PROJECT TITLE:

A Discrete-Time Direct Torque Control for Direct-Drive PMSG-Based Wind Energy Conversion Systems - 2015

ABSTRACT:

This paper proposes a completely unique flux-house-vector-based direct torque management (DTC) theme for permanent-magnet synchronous generators (PMSGs) employed in variable-speed direct-drive wind energy conversion systems (WECSs). The discrete-time control law, that comes from the attitude of flux house vectors and load angle, predicts the specified stator flux vector for the next time-step with the torque and stator flux data only. The area vector modulation (SVM) is then employed to come up with the reference voltage vector, leading to a fastened switching frequency, with lower flux and torque ripples, compared to the traditional DTC. Compared with alternative SVM-based DTC strategies in the literature, the proposed DTC theme eliminates the use of proportional-integral regulators and is a smaller amount enthusiastic about machine parameters, e.g., stator inductances and permanent-magnet flux linkage, while the most advantages of the DTC, e.g., quick dynamic response and no need of coordinate remodel, are preserved. The proposed DTC theme is applicable for both nonsalient-pole and salient-pole PMSGs. The overall management theme is simple to implement and is robust to parameter uncertainties and variations of the PMSGs. The effectiveness of the proposed discrete-time DTC theme is verified by simulation and experimental results on a a hundred and eighty-W salient-pole PMSG and a two.4-kW nonsalient-pole PMSG used in variable-speed direct-drive WECSs.