DSP-Based Fault Tolerant Grid Side Converter in PMSG Wind Turbine Using Improved Vector Current Control with Modified SVPWM

Abstract

In permanent magnet synchronous generator (PMSG) based wind turbine system, back-to-back converter i.e., Machine side converter (MSC) and Grid side converter (GSC) is essential sub-assembly that develop interface between wind power generated and utility grid however, GSC of PMSG based wind turbine suffer from voltage suppression at DC-link, reactive current injection and active power fluctuation under fault condition which deteriorate overall system efficiency and causes system shut-down. To overcome the aforesaid issues and avoid system shutdown, in this paper modified SVPWM based improve vector current control (VCC) is proposed that is developed from direct power control (DPC) and open-switched fault tolerant control. Compared with the conventional VCC that employ complex phase lock loop (PLL) to extract voltage angle of grid, the proposed PLL-free improved VCC (IVCC) based on DPC, uses Clarke’s transformation and instantaneous active and reactive power that simplifies control scheme. Furthermore, under fault condition (grid side distortion), conventional VCC fails to tract grid voltage angle due to inability of PLL and poor transient stability whereas in proposed IVCC based on DPC (IVCC-DPC), PLL-free inner close loop is utilized to control GSC. To show the effectiveness of proposed IVCC-DPC based on modified eight-sector SVPWM based, a 2-level GSC is modelled and simulated via MATLAB-Simulink. Simulated model is examined for fault-tolerant capability (in context of low voltage ride through) and power quality. Finally, DSP based 1.8 kVA experimentally test platform using IVCC-DPC based on modified SVPWM is designed to validate the proposed developed model.