind power become the main force of wind power. This paper describes a mathematical model of the various parts of5MW doubly-fed wind power generation system and operating characteristics, designs the control strategy of the generator-side converter based on stator flux orientation and the control strategy of the grid-side converter, proposes an improved maximum power point tracking hill-climbing method based on differential signals of power and the speed of the wind turbine, and establishes the model of the wind speed, wind turbine and back-to-back PWM converter in PSCAD/EMTDC.Then this paper analyses the unbalanced grid voltage particular impact on5MW doubly-fed wind power generation system. Then the paper describes the theoretical analysis for the unbalanced grid voltage, including symmetric component method, the rotation transformation method of sequence component and so on. And then the operating characteristics of the double-fed generator and grid-side converter under unbalanced grid voltage are introduced, the control strategy of the grid-side converter and generator-side converter based on the double dq current are proposed on the basis of the operating characteristics of the double-fed generator and grid-side converter. Then the modified control strategy of converter under unbalanced grid voltage is achieved in the basis of normal5MW doubly-fed wind power generation system model in PSCAD/EMTDC.Finally, the paper introduces the design and implementation of a2.2kW double-fed wind power generation system hardware test platform. The main components of the platform and the interface design of each control part are recommended, and then the software design of grid-side and generator-side converter based on the TMS320F28335DSP control board are introduced. The hardware experiment platform waves prove the practicability and availability in the engineering application of the theoretical research work in this paper which lays a solid theoretical research foundation for the research and manufacture of5MW double-fed wind power generation system converter.