Continuous Load-Frequency Control for Interconnected Power Systems

Functioning in response to integrated deviation from a tuning fork-controlled standard frequency, and biased by deviation from scheduled tie-line load as telemetered to this location, this improved load-frequency control equipment provides continuous comparison of system frequency and tie-line load with their respective scheduled values. This continuous comparison, in conjunction with strict proportionality between deviation and correcting effect on the prime mover governor speed level adjustment, has proved in several years of service to be beneficial in minimizing governor and inlet valve movement and hence wear, as compared with the periodic intermittent correcting impulses used in earlier types of frequency controllers, even of the integrated-deviation type. The use of integrated frequency deviation as the quantity to which the controller responds inherently eliminates frequency deadband, but the tie-line load controller retainsi an adjustable deadband to render it oblivous of inevitable minor oscillations in tie line loading.