Talk:Gauss-Seidel Distribution Powerflow Solver

As of February 20, 2008, these are the known issues or incomplete items relating to the Gauss-Seidel Distribution Powerflow Solver.

= Current Issues with Gauss-Seidel Solver =


 * 1) Large systems
 * 2) * Small discrepancies between Gauss-Seidel and FBS results. Voltages are within &plusmn;10 volts on 332 bus system.
 * 3) * Convergence times are excessive and solver shouldn't take as long as is does. Consider whether we need a critical node solution implemented?
 * 4) Small impedance/large admittance systems an issue still. Low length lines (<50 ft) have very large admittance values.  The adversely affects convergence rate (4 node system – 1698 iterations for length 20, 731 iterations for length 50, 267 iterations for length 150, 32 iterations for length 2500).  Consider whether we want to use a threshold admittance before nodes are merged?
 * 5) Multithreading issue. Consider whether additional locks are required or if something else needed for multithreading with acceleration > 1.0.
 * 6) Triplex lines/nodes/meters – Appear to work, but further testing will be required once triplex/split-phase transformers are operational
 * 7) Meters – work fine from solver perspective.  Untested as to if current accumulation (and reporting) is correct.
 * 8) Power in/out measurements for transformers – initial investigations seem to attribute this with delta-based windings.  Possible line vs. phase current issue?

= Unimplemented devices with Gauss-Seidel Solver =
 * 1) Split phase (triplex) transformer implementation – (in progress)
 * 2) Regulators – Almost works in one form…more generic fix will be available from triplex implementation solution (when working)?
 * 3) Switches/fuses – implementation idea in progress, but untested and uncoded
 * 4) Relays – related to switches/fuses.  Idea how to implement, untested and uncoded.

= Other PowerFlow Issues =
 * 1) Need a method to output GS Acceleration factor and/or iteration counts to XML output (extremely low importance, if at all)