Development of weatherproof mobile impulse voltage generator and its application to experiments on nonlinearity of grounding resistance

Abstract

Abstract This paper describes a newly developed impulse voltage generator (IG). It has the following features: (1) The IG consists of three components (a 1.6 MV unit, a 1.4‐MV unit and a base box); this facilitates mounting on 10‐ton trucks, therefore making it easier to move to a test field. (2) Capacitors, discharge gaps and a control unit are enclosed in fiber‐reinforced plastics, making it possible to use the IG in all weather. (3) The IG can generate several ten kA when a load is a few ten Ω. (4) Composition of the circuits for lightning/switching impulse voltage/current tests can be easily done by changing the damping and discharge resistance cassettes. Control and data acquisition are made by personal computer. For IG application during an outdoor test, this paper presents the characteristics of resistances of a 77‐kV substation grounding and a concrete pole when applying a high impulse current. The resistances are dependent on the crest value of the applied current.