Struct StateLayout 

pub struct StateLayout {
    pub n_buses: usize,
    pub angle_ref: Option<usize>,
    /* private fields */
}

Maps buses to positions in the state vector.

Fields

n_buses: usize

angle_ref: Option<usize>

The bus whose angle is held at zero, if one is pinned.

A network measured only in magnitudes and powers is invariant under a global phase shift, so without a reference G is singular by construction no matter how many measurements there are. But that invariance disappears the moment a phasor measurement supplies an absolute angle — and pinning a reference on top of one would then be a false constraint, rotating the whole estimate away from the angles that were actually measured. So this is None exactly when the measurement set determines the phase by itself.

Implementations

impl StateLayout

pub fn new(buses: &[Bus], measurements: &[Measurement], net: &SeNetwork) -> Self

Builds the layout for a measurement set.

A reference is pinned only when the measurements contain no voltage angle; see angle_ref.

When one is pinned it is the physical node a source feeds, not the virtual slack bus behind it. power-grid-model normalizes by setting its slack bus’s angle to zero, and its slack bus is that physical node, since it has no virtual bus at all. Pinning the virtual bus instead leaves every angle offset by the drop across the source impedance — a constant, invisible in magnitudes, and exactly the 6.5e-3 rad uniform shift the transmission-case fixture showed before this was fixed. Stiff sources hide it, which is why the smaller fixtures agreed either way.

pub fn n_unknowns(&self) -> usize

Number of unknowns: 2N when the phase is measured, 2N − 1 when a reference has to be pinned.

pub fn theta(&self, bus: usize) -> Option<usize>

Column of a bus’s angle, or None for the reference bus.

pub fn vmag(&self, bus: usize) -> usize

Column of a bus’s voltage magnitude.