def test_empty_storage_min_flow():
model = Model()
storage = Storage(model, "storage", initial_volume=100, max_volume=100, num_inputs=1, num_outputs=0)
otpt = Output(model, "output", min_flow=75)
storage.connect(otpt)
model.check()
model.step()
with pytest.raises(RuntimeError):
model.step()
def test_reservoir_circle():
"""
Issue #140. A model with a circular route, from a reservoir Input back
around to it's own Output.
Demand
^
|
Reservoir <- Pumping
| ^
v |
Compensation |
| |
v |
Catchment -> River 1 -> River 2 ----> MRFA -> Waste
| ^
|---> MRFB ----|
"""
model = Model()
catchment = Input(model, "catchment", max_flow=500, min_flow=500)
reservoir = Storage(model,
"reservoir",
max_volume=10000,
initial_volume=5000)
demand = Output(model, "demand", max_flow=50, cost=-100)
pumping_station = Link(model, "pumping station", max_flow=100, cost=-10)
river1 = Link(model, "river1")
river2 = Link(model, "river2")
compensation = Link(model, "compensation", cost=600)
mrfA = Link(model, "mrfA", cost=-500, max_flow=50)
mrfB = Link(model, "mrfB")
waste = Output(model, "waste")
catchment.connect(river1)
river1.connect(river2)
river2.connect(mrfA)
river2.connect(mrfB)
mrfA.connect(waste)
mrfB.connect(waste)
river2.connect(pumping_station)
pumping_station.connect(reservoir)
reservoir.connect(compensation)
compensation.connect(river1)
reservoir.connect(demand)
model.check()
model.setup()
# not limited by mrf, pump capacity is constraint
model.step()
assert_allclose(catchment.flow, 500)
assert_allclose(waste.flow, 400)
assert_allclose(compensation.flow, 0)
assert_allclose(pumping_station.flow, 100)
assert_allclose(demand.flow, 50)
# limited by mrf
catchment.min_flow = catchment.max_flow = 100
model.step()
assert_allclose(waste.flow, 50)
assert_allclose(compensation.flow, 0)
assert_allclose(pumping_station.flow, 50)
assert_allclose(demand.flow, 50)
# reservoir can support mrf, but doesn't need to
compensation.cost = 200
model.step()
assert_allclose(waste.flow, 50)
assert_allclose(compensation.flow, 0)
assert_allclose(pumping_station.flow, 50)
assert_allclose(demand.flow, 50)
# reservoir supporting mrf
catchment.min_flow = catchment.max_flow = 0
model.step()
assert_allclose(waste.flow, 50)
assert_allclose(compensation.flow, 50)
assert_allclose(pumping_station.flow, 0)
assert_allclose(demand.flow, 50)
