It has been another week of skimming through different articles and books to fill my brain with inverter, grid, and solar technology. Although this background phase will be the driest of my project, I am thoroughly enjoying every moment of it!
This week I have studied specific types of inverters, rather than just a general power inverter, and analyzed them for their strengths and weaknesses. Of the many that inverters that exist and are used, I will be focused on solar inverters. Although the name suggests that these are the only inverters used for to convert solar energy to AC, there are many other inverters that preform this function; however, soalr inverters are the most popular/useful. In this post, I will be focusing on a specific kind of solar inverters, grid tie inverters (GTI).
The GTI is one of the only, and most efficient, methods of connecting to the power grid. To do so, the GTI synchronizes with the frequencies of the grid using an oscillator and limits its output voltage with that of the grid's voltage. The more advanced GTI's have fixed unity power factors (output voltage and current are perfectly synced). The downside to the modern GTI's is that they are almost too perfect! Shocking, right? The problem with perfectly syncing the voltage with the current is that we get rid of reactive power (the byproduct of current and voltage being out of phase). Usually, we supply the grid with this reactive power; however, by getting rid of it, we now create too much power for the grid to handle at peak times (i.e., noon) and we break our aforementioned limitations. One other downfall to using a grid tie inverter is that it must be connected to the main power grid. In other words, a grid tie inverter cannot be used to convert DC solar energy to AC electrical energy to power an appliance directly; it must first be connected to the grid, which can then power the appliance. This indirect route is less efficient as it provides more time and space for friction losses.
Finally, grid tie inverters, like many, can use different kinds of transformers, or none at all. This differentiation may seem insignificant; however, getting rid of a transformer not only reduces the production cost of an inverter, it also makes the inverter more efficient. Many European countries have taken the first step towards smarter inverters and primarily use transformerless inverters. The U.S.'s reluctance to follow Europe stems from a safety concern: would the lack of a transformer lead to faulty DC energy to leak into the AC side. However, since 2005, the NFPA's NEC has allowed the use of transformerless inverters and regulations have even been amended in order to encourage their use. Hopefully, the U.S.'s reluctance eventually fades as they observe the lack of danger that transformerless inverters pose.
That's it for this week! Next week I will begin working at Intel itself and cannot wait to start my journey! I will also be finishing my background phase of my project and entering phase 2 by the end of the week! See you then and thanks for stopping by!
Signing off,
Kayvon Tadj
Finally, grid tie inverters, like many, can use different kinds of transformers, or none at all. This differentiation may seem insignificant; however, getting rid of a transformer not only reduces the production cost of an inverter, it also makes the inverter more efficient. Many European countries have taken the first step towards smarter inverters and primarily use transformerless inverters. The U.S.'s reluctance to follow Europe stems from a safety concern: would the lack of a transformer lead to faulty DC energy to leak into the AC side. However, since 2005, the NFPA's NEC has allowed the use of transformerless inverters and regulations have even been amended in order to encourage their use. Hopefully, the U.S.'s reluctance eventually fades as they observe the lack of danger that transformerless inverters pose.
That's it for this week! Next week I will begin working at Intel itself and cannot wait to start my journey! I will also be finishing my background phase of my project and entering phase 2 by the end of the week! See you then and thanks for stopping by!
Signing off,
Kayvon Tadj
Glad the research seems to be going well. Have fun at Intel. Will you be working on a specific type of inverter there or a wider variety?
ReplyDeleteIt sounds like you're finding your research interesting so far! What did you mean about reactive power? Are GTIs just getting too efficient for the systems they're attached to?
ReplyDeleteFascinating second week Kayvon! After the 2005 decision, has the US implemented the GTI anywhere yet?
ReplyDeleteThis is so interesting! It sounds like your learning a lot. I can't wait to see what else you will learn at Intel next week!
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