Calculation of large ion densities under HVDC transmission lines by the finite difference method

A calculation method for large ion densities (charged aerosols) under HVDC transmission lines was developed considering both the charging mechanism of aerosols by small ions and the drifting process by wind. Large ion densities calculated by this method agreed well with the ones measured under the Shiobara HVDC test line on the lateral profiles at ground level up to about 70 m downwind from the line. Measured values decreased more quickly than calculated ones farther downwind from the line. Considering the effect of point discharge from ground cover (earth corona) improved the agreement in the farther downwind region.<
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