Modeling and Investigation of Self-Excited Reluctance Generators for Wind Applications

In the last few years, wind energy conversion systems have been increasingly installed worldwide. The self-excited reluctance generators (SERGs) are found to be potential candidates as isolated wind turbine generators, especially for low- and medium-power applications. This article focuses on the characteristics of SERG for wind turbine generation system. A simplified dynamic model of the generation system is developed, discretized by backward Euler formula, and simulated. With this model, the process of self-excitation and operation characteristic of SERG are investigated. Considering the varying generated voltage at different speeds, variable capacitances allow suitable regulation of the voltage. The variation of capacitance with speed is obtained by the active and reactive power (PQ) balances method. Combining the power speed characteristics of wind turbine and SERG, the PQ balances method is also used to determine the "optimal capacitor and resistor combination" that achieves the highest usage of wind power. This article exhibits the performance of SERG for wind applications, and most importantly, makes the prediction of the highest energy conversion efficiency of the system.