Interconnection of the 25- and 60-cycle system of the union electric light & power co.

FREQUENCY conversion was determined as the best means of supplying differences between the 25-cycle and 60-cycle loads and generating abilities of the Union Electric Light and Power Company system. The hydroelectric plant at Keokuk, Iowa, was developed as a 25-cycle run-of-river plant to supply the 25-cycle load in that vicinity and to transmit power to St. Louis, where the load is largely 60 cycles. Various possibilities in 25-cycle and 60-cycle steam and hydroelectric plants presented themselves but a frequency converter was decided upon as the most desirable.