hermess.tests.test_algebraic_parity

Parity test for the device-private algebraic-equation mechanism.

Runs the stock SynchronousSubtransientSP machine (stator currents inlined as explicit expressions) and SynchronousSubtransientSP_DAE (the same currents declared as device-private algebraic variables/equations and handed to the DAE solver) on the same system, and asserts the differential-state trajectories agree to integrator tolerance.

This validates the full private-algebraic path: declaration, index allocation, finit with private unknowns, DAE assembly/solve, and the grid/output slicing.

Attributes

`FIXTURE_ROOT`
`_COMMON`

Functions

`test_sp_dae_matches_eliminated_sp`()	SP_DAE (explicit algebraic stator currents) must reproduce the stock SP
`test_sp_dae_private_constraints_hold`()	The private stator-current constraints g = -i + <expr> must be satisfied
`test_sp6_dae_matches_eliminated_sp6`()	Subtransient Sauer-Pai 6th-order machine with the 4-equation stator block
`test_sp_dae_line_dyn_mixed_dae`()	Under line_dyn=True the network (voltages + line currents) is differential
`_sorted_eig`(sim)
`test_eigenvalue_analysis_line_dyn_mixed`()	Small-signal eigenvalue analysis for the mixed DAE (line_dyn=True with

Module Contents

hermess.tests.test_algebraic_parity.FIXTURE_ROOT

hermess.tests.test_algebraic_parity._COMMON

hermess.tests.test_algebraic_parity.test_sp_dae_matches_eliminated_sp()[source]: SP_DAE (explicit algebraic stator currents) must reproduce the stock SP (eliminated currents) on identical systems, to integrator tolerance.

hermess.tests.test_algebraic_parity.test_sp_dae_private_constraints_hold()[source]: The private stator-current constraints g = -i + <expr> must be satisfied along the SP_DAE trajectory: the recovered i_d/i_q (in y_full) equal the explicit expression evaluated on the states.

hermess.tests.test_algebraic_parity.test_sp6_dae_matches_eliminated_sp6()[source]: Subtransient Sauer-Pai 6th-order machine with the 4-equation stator block (i_d, i_q, psi_d, psi_q) declared as device-private algebraics. Must reproduce the eliminated SynchronousSubtransientSP6 to integrator tolerance.

hermess.tests.test_algebraic_parity.test_sp_dae_line_dyn_mixed_dae()[source]: Under line_dyn=True the network (voltages + line currents) is differential and the device-private algebraics are the only algebraic block — a mixed DAE. SP_DAE must run in this mode and reproduce the eliminated SP (which is a pure ODE there). The match is near machine precision because both integrate the same differential network states; only the linear private solve differs.

hermess.tests.test_algebraic_parity._sorted_eig(sim)[source]

hermess.tests.test_algebraic_parity.test_eigenvalue_analysis_line_dyn_mixed()[source]: Small-signal eigenvalue analysis for the mixed DAE (line_dyn=True with device-private algebraics). The privates are Schur-complemented out, leaving an nd = nx + nv + nl differential system. Because the eliminated ground model reduces to the same nd-dimensional system, the two spectra must coincide. Covers both SP_DAE (2 privates) and SP6_DAE (4 privates).