Direct Power Control of Doubly-Fed Generator Based Wind Turbine Converters to Improve Low Voltage Ride-Through during System Imbalance

A novel control technique using direct active and reactive power control called Direct Power Control (DPC) is discussed for Low Voltage Ride Through (LVRT) of DFIG based wind turbine converters. This controller eliminates the conventional current loops and uses delta modulation comparators, which yields a faster response. The switching of the converter is done using a simple optimum switching table. This control achieves real and reactive power stability with simple active and reactive power control variables. A modified DPC algorithm is proposed to eliminate the current harmonics created by DPC during system disturbances. The practical verification of DPC is carried out by a scaled converter. The control is coded in C and implemented on a TMS320F2812 DSP. The converter using DPC is tested for system unbalance conditions created by an Industrial Power Corruptor (IPC) in the laboratory.