Performance Analysis of Synchronous Reluctance Generator

Abstract: The synchronous reluctance generators are a species of self-excited generators such as the induction generators. The self-excited synchronous reluctance generator (SynRG) has become a promising and viable replacement of self-excited induction generator because of the supply frequency dependence on the prime speed and not load. The self-excited synchronous reluctance generator has high reliability, low cost and robustness and capacity of variable speed operation. The aim of this research is to carry out performance analysis of shunt connected three-phase synchronous reluctance generator feeding an R-L load. The dynamic analysis is based on the classical d-q model where equations for electrical quantities were derived and implemented using a computer simulation tool, MATLAB®. The equations for steady state analysis were derived from the dynamic equations by setting all time variables to zero. The dynamic analysis was carried out on a 4-pole, speed of 1500 rpm with connected load at a fixed excitation capacitor value of 50uF for a 2.5kVA machine. Effect of excitation-capacitance variation and loadingconditions variation on the generated output voltage and frequency are presented and discussed. The load variations were done based on energy-current perturbation at a fixed power factor of 1.0. The load variations were done at several points and result shows that with the variations in the connected loads, the output frequency of the synchronous reluctance generator remains constant, which makes it a good alternative for induction generator. On the steady state analysis, it was discovered that on increasing the excitation capacitor, the terminal voltage increases as well as the output power. The result specifically revealed that when the capacitance increases from 25uF to 45uF, the terminal voltage and the output power increases from 200volts to 300volts; and 200watt to 1700watt. Therefore, it is recommended that to ensure machine excitation, the capacitor should not be reduced below a certain value. The study is beneficial for operation of an isolated power supply. Keywords: Synchronous Reluctance Generator, Direct Current and Indirect Current