Wind Turbine With Mechanical Power Split Transmission to Reduce the Power Electronic Devices: An Experimental Validation

Abstract

This paper describes the structure, control, and performance of a novel concept wind turbine with a planetary gearbox. The power extracted from the wind is split into two parts by a free-running planetary gearbox. The major part of the power is delivered to a synchronous generator that is directly connected to the power grid without any power electronic devices. Only a very small part of the power is delivered to a servo machine that is controlled by a small-scale back-to-back converter. The servo machine operates the sun gear of the planetary gearbox. In order to show the variable speed operation with maximum power point tracking of the wind turbine at both low and high wind speed, a test bench is constructed and several experiments are performed. The experimental results in both steady state and transient state validate the performance and power split behavior of the wind turbine. The power ratio of the back-to-back converter in the new wind turbine is much smaller than the one in conventional wind turbines, which implies the possibility to reduce the power electronic devices.