Research on improvement of low voltage crossing of isolated island permanent magnet wind turbine

Abstract

Aiming at the low voltage crossing problem of permanent magnet wind turbine in isolated island microgrid, a low voltage ride through strategy based on emergency pitch Angle control and side-converter load reduction control is proposed based on the analysis of the voltage unbalance in DC link by studying the operating characteristics of permanent magnet wind turbine when voltage sag occurs. This strategy rapidly and accurately balances the active power flow through variable power tracking methods such as emergency paddle change and load reduction control during low voltage traverse, so as to balance the active power on the network side of the machine, reduce the capacitor voltage pressure on the DC side, and improve the grid-connected survivability of the unit under continuous low traverse condition. Finally, combined with Matlab/Simulink simulation platform for simulation verification.