Tx line in DP formulation

andes/core/symprocessor.py

@@ -118,19 +118,26 @@ def generate_symbols(self):
  self.tex_names[name] = sp.Symbol(tex_name)
  # -----------------------------------------------------------
 
+ # `all_params_names` include parameters, services, exports from blocks, etc.
  for var in self.cache.all_params_names:
+ is_real = True
+
+ if var in self.parent.services:
+ if self.parent.services[var].vtype == complex:
+ is_real = False
+
  self.inputs_dict[var] = sp.Symbol(var)
 
  for var in self.cache.all_vars_names:
- tmp = sp.Symbol(var)
+ tmp = sp.Symbol(var, real=True) # all DAE variables are real
  self.vars_dict[var] = tmp
  self.inputs_dict[var] = tmp
  if var in self.cache.vars_int:
  self.vars_int_dict[var] = tmp
 
  # store tex names defined in `self.config`
  for key in self.config.as_dict():
- tmp = sp.Symbol(key)
+ tmp = sp.Symbol(key, real=True) # not expecting complex numbers in config
  self.inputs_dict[key] = tmp
  if key in self.config.tex_names:
  self.tex_names[tmp] = sp.Symbol(self.config.tex_names[key])
@@ -411,6 +418,8 @@ def generate_jacobians(self, diag_eps=1e-8):
  self.calls.append_ijv(f'{var.e_code}{var.v_code}c', e_idx, v_idx, eps)
  self.calls.need_diag_eps.append(var.name)
 
+ self.calls.need_diag_eps = sorted(list(set(self.calls.need_diag_eps)))
+
  def generate_pretty_print(self):
  """
  Generate pretty print variables and equations.

andes/models/__init__.py

@@ -18,7 +18,7 @@
  ('static', ['PQ', 'PV', 'Slack']),
  ('shunt', ['Shunt', "ShuntTD", 'ShuntSw']),
  ('interface', ['Fortescue']),
- ('line', ['Line', 'Jumper']),
+ ('line', ['Line', 'Jumper', 'DPLine']),
  ('area', ['Area', 'ACE', 'ACEc']),
  ('dynload', ['ZIP', 'FLoad']),
  ('synchronous', ['GENCLS', 'GENROU', 'PLBVFU1']),

andes/models/line/__init__.py

@@ -4,3 +4,4 @@
 
 from andes.models.line.line import Line # noqa
 from andes.models.line.jumper import Jumper # noqa
+from andes.models.line.dpline import DPLine # noqa

