Performance analysis and control of a stand-alone wind-driven PMSG including unbalanced conditions

This paper analyses the performance and control characteristics of a stand-alone wind-generating system based on Permanent Magnet Synchronous Generator (PMSG). The presented wind generating-system consists of a wind turbine, PMSG, uncontrolled rectifier, DC-DC boost converter and voltage source inverter. A simple control strategy is presented in order to supply the load with a constant voltage and frequency under different operating conditions including prime-mover speed variation, load variation and the unbalanced conditions. The presented control strategy is based upon controlling the duty cycle of the DC-DC boost converter in order to convert the variable input dc-voltage, due to different operating conditions, to an appropriate constant dc-voltage. Hence, a sinusoidal pulse width modulated (SPWM) inverter is used to regulate the magnitude and frequency of the load voltage via controlling the modulation index. The overall control-system algorithms are modeled, using Matlab/Simulink software, and compiled to a real time based on DSP1104 controller. Hence, in order to verify the performance of the employed wind generating-system with the presented control strategy, a sample of simulation and experimental results is obtained and analyzed. The presented results confirm the validity of the presented control strategy to regulate the load voltage and frequency under different operating conditions.