GB623006A - Improvements in or relating to the control of electric power generating systems - Google Patents

Abstract

623,006. Automatic control systems. STANDARD TELEPHONES & CABLES, Ltd., and CHAMBERS, C. H. Nov. 9, 1945, No. 29997. [Class 38 (iv)] In control station equipment for an interconnected electric power generating system, electrical means compare signals received from a remote point, indicative of the generated power at that point, with an allocated power and control the transmission of change of power signals to the remote point. The readings of watt-hour meters associated with turbo-generators at each of two or more power stations are successively transmitted over lines as described in Specification 553,433, [Group XXXVIII], to operate indicators in a remote control station. In known manner the readings are aggregated by a summator at the control station. Also in known manner a regulator at the control station is arranged to be successively connected to permit control of each generator at the power stations, during idle periods of forward transmission of meter readings, over the same lines as for the forward transmission. Control of the generators is by servomotor control of the governors of their prime movers together with control of furnace rate of feed if necessary. In the arrangement described, this control is effected automatically to maintain a desired power output from each generator. In Fig. 2, the D.C. energization of one set of windings of differential relays DR1, DR2 at a control station, associated with generators at two power stations A and B respectively, is controlled by decoders, responsive to meter signals from the generators, which adjust resistances in the relay winding circuits. The other set of relay windings is series-connected across a D.C. source with variable shunt resistances YA, YB, adjusted' so that the energization of a relay winding represents a desired generator output. When the generator outputs have the desired values, each relay is balanced, otherwise an auxiliary relay R or L is operated to send " raise power " or " lower power " signals to correct the generator which has deviated. Rheostat YP serves for setting the total power output while rheostats YA, YB permit variation in relative power output of the generators. Allowance for additional uncontrolled generators may be made.