As part of my Advanced Writing in the Technical Professions course, I was tasked with composing a series of papers about a chosen topic in my field of study; two of these documents are provided below. In this case, I decided to write about the issues stemming from excessive harmonic components in the United States’ electrical grid as a result of [theoretical] high solar penetration.
The non-linear behavior of the power electronic inverters used by solar installations to connect to the grid produces voltage and current harmonics on the devices’ output, and large-scale filtering solutions have the potential to either create damaging resonant conditions (i.e. passive filtering) or are quite expensive (i.e. active filtering). The presence of a significant level of harmonics within a power system can lead to inefficiencies and equipment damage due to overheating, as well as degraded operation of sensitive electronic components. Existing IEEE and IEC standards (e.g., IEEE 519 and IEEE 1547) may not sufficiently account for the possibility of large quantities of inverters (and similar harmonic-contributing equipment such as VFDs or UPSs) being connected to the grid—as is the case in a high solar penetration scenario. Therefore, additional research and possible standard/regulation modifications are required to better understand the circumstances necessary to create a problematic level of harmonics in the United States’ grid.
In the first document, “Adverse Harmonic Effects of High Renewable Energy Penetration on the United States’ Bulk Power System,” an initial inquiry is provided into the issue of excessive solar inverter harmonics for my instructor and interdisciplinary peers. A problem statement—essentially an extension of the aforementioned details—is given, in addition to a rhetorical analysis of a research paper written on the topic by scholars from the University of Queensland.
“Cleaning Clean Power” was written to propose a research-based solution for the problem described in the first document. Intended to be read by an audience knowledgeable of the fields of power engineering and/or power electronics, this paper delves deeper into the details surrounding harmonics and their effects on connected loads, and it provides an overview of the current status of research on the issue. The five-phase solution offered within involves extensive modeling of various sub-grids within each of the United States’ three AC interconnections, progressing in scale from individual utilities to entire interconnections, with the goal of performing harmonic analyses at each stage. At the completion of this study, experts would then have sufficient knowledge to assess the adequacy of existing harmonic injection limitation regulations.
Both documents are available for download below.