Yukio Yoshida

Study of the Effect of the DC Link on Frequency Control in Interconnected AC Systems

This paper presents a control effect of automatic frequency ratio control (AFRC) on an HVDC transmission to the AFC on ac systems when AFRC is applied to a random load disturbance in a steady state. The analysis of dynamic response of an ac-dc transmission system has been made by an analog computer. The frequency-improving and reduction effects of the output power of regulating power stations by AFRC are statistically analyzed by a digital computer.

Analog Computer Study of Automatic Frequency Ratio Control on an HVDC Transmission System

A method has been developed to simulate an automatic frequency control system in ac-dc power transmission on an analog computer. As an example of an ac-dc system a model of Sakuma frequency changer, between Tokyo Electric Power Co. system (50 Hz) and Chubu Electric Power Co. system (60 Hz), is studied in detail. Three new methods of automatic frequency ratio control (AFRC) by dc transmission are considered and compared. The variation of frequencies in the ac systems and the dc power change due to a step load increase in the Chubu power system are examined. These frequency variations and power change are used to optimize the parameters of the AFRC devices.