Optimal Control of Single-Pulse-Operated Switched Reluctance Generator to Minimize RMS Phase and RMS DC-Bus Current

In recent years, switched reluctance generator (SRG) is becoming more popular in power generation applications. Power is usually generated at speeds close to the machine's rated speed. At such speeds, only single-pulse operation of the SRG is possible where the turn-on and turn-off switching angles are the only control parameters at a given dc-bus voltage and prime-mover speed. First, this paper determines all the feasible pairs of switching angles at a given dc-bus voltage and speed through repeated simulation runs. Then, an optimization procedure is used to determine the optimal pair of switching angles for the desired output power. Two optimal techniques are reported in this paper. Optimal technique-1 minimizes the phase rms current while delivering the commanded output power. Optimal technique-2 minimizes the dc-bus rms current while delivering the desired output power. Optimal switching angles using both techniques are determined for a 4 kW, 1500 rpm, 8/6 pole, and 4-phase SRG drive. The optimal techniques lead to a very significant reduction in the phase rms current, dc-bus rms current, capacitor rms current, and loss in SRG drive over the wide range of power output, as shown by experimental results.