A Novel Position-Sensorless Algorithm for Field-Oriented Control of DFIG With Reduced Current Sensors

Abstract

Position-sensorless field-oriented control of doubly fed induction generator (DFIG) necessitates at least 4–6 current sensors. In this paper, a novel rotor position and current estimation algorithms are proposed, which make the control of DFIG feasible using only three current sensors. The elimination of one current sensor improves hardware reliability by reducing the redundancy of physical components to be used, thereby reducing the complexity and also the system cost. The proposed algorithms employ two rotor current sensors and one stator current sensor. The current estimation algorithm extracts the components of $\vec{{i}_{s}}$ in ${{d}^{s}}{{q}^{s}}$ frame using the sensed value of one stator current and the reference values of $\vec{{i}_{r}}$ components in ${{d}^{e}}{{q}^{e}}$ frame. The proposed algorithms reduce mathematical burden and dependency on machine parameters. The effectiveness of proposed algorithm is validated using the real-time control hardware-in-loop, which comprises OPAL-RT and STM32F407VG microcontroller with ARM Cortex-M4 32 bit MCU. Simulation and experimental results on 2 MW DFIG-based WECS are presented under steady-state and dynamic wind speed conditions. The performance of proposed algorithm is found to be satisfactory under different operating conditions.