# roseau LOAD FLOW

# roseau LOAD FLOW

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

` ````
```# Create two buses
source_bus = Bus(id="sb", phases="abcn")
load_bus = Bus(id="lb", 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 load at the second bus
load = PowerLoad(id="load", bus=load_bus, phases="abcn", powers=Q_([10 + 0j, 10 + 0j, 10 + 0j], "kVA"))
# 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)
# >>>
# Solve the load flow
activate_license(key="")
en.solve_load_flow()
# >>> 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**-
Solves for

**unbalanced loading conditions**and**unbalanced faults**

#### 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")
)
flexible_load = PowerLoad(
id="load",
bus=load_bus,
phases="abcn",
powers=Q_([-3.5, 0, 0], "kVA"),
flexible_params=[
fp,
FlexibleParameter.constant(),
FlexibleParameter.constant()
],
)
# Solve the load flow
en.solve_load_flow()
# >>> 2 iterations
# Get the results
abs(load_bus.res_voltages)
# >>> [242.72 232.62 233.68]

## Fully generic modeling of loads and generators

- Library of
**standard loads**(constant active/reactive loads, impedance loads…) - 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

**Synthetic**,**well-documented****Python API**

- 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
abs(load_bus.res_voltages).to("kV")
# >>> [0.22193 0.22193 0.22193]
abs(line.res_currents[0])
# >>> [45.06, 45.06, 45.06, 0. ]
# 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_id phase
# >>> 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**. - More info
**here**!

## Get your Roseau Load Flow licence

A** free, public licence key** is available for calculations on networks with up to ten nodes. Want to go further? Contact us to obtain your personal licence key.

Students and teachers: enter your academic email address below and you will receive **your free licence key**.

## Installing and using Roseau Load Flow

Now that you’ve received your login details, let’s get started: