February 2004 • NREL/CP-560-35569 

Interconnection Testing of 

Distributed Resources 

Preprint 

B. Kroposki, T. Basso, and R. DeBlasio 

To be presented at the 2004 Power Engineering Society 

General Meeting 

Denver, Colorado 

June 7, 2004 

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Interconnection Testing of Distributed Resources 

Benjamin Kroposki, Senior Member, IEEE, Thomas Basso, Member, IEEE, 

and Richard DeBlasio, Senior Member, IEEE 

Abstract—With the publication of IEEE 1547-2003TM 

Standard for Interconnecting Distributed Resources With 

Electric Power Systems, the electric power industry has a need to 

develop tests and procedures to verify that interconnection 

equipment meets 1547 technical requirements. A new standard, 

IEEE P1547.1TM, is being written to give detailed tests and 

procedures for confirming that equipment meets the 

interconnection requirements. The National Renewable Energy 

Laboratory has been validating test procedures being developed 

as part of IEEE P1547.1. As work progresses on the validation of 

those procedures, information and test reports are passed on to 

the working group of IEEE P1547.1 for future revisions. 

Index Terms—Dispersed storage and generation, power 

distribution, power system testing, power system transients, 

synchronous generators, test equipment, test facilities. 

I. INTRODUCTION 

ECENT advancements in distributed resources (DR) have 

allowed for their increased use and integration into the 

electric power system (EPS). DR are generation and storage 

located at or near the point of use. Examples include 

photovoltaics, wind turbines, microturbines, fuel cells, and 

internal combustion engines. 

R 

When interconnected with the electric power system at or 

near load centers, these technologies can provide increased 

efficiency, availability, and reliability; better power quality; 

and a variety of economic and power system benefits. These 

benefits have created new interest in distributed power 

applications, which has led industry to call for standards that 

address the interconnection of DR. 

In response, the Institute of Electrical and Electronics 

Engineers (IEEE) approved a standard to help utilities use 

electricity from dispersed sources: IEEE 1547-2003 Standard 

for Interconnecting Distributed Resources With Electric 

Power Systems [1]. This standard established the technical 

requirements for interconnecting DR with EPSs. 

The 1547 standard focuses on the technical specifications 

for, and the testing of, the interconnection itself. It provides 

requirements relevant to the performance, operation, testing, 

safety, and maintenance of the interconnection. It covers 

general requirements, response to abnormal conditions, power 

This work was supported in part by the U.S. Department of Energy under 

Contract No. DE-AC36-99-GO10337. 

B. Kroposki is with the National Renewable Energy Laboratory, Golden, 

CO 80401 USA (e-mail: ben_Kroposki@nrel.gov). 

T. Basso is with the National Renewable Energy Laboratory, Golden, CO 

80401 USA (e-mail: thomas_basso@nrel.gov). 

R. DeBlasio is with the National Renewable Energy Laboratory, Golden, 

CO 80401 USA (e-mail: deblasid@tcplink.nrel.gov). 

quality, islanding, and test specifications and requirements for 

design, production, installation evaluation, commissioning, 

and periodic tests. These requirements are universally needed 

for the interconnection of DR—including synchronous 

generators, induction generators, and power 

inverters/converters—and will be sufficient for most 

installations. They are applicable to all DR technologies with 

aggregate capacity of 10 MVA or less at the point of common 

coupling that are interconnected with EPSs at typical primary 

or secondary distribution voltages. The installation of DR on 

radial primary and secondary distribution systems is the 

emphasis of the 1547 standard, but installation on primary and 

secondary network distribution systems is also considered. 

IEEE Standards Coordinating Committee (SCC) 21 [2] is 

also developing IEEE P1547.1 Draft Standard Conformance 

Test Procedures for Equipment Interconnecting Distributed 

Resources With Electric Power Systems” [3], an 

accompanying standard that will address conformance tests 

and procedures for verifying interconnection equipment. 

Standards are created through collaboration and agreement 

among experts from all related fields, including utilities, 

equipment manufacturers, and government laboratories. 

Uniform interconnection requirements should help all parties 

realize the benefits of DR while saving time and money. 

