respice 0.3.6

Flexible and easy to use non-linear transient electric circuit simulator.

Flexible and easy to use non-linear transient electric circuit simulator.

Install

pip3 install respice

Usage

Create your circuit and simulate it!

from respice.analysis import Circuit
from respice.components import CurrentSourceDC, R, C

# Define components for our circuit.
R1 = R(100)
R2 = R(200)
C3 = C(10e-6)
R4 = R(200)
R5 = R(100)
Isrc = CurrentSourceDC(0.1)

# Construct the circuit. All circuits are just
# Digraphs allowing multiple edges. On each edge
# one component.
wheatstone_bridge = Circuit()
wheatstone_bridge.add(R1, 0, 1)
wheatstone_bridge.add(R2, 0, 2)
wheatstone_bridge.add(C3, 1, 2)
wheatstone_bridge.add(R4, 1, 3)
wheatstone_bridge.add(R5, 2, 3)
wheatstone_bridge.add(Isrc, 3, 0)

# Simulate! From t1 = 0ms to t2 = 5ms with 100 steps.
simulation = wheatstone_bridge.simulate(0, 0.005, 100)

The results are stored in the returned object and can be easily accessed via simulation.v(component), simulation.i(component) or simulation.p(component). Those contain the voltages, currents and powers respectively for each time step as a list. The time steps can be accessed with simulation.t().

All simulations are asynchronous. Accessing results early may only give partial results. Use simulation.wait() to wait until the result is ready.

Circuits are graphs (like mentioned in the snippet). More precisely, a Digraph allowing multiple edges from and to the same nodes. Each edge represents a single two-terminal component (like a resistor). Those are connected to nodes, which are simple joints that can be arbitrarly named or identified (for example numbers like in the example above, but strings, or even other objects are possible if necessary).

Example Plotting

Results can be immediately plotted. For plotting, plotly is required.

from respice.examples import RC

# Define an example RC circuit. The package respice.examples
# contains a few!
rc = RC(100, 100e-6, 10)  # 100Ohm, 100uF, 10V
simulation = rc.simulate(0, 0.1, 100)
simulation.plot()

The plot function will wait automatically until the result is finished. Live-plotting is not supported yet.

Supports

• MNA - Modified Nodal Analysis

  This is the algorithm employed by this software. So it’s easily possible to handle voltages as well as currents.

• Transient steady-state analysis

  Find quickly periodic steady-state solutions of a circuit that appear when the circuit transients have settled.

• Multi-terminal components

  Components with more than just two terminals can be handled easily. Whether each sub-branch of them is a current- or voltage-branch, or whether they are current- or voltage-driven.

• Mutual coupling

  Usually required by multi-terminal components, mutual coupling is easily implementable. Each sub-branch in a component is automatically receiving the voltages and currents of all other branches comprising the component.

The Future

• Incorporating interfaces for heat-dynamics

  Components are often depending on operation temperature. This can highly change behaviour of the whole circuit. Implementing new simulation variables like current component temperature could allow to simulate temperature influence. This is especially useful for safety analysis and estimating the maximum critical operation point.

  This might even serve as a general concept to introduce even more parameters besides heat that influence component performance and behaviour.

• Enhancing components (maybe heat-dynamics coupled) to simulate breakage

  Components can break. Either due to age, or because currents where to high. Consecutively extending components to contain “breakage-states” (so state variables that tell you if the element is destroyed or not) could improve analysis for circuits operating near critical operation points.