Category Archives: Photovoltaic Systems and Distributed Generation

Discussions of PV systems and other forms of DG applied at 69 kV or lower voltages.

Flicker Trouble Ahead for Solar PV Inverters?

A small, slow-moving cloud will only affect a few panels at a time. The worst effect comes from large, fast-moving clouds that cover many panels nearly simultaneously, and then subsequently uncover them with the same speed. For these conditions, multiple inverters will respond to the same solar coverage effect, which results in the most severe levels of flicker. Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs | Tagged , , , , , , , , , , , , , , , , | Leave a comment

Integrating Solar PV Power with Existing Distribution Circuits; Part 2

(This Blog is a continuation of an ongoing series on integrating inverter-based solar photovoltaic generation with existing electric distribution circuits.  Link to Part 1) Solar PV (shorthand for photovoltaic) generation is growing in support and implementation in part because of a supportive … Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs | Tagged , , , , , , , , , , , , , , , , , | 1 Comment

Harmonics Limit Amount of PV on a Distribution Circuit

Harmonics is a very specialized and not widely understood topic in the electric power field which can become a major issue when inverter-based photovoltaic (“PV”) generators, (popularly referred to as solar power), are added to existing distribution circuits.  This Blog … Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs | Tagged , , , , , , , , , , | Leave a comment

Banking on grounding of solar and wind farms

One more item to add to the list of technical items to consider when interconnecting solar and wind farms is grounding.  The grounding issue often appears when (a) integrating solar power inverters or wind turbines to existing distribution circuits, or … Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs, Wind Power Integration | Tagged , , , , , , , , , , , , , , , , , , , , | Leave a comment

Solar Photovoltaic Inverters and Ride-Through Capability

In study after study, we (Pterra) are encountering this seemingly mounting issue of ride-through capability in solar photovoltaic (“PV”) inverters. For now, the matter is isolated to frequency ride-through in small grids such as those that may be found in the Hawaiian islands. However, there is potential for this to be critical in even larger systems as the number of inverter-based PV arrays interconnecting to existing distribution and transmission systems increases. Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs | Tagged , , , , , , , , | Leave a comment

Can wind turbines and solar inverters contribute to frequency control?

Renewable energy resources such as solar and wind, produce power in a manner that generally does not contribute to frequency control of interconnected power systems. However, both wind turbines and solar inverters have the important characteristic of fast, programmable controls. The question then comes up: Is it possible for these power sources to participate in frequency control response of interconnections? Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs, Wind Power Integration | Tagged , , , , , , , , , , , , , | Leave a comment

Integrating Solar PV Power with Existing Distribution Circuits; Part 1

A wave of new solar photovoltaic (“PV”) installations for power generation is hitting many distribution circuits around the country.  These installations are typically in the range of 10-2000 kW and comprise of a set of solar PV arrays or trays … Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs | Tagged , , , , , , , , , , , , , , , , , , , | Leave a comment

Transient Overvoltages in Wind Farms, and a Case Study

In various Blogs on this site, we have talked about unique technical issues associated with integrating wind farms into existing grids.  This Blog now addresses the matter of transient overvoltages, or TOV, specifically with respect to potential risks to customers … Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs, Wind Power Integration | Tagged , , , , , , , , , , , , , , , , , | Leave a comment

Transmission bases for sizing wind and solar projects

Unlike base load power plants such as nuclear and some coal plants which operate near full capacity for days at a time, solar photovoltaic (PV) and wind farms are variable resources whose output is dependent on the minute-by-minute change in … Continue reading

Posted in Photovoltaic Systems and Distributed Generation, Tech Blogs, Wind Power Integration | Tagged , , , , , , , , , , , , , | 1 Comment

Integrating Solar Photovoltaics and Other Renewables in Distribution Systems

Distributed generation (DG) has become a viable option and is gaining wider acceptance to utilities, customers, and independent power producers. While DG offers many advantages, the interconnecting utility typically requires a system impact study for interconnecting DG to the existing … Continue reading

Posted in Photovoltaic Systems and Distributed Generation | Tagged , , , , , , , , | Leave a comment