The Research On DC Interconnection Of Wind Farm

In recent years, the wind turbine continuously develops toward the large capacity and the large-scale on the grid system,the share of power from wind turbine in the entire electrical network grows unceasingly, the large-scale wind turbine field internal operation and the technology of on-grid will be focus the wind turbine domain in the futureThis article proposes the DC interconnection method in wind turbine field which based on Direct-Drive permanent magnet synchronous generator and combined with DC micro grid related technology, the power from generator is rectified into DC, then the power connected to the grid by the inverter Studied the generator control, DC voltage control, power management of wind turbine LVET, and verifies the study results by simulation software.First of all, introduced structure of the DC interconnection Wind farm, then described how to select the DC voltage level, reference to the experimental data, select the best voltage level. Introducing auxiliary equipment that used in the DC interconnection Wind farm, proposed the method which manage power of wind turbine. Finally, details the method of two kinds of DC step-up.Secondly, introduction the control strategy that PMSG, Spare generator,battery and DC load on DC bus. Direct drive wind turbine include wind machine, pulp pitch control and generator side converter control First derives mathematical models of each part, proposed the control strategy and made the control block diagram based on mathematical model. Finally, introduction the control strategy of grid-connected converter.Thirdly, on the Digsilent/Powerfactory. simulation platform, builds the simulation model make use of control strategy referred to in chapter Ⅲ, analysis of simulation results,include active power and stator voltage of generator,DC voltage of Micro generator rectifier, process of battery work, DC voltage and reactive exchange. When the wind speed change, regulation active power by controlling auxiliary equipment. Verify whether the power of wind turbine field outputs stabilizes.At last, introduction LVET Grid standards, LVET techniques and LVET feature of DC interconnection wind farm. Increased three kind of protection circuit model on the original simulation model, simulate and tests three kinds of protection circuit ability of LVRT, analysis the simulation results, comparison the LVET capability of three protection circuit model...