Dual current control strategy to fulfill LVRT requirements in WECS

Abstract

Purpose

The purpose of this paper is to investigate a control strategy to fulfill low-voltage ride through (LVRT) requirements in wind energy conversion system (WECS).

Design/methodology/approach

This paper considers an active front-end converter of a grid connected WECS working under grid fault conditions. Two strategies based on symmetrical components are studied and proposed: the first one considers control only for positive sequence control (PSC); the second one considered a dual controller for positive and negative sequence controller (PNSC). The performance of each strategy is studied on LVRT requirements fulfillment.

Findings

This paper shows presents a control strategy based on symmetrical component to keep the operation of grid-connected WECS under unsymmetrical grid fault conditions.

Research limitations/implications

This work is being applied to a 2 kVA laboratory prototype. The lab prototype emulates a grid connected WECS.

Originality/value

This paper validate the PNSC strategy to LVRT requirements fulfillment by experimental results obtained for a 2 kVA laboratory prototype. PNSC strategy allows constant active power delivery through grid-voltage dips. In addition, the proposed strategy is able to grid-voltage support by injection of reactive power. Additional features are incorporated to PNSC: sequence separation method using delay signal cancellation and grid frequency identification using phase locked loop.

Citation

Díaz, M. and Cárdenas-Dobson, R. (2014), "Dual current control strategy to fulfill LVRT requirements in WECS", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 33 No. 5, pp. 1665-1677. https://doi.org/10.1108/COMPEL-09-2013-0305