Loss allocation algorithm description could be found Here.
InterPSS currently supports three types of contingency analysis: N-1 Analysis; N-1-1 Analysis and N-2 Analysis.
Open each branch in the power network and run complete AC loadflow analysis for each contingency.
First open each branch in the power network and run complete AC loadflow analysis for each contingency. Then for each N-1 contingency, open each branch with branch Mva rating violation and run complete AC loadflow analysis for each N-1-1 contingency.
Open all combination of two branches in the power network and run complete AC loadflow analysis for each N-2 contingency.
The following three reports are generated after the analysis:
Non-converged loadflow case [ tolerance: 0.0010 pu ]
Case Max Error Info
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[x]Bus120->Bus200(1) dPmax : 0.00967(pu) at Bus : Bus141, dQmax : 0.01829(pu) at Bus : Bus265
[x]Bus1010->Bus1(1) dPmax : 11.86389(pu) at Bus : Bus1010, dQmax : 4.40034(pu) at Bus : Bus1020
The non-converged case report listed all cases with non-converged loadflow against the tolerance. InterPSS use a non-diverge loadflow algorithm, which guarantees that the loadflow will never diverge.
Bus Voltage Limit: [1.10, 0.85]
Bus Id LowVolt LowMargin Description
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Bus340 0.8774 2.7% [x]Bus110->Bus280(1)
Bus141 0.7850 -6.5% [x]Bus110->Bus280(1)
Bus140 0.8437 -0.6% [x]Bus110->Bus280(1)
The voltage margin report lists the lowest voltage for the bus for all contingencies and compare it with a Bus Low Voltage Limit. The description tells which contingency caused the lowest voltage. For example, [x]Bus110->Bus280(1) indicates that the open branchBus110->Bus280(1) contingency caused the lowest voltage.
Branch Id MvaFlow MvaRating P + jQ Margin Description
==============================================================+=================================
Bus260->Bus263(1) 56.2 65.0 ( 53.4+j 17.4) 14% [x]Bus110->Bus280(1)
Bus151->Bus150(1) 369.0 300.0 ( 362.0+j 71.4) -23% [x]Bus111->Bus110(1)
Bus111->Bus110(1) 378.3 150.0 ( 368.0+j 87.9) -152% [x]Bus151->Bus150(1)
The branch Mva margin report lists the most severe branch Mva rating violation, indicating with a - sign. The description tells which contingency caused the most severe branch rating violation.