A Python-based circuit simulation program that implements both Modified Nodal Analysis (MNA) for DC analysis and Differential Algebraic Equations (DAE) for transient analysis.
PlasmaSpice is a circuit simulation tool that can handle both DC and transient analysis of electronic circuits. It uses MNA for DC analysis and DAE for transient analysis, with support for various circuit elements.
- DC Analysis using Modified Nodal Analysis (MNA)
- Transient Analysis using Differential Algebraic Equations (DAE)
- Automatic matrix construction for both analysis types
- Resistors (R)
- Capacitors (C)
- Inductors (L)
- Voltage Sources (V)
- Current Sources (I)
- DC Analysis (MNA):
[G B] [v] = [i]
[C D] [j] [e]
- Transient Analysis (DAE):
A * dx/dt = B * x + C
- Automatic identification of algebraic and differential variables
- Consistent initial condition calculation through DC analysis
- Variable step-size integration using IDA solver
- Robust numerical solver with configurable tolerances
plasmaSpice/
├── __init__.py
├── core/
│ ├── __init__.py
│ ├── circuit.py # Main circuit class
│ ├── elements.py # Circuit elements
│ └── dae_solver.py # DAE solver implementation
│
tests/
├── test_dae_solver.py # DAE solver tests
├── test_dae_system.py # DAE system tests
├── test_elements.py # Component tests
├── test_voltage_divider.py # Basic circuit tests
└── test_outputs/ # Simulation results
├── auto_dae_solution.txt
├── solution_data.txt
├── solution_data_example.txt
└── *.png # Response plots
Each circuit element contributes to the system matrices through its stamp (DC) and stamp_dae (transient) methods:
class Component:
def stamp(self, matrix, vector, node_map, vsrc_map):
"""Contribute to MNA matrix for DC analysis"""
pass
def stamp_dae(self, A, B, C, node_map, vsrc_map):
"""Contribute to DAE system matrices for transient analysis"""
passThe state vector is organized as:
x = [v1,...,vn, iV1,...,iVm, iL1,...,iLk]
where:
- v1 to vn: node voltages
- iV1 to iVm: voltage source currents
- iL1 to iLk: inductor currents
The DAE solver supports various configuration options:
solver = DAESolver({
'atol': 1e-6, # Absolute tolerance
'rtol': 1e-3, # Relative tolerance
'maxsteps': 10000, # Maximum steps
'inith': 1e-14, # Initial step size
'suppress_alg': True, # Suppress algebraic warnings
'algvar': algvar_list # Variable type indicators
})from plasmaSpice.core import Circuit
from plasmaSpice.core.elements import VoltageSource, Resistor, Capacitor, Inductor
# Create circuit
ckt = Circuit()
# Add elements
ckt.add_element(VoltageSource("V1", 1, 0, 500.0))
ckt.add_element(Resistor("R1", 1, 2, 50))
ckt.add_element(Capacitor("Cm1", 2, 0, 1.5e-10))
ckt.add_element(Capacitor("Cm2", 2, 3, 2e-10))
ckt.add_element(Inductor("Lm", 3, 4, 4.3e-6))
# DC analysis
dc_result = ckt.solve_dc()
# Transient analysis
t_span = (0, 1e-6) # 1 microsecond
transient_result = ckt.solve_dae(t_span)
Complex RLC circuit showing voltage and current responses with oscillations.
- numpy: Matrix operations
- Assimulo: DAE solver (IDA)
- matplotlib: Plotting results
To run all tests:
python -m unittest discover testsTo run a specific test:
python -m unittest tests/test_dae_system.pyThe simulation generates:
- PNG files: Visualization of circuit responses
- TXT files: Raw numerical data for analysis
- solution_data.txt: Basic solution data
- auto_dae_solution.txt: Detailed DAE solution data
MIT License