What is IEEE 1547-2018 and how is it relevant to utility scale solar projects? – Ask an Expert

In the Ask an Expert series, HeatSpring instructors and industry thought leaders answer a question on the minds of the HeatSpring community. We are joined by Tim Taylor, instructor of the Interconnection of Utility-Scale Solar to Distribution course. Tim discusses the high-level basics of IEEE Standard 1547-2018 – Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces. To learn more about this standard affecting utility scale solar and distributed energy resources (DER), you can either watch the video or read the transcript below.

Hey everyone. This is Tim Taylor with Electric Distribution Academy. I’m also an instructor on HeatSpring, and I just finished a free webinar around distribution system voltages and the impacts that utility scale solar can have on those voltages. And 1547, which is an IEEE standard, has a lot to say about voltages.

And I thought I would go ahead and do a short video on what IEEE 1547-2018 is all about. IEEE stands for the Institute of Electrical and Electronics Engineers, and it develops and maintains hundreds of standards, including many that are followed by electric utilities. 

Now standard 1547 was initially developed in 2003 and it was updated in 2018 because of the large number of DER, including solar PV that are now interconnecting to the electric grid.

1547 only applies to distribution and not transmission. There are not voltage levels that are defined in 1547, but it varies according to the utility or coop or muni that you’re working in. 

With respect to transmission, there is a new standard. That was just released and it is IEEE 2800 and it was just released in May of 2022.

1547 applies to all types of DER, solar PV, or fuel cells or synchronous machines, what have you, and there are some exemptions for emergency and a standby generation, and in terms of the different requirements that those types of generators have to follow. There is no size limit. There’s no size constraints on what 1547 applies to, and it is focused on individual DER installations rather than the system considerations. For example, for how much DER generation can individual feeders accommodate, that is not included in 1547. It is technology neutral. So that it’s focused on capabilities and performance.

It does contain requirements, but it’s not a specification or an application guide. It is voluntary, but there are many jurisdictions, including state regulators and other bodies that are starting to make it mandatory for distribution organizations to follow. So you’ll see it more and more often in different locations, particularly around the US, but it could be adopted in other countries as well.

The major topics in 1547 include abnormal system events and this is particularly important for the bulk power system, meaning the large scale generation and transmission system. And a DER needs to have capabilities to ride through these events and those capabilities are specified particularly with respect to a voltage and a frequency.

Voltage control and regulation pertains to a voltage control on distribution. And a DER has had increasing impacts on distribution system voltage. 1547 specifies at different capabilities that DER, including solar PV, needs  to have with respect to helping with the voltage control and regulation.

A frequency droop is related to real power output as a function of frequency and the variation of the DER and its ability to supply real power, either increased or decreased, depending upon whether the frequency has increased or decreased outside a certain bandwidth. 

Unintentional islanding – DER must be able to detect and cease to energize any unintentional islanding islands that are formed, meaning that islands that are created by the distribution feeder or portion of a feeder separating from a substation and the bulk power system. 

Power quality – the DER has to have capabilities with respect to topics such as DC current injections, voltage fluctuations, current harmonics injections into the system system, grounding and temporary overvoltage.

DER must have the capability to provide support to the system and supply effective grounding so that overvoltages, like ground fault overvoltages, load rejection overvoltages, are not contributed by DER, except within permissible limits as specified in the standard.

And then there’s some communication interoperability that the DER needs to provide these communication interfaces and it needs to supply one of three protocols, which are a DNP3, SunSpec Modbus, or IEEE 2030.5. 

You can go to HeatSpring.com for more information, including these courses that are hosted by HeatSpring. HeatSpring hosts a lot of different courses with respect to the emerging green energy economy, whether it be DER and solar PV or batteries or microgrids or smart buildings, – many different topics up there.

Or you can go to my website, which is ElectricDistribution.net. Thanks for watching!