Modeling & analysis of grid-tied PMA based offshore wind energy system using PSCAD/EMTDC

Abstract

A comprehensive dynamic model approach of Permanent Magnet Alternator (PMA) based grid tied wind energy system using PSCAD/EMTDC is presented. This paper proposes an improved dynamic system for controlling a Current Source Inverter (CSI) with a Generic Current Controller (GCC) using Voltage Dependent Current Limits (VDCL). This technique is employed to maintain the continuity of DC link current irrespective of the load conditions and grid voltage with real and reactive power transfer capabilities. The proposed controller reduces the complexity and maintains suitable gate pulse distribution for CSI. Furthermore, the proposed controller is independent of external current limiters, additional monitoring devices and grid voltage and frequency. Based on the system model, the dynamic behavior of the WT system to wind speed variation and inverter control scheme were simulated, output performance is analyzed. Simulation results illustrate the proper performance of the developed dynamic model of the wind turbine and control scheme performance. Keywords: Permanent Magnet Alternator, Wind turbine, DC link, VDCL, GCC, PSCAD