Experimental investigation on correlation of corona-induced vibration and audible noise from DC conductor

In this study, the corona-induced vibration and audible noise (AN) on stranded conductor from positive and negative corona discharges were measured and analysed. The experiments were conducted in a semi-anechoic chamber to reduce the inferences from environment. For the measurement of vibration, the conductor was kept in dry condition without water drops on the conductor, which is different from previous investigations and can reveal the contributions of corona-generated space charges on the corona-induced vibration. Besides, the measurement of vibration on the conductor was performed by using a laser vibrometer which was a non-contact measurement device for measuring the vibration velocity. Furthermore, waveforms of corona-induced vibration and AN were measured simultaneously to analyse the correlation between them. The time and frequency domains characteristics of the vibration velocity and AN from negative and positive corona discharge are carefully analysed and no correlated relationship in time and frequency domains can be found in the two corona effects. It can be concluded that disturbance of air molecules caused by the vibration of conductor does not contribute the corona-generated AN.