Shunt C in a Floating Y Connection

In EMTP, the R, L, C elements of the library (RLC branches) are considered as series connection elements. To characterize them as shunts, the user should use the grounded components of the library. Alternately, the user can use a ground element to create the neutral (Neutral). A star connection can be floated or grounded (see figure below).

In HYPERSIM the R, L, C elements of its library are characterized either in series connection or in shunt connection (Y grounded, floating Y, or delta).

The following figure shows a capacitor floating neutral using the "neutral" element.

The following figure shows the "neutral" element for the creation of a neutral point.

HYPERSIM only recognizes the star connection with grounding. The floating-neutral connection on EMTP as described is not recognized (because of the user's external connections). In this case, HYPERSIM identifies it as a series connection with one end connected to the bus and the other end floating (therefore, no power is consumed). To address this, a "Bus to ABC" element can be added to represent the C component as floating shunts, recognizable in HYPERSIM.

R, L, C components - Series or Shunt

In HYPERSIM, an RLC component is an RLC branch that can be composed by a resistance (R), and inductance (L) and a capacitor (C) connected in series or in shunt. The value of at least one of these elements must not be zero. An element equal to zero means that this element is not activated and is removed from the circuit equations. However, in EMTP all the RLC elements in the branch can be zero. For example the impedance (R and L) of one of the windings in a transformer. 

When all the RLC elements in an RLC component are zero in HYPERSIM, an error message is shown at the initialization of the simulation. To address this problem, the value of at least one of these elements must not be zero. A very small value can be use to simulate a short circuit. HYPERSIM accepts values larger than 1e-10.