High voltage DC bushing and device comprising such high voltage bushing
View Patent ↗A high voltage DC bushing including a fluid duct with non-constant width (Δr) along the axial direction of the bushing.
1. A high voltage DC bushing, comprising:
a housing being symmetrical about a center axis and comprising a grounding flange;
a high voltage conductor provided in the housing;
a condenser core provided around the high voltage conductor;
a barrier layer provided in the housing; and
a fluid duct filled with fluid and provided between the barrier layer and the condenser core;
wherein the fluid duct has non-constant width (Δr) along an axial direction of the bushing to achieve a desired voltage potential distribution in the bushing.
2. The high voltage DC bushing according to claim 1 , wherein the cross-sectional area of the fluid duct is essentially constant.
3. The high voltage DC bushing according to claim 2 , wherein width variations of the fluid duct satisfy the following equation:
(Δ r ) 2 +2 r 1 Δr=C,
wherein Δr is the width of the fluid duct, r 1 is an inner radius of the fluid duct and C is a constant.
4. The high voltage DC bushing according to claim 1 , wherein the width (Δr) increases with smaller radius of the oil duct.
5. The high voltage DC bushing according to claim 1 , wherein the fluid duct has tapering end portions.
6. The high voltage DC bushing according to claim 1 , wherein the width of the fluid duct is wider close to end portions of the bushing.
7. The high voltage DC bushing according to claim 1 , wherein the width (Δr) variations along the axial direction of the bushing results in a voltage distribution similar to that of a corresponding high voltage AC bushing.
8. The high voltage DC bushing according to claim 1 , wherein the fluid duct is an oil duct filled with oil.
9. A high voltage DC device, comprising:
a high voltage DC bushing comprising a housing being symmetrical about a center axis and comprising a grounding flange, a high voltage conductor provided in the housing, a condenser core provided around the high voltage conductor, a barrier layer provided in the housing, and a fluid duct filled with fluid and provided between the barrier layer and the condenser core, wherein the fluid duct has non-constant width (Δr) along an axial direction of the bushing to achieve a desired voltage potential distribution in the bushing.