From df2a982ebde9421ab4d76bef18a25a93dd324547 Mon Sep 17 00:00:00 2001 From: Hantao Cui Date: Sat, 18 Mar 2023 14:27:41 +0000 Subject: [PATCH] Improve documentation. --- andes/models/static/pq.py | 8 ++++++-- andes/models/timer.py | 11 +++++++++++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/andes/models/static/pq.py b/andes/models/static/pq.py index 64c92a7e7..db2b571fe 100644 --- a/andes/models/static/pq.py +++ b/andes/models/static/pq.py @@ -67,9 +67,13 @@ class PQ(PQData, Model): .. code-block :: python - ss.PQ.config.p2p = 1.0 ss.PQ.config.p2i = 0 ss.PQ.config.p2z = 0 + ss.PQ.config.p2p = 1.0 + ss.PQ.config.p2i = 0 + ss.PQ.config.p2z = 0 - ss.PQ.config.q2q = 1.0 ss.PQ.config.q2i = 0 ss.PQ.config.q2z = 0 + ss.PQ.config.q2q = 1.0 + ss.PQ.config.q2i = 0 + ss.PQ.config.q2z = 0 Then, the constant power portion can be altered by changing the ``Ppf`` and ``Qpf`` constants for active power and reactive power. diff --git a/andes/models/timer.py b/andes/models/timer.py index f1a67ead7..a71f826a6 100644 --- a/andes/models/timer.py +++ b/andes/models/timer.py @@ -108,6 +108,17 @@ class Fault(ModelData, Model): Non-convergence can occur in the proximity of a fault due to various reasons, including network power transfer capability limitation and parameter issues of controllers. + + When a fault gets cleared, algebraic variables change drastically. E.g., + voltages can go from nearly zero back to 1.0. As we are using Newton's + method for solving the DAE, the initial values are crucial for the immediate + step after fault clearance. + + This Fault model restores the pre-fault values for algebraic variables + ``Fault.config.scale`` is the scaling factor to be multiplied to the + pre-fault values for adjusting the initial values. Some trial and error are + expected for severe disturbances, combined with increasing the fault + reactance ``xf``. """ def __init__(self, system, config):