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SUMMARYIn Japan, since the development of large power systems, there have been spontaneous low-frequency oscillation and local mode oscillation. The conventional PSS has been applied to generators in a trunk power system as a measure to improve the damping power oscillation. However, it is difficult for this PSS to improve the damping power system oscillation because of the hardware and the design of fixed PSS control constants. It has therefore become necessary to develop a new adaptive PSS system. This paper explains the development of a new adaptive PSS system and the simulation of low-frequency and local mode oscillation for this new PSS system.

SUMMARYWith the advent of interconnection of large-scale electric power systems, many new dynamics power system problems have emerged, which include low-frequency intersystem oscillations and many others. To date, most major generators in trunk electric power systems in Japan are equipped with supplementary excitation control, commonly referred to as the conventional single and two input PSS. However, low-frequency oscillations still occur. It is difficult for these conventional PSS to improve the additional damping of power system oscillation, because of the hardware and design of fixed PSS control constants from a one-machine infinite-bus model. It has therefore become necessary to develop a new adaptive LQG system generator. This paper explains the development of the new adaptive LQG system and the simulation of low-frequency and local mode oscillation for this new adaptive LQG system.

An optimal transmission c o n troller for an automobile traveling with variable loads is designed and tested by using a transmission systeiii ( I s u z u N A V i -5 ) w h i c h c o n s i s t s of a c t u a t o r s a n d s e n s o r s b e s i d e g e a r s , a throttle and a clutch. T h i s system engages and disengages the clutcli and gears up mid down automatically. In other words a manual gear shift system is automated. As iieiiro and fuzzy approaches are promising i n e t h o d s to i n t e r f a c e b e t w e e n a v e h i c l e operator and ail automobile, they are used to design ai1 optirnal transmission controller. Tlie automobile loads are estimated from the signals of tlie status sensors by fuzzy logic. Tlie vehicle operator's intention is inferred by fuzzy logic using tlie information from tlie a u t o i n o h i l e s t a t u s s e n s o r s o n w h i c h the operator's intention is reflected. Tlieii,tliese are fed into a neural network. An experienced d r i v e r ( a l o t of d a t a ) t e a c h e r t h e n c u r a l net\vork an optimal gear shift scheduling sucli t h a t a v e h i c l e o p e r a t o r f e e l s c o m f o r t a b l e even when the automobile loads change (for example when an automobile is traveling up aiid dowii hill).