Naturally-commutated cycloconverter versus rectifier-inverter pair grid-connected distributed power generation based on high-speed microturbines

Grid-connected distributed power generation based on high-speed microturbines gives the customers control over their electric power supply and provides a reliable, high-quality, low-cost, and clean source of electric power. As the frequency of the AC power generated by the high-speed microturbine-generator sets is variable and much higher than that of the utility grid, a static frequency changer will be required to match the two frequencies and also control the power delivered to the grid. Among different static frequency changer schemes, naturally-commutated cycloconverter (NCC) and rectifier-inverter pair have received more attention from the electric power industry, due to their desirable cost-versus-performance tradeoff. This paper compares different aspects of these frequency changer schemes when used in conjunction with microturbines for grid-connected distributed power generation. The conclusions drawn based on the analytical and simulation results can serve as guidelines in selecting the right topology for a specific application.