The National Renewable Energy Laboratory (NREL) has 

been instrumental in the development of standard 

interconnection requirements for DR and the validation of test 

procedures for the IEEE 1547 and P1547.1 standards [4]. 

II. INTERCONNECTION TESTS 

Historically, utility EPSs were not designed to 

accommodate active generation and storage at the distribution 

level. In addition, the multitude of utility companies 

employed numerous EPS architectures based on differing 

designs and choices of equipment. As a result, there are major 

obstacles to an orderly transition to using DR with the grid. 

IEEE 1547 lists technical requirements for interconnection. 

IEEE P1547.1 specifies the type, production, and 

commissioning tests necessary to demonstrate that the 

interconnection equipment of DR conform to IEEE 1547. 

Standardized test procedures are necessary to establish and 

verify compliance with those requirements. These test 

procedures must provide both repeatable results, independent 

of test location, and flexibility to accommodate a variety of 

DR technologies. 

1
IEEE P1547.1 details specific procedures for: 

Type (Design) Tests 

• Response to abnormal voltage conditions 

• Response to abnormal frequency conditions 

• Synchronization 

• Interconnection integrity (includes protection from 

electromagnetic interference, surge withstand, and 

ability of the paralleling device to withstand out-ofphase voltage) 

• DC injection 

• Unintentional islanding 

• Reverse power 

• Cease to energize and loss of phase 

• Reconnect following abnormal conditions 

• Harmonics 

• Flicker 

• Temperature stability 

Production Tests 

• Response to abnormal voltage conditions 

• Response to abnormal frequency conditions 

• Synchronization 

Commissioning Tests 

The working group developing the standard is using the 

body of testing knowledge as much as possible. For example, 

the surge withstand tests are based on currently accepted 

industry practice IEEE C62.41 [5] and IEEE C62.45 [6]. 

However, during testing standard development, it was 

recognized that some procedures for confirming 

interconnection requirements did not exist. 

These new test procedures are being developed as part of 

IEEE P1547.1 and validated on a variety of DR types at 

NREL’s Distributed Energy Resources Test Facility [7] in 

Colorado. As work on the validation of procedures 

progresses, information and test reports are passed on to the 

working group of IEEE P1547.1. 

III. TEST FACILITY AND EQUIPMENT 

NREL’s Distributed Energy Resources Test Facility 

provided the platform used to validate some of the IEEE 

P1547.1 tests. It includes a DR interconnection monitoring 

system and test switchboard that facilitates connecting a utility 

source, a DR source, and a local load bus. For most of the 

testing, the DR source (inverter- or synchronous generatorbased), interconnection equipment, a 200-kW grid simulator, a 

100-kW real load bank, and a 200-kW real and reactive 

(inductive and capacitive) load bank were incorporated into 

the switchboard. 

A. Data Acquisition System 

Because many of the parameters tested involve subcycle 

transient times, a relatively high-speed data acquisition system 

was necessary. The data acquisition system is capable of 

sampling rates up to 5 million samples per second (S/s). For 

this testing, however, sampling rates ranged from 10,000 to 

250,000 S/s. The voltage and current measurements are 

accurate to ±0.2% of the reading values, with a time scale 

accuracy of ±0.05%. 

B. Utility Grid Simulator 

An array of four grid simulators was used to perform 

controlled simulations of abnormal grid conditions. Four 

units were paralleled to provide a combined capacity of 250 

kVA (200 kW) at 120/208 V. All four units are controlled via 

a master-slave arrangement that allows the units to operate 

simultaneously. Each unit is rated at 62.5 kVA and is capable 

of delivering power at frequencies from 50 Hz to 400 Hz. 

The grid simulator is a double-conversion power source. 

Commercial input power is rectified and then converted to 

precision AC power through high-frequency, pulse-width 

modulation. This design allows fully programmable control 

of individual phase voltage, current, and frequency. 

The grid simulator is capable of fast response times, 

reacting to a 100% step load change in less than 300 μs. 

The output of the four-unit array is connected to a 125:277-

V wye autotransformer to provide a three-phase, 480-VL-L 

output. Output regulation and total harmonic distortion are 

less than 1% for normal 60-Hz operations. 

