Development of Connectivity Manager

andes/core/__init__.py

@@ -17,3 +17,4 @@
 from andes.core.var import (Algeb, BaseVar, ExtAlgeb, ExtState, ExtVar,  # NOQA
                             State,)
 from andes.core.symprocessor import SymProcessor  # NOQA
+from andes.core.connman import ConnMan  # NOQA

andes/core/connman.py

@@ -0,0 +1,160 @@
+"""
+Module for Connectivity Manager.
+"""
+
+import logging
+from collections import OrderedDict
+
+from andes.utils.func import list_flatten
+from andes.shared import np
+
+logger = logging.getLogger(__name__)
+
+
+# connectivity dependencies of `Bus`
+# NOTE: only include PFlow models and measurements models
+# cause online status of dynamic models are expected to be handled by their
+# corresponding static models
+# TODO: DC Topologies are not included yet, `Node`, etc
+bus_deps = OrderedDict([
+    ('ACLine', ['bus1', 'bus2']),
+    ('ACShort', ['bus1', 'bus2']),
+    ('FreqMeasurement', ['bus']),
+    ('Interface', ['bus']),
+    ('Motor', ['bus']),
+    ('PhasorMeasurement', ['bus']),
+    ('StaticACDC', ['bus']),
+    ('StaticGen', ['bus']),
+    ('StaticLoad', ['bus']),
+    ('StaticShunt', ['bus']),
+])
+
+
+class ConnMan:
+    """
+    Define a Connectivity Manager class for System.
+
+    Connectivity Manager is used to automatically **turn off**
+    attached devices when a ``Bus`` is turned off **after** system
+    setup and **before** TDS initializtion.
+
+    Attributes
+    ----------
+    system: system object
+        System object to manage the connectivity.
+    busu0: ndarray
+        Last recorded bus connection status.
+    is_needed: bool
+        Flag to indicate if connectivity update is needed.
+    changes: dict
+        Dictionary to record bus connectivity changes ('on' and 'off').
+        'on' means the bus is previous offline and now online.
+        'off' means the bus is previous online and now offline.
+    """
+
+    def __init__(self, system=None):
+        """
+        Initialize the connectivity manager.
+
+        Parameters
+        ----------
+        system: system object
+            System object to manage the connectivity.
+        """
+        self.system = system
+        self.busu0 = None               # placeholder for Bus.u.v
+        self.is_needed = False          # flag to indicate if check is needed
+        self.changes = {'on': None, 'off': None}    # dict of bus connectivity changes
+
+    def init(self):
+        """
+        Initialize the connectivity.
+
+        `ConnMan` is initialized in `System.setup()`, where all buses are considered online
+        by default. This method records the initial bus connectivity.
+        """
+        # NOTE: here, we expect all buses are online before the system setup
+        self.busu0 = np.ones(self.system.Bus.n, dtype=int)
+        self.changes['on'] = np.zeros(self.system.Bus.n, dtype=int)
+        self.changes['off'] = np.logical_and(self.busu0 == 1, self.system.Bus.u.v == 0).astype(int)
+
+        if np.any(self.changes['off']):
+            self.is_needed = True
+
+        self.act()
+
+        return True
+
+    def _update(self):
+        """
+        Helper function for in-place update of bus connectivity.
+        """
+        self.changes['on'][...] = np.logical_and(self.busu0 == 0, self.system.Bus.u.v == 1)
+        self.changes['off'][...] = np.logical_and(self.busu0 == 1, self.system.Bus.u.v == 0)
+        self.busu0[...] = self.system.Bus.u.v
+
+    def record(self):
+        """
+        Record the bus connectivity in-place.
+
+        This method should be called if `Bus.set()` or `Bus.alter()` is called.
+        """
+        self._update()
+
+        if np.any(self.changes['on']):
+            onbus_idx = [self.system.Bus.idx.v[i] for i in np.nonzero(self.changes["on"])[0]]
+            logger.warning(f'Bus turned on: {onbus_idx}')
+            self.is_needed = True
+            if len(onbus_idx) > 0:
+                raise NotImplementedError('Turning on bus after system setup is not supported yet!')
+
+        if np.any(self.changes['off']):
+            offbus_idx = [self.system.Bus.idx.v[i] for i in np.nonzero(self.changes["off"])[0]]
+            logger.warning(f'Bus turned off: {offbus_idx}')
+            self.is_needed = True
+
+        return self.changes
+
+    def act(self):
+        """
+        Update the connectivity.
+        """
+        if not self.is_needed:
+            logger.debug('No need to update connectivity.')
+            return True
+
+        if self.system.TDS.initialized:
+            raise NotImplementedError('Bus connectivity update during TDS is not supported yet!')
+
+        # --- action ---
+        offbus_idx = [self.system.Bus.idx.v[i] for i in np.nonzero(self.changes["off"])[0]]
+
+        # skip if no bus is turned off
+        if len(offbus_idx) == 0:
+            return True
+
+        logger.warning('Entering connectivity update.')
+        logger.warning(f'Following bus(es) are turned off: {offbus_idx}')
+
+        logger.warning('-> System connectivity update results:')
+        for grp_name, src_list in bus_deps.items():
+            devices = []
+            for src in src_list:
+                grp_devs = self.system.__dict__[grp_name].find_idx(keys=src, values=offbus_idx,
+                                                                   allow_none=True, allow_all=True,
+                                                                   default=None)
+                grp_devs_flat = list_flatten(grp_devs)
+                if grp_devs_flat != [None]:
+                    devices.append(grp_devs_flat)
+
+            devices_flat = list_flatten(devices)
+
+            if len(devices_flat) > 0:
+                self.system.__dict__[grp_name].set(src='u', attr='v',
+                                                   idx=devices_flat, value=0)
+                logger.warning(f'In <{grp_name}>, turn off {devices_flat}')
+
+        self.is_needed = False      # reset the action flag
+        self._update()              # update but not record
+        self.system.connectivity(info=True)
+        return True

