Search results
Results From The WOW.Com Content Network
Vector group. In electrical engineering, a vector group, officially called a connection symbol, is the International Electrotechnical Commission (IEC) method of categorizing the high voltage (HV) windings and low voltage (LV) winding configurations of three-phase transformers. The vector group designation indicates the windings configurations ...
Christoffel symbols. In mathematics and physics, the Christoffel symbols are an array of numbers describing a metric connection. [1] The metric connection is a specialization of the affine connection to surfaces or other manifolds endowed with a metric, allowing distances to be measured on that surface. In differential geometry, an affine ...
In electrical engineering, the Y-Δ transform, also written wye-delta and also known by many other names, is a mathematical technique to simplify the analysis of an electrical network. The name derives from the shapes of the circuit diagrams , which look respectively like the letter Y and the Greek capital letter Δ .
High-leg delta. High-leg delta (also known as wild-leg, stinger leg, bastard leg, high-leg, orange-leg, red-leg, dog-leg delta) is a type of electrical service connection for three-phase electric power installations. It is used when both single and three-phase power is desired to be supplied from a three phase transformer (or transformer bank).
An example delta-wye transformer schematic. A delta-wye transformer is a type of three-phase electric power transformer design that employs delta-connected windings on its primary and wye/star connected windings on its secondary. A neutral wire can be provided on wye output side. It can be a single three-phase transformer, or built from three ...
Zigzag transformer. A zigzag transformer winding is a special-purpose transformer winding with a zigzag or "interconnected star" connection, such that each output is the vector sum of two (2) phases offset by 120°. [1] It is used as a grounding transformer, creating a missing neutral connection from an ungrounded 3-phase system to permit the ...
The Levi-Civita connection (like any affine connection) also defines a derivative along curves, sometimes denoted by D. Given a smooth curve γ on (M, g) and a vector field V along γ its derivative is defined by. Formally, D is the pullback connection γ*∇ on the pullback bundle γ*TM. In particular, is a vector field along the curve γ itself.
Principal symbol. The variation formula computations above define the principal symbol of the mapping which sends a pseudo-Riemannian metric to its Riemann tensor, Ricci tensor, or scalar curvature. The principal symbol of the map assigns to each a map from the space of symmetric (0,2)-tensors on to the space of (0,4)-tensors on given by.