A tree search in Mathcad

[Bung]

I'm looking for a method of examining the nodes in an electric circuit and modifying some parameters associated with nodes which meet certain criteria. Can anyone help? I will have to do it via a little program obviously. (I use Mathcad 2000 Professional).

The specific problem I have is to modify the voltage vector on all nodes "downstream" of a delta-star transformer, but only as far as the next transformer. Any nodes beyond the next transformer will need the same treatment, but with that transformer's phase shift added.

Bung

 

It seems to me that a look in any elementary texts on data structures would find your answer, e.g. linked lists, btree etcs. but MathCad is not reaaly built to handle this sort of data analysis - but I may be wrong so try the MatchCad collaboratory

 

[cuky2000]

Hi Bung,

Please present a short sample to understand better your question and perhaps I could help.

 

[Bung]

cuky2000 - let's say I have a circuit in which the nodes are numbered uniquely. Transformers connect two nodes, and separate the network into areas with at a common voltage level. A transformer shifts the voltage phase by some multiple of 30deg (three phase system). I need to be able to track which nodes are connected to each other and are not separated by a transformer, so that I can apply the correct phase shift.

Example: nodes 1&2 are connected by a transformer. Node 2 and all other nodes connected to it by any circuit element except a transformer have their voltage phasor shifted by lets say 30 degrees. Let's say nodes 3,5, 8 and 9, are all connected to node 2, but there is another transformer on node 8 to node 10 with a phase shift of 30deg. If nodes 2,4 and 6 are connected to node 10, then a further phase shift of -30deg is required.

I have three groups of nodes in this example:

group 1, consisting of node 1, phase shift 0deg.
group 2, nodes 2,3,5,8,9 phase shift 30deg
group 3, nodes 10, 2, 4, 6 phase shift =group 2 +30deg (or total relative to group 1 60deg)

I need some way of Mathcad tracking which node belongs in which group so that it can apply the phase shift properly. (Beware - there is a bug in the Electrical Power Systems Engineering Handbook pack from Mathcad, in the Faults Applications section - it only gets the phase shift right on the node the transformer is connected to and downstream from there. I am basically modifying and extending this to assist in semi-automating protection relay settings).

Hope I've made myself clear!

thanks
Bung
Life is non-linear...