C. Load Bank 

The load bank used for these tests is a customized version 

modified to provide up to 165 kW resistive and 404 kVAR 

inductive and capacitive loads in step sizes as small as 125 W 

and 312.5 var. A graphical user interface controls the unit 

through serial ports. 

D. Synchronous Generators 

A Cummins/Onan 125-kW model DGEA diesel generator 

was used to test ASCO and GE interconnection equipment. 

E. ASCO 7000 Series Soft-Load Transfer Switch 

The ASCO 7000 Soft-Load Transfer Switch (SLTS) is 

designed to provide a safe and controllable interconnection of 

the EPS, a synchronous generator, and load. This 

interconnection switch has traditionally been used for 

emergency power applications but is increasingly being used 

for grid-parallel operation. Avoiding significant voltage or 

frequency transients, the ASCO SLTS can seamlessly transfer 

or share load between the generator and utility bus. 

The setup employed for the ASCO SLTS is typical of 

devices used to interconnect DR equipment with utility buses 

and therefore provides a general platform for the development 

and verification of standard test procedures. Both the utility 

and generator breakers used in the installation have shunt trip, 

and the output of the auxiliary contact of the utility shunt trip 

breaker is used as a trigger for capturing test data. 

The ASCO SLTS has a variety of protective relay 

functions, and many have adjustable tolerance ranges through 

the ASCO controls [8], [9]. 

2
These include: 

• Synchronization 

• Overvoltage and undervoltage 

• Overfrequency and underfrequency 

• Reverse power and underpower 

• Negative sequence voltage and current 

• Directional overcurrent 

• Loss of excitation 

• A proprietary algorithm for detecting and 

disconnecting a generator during an island condition. 

F. GE Universal Interconnect Prototype 

The GE Universal Interconnect (UI) is a prototype 

interconnection system based on the GE G60 Universal 

Generator protection relay from GE Multilin and a GE Zenith 

transfer switch. The GE UI is designed to allow the 

interconnection of any distributed generator with the EPS and 

provide a local load connection. It operates in a manner 

similar to the ASCO STLS and provides seamless transfer 

between the utility and generator to provide power to the load. 

IV. TEST RESULTS 

The testing reported in this section focuses on three 

requirements of IEEE 1547: response to abnormal voltage 

conditions, response to abnormal frequency conditions, and 

unintentional islanding. Tables I and II give the required 

clearing times for the interconnection system to respond to 

abnormal voltage and frequency conditions. 

TABLE I 

RESPONSE TO ABNORMAL VOLTAGE

TABLE II 

RESPONSE TO ABNORMAL FREQUENCY

The grid simulators were used to set test conditions. Only 

the parameter under test (PUT) was allowed to vary for each 

test. After establishing a certain test condition (undervoltage, 

overfrequency, unintentional island, etc.), the interconnection 

system must disconnect the DR from the utility system in less 

than the time required by IEEE 1547. 

Adhering to IEEE P1547.1, both a magnitude and a time test 

were performed for the voltage and frequency response. The 

function of the magnitude test was to determine the actual trip 

point. This was accomplished by varying the PUT in tiny 

increments gradually approaching the trip set point. The slow 

approach accounts for any time delays and ensures that the bus 

conditions at the time of the trip are virtually identical to the 

actual trip magnitudes. Ramp functions from IEEE P1547.1 

were programmed into and executed by the grid simulator. 

After the trip magnitude was found, the time tests were used 

to determine the time until the device tripped when the trip 

conditions, as determined in the magnitude test, were 

established. The goal is to step from below to above 

(ordinarily at least 10% above) the trip magnitude fast enough 

to know when the parameter jumps out of bounds and avoid 

introducing significant delays into the trip time. Testing of 

each parameter is conducted a minimum of five times to 

acquire a statistically significant sample. 

For unintentional islanding, the requirement is that the DR 

interconnection system detect the island and cease to energize 

the Area EPS within 2 s of the formation of an island [1]. 

Islanding is when a distributed generator continues to supply 

power to a portion of the EPS when that portion of the grid is 

otherwise de-energized. Power utilities and regulatory 

requirements demand the prevention of unintentional islands to 

ensure the safety of utility personnel and the integrity of the 

power system. Ideally, the event that caused the local section 

of the grid to shut down should also trip the DR protective 

function, or the sudden increase in load from the loss of grid 

power should disrupt system conditions enough to trip the DR. 

