From cb03c30548211d6102f1f3a53c8cef2b90a6e777 Mon Sep 17 00:00:00 2001
From: Hantao Cui <cuihantao@gmail.com>
Date: Wed, 10 Apr 2024 02:36:19 +0000
Subject: [PATCH] Fix a bug in island detection to properly set
 `Bus.n_islanded_buses`.

---
 andes/system.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/andes/system.py b/andes/system.py
index 1536cd87a..2497fc1a6 100644
--- a/andes/system.py
+++ b/andes/system.py
@@ -1256,6 +1256,9 @@ def connectivity(self, info=True):
         # store `a` and `v` indices for zeroing out residuals
         self.Bus.islanded_a = np.array(self.Bus.islanded_buses)
         self.Bus.islanded_v = self.Bus.n + self.Bus.islanded_a
+        # `self.Bus.n_islanded_buses` is used to determine if `g_islands`
+        # needs to be call
+        self.Bus.n_islanded_buses = len(self.Bus.islanded_a)
 
         # find islanded areas - Goderya's algorithm
         temp = spmatrix(list(u) * 4,