Tx Stepping Experiments

[luke-kiernan]

Matrix backend for NREL-Sienna/PowerFlows.jl#321. See that PR for more details--not compatible with network reductions.

With splitting the ybus into separate series and shunt pieces, I decided to switch to 64-bit datatypes. Otherwise the difference in order of magnitudes between the two parts is close enough to the precision limit that we run into numerical inaccuracies.

[github-actions]

Performance Results

Version	Precompile Time
Main	2.280702713
This Branch	2.250307329

Version	Run Time
Main-matpower_ACTIVSg2000_sys-Build PTDF First	10.015248306
Main-matpower_ACTIVSg2000_sys-Build PTDF Second	0.112391847
Main-matpower_ACTIVSg2000_sys-Build Ybus First	0.023425014
Main-matpower_ACTIVSg2000_sys-Build Ybus Second	0.014065765
Main-matpower_ACTIVSg2000_sys-Build LODF First	0.664396902
Main-matpower_ACTIVSg2000_sys-Build LODF Second	0.524773377
Main-matpower_ACTIVSg2000_sys-Radial network reduction First	0.623367429
Main-matpower_ACTIVSg2000_sys-Radial network reduction Second	0.007326008
Main-matpower_ACTIVSg2000_sys-Degree two network reduction First	1.953959016
Main-matpower_ACTIVSg2000_sys-Degree two network reduction Second	0.001111059
Main-Base_Eastern_Interconnect_515GW-Build Ybus First	4.498628588
Main-Base_Eastern_Interconnect_515GW-Build Ybus Second	3.815407301
Main-Base_Eastern_Interconnect_515GW-Radial network reduction First	8.726493906
Main-Base_Eastern_Interconnect_515GW-Radial network reduction Second	8.601512252
Main-Base_Eastern_Interconnect_515GW-Degree two network reduction First	0.366333457
Main-Base_Eastern_Interconnect_515GW-Degree two network reduction Second	0.046382662
This Branch-matpower_ACTIVSg2000_sys-Build PTDF First	9.995477915
This Branch-matpower_ACTIVSg2000_sys-Build PTDF Second	0.123431217
This Branch-matpower_ACTIVSg2000_sys-Build Ybus First	0.022835524
This Branch-matpower_ACTIVSg2000_sys-Build Ybus Second	0.013477568
This Branch-matpower_ACTIVSg2000_sys-Build LODF First	0.719041864
This Branch-matpower_ACTIVSg2000_sys-Build LODF Second	0.456022143
This Branch-matpower_ACTIVSg2000_sys-Radial network reduction First	0.614567889
This Branch-matpower_ACTIVSg2000_sys-Radial network reduction Second	0.006980658
This Branch-matpower_ACTIVSg2000_sys-Degree two network reduction First	1.936292906
This Branch-matpower_ACTIVSg2000_sys-Degree two network reduction Second	0.00105895
This Branch-Base_Eastern_Interconnect_515GW-Build Ybus First	4.489618747
This Branch-Base_Eastern_Interconnect_515GW-Build Ybus Second	3.515347099
This Branch-Base_Eastern_Interconnect_515GW-Radial network reduction First	8.516516315
This Branch-Base_Eastern_Interconnect_515GW-Radial network reduction Second	8.521024796
This Branch-Base_Eastern_Interconnect_515GW-Degree two network reduction First	0.35766706
This Branch-Base_Eastern_Interconnect_515GW-Degree two network reduction Second	0.132099348