The IEEE 1547.1 unintentional islanding test is designed to 

simulate the worst-case scenario of matching the DR output to 

the load, adding capacitive and inductive load for a quality 

factor (Q) of 1.8, and dropping out the utility power without 

disturbing other system parameters. Previous islanding testing 

used Q = 2.5 [10]; IEEE 1547.1 standards now use Q = 1.8. 

Q = 2.5 corresponds to a load power factor (PF) of 0.37, and 

Q = 1.8 corresponds to a load power factor of 0.55. Q = 2.5 

was selected as the most difficult operating condition that an 

inverter anti-islanding algorithm would typically see. Further 

work has shown that utility circuits typically operate above 

0.75 PF in steady-state conditions; therefore, Q = 1.8 (PF = 

0.55) is below the load power factor that the DR would be 

expected to operate. Although it is unlikely in the field, 

successful worst-case testing demonstrates that the device can 

identify islands and quickly disconnect in most situations. 

The testing procedure for unintentional islanding was 

similar to that for abnormal voltage and frequency. Initially, 

with the DR disconnected, the grid simulator would supply a 

local load 10 kW or 20 kW greater than the desired DR to 

avoid backfeeding the grid simulators when ramping up the 

output power of the DR. The DR was then paralleled and 

supplied most of the local load; the simulated utility still 

contributed 10–20 kW. Next, matched inductive and 

capacitive loads were added to achieve a quality factor of 

about 1.8. The capacitive load was then increased to reach the 

Voltage Range 

(Based on 480 V) Clearing Time (s) 

V<240 0.16 

240≤V<422.4 2 

528<V<576 1 

V≥576 0.16 

DR 

SIZE Frequency Range (Hz) Clearing Time (s) 

≤30 kW >60.5 0.16 

<59.3 0.16 

>30 kW 

>60.5 0.16 

<{59.8–57.0} (adjustable 

setpoint) 

Adjustable 0.16–300 

<57.0 0.16 

3
desired power factor (accounting for transformer and other 

system inductances), and the resistive load setting was slowly 

reduced to match the DR output with the load and eliminate 

current from the utility. Finally, the utility breaker was tripped 

to create the island, and the disconnect time was recorded. 

The following sections describe selected results from the 

testing of the ASCO SLTS and GE UI. Complete details of the 

testing can be found in the final test reports [11], [12]. 

A. ASCO SLTS 

The ASCO SLTS was tested for response to over and 

underfrequency, over and undervoltage, and unintentional 

islanding. The testing described in this paper builds on testing 

conducted previously at a field site [13]. The ASCO unit 

meets IEEE 1547 interconnection requirements by monitoring 

power conditions and sending a trip signal to the utility 

breaker after detecting any value outside of preset ranges. 

Under the frequency test conditions, the ASCO unit 

controlled the diesel frequency to maintain a set export power 

level. By maintaining the grid simulator rate of frequency 

change below the time response of the diesel governor, the 

export power level could be held constant while bus frequency 

was decreased or increased. Table III shows the results from 

the magnitude portion of the overfrequency test, and Table IV 

shows the results from the time portion of the overfrequency 

test. The testing shows that the ASCO STLS disconnects 

from the abnormal frequency condition in the required time. 

The general conditions established for the voltage tests 

were identical to those for frequency testing. Under the 

voltage test conditions, the ASCO controlled the genset 

excitation to maintain power factor. By maintaining the grid 

simulator rate of voltage change below the time response of 

the diesel exciter, power factor could be held constant while 

bus voltage was decreased or increased. 

For the voltage testing, the most consistent results were 

with a non-unity power factor setting for the diesel generator. 

A power factor of 0.9 was used for these tests. This also 

provided a reactive load sink to limit generator reverse vars. 

TABLE III 

RESPONSE TO OVERFREQUENCY MAGNITUDE

Test Run Frequency (Hz) 

1 458 

2 604 

3 461 

4 534 

5 531 

Average 518 

Setting 5 

60.

60.

60.

60.

60.

60.

60.

