Work summary of week 1 and before

Getting the topic of this experiment, I, Liang Tang and my teammate Chunyang Song started to think about the topic together with searching for the related information about the topic. The topic of our year 2 project is "Online measurement of the discharge power in a DBD plasma reactor".

Before meeting our project tutor, we had already gained much knowledge about the topic by searching on the internet. The information we got related to the topic can be found via the following links:
http://en.wikipedia.org/wiki/Dielectric_barrier_discharge
http://hal.archives-ouvertes.fr/docs/00/25/55/61/PDF/ajp-jp4199707C405.pdf

Then on the 11 of December we first met our project tutor, Dr. Tu, and learned that our topic is about using the software Matlab to calculate the discharge power in a typical DBD(dielectric-barrier discharge) plasma reactor. Moreover, we got a few files from Dr. Tu of the background knowledge related to the DBD plasma reactor and some conventional rules of calculating the discharge power.

Before the experiment period in week 1, we have been quite familiar with the DBD plasma reactor and the method of calculating the discharge power. Then on last Friday, which is the experiment day, we met our project tutor again and got the input data of the project.

According to the information, to calculate the discharge power of a DBD plasma reactor, the circuit needs to be connected as follows:

Then with the voltage across the plasma reactor and the instantaneous charge on the capacitor, the discharge power of the plasma reactor can be calculated. Luckily, the applied voltage, the capacitor valtage and the capacitance are known value to this experiment, and the problem that the experimenters need to face is how to handle the data so as to get the value of the discharge power.

Firstly, we drawed the waveform of the appiled voltage and capacitor voltage shown as below.

  
With the input data given, we eventually got the Lissajous figure using Matlab, as shown in the following figure.

This is ought to be the first step of calculating the discharge power of a DBD plasma reactor according to the information we gathered.

However, as there were too many groups of data(approximately 200000 groups), we did not know how to calculate the frequency of the given signal, which stopped us from going further.

After the experiment time, we decided to review the information we had and try to find out the method of calculating the frequency of the voltage signal using Matlab.