| The fossil energy is limited and the problems such as short of power andenvironmental deterioration are evident, nowadays. It has a very important strategicsignificance for the development and utilization of renewable energy such as windenergy. The author of the paper has studied on the Quasi-Z source network with theperformance of boosting output voltage in the inverter, and will apply the Quasi-Zsource network in the traditional matrix converter to make a breakthrough inincreasing the voltage transfer ratio of only0.866. This paper also analyzes theadvantages of using the Quasi-Z source topology in matrix converter, for example, itcan improve the voltage transfer ratio effectively; output side of the input voltage andcurrent waveforms are not affected side; the output waveform of the inverter is notaffected by the input side; and effectively reduce the inrush current of switchingdevices on startup. The main contact of this paper will be illustrated with threeaspects.Firstly, this paper analyzes the overall structure of VSCF double-fed machine,giving the derivation of steady-state mathematical model of DFIG and its speedcontrol theory. Combined with the characteristic of matrix converter and the DFIG ofVSCF, the DFIG’s vector control mathematical model in d-q synchronous rotatingframe was deduced. Considering the current coupling, this paper proposes a new typesimple current feed forward decoupling control algorithm.Secondly, under Matlab-Simulink software surrounding, simulation is made totestify the performance of Quasi-Z source matrix converter. Working is focus on thevoltage gain simulation. The simulation shows that a high-performance outputvoltage control which can be achieved with an excellent transient performance even ifthere are input voltage and load current variations. What’s more the input/outputwaves of the Quasi-Z source matrix converter have a low harmonic distortion.Finally, this paper will build the simulation models of DFIG of VSCF based onthe Quasi-Z source matrix converter by PSCAD which is embedded M-function in MATLAB. By analyzing the output waveforms of active power and reactive power inthe DFIG, the use of Quasi-Z source matrix converter for a DFIG wind turbine hasbeen verified in this paper. |
