Actually allow var negative power

gridpath/project/operations/operational_types/gen_var.py

@@ -173,7 +173,9 @@ def add_model_components(
  | | :code:`GenVar_Max_Downward_Reserves_Constraint` |
  | | *Defined over*: :code:`GEN_VAR_OPR_TMPS` |
  | |
- | Downward reserves cannot exceed power provision. |
+ | Downward reserves cannot exceed power provision when the capacity |
+ | factor is non-negative (power is non-negative); otherwise they are set |
+ | to zero. |
  +-------------------------------------------------------------------------+
 
  """
@@ -203,7 +205,7 @@ def add_model_components(
  # Variables
  ###########################################################################
 
- m.GenVar_Provide_Power_MW = Var(m.GEN_VAR_OPR_TMPS, within=NonNegativeReals)
+ m.GenVar_Provide_Power_MW = Var(m.GEN_VAR_OPR_TMPS, within=Reals)
  m.GenVar_Scheduled_Curtailment_MW = Var(m.GEN_VAR_OPR_TMPS, within=NonNegativeReals)
 
  # Expressions
@@ -317,7 +319,7 @@ def max_power_rule(mod, g, tmp):
  **Constraint Name**: GenVar_Max_Power_Constraint
  **Enforced Over**: GEN_VAR_OPR_TMPS
 
- Power provision plus upward services cannot exceed available power, which
+ Power provision plus curtailment cannot exceed available power, which
  is equal to the available capacity multiplied by the capacity factor.
  """
  return (
@@ -346,10 +348,13 @@ def max_downward_reserves_rule(mod, g, tmp):
 
  Downward reserves can't exceed power provision.
  """
- return (
- mod.GenVar_Provide_Power_MW[g, tmp] - mod.GenVar_Downwards_Reserves_MW[g, tmp]
- >= 0
- )
+ if mod.gen_var_cap_factor[g, tmp] >= 0:
+ return (
+ mod.GenVar_Downwards_Reserves_MW[g, tmp]
+ <= mod.GenVar_Provide_Power_MW[g, tmp]
+ )
+ else:
+ return mod.GenVar_Downwards_Reserves_MW[g, tmp] == 0
 
 
 # Operational Type Methods