Introduction

The aim of this code is to repeat the simulation results according to the following article:

Bacelli, Giorgio & Ringwood, John & Iordanov, Petar. (2007). Impedance matching controller for an inductively coupled plasma chamber - L-type matching network automatic controller.. ICINCO 2007 - 4th International Conference on Informatics in Control, Automation and Robotics, Proceedings. 202-207.

This code sample is shared for the purpose of a recruitment process only. It has neither scientific nor practical value.

Details

By this exercise I've tried:

• to refresh knowledge on electrical engineering,

• to learn something about plasma power controllers,

• to prove general command of python by writing a sample code basing on the abovementioned article,

• to provide some tests cases using pytest,

• to show examples of using common libraries (numpy, matplotlib),

• to practice (complex-number) computations in python,

• to prove my expertise in PyCharm, venv, jupyter notebook and git.

Before committing to git

• all tests should pass

• update requirements.txt

• clean all jupyter notebook outputs

• update this README.md

• update the project structure below

Project structure

./
├── imc/
│ ├── coarse_tuner.py
│ ├── controller.py
│ ├── fine_tuner.py
│ ├── impedance_tuner.py
│ ├── matching_network.py
│ └── tests/
│     ├── test_coarse_tuner.py
│     ├── test_controller.py
│     ├── test_fine_tuner.py
│     ├── test_impedance_tuner.py
│     └── test_matching_network.py
├── main.py
└── notebook/
    └── reflection_function.ipynb

command: power_sample$ tree -F -P '*.py|*.ipynb' -I 'venv|jupyterenv|__pycache__|__init__.py|conftest.py'

How to run tests

Tests are written using the pytest framework.

in the terminal

(venv has to be activated)

py.test

or a single test suite (e.g.):

power_sample$ py.test imc/tests/test_impedance_tuner.py

in PyCharm

select the test configuration and press the ▶ button

(a single test suite can also be run by right-clicking on the test file)

How to set-up the virtual environment

for pycharm

python -m venv venv

source venv/bin/activate

pip install -r requirements.txt

deactivate

for jupyter notebook

cd notebook/

python -m venv jupyterenv

source jupyterenv/bin/activate

pip install -r requirements.txt

deactivate

cd ..

How to update requirements.txt

within a given virtual env

pip freeze > requirements.txt

and add it to git

How to run jupyter notebook

cd notebook/

source jupyterenv/bin/activate

jupyter notebook

deactivate

cd ..

TODO

matching_network.gamma()

• verify usages, it is used for both coarse and fine tuning
• check (4) against the formula from notebook exercises

coarse_tuner._trigger_impl()

• check whether it is triggered every fifth tick
• verify whether it is ok to take the gamma basing on the load capacitor, or a sensor simulator is needed

fine_tuner._trigger_impl()

• in my opinion the formula (4) from the article is valid only for a coarse tuning, but it is also used here

main()

• currently it does not correctly simulate the circuit from Fig. (8) in the article

Misc

How to use octave (e.g.)

octave:1> output_precision(8)
octave:2> omega = 2 * pi * 13.56e6
omega = 8.5199993e+07
octave:3> c = 150e-12
c = 1.5000000e-10
octave:4> term = i * omega * c
term =            0 + 0.012779999i
octave:5> z = 1 / term
z =           0 - 78.2472680i

How to push to git

git push --tags origin main

Experimental results from notebook

ZPL values that give something like Fig. 6 (coarse tuning, e.g.)

ZPL=(5.0, 109.0) min(|Γ|)=0.01 Cl=700pF Ct=125pF