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The Future of Distributed 

Generation and IEEE 1547

Robert Preus

Small Wind Conference

June 16, 2014

Stevens Point, Wisconsin

PR-5000-62239
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IEEE 1547 background

• Developed to facilitate connection of distributed 

generation (DG)

o Consensus based 

o Focused on safety and protecting power quality of 

grid from DG faults

o Based on premise that DG not significant penetration

o Incorporated into UL inverter standards.

• Since widely adapted, gave inverter makers one 

standard to work to

• Key foundational piece for the DG industry we 

have today.
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Context for starting IEEE 1547 in 1999

• DG is not significant power contributor on 

the grid

• DG should be prevented from causing a 

problem or safety hazard

o Anti-islanding is a prime focus

o DG must not cause power quality issues

o DG must disconnect if there is a grid system 

problem in power quality

o Fault ride through or power quality support is not 

allowed 
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Changing situation

• In some areas DG is a significant percentage of 

peak load on a feeder, or soon will be

o In Honolulu many distribution feeders hit 100% of 

minimum daytime load from PV.

• Germany has hit 34% of country wide load from 

PV. 

o Germany changing software for inverters greater than 

10 kW installed after 2005 on low-voltage feeders.

o This is to avoid sudden loss of large amount of PV 

power in a frequency event.
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New situation

• With high penetrations of DG a present or 

looming reality the role of DG changes. 

• Utilities cannot rely on conventional plants to 

provide all grid support services. 

• DG must participate in provision of grid 

support services. 
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New boundary issues

• When to help and how much?

o Will inverters provide grid support autonomously?

– Will that create oscillation and stability issues?

o Will inverters provide grid support on call? 

– How would that be managed?

o Will utilities pay for ancillary services and 

capacity?

– This is a key issue for storage, but will impact all DG.

– Could drive big changes in DG revenue landscape.
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What are new requirements in IEEE 1547?

• Low voltage ride-through (LVRT)

o Currently required for large wind plants

• Real and reactive power support 

• Will they be set:

o In the new IEEE 1547? 

o By the utility or by utility to DG provider contract?

o Dynamic response of network of DG.
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Islanding issues

• The capability of inverters to support 

frequency, voltage and power factor could 

make anti-islanding challenging.

o Will new approaches be required?

o What about microgrids that will intentionally 

island? 

o Key concern of utilities
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How significant is this change?

• Development and adaption of IEEE 1547 is one 

of the keys to DG industry developed to date.

• The new IEEE 1547 will be one key to how the 

DG future develops.

• Distributed wind will be part of this market. 

• Will we be ready to supply: 

o Reactive power support 

o Frequency support

o Low voltage ride through

o Response to frequency events?
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What does this mean for distributed wind

• The new IEEE 1547 does not require real and 

reactive power support and LVRT

• Utilities may require these grid support 

functions

o HECO already does

• What is the impact for distributed wind?

o Higher inverter costs possible

o More expensive development and testing

o PV leading the way. 
Robert Preus

Robert.Preus@nrel.gov