Matt Reno, a Georgia Tech student in Sandia’s Photovoltaic and Distributed Systems Dept.
Matthew Reno, a Sandian and an electrical engineering PhD candidate at the Georgia Institute of Technology, was given a Best Student Paper award for research reported in, “Impact of PV Variability and Ramping Events on Distribution Voltage Regulation Equipment” at the 40th Institute of Electrical and Electronics Engineers (IEEE) Photovoltaic Specialists Conference (PVSC) held in Denver, Colorado, on June 8–13, 2014.
As PV penetration increases, there is rising concern about the interaction between PV variability and electric grid distribution system voltage-regulation equipment. The impact to the grid depends on the PV variability’s frequency, magnitude, and timescale. Very fast PV power output ramps can cause voltage flicker and extreme voltages, due to their speed and magnitude, before voltage-regulation equipment can react to bring the voltage back into the grid’s design range. Additionally, frequent PV output fluctuations can create a large increase in the number of tap changes over time—prematurely wearing out the existing grid infrastructure.
On-load tap changer position as a function of PV output and electric grid distribution system feeder load.
Interconnection studies are required before proposed PV installations are allowed to connect to the grid. With a growing number of interconnection requests, a standardized method is needed to rapidly, efficiently manage the interconnection queues.
To increase interconnection study efficiency, the paper proposes two methods for screening potential PV systems for adverse PV-variability impacts on the grid’s distribution system without using time-series simulations. First, a technique to accurately characterize extreme feeder voltages due to high PV ramp rates is demonstrated using voltage-regulation equipment locking and expected extreme PV ramping scenarios. Another method is described to determine the potential impact of a PV system on on-load tap changer devices. The methodology is used to model the voltage-regulation equipment tap position throughout an entire year and to calculate the number of tap changes. Each of these methods aids in decreasing the complexity and length of time involved in screening potential PV interconnections.
The IEEE PVSC Best Student Paper Award recognizes outstanding work by students in each of the conference’s 12 technical areas. Winners are determined by
- Significance of Results: novelty of work, advancement of field, thoroughness of work, accuracy of analysis.
- Clarity of Presentation Material: Usefulness of written and graphical information, efficient use of graphics/figures to convey complex information, logical flow of results, aesthetics of presentation slides.
- Mastery of Topic: Knowledge of topic demonstrated in oral delivery and in answering questions.
- Oral Presentation: Organized summary of work is provided including the necessary background, description of approach, description of results, and conclusions; knowledgeable of presented research and its relation to the state of field; succinctness, efficient use of time.
In addition to judging the technical content of the student’s work, oral presentations and the student’s role in the work are assessed. One “Best Student Paper Award” is given out for each PVSC technical area. Matthew Reno’s award was in Area 11: PV Deployment.