Design of the DC/DC converter for aerodynamic characteristics testing of wind turbine

In this paper, first, a new type of DC/DC converter which is composed by a variable winding DC transformer as its front-end and a back-end converter, which is combined by four buck converters interleaved with a 90 degree phase shift to each other (the output voltage is about 25 V and uncontrolled for there are several batteries connected to it) is designed and produced on the existing wind power testing and experimental integration system. This converter not only has the merits of ultra-wide range of input voltage, high-precision control of output current and fast dynamic response, but also can meet the operational requirements of ultra-wide changing of wind speed and power because of the wide-range changing of tip speed ratio. Then wind tunnel experiments are done and the curve of C_p-lambda of a certain 2 KW wind turbine is measured out. Also, some efforts are done to optimize the dynamic performance. Finally, All the experimental results show that the converter designed in this paper can adapt the operational requirements of the system well. Based on this platform, not only the curve of C_f-lambda can be measured more accurately with which the aerodynamic characteristics of turbine can be handled, but also laid the foundation for exploiting high-power system in the future.