andes/models/line/dpline.py

@@ -0,0 +1,145 @@
+"""
+AC transmission line in dynamic phasor (shift frequency) formulation.
+"""
+
+
+from andes.core import (ModelData, IdxParam,
+ Model, ExtAlgeb, ConstService, ExtParam, State)
+
+
+class DPLineData(ModelData):
+ """
+ Data for Line.
+ """
+
+ def __init__(self):
+ super().__init__()
+
+ self.line = IdxParam(info='Line index', model='Line')
+
+
+class DPLine(DPLineData, Model):
+ """
+ WIP
+
+ AC transmission line model in dynamic phasor (shift frequency) formulation.
+
+ The connectivity `u` logic is as follows:
+ - `u = 0` means the line is not replaced by DPLine. The line remains in the
+ phasor model, and the `u` of the phasor Line device applies.
+ - `u = 1` means the line is replaced by DPLine. Still, the connectivity
+ status of the DP line depends on the `u` of the phasor Line device.
+
+ """
+
+ def __init__(self, system=None, config=None):
+ DPLineData.__init__(self)
+ Model.__init__(self, system, config)
+ self.group = 'ACLine'
+ self.flags.pflow = False
+ self.flags.tds = True
+ self.flags.tds_init = True
+
+ self.bus1 = ExtParam(model='Line', src='bus1', indexer=self.line, export=False)
+ self.bus2 = ExtParam(model='Line', src='bus2', indexer=self.line, export=False)
+
+ self.a1 = ExtAlgeb(model='Bus', src='a', indexer=self.bus1, tex_name='a_1',
+ info='phase angle of the from bus',
+ ename='Pij',
+ tex_ename='P_{ij}',
+ )
+ self.a2 = ExtAlgeb(model='Bus', src='a', indexer=self.bus2, tex_name='a_2',
+ info='phase angle of the to bus',
+ ename='Pji',
+ tex_ename='P_{ji}',
+ )
+ self.v1 = ExtAlgeb(model='Bus', src='v', indexer=self.bus1, tex_name='v_1',
+ info='voltage magnitude of the from bus',
+ ename='Qij',
+ tex_ename='Q_{ij}',
+ )
+ self.v2 = ExtAlgeb(model='Bus', src='v', indexer=self.bus2, tex_name='v_2',
+ info='voltage magnitude of the to bus',
+ ename='Qji',
+ tex_ename='Q_{ji}',
+ )
+
+ self.ul = ExtParam(model='Line', src='u', indexer=self.line, tex_name='u', export=False)
+ self.g1 = ExtParam(model='Line', src='g1', indexer=self.line, tex_name='g_1', export=False)
+ self.g2 = ExtParam(model='Line', src='g2', indexer=self.line, tex_name='g_2', export=False)
+ self.b1 = ExtParam(model='Line', src='b1', indexer=self.line, tex_name='b_1', export=False)
+ self.b2 = ExtParam(model='Line', src='b2', indexer=self.line, tex_name='b_2', export=False)
+ self.r = ExtParam(model='Line', src='r', indexer=self.line, tex_name='r', export=False)
+ self.x = ExtParam(model='Line', src='x', indexer=self.line, tex_name='x', export=False)
+ self.g = ExtParam(model='Line', src='g', indexer=self.line, tex_name='g', export=False)
+ self.b = ExtParam(model='Line', src='b', indexer=self.line, tex_name='b', export=False)
+ self.tap = ExtParam(model='Line', src='tap', indexer=self.line, tex_name='tap', export=False)
+
+ self.gh = ConstService(tex_name='g_h')
+ self.bh = ConstService(tex_name='b_h')
+ self.gk = ConstService(tex_name='g_k')
+ self.bk = ConstService(tex_name='b_k')
+
+ self.yh = ConstService(tex_name='y_h', vtype=complex)
+ self.yk = ConstService(tex_name='y_k', vtype=complex)
+ self.yhk = ConstService(tex_name='y_{hk}', vtype=complex)
+
+ self.ghk = ConstService(tex_name='g_{hk}')
+ self.bhk = ConstService(tex_name='b_{hk}')
+
+ self.itap = ConstService(tex_name='1/t_{ap}')
+ self.itap2 = ConstService(tex_name='1/t_{ap}^2')
+
+ self.Leq = ConstService(v_str='x/(2*pi*60)')
+
+ self.ue = ConstService(v_str='ul * u')
+
+ self.gh.v_str = 'g1 + 0.5 * g'
+ self.bh.v_str = 'b1 + 0.5 * b'
+ self.gk.v_str = 'g2 + 0.5 * g'
+ self.bk.v_str = 'b2 + 0.5 * b'
+
+ self.yh.v_str = 'u * (gh + 1j * bh)'
+ self.yk.v_str = 'u * (gk + 1j * bk)'
+ self.yhk.v_str = 'u/((r+1e-8) + 1j*(x+1e-8))'
+
+ self.ghk.v_str = 're(yhk)'
+ self.bhk.v_str = 'im(yhk)'
+
+ self.itap.v_str = '1/tap'
+ self.itap2.v_str = '1/tap/tap'
+
+ self.r2x2 = ConstService(v_str='r*r + x*x')
+
+ # in implicit form but has the same dq-axis alignment as in ANDES implementation)
+ self.idd = State(info='real current',
+ tex_name='idd',
+ v_str='ue * (r*v1*sin(a1)/r2x2 - r*v2*sin(a2)/r2x2 - v1*x*cos(a1)/r2x2 +'
+ ' v2*x*cos(a2)/r2x2)',
+ e_str='ue * (-x*iqq - r*idd - v2*sin(a2) + v1*sin(a1)) + (1-ue) * idd',
+ t_const=self.Leq,
+ )
+
+ self.iqq = State(info='real current',
+ tex_name='iqq',
+ v_str='ue * (r*v1*cos(a1)/r2x2 - r*v2*cos(a2)/r2x2 + v1*x*sin(a1)/r2x2 -'
+ ' v2*x*sin(a2)/r2x2)',
+ e_str='ue * (x*idd - r*iqq - v2*cos(a2) + v1*cos(a1)) + (1-ue) * iqq',
+ t_const=self.Leq,
+ )
+
+ self.a1.e_str = 'ue * (idd*v1*sin(a1) + iqq*v1*cos(a1))'
+
+ self.v1.e_str = 'ue * (-idd*v1*cos(a1) + iqq*v1*sin(a1))'
+
+ self.a2.e_str = 'ue * (-idd*v2*sin(a2) - iqq*v2*cos(a2))'
+
+ self.v2.e_str = 'ue * (idd*v2*cos(a2) - iqq*v2*sin(a2))'
+
+ def v_numeric(self, **kwargs):
+ """
+ Disable phasor lines that have been replaced by DP lines.
+ """
+
+ mask_idx = [self.line.v[i] for i in range(self.n) if self.u.v[i] == 1]
+ self.system.groups['ACLine'].set(src='u', idx=mask_idx, attr='v', value=0)

andes/routines/tds.py

@@ -813,7 +813,7 @@ def do_switch(self):
 
  # check system connectivity after a switching
  if ret is True and self.config.check_conn == 1:
- system.connectivity(info=False)
+ system.connectivity(info=False, routine='tds')
 
  return ret
 

andes/system.py

@@ -1196,7 +1196,7 @@ def vars_to_models(self):
  if var.n > 0:
  var.v[:] = self.dae.x[var.a]
 
- def connectivity(self, info=True):
+ def connectivity(self, info=True, routine='pflow'):
  """
  Perform connectivity check for system.
 
@@ -1225,6 +1225,11 @@ def connectivity(self, info=True):
  to.extend(self.Line.a2.a.tolist())
  u.extend(self.Line.u.v.tolist())
 
+ if routine == 'tds':
+ fr.extend(self.DPLine.a1.a.tolist())
+ to.extend(self.DPLine.a2.a.tolist())
+ u.extend(self.DPLine.u.v.tolist())
+
  # collect from Jumper
  fr.extend(self.Jumper.a1.a.tolist())
  to.extend(self.Jumper.a2.a.tolist())

docs/source/release-notes.rst

@@ -9,6 +9,12 @@ The APIs before v3.0.0 are in beta and may change without prior notice.
 v1.9 Notes
 ==========
 
+v1.9.3 (2024-04-XX)
+-------------------
+- In symbolic processor, most variables are assumed to be real, except some
+ services that are specified as complex. This will allow generating simplified
+ expressions.
+
 v1.9.2 (2024-03-25)
 -------------------
 - Improve PSS/E parser for the `wmod` field in the static generator