A Dynamic Surge Arrester Model for Use in Power System Transient Studies

The valve-type surge arrester with current-limiting gap has dynamic performance capabilities which provide improved protection against system transient overvoltages. This paper interprets these dynamic characteristics as revealed in laboratory tests and translates them to a set of differential equations which can be solved with the aid of a computer. Alternatively, the differential equations can serve as an important guide in developing an equivalent circuit, and hence a physical model for the arrester which might be found useful in direct analog studies. Comparison between laboratory test results and computer results establish the validity of the simulation. Extension of the approach to more general system voltage transient studies is contemplated.