Remote automatic control for line capacitors

STEADILY DECREASING peak-load power factor has amplified the problem of providing a supply for the ever-increasing reactive load on the Baltimore Gas and Electric Company system. The location of new generation in more remote areas has increased the attractiveness of static capacitors located near the load for reactive supply. However, in order to avoid excessive voltage and generator instability at light loads, suitable switching provisions for these capacitors must be available. Capacitors located on substation busses, so as to facilitate this switching, are a step in the right direction, but do not provide relief to the most costly element of the system — the distribution facilities. Pole-mounted line capacitors provide maximum feasible system relief, but the switching must be accomplished by automatic means. Time clocks, voltage, current, temperature, and other types of control are available for this function, and each type has its place. However, the extensive use of these controls presents a substantial co-ordination problem if excessive voltage changes are to be avoided. Considerable maintenance can be expected, and lack of operation supervision would indicate that some routine inspection may be deemed essential.