TABLE IV 

RESPONSE TO OVERFREQUENCY TIME

Test Run Clearing Time (ms) 

1 47 

2 58 

3 40 

4 40 

5 39 

Average 45 

Required 160 

One of the issues of conducting the testing on an actual DR 

instead of testing via secondary injection methods is the 

operation of and pre-designed voltage regulator present on 

generator sets. The narrow range of the diesel voltage 

regulator would not allow testing at the voltage levels required 

by the IEEE 1547 and draft P1547.1 standards. IEEE 1547 has 

no disconnect or testing requirements for voltages ranging 

between 89% and 109% of normal. The voltage levels closest 

to nominal values that IEEE 1547 requires be tested are 88% 

of the nominal 480 V (422.4 V) for undervoltage and 110% 

(528 V) for overvoltage. These levels are for the slow 

response testing; the fast response goes to less than 50% or 

greater than 120%, but even the slow response minimum 

values were unattainable with the voltage regulator 

configuration. Voltage regulator settings prohibited the diesel 

generator from operating outside a range of only about ±6% 

of nominal voltage (450 V and 505 V). To work around this 

restriction, set points within the range of the diesel were 

tested. This was done by manually relaxing the voltage set 

points programmed into the ASCO controller to only ±25–30 

V around the nominal 480 V. Testing over the full voltage 

range might have been possible after adjusting the diesel 

voltage regulator settings but could damage the generator. 

Table V shows the results of the magnitude portion of the 

overvoltage test, and Table VI shows the results of the time 

portion of the overvoltage test. The testing shows that the 

ASCO STLS disconnects from the abnormal voltage condition 

in the required time. 

TABLE V 

RESPONSE TO OVERVOLTAGE MAGNITUDE

TABLE VI 

RESPONSE TO OVERVOLTAGE TIME

Test Run Clearing Time (s) 

1 436 

2 428 

3 378 

4 396 

5 468 

Average 421 

Required 0 

0.

0.

0.

0.

0.

0.

1.

Unintentional islanding tests were conducted per the IEEE 

P1547.1 procedure. Placement of the load, whether entirely at 

the utility load or the local load, did not significantly influence 

the ASCO detection times, which averaged 17.12 or 17.14 s 

without the anti-islanding function operational. Therefore, all 

the later tests used only the local load to better simulate a 

generator interconnected with the grid but completely 

supplying only a local load. When the grid becomes deenergized, local system conditions do not immediately change, 

Test Run Voltage (V) 

1 504.300 

2 502.500 

3 504.700 

4 504.600 

5 504.150 

Average 504.050 

Setting 504.0 

4
5

but the ASCO unit must still recognize the island and 

disconnect the generator within 2 s. To further challenge the 

ASCO unit, inductive and capacitive elements were added to 

the local load to create a 1.8 load quality factor to help 

maintain local power characteristics after the loss of the utility. 

Tests were conducted to investigate the effects of the diesel 

power factor setting, the generator load level, and the antiislanding deadband setting on the ASCO trip time. Loads at 

25% (30 kW), 50% (63 kW), and near 100% (100 kW) were 

tested at unity load power factor with matching inductive and 

capacitive loads to create a 1.8 quality factor. Testing was 

conducted with the diesel power factor setting at unity, 0.9 

lagging, and in some cases, 0.95 lagging. The deadband 

setting of the anti-islanding function is an adjustable sensitivity 

range. The active anti-islanding scheme attempts to disrupt the 

grid, and with no energized grid to maintain voltage and 

frequency, the ASCO can force values beyond the set 

deadband cushion before disconnecting the generator. 

Deadband settings of 0.1, 0.05, and 0.03 were used in tests. 

Fig.1 shows that with the anti-islanding algorithm turned 

off, the ASCO unit could not meet the 2-s unintentional 

islanding requirement. With the anti-islanding algorithm 

turned on and a deadband setting of at least 0.05, the unit could 

meet the 2-s trip requirement. 

Clearing Time of Anti-Islanding Deadband Settings 

for a Range of Loads at 0.90 Diesel Power Factor 

0

5

10

15

20

25

30

Off 0.1 0.05 0.03

Anti-Islanding Deadband Setting

Clearing Time (sec) 

25% Load 50% Load 100% Load

Did not trip in 3 minutes

2-Second Required Trip Time

Fig 1. Clearing times for ASCO unintentional islanding tests 

B. GE Universal Interconnect 

Because the GE UI is based on a well-tested commercial 

relay, testing focused on the advanced modifications used to 

meet the unintentional islanding requirements of IEEE 1547. 

