What is geometric mean radius of conductors?
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Geometrical Mean Radius GMR is basically the Geometric Mean of distances between the strands of a conductor. It is the fictitious radius of a conductor having no internal flux linkage but only external flux linkage.
What are GMD and GMR of a conductor?
GMD & GMR stands for Geometrical Mean Distance and Geometrical Mean Radius. This concept is very useful in Power System for the calculation of Inductance and Capacitance of Transmission Line.
How is GMR calculated?
GMR is the effective radius of the conductor which is caused due to the internal flux linkage. If there was no internal flux linkage then the GMR is equal to the radius of the conductor. GMR = e^-1/4 * r .
What is the distance between conductors?
Vertical Distance between Conductors of different Circuit (On Different Support)
| Higher Voltage of either Circuit | Distance between Circuits |
|---|---|
| 1 KV to 33 KV | 1.2 Meter |
| 33 KV to 66 KV | 1.8 Meter |
| 110 KV | 2.4 Meter |
| 220 KV | 2.8 Meter |
What is the utility of the geometric mean radius of the bundle conductor?
A bundled conductor reduces the reactance of the electric transmission line. It also reduces voltage gradient, corona loss, radio interference, surge impedance of the transmission lines. By making bundle conductor, the geometric mean radius (GMR) of the conductor increased.
What do you mean by corona loss?
Corona appears in the transmission line when the surface voltage gradient at the line conductor reaches the breakdown stress. Due to corona, heat and bluish light produce. There is a loss of power and energy dissipation. This loss is known as the corona loss.
What is GMR Geometric Mean radius?
Geometrical Mean Radius GMR is basically the Geometric Mean of distances between the strands of a conductor. It is the fictitious radius of conductor having no internal flux linkage but only external flux linkage.
How do you calculate GMD of a conductor?
GMD of Two Adjacent Conductors : If two conductors are placed adjacent to each other and if the spacing between them is much greater than the diameter of the conductor then, the mutual GMD is equal to the distance between their centers. Therefore, mutual GMD, Dm = Spacing between conductors = D.
What is GMR geometric mean radius?
How do you calculate bundled conductor GMR?
Related Calculations. For a two-conductor bundle, GMR=(GMR c D) 1/2 and for a four-conductor bundle, GMR=(GMR c D 32 1/2) 1/4. In each case, D is the distance between adjacent conductors.
What is the distance between two transmission towers?
Indian Electricity Rule 1956, Clause No 77, mentions, the minimum distance between bottom conductor and ground of different overhead transmission lines. As per Indian Electricity Rule 1956, Clause No 77, the minimum distance between bottom conductor and ground of a 400KV transmission line is 8.84 meter.
What is the minimum distance between conductors that should be maintain?
Min. Distance between two Conductors on Different Supports
| High Voltage Circuit | Distance (min) |
|---|---|
| 1 KV to 33 KV | 1.2 Meter |
| 33 KV to 66 KV | 1.8 Meter |
| 110 KV | 2.4 Meter |
| More than 220 KV | 2.8 Meter |