Modeling and control of an electromechanical system with a permanent magnet generator and a voltage source converter

Abstract

In the paper simulation dynamic models for the analysis of characteristics and transients of electromechanical system using a permanent magnet electric generator (PMG) connected to a variable speed fixed pitch wind turbine (WT) and a voltage source converter (VSC) mathematical models are developed. The system supplies a direct current (dc) resistive load through a controlled switch. The objective of the controlled resistive load connected to the VSC dc circuit of the system is to perform the dc output voltage stabilization for simulating the mode of generating the active power into a grid via a grid invertor. Two algorithm structures of realization of tracking the optimal WT motion trajectory in the coordinates “WT aerodynamical power – rotary speed” have been considered. The tracking algorithms function is to provide the maximization of power extraction from wind flow by WT. Electromechanical processes in the PMG – VSC system for both tracking algorithms have been investigated using developed dynamic simulation models and vector control technique of electromagnetic torque of the generator at variable WT mechanical power. The results of numerical investigations of the electromagnetic processes in the system have been analized. The efficiencies of the proposed control algorithms applied to the VSC in the considered electromechanical system have been compared and discussed.