The GE strategy was to use a passive anti-islanding algorithm 

based on rate of change of frequency in addition to 

over/undervoltage and frequency limits to detect the 

unintentional island condition and disconnect within 2 s. 

The objective of the first set of tests was to find the nondetection zone for the anti-islanding function. By 

incrementally increasing or decreasing the mismatch in power 

between the generator and the load, the boundary at which the 

UI can detect an island condition can be found for any given 

power base load. The non-detection zone testing identifies the 

minimum power supplied by the utility that causes the UI to 

trip when the utility is removed. Within that power limit, the 

load matches the DR too closely, and the generator can run 

islanded indefinitely without the anti-islanding protection 

responding. This level gives an indication of how well the 

anti-islanding software operates and can be used as a 

performance index to compare anti-islanding techniques. The 

UI was tested at a variety of base loads but always with a 

consistent quality factor, taken as the ratio of the reactive load 

to the real load, of 1.8. 

After the active power mismatch testing, the UI was also 

tested with reactive power mismatch. The UI was never able to 

detect islanding with reactive power mismatch. The reason is 

that the diesel generator can quickly respond to the reactive 

power change, thus maintaining its terminal voltage. 

Theoretically, if the generator is controlled as a constant P and 

Q source, the active power mismatch will drive the frequency 

change, as the results above show. The reactive power 

mismatch, however, should cause voltage change, thus tripping 

under/overvoltage protection. However, it was not observed in 

the testing with this particular diesel generator, which 

apparently is not controlled as a constant reactive power source 

(or with a constant power factor). In these tests, the generator 

reactive output (DG Q) jumps up following the grid 

disconnection to compensate for the reactive power mismatch. 

As a result, the output voltage still remains within the normal 

range. If this is the typical or desired behavior of diesel 

generators used as DR, then anti-islanding protection based on 

voltage detection for this type of machine DR appears 

unfeasible. Other schemes that detect reactive power mismatch 

need to be developed in the future, though active power 

mismatch will be more common in practice. 

In all test cases using only the passive anti-islanding 

detection scheme, even with the parameters tightened, the UI 

could not detect the island under exactly matched power 

conditions. To meet IEEE 1547 requirements, a reverse or 

minimum power trip setting would have to be used. Also, care 

must be taken when increasing the sensitivity of the antiislanding parameters because better protection can come at the 

potential price of increased nuisance tripping from unavoidable 

grid disturbances. 

V. SUMMARY

This paper outlines some of the specific interconnection 

tests being validated for inclusion in IEEE 1547.1. The results 

of the testing have been passed on to the IEEE P1547.1 

working group and help manufacturers of interconnection 

systems design equipment to meet the requirements. 

The results of the validation studies include: 

• Generic monitoring, measurement, and testing 

strategies could be useful in P1547.1. The file size, 

sampling rate, and correct sampling window were 

significant factors of testing that could be mentioned in 

P1547.1. The document should dictate universally 

prescriptive values and equipment-specific procedures. 

Advice and warnings of issues to be aware of to aid 

smooth and accurate testing should also be included. 
• Some values from the current P1547.1 draft standard 

were incompatible with the testing setup and will need 

modification. This information has been passed on to 

members of the IEEE P1547.1 working group for 

revision in future drafts. 

• Care must be taken to test each parameter individually 

without other protective functions operating. 

VI. ACKNOWLEDGMENTS 

The authors gratefully acknowledge the contributions of C. 

Pink and S. Engelbretson from the Colorado School of Mines 

for their assistance conducting tests. The authors also thank J. 

Daley, R. Siciliano, and D. Hinton from ASCO Power 

Technologies and Z. Ye and D. Finney from GE for their 

contributions with conducting tests and providing equipment. 

VII. REFERENCES 

[1] IEEE Standard for Distributed Resources Interconnected With Electric 

Power Systems, IEEE Standard 1547-2003, July 2003. 

[2] http://grouper.ieee.org/groups/scc21 

[3] Draft Standard for Conformance Test Procedures for Interconnecting