Steady state analysis and performance characteristics of a three-phase induction generator self excited with a single capacitor

Steady-state analysis and performance characteristics of a three-phase isolated star or delta connected induction generator self-excited with a single capacitor are discussed. Analytical expressions are derived to determine the no-load capacitance required to maintain self-excitation. The performance characteristics of a self-excited induction generator are affected by the terminal capacitance, C, machine speed, ν, and the load parameters. Generally, the value of C has a stronger influence on the performance characteristics and should be selected such that the terminal voltage, V_t, is near its rated value while keeping C close to its lower limiting value. The accuracy of the method was experimentally verified, and good agreement is obtained between the two sets of results. The performance characteristics of star and delta connected induction generators are compared. In the mode of operation discussed, the voltages and currents are unbalanced with relatively high losses and rather low efficiency. Among the two configurations discussed, the delta connected generator offers a higher current and lower terminal voltage and a wider range of excitation capacitance