andes/models/bus.py

@@ -124,3 +124,32 @@ def __init__(self, system=None, config=None):
                        '(1-flat_start)*a0'
         self.v.v_str = 'flat_start*1 + ' \
                        '(1-flat_start)*v0'
+
+    def set(self, src, idx, attr, value):
+        super().set(src=src, idx=idx, attr=attr, value=value)
+        _check_conn_status(system=self.system, src=src, attr=attr)
+
+
+def _check_conn_status(system, src, attr):
+    """
+    Helper function to determine if connectivity update is needed.
+
+    Parameters
+    ----------
+    system : System
+        The system object.
+    src : str
+        Name of the model property
+    attr : str
+        The internal attribute of the property to get.
+    """
+    # Check if connectivity update is required
+    if src == 'u' and attr == 'v':
+        if system.is_setup:
+            system.conn.record()  # Record connectivity once setup is confirmed
+
+        if not system.TDS.initialized:
+            # Log a warning if Power Flow needs resolution before EIG or TDS
+            if system.PFlow.converged:
+                logger.warning('Bus connectivity is touched, resolve PFlow before running EIG or TDS!')
+            system.PFlow.converged = False  # Flag Power Flow as not converged

andes/routines/base.py

@@ -7,6 +7,31 @@
 from collections import OrderedDict
 
 
+def check_conn_before_init(func):
+    """
+    A decorator that ensures the connection is active before calling the `init` or `run`
+    method of a `BaseRoutine` derived class.
+
+    This decorator calls the `act` method on `self.system.conn` to ensure the connection
+    is active before proceeding with the initialization.
+
+    Parameters
+    ----------
+    func : function
+        The `init` method of a `BaseRoutine` derived class.
+
+    Returns
+    -------
+    function
+        The wrapped function with connection check.
+    """
+
+    def wrapper(self, *args, **kwargs):
+        self.system.conn.act()
+        return func(self, *args, **kwargs)
+    return wrapper
+
+
 class BaseRoutine:
     """
     Base routine class.

