ImmittanceResult

class pmrf.models.components.lines.base.ImmittanceResult(Z: Array, Y: Array, omega: Array)

Bases: Module

Per-unit-length series impedance and shunt admittance of a line.

Immittance is the internal currency between a formulation and a line. \(R\), \(L\), \(G\) and \(C\) are derived views on it rather than the primary form, because \(L = \Im(Z)/\omega\) and \(C = \Im(Y)/\omega\) both carry a removable \(0/0\) at DC that \((Z, Y)\) does not, and because AbstractImmittanceLine.zc_and_gammaL() then reduces to \(\sqrt{Z/Y}\) and \(\sqrt{ZY}\) with no division by \(\omega\) anywhere.

Parameters:

• Z (jnp.ndarray) – Series impedance per unit length, \(Z = R + j\omega L\), in ohm/m.

• Y (jnp.ndarray) – Shunt admittance per unit length, \(Y = G + j\omega C\), in S/m.

• omega (jnp.ndarray) – Angular frequency axis, kept so that L and C can be recovered.

classmethod from_rlgc(R, L, G, C, omega) → ImmittanceResult

Build an immittance from per-unit-length \(R\), \(L\), \(G\) and \(C\).

classmethod from_zc_gamma(zc, gamma, omega) → ImmittanceResult

Invert characteristic impedance and propagation constant exactly.

The per-unit-length quantities are the exact bijection

\[Z = \gamma Z_c \qquad Y = \frac{\gamma}{Z_c}.\]

A passive line must have non-negative series resistance and shunt conductance. Violating that condition indicates that an empirical formulation has been evaluated outside its physical regime.

property C: Array

Shunt capacitance per unit length in F/m, \(\Im(Y)/\omega\).

property G: Array

Shunt conductance per unit length in S/m.

property L: Array

Series inductance per unit length in H/m, \(\Im(Z)/\omega\).

property R: Array

Series resistance per unit length in ohm/m.

Y: Array

Shunt admittance per unit length in S/m

Z: Array

Series impedance per unit length in ohm/m

omega: Array

Angular frequency axis in rad/s