Study On Electrical Contact Performance Of Air Circuit Breaker In SO₂ Environment

Distribution system is an important part of the whole power system, circuit breaker plays a major role in the distribution system. With the use of an increasingly wide range and the environment of increasingly complex, circuit breaker is required to be more and more reliable. Air circuit breaker(ACB) in the distribution system is responsible for connecting, bearing and breaking current in normal and abnormal conditions. While working in the actual environment of pollution for a long time continuously, the air circuit breaker will emerge some corrosion on contact material. When the corrosion products accumulated to a certain extent, the electrical contact performance of air circuit breaker will be affected, even lead to a electrical contact failure. Impact of environment on electrical contact performance of air circuit breaker has already been one of the most important issues of concerning in the minds of both producers and users.Based on the effects of sulfur dioxide in industry air on operational reliability of air circuit breaker, the accelerated test on electrical contact performance of busbar and bridge contact model of air circuit breaker is conducted, and concentration of sulfur dioxide is taken as accelerated factor in the test. By measuring the contact resistance of samples at different concentration of sulfur dioxide and at different corrosion time, the relationships between electrical contact performance and concentration of sulfur dioxide, electrical contact performance and corrosion time are studied. At the same time, the test device of electrical contact performance of air circuit breaker is developed, by which electrical contact performance of air circuit breaker can be detected automatically.