## A simple yet powerful power flow solver accessible through a Python API

```				```
# Create two buses
source_bus = Bus(id="sb", phases="abcn")

# Define the reference of potentials to be the neutral of the source bus
ground = Ground(id="gnd")
pref = PotentialRef(id="pref", element=ground)  # Fix the potential of the ground at 0 V
ground.connect(source_bus, phase="n")

# Create a LV source at the first bus
un = 400 / np.sqrt(3)  # Volts (phase-to-neutral because the source is connected to the neutral)
source_voltages = Q_([un, un * np.exp(-2j * np.pi / 3), un * np.exp(2j * np.pi / 3)], "V")
vs = VoltageSource(id="vs", bus=source_bus, phases="abcn", voltages=source_voltages)

# Add a LV line between the source bus and the load bus
lp = LineParameters("lp", z_line=Q_((0.1 + 0.0j) * np.eye(4, dtype=complex), "ohm/km"))  # R = 0.1 Ohm/km, X = 0
line = Line(id="line", bus1=source_bus, bus2=load_bus, phases="abcn", parameters=lp, length=Q_(2.0, "km"))

# Create the electrical network
en = ElectricalNetwork.from_element(source_bus)
# >>> <ElectricalNetwork: 2 buses, 1 branch, 1 load, 1 source, 1 ground, 1 potential ref>

# >>> 2 iterations
```
```

## In need of a trustful load flow solver? We'll share ours!

Roseau Load Flow was originally developed for Roseau Technologies’ internal use, but good things are meant to be shared. That’s why we made a first public release of the solver in February 2023. Give it a try!

## Static power network analysis

Standard load flow computation and other applications such as fault current calculation

## Full support of meshed networks, multiple phases and grid imbalance

• Models of polyphase lines and transformers

#### Accessible from a Python API

• Human-readable, object-oriented modeling of the grid
• Scripting for process automation
• Easy integration with other software

```				```
# Let's use a pq(u) control injecting reactive power
# before reducing active power

fp = FlexibleParameter.pq_u_production(
up_up=Q_(240, "V"),
up_max=250, # Volt by default
uq_min=Q_(200, "V"),
uq_down=Q_(210, "V"),
uq_up=Q_(235, "V"),
uq_max=Q_(240, "V"),
s_max=Q_(4, "kVA")
)

phases="abcn",
powers=Q_([-3.5, 0, 0], "kVA"),
flexible_params=[
fp,
FlexibleParameter.constant(),
FlexibleParameter.constant()
],
)

# >>> 2 iterations

# Get the results
# >>> [242.72 232.62 233.68] <Units('volt')>

```
```

## Fully generic modeling of loads and generators

• Flexible generators can be finely modeled with P(U) and/or Q(U) curves and apparent power limits
• Generic design that makes it easy to add any new type of voltage-dependent loads/generators in the future

## Simplicity and user-friendliness

• Straightforward, transparent mathematical models: no transformation of the natural model, such as eliminating the neutral wire (Kron’s reduction) or changing the units to “p.u.”
• Support for physical units to avoid errors (e.g. confusing W and kW) and let everyone work with their preferred units (metric / imperial)
```				```
# Results per object
# >>> [0.22193 0.22193 0.22193] <Unit('kilovolt')>

abs(line.res_currents[0])
# >>> [45.06, 45.06, 45.06,  0.  ] <Unit('ampere')>

# Global Results (data frame)
en.res_buses_voltages.transform([np.abs, np.angle]) # in V
# >>>                         voltage
# >>>                absolute         angle
# >>> bus_id phase
# >>> sb     an     230.940108  6.671617e-37
# >>>        bn     230.940108 -2.094395e+00
# >>>        cn     230.940108  2.094395e+00
# >>> lb     an     221.928183  2.599590e-22
# >>>        bn     221.928183 -2.094395e+00
# >>>        cn     221.928183  2.094395e+00

en.res_loads # in A, VA and V
# >>>                 current         power       potential
# >>> load	a	  45.06+0.00j   10000.00-0.00j  221.93-0.00j
# >>>       b    -22.53-39.02j  10000.00-0.00j -110.96-192.20j
# >>>       c    -22.53+39.02j  10000.00+0.00j -110.96+192.20j
# >>>       n	 -0.00+0.00j	 -0.00+0.00j      0.00-0.00j

en.res_line_losses # in VA
# >>>               series_losses shunt_losses	total_losses
# >>> line_id phase
# >>> line	   a	406.07+0.00j  0.00+0.00j	406.07+0.00j
# >>>          b	406.07+0.00j  0.00+0.00j	406.07+0.00j
# >>>          c    406.07+0.00j  0.00+0.00j	406.07+0.00j
# >>>          n      0.00+0.00j  0.00+0.00j    0.00+0.00j

```
```

## Samples of grid data included

• Get started with ease thanks to the 20 Low Voltage and 20 Medium Voltage feeders included in Roseau Load Flow. Need to go further? We can provide you with the electrical model of the French distribution network, with tens of thousands of MV and LV feeders already modelled.
• Each network is given with its summer and winter load point.