Numerical model of negative DC corona inception voltage of stranded conductors

Energy loss, radio interference, and audible noise interference caused by corona discharge bring many special problems to the design and operation of the transmission lines. The smooth conductor is adopted in the traditional calculation model. The electric field intensity of stranded conductor which is used in practice is larger than that of smooth conductor. Therefore, a computation model is adopted for evaluating the corona inception voltage of stranded conductors. The electric field intensity is calculated by the charge simulation method in the computation model. Then the negative corona inception voltage is calculated according to the negative corona criterion. The results from numerical computation are compared with that from test in the others papers. Good agreement is obtained between the computation and test results, which demonstrate the validity of the numerical simulation program. The numerical simulation program may therefore be applied to study characteristics of negative DC corona inception voltage of stranded conductors. Surface roughness coefficient is in inverse proportion to the conductor radius, which is in proportion to conductor strand number.