Por Amor al Arte

The electricity that is produced from coal plants, wind turbines, or solar panels is rarely at the necessary voltage and current that is practical for our uses and electricity needs. Consequently, it is necessary to use a converter, a device that converts electricity from one form to another. Additionally, energy sources such as solar panels are not always constant because the amount of available sunlight is always changing. The electricity being drawn from the load is also variable because our electricity needs are never constant. As a result, there are two variables in this system: the source and the load, or in other words, the input and the output. For these reasons, it is necessary to design converters and controllers for the converter that can account for these variables and changes in needs. Converters use capacitors and inductors to store energy, but this creates problems such as voltage ripple which is wasted power that generates noise. Electrical engineers and physicists have studied many different types of converters that use capacitors, inductors, transistors, switches, and other components in clever ways to properly handle changing variables and eliminate undesirable effects such as voltage ripple. One such converter is the quadratic gain converter which uses two capacitors and two inductors to amplify the input voltage by a factor of D(1-D)2, where D is the duty cycle of the circuit.

My research project consisted of three parts: the creation of a controller for the converter, the design of the printed circuit board (PCB), and the generation of a variable pulse width modulation (PWM) to change the duty cycle of the circuit. I first used LabVIEW to simulate the circuit so that I could create a PID controller for the converter. The point of the controller is to control the duty cycle of the circuit to track a variable to achieve a desired output in spite of noise, disturbances, and other changes in the system. I used the output voltage as well as the current through one of the inductors as reference variables to control the converter. Next, I designed circuits for the converter, driver, and sensors using KiCad. Once the PCBs were printed, I assembled, searched for, and soldered the necessary components. Finally, I put together a breadboard circuit to generate a variable PWM signal to control the output of the converter. This PWM was directly variable from a LabVIEW program that I also made. The sensors on the circuit of the converter and the variable PWM breadboard circuit can be used together with the LabVIEW controller to convert the input voltage to any desired output voltage regardless of any changes in the source or the load. In the future, researches working on various controllers for converters can use my circuit to run tests and learn more about which component values are more appropriate for different applications.

 

 

I spent my last week in the lab working on connecting the circuits for the sensors and the PWM to the circuit of the converter to be used with LabVIEW. I also collected data of the different voltages and currents passing through each of the components in the circuit at different duty cycles. This was exciting because the professor said that this data would be published in the paper that they are writing about the converter for a scientific journal.

Reflecting on these past few months, I feel extremely grateful for all of the great opportunities and learning experiences I had. I learned how to use LabVIEW to design controllers, and I learned how to decide which variables and gains should be used to successfully control a system. I learned how to use devices from National Instruments to read, generate, and manipulate signals and data from the real world. I learned about the different types of circuits that can be used to convert electricity, and I learned which ones are useful for varying applications and circumstances (like voltage ripple mitigation). I learned how to use KiCad to make my own circuits, and I learned the proper techniques of circuit design (I learned that designing a complex circuit is not as easy as just connecting all of the components like we do in physics class at school). I learned how to wind a wire into a coil to make an inductor (this process involves two people standing 20 feet apart and a power drill). I learned how to choose which components should be used in a circuit and how to figure out what each pin does and corresponds to. I learned how to solder (really, really well), and I learned clever soldering techniques and tricks. I learned how to strip wires with my teeth. I learned how to test circuits, and how to determine which parts of the circuit aren’t working. This might sound cheesy, but most importantly, I learned how to learn. I learned how to figure things out by reading the documentation, watching Youtube videos, and asking the right questions. I was talking with my coworker, José, about the difference between research and regular internships, and he mentioned a Spanish expression which I really liked: “por amor al arte.” This literally translates to “for the love of art,” but it is used to describe doing something just for the sake of doing that thing. I had never done such intensive research in my life before, but I really enjoyed the experience of fully dedicating myself to a specific problem just for the sake of learning more about the topic of interest. Sometimes we would stay in the lab until 8pm just to finish something because we wanted to see the results. The difference between research and industry is that people do research purely for the sake of learning and expanding human knowledge rather than to make a profit. People do research “por amor al arte.”  

Aside from learning a lot about power electronics and electrical engineering, I also learned about another culture and country, and I think this was the most valuable part of my internship. I learned where to find the best tacos in Monterrey. I learned that even though I can drink a liter of horchata in one sitting, I probably shouldn’t do it. I learned more Mexican slang than I will ever need. I learned about Aztec history and Mexican politics and Zapatistas. I learned how to use salt and rubbing alcohol to get rid of a spirit living in my apartment. I learned how to write songs and play sports in another language. I learned how to dance salsa, and I learned the lyrics to the best reggaeton songs of the summer. As someone who is still not fluent in the Spanish language, I learned how to become an excellent listener. I learned that Mexico is one of the most beautiful countries I have ever visited. I learned how to make friends in a new country and how to adapt to a new culture, and these are all things I could never learn by just going to school.

For anyone who actually read my blog and made it this far, I will let you in on a little secret. When I first arrived in Monterrey, I spent my first week here being absolutely miserable. I was looking for flights home because I didn’t know anyone, I was confused at work, I couldn’t go anywhere without having a car, and I didn’t think I would ever be able to feel at home in Mexico. However, feeling this isolated and lonely forced me to go out to meet people and see things. I never would have discovered so many new places, dishes, songs, people, colors, etc. if I had stayed in Berkeley this summer. I want to thank all of my coworkers, teammates, roommates, and friends in Mexico for making these few months so special. This summer has been amazing, and I am so happy that I had the opportunity to work in Mexico. México, te voy a extrañar. I’ll be back soon!