New Method of Simulating Rainfall in High-Voltage Testing

A method is described for simulating rainfall during tests of high-voltage equipment. The system as described delivers controllable rain rates ranging from 0.2 to 2.0 in/h with water drops 4.5 mm in diameter over an outdoor area of 3 by 200 feet. A new method for simulating rain had to be developed for an investigation of the corona performance of conductors for high-voltage transmission lines, because conventional rain sprays cannot provide the intensities and drop sizes that occur in natural rain. The effect of wind on the uniformity of rain rate during outdoor testing is analyzed. The information presented should be useful in adapting this system for tests on other equipment.