andes/routines/eig.py

@@ -12,7 +12,7 @@
 
 from andes.io.txt import dump_data
 from andes.plot import set_latex, set_style
-from andes.routines.base import BaseRoutine
+from andes.routines.base import BaseRoutine, check_conn_before_init
 from andes.shared import div, matrix, plt, sparse, spdiag, spmatrix
 from andes.utils.misc import elapsed
 from andes.variables.report import report_info
@@ -492,6 +492,7 @@ def _pre_check(self):
 
         return status
 
+    @check_conn_before_init
     def run(self, **kwargs):
         """
         Run small-signal stability analysis.

andes/routines/pflow.py

@@ -6,7 +6,7 @@
 from collections import OrderedDict
 
 from andes.utils.misc import elapsed
-from andes.routines.base import BaseRoutine
+from andes.routines.base import BaseRoutine, check_conn_before_init
 from andes.variables.report import Report
 from andes.shared import np, matrix, sparse, newton_krylov
 
@@ -63,6 +63,7 @@ def __init__(self, system=None, config=None):
         self.x_sol = None
         self.y_sol = None
 
+    @check_conn_before_init
     def init(self):
         """
         Initialize variables for power flow.

andes/routines/tds.py

@@ -9,7 +9,7 @@
 import time
 from collections import OrderedDict
 
-from andes.routines.base import BaseRoutine
+from andes.routines.base import BaseRoutine, check_conn_before_init
 from andes.routines.daeint import Trapezoid, method_map
 from andes.routines.criteria import deltadelta
 from andes.shared import matrix, np, pd, spdiag, tqdm, tqdm_nb
@@ -174,6 +174,7 @@ def __init__(self, system=None, config=None):
         self.method = Trapezoid()
         self.set_method(self.config.method)
 
+    @check_conn_before_init
     def init(self):
         """
         Initialize the status, storage and values for TDS.

andes/system.py

@@ -23,7 +23,7 @@
 from typing import Dict, Optional, Tuple, Union
 
 import andes.io
-from andes.core import AntiWindup, Config, Model
+from andes.core import AntiWindup, Config, Model, ConnMan
 from andes.io.streaming import Streaming
 from andes.models import file_classes
 from andes.models.group import GroupBase
@@ -193,6 +193,7 @@ def __init__(self,
         self.files = FileMan(case=case, **self.options)    # file path manager
         self.dae = DAE(system=self)                        # numerical DAE storage
         self.streaming = Streaming(self)                   # Dime2 streaming
+        self.conn = ConnMan(system=self)                   # connectivity manager
 
         # dynamic imports of groups, models and routines
         self.import_groups()
@@ -488,6 +489,9 @@ def setup(self):
         self.store_sparse_pattern(self.exist.pflow)
         self.store_adder_setter(self.exist.pflow)
 
+        # init connectivity manager
+        self.conn.init()
+
         if ret is True:
             self.is_setup = True  # set `is_setup` if no error occurred
         else:

docs/source/release-notes.rst

@@ -11,6 +11,15 @@ v1.9 Notes
 
 v1.9.3 (2024-04-XX)
 -------------------
+Development of connectivity manager `ConnMan`:
+
+- Add case `ieee14_conn.xlsx` for demonstration.
+- Add `ConnMan` class to manage connectivity.
+- Add `ConnMan` to `System` to as an attribute `conn`.
+- Add a demo notebook for `ConnMan`.
+
+Other changes:
+
 - In the ``dae`` module, change `self.t.itemset` to array assignment to ensure compatibility with NumPy 2.0.
 - Follow RTD's deprecation of Sphinx context injection at build time
 - In symbolic processor, most variables are assumed to be real, except some
@@ -22,6 +31,7 @@ v1.9.3 (2024-04-XX)
 - Add parameter `allow_all=False` to `ModelData.find_idx()` `GroupBase.find_idx()` to allow searching all matches.
 - Add method `GroupBase.get_all_idxes()` to get all indices of a group.
 - Enhanced three-winding transformer parsing in PSS/E raw files by assigning the equivalent star bus `area`, `owner`, and `zone` using the high-voltage bus values.
+- Specify `multiprocess <=0.70.16` in requirements as 0.70.17 does not support Linux.
 
 v1.9.2 (2024-03-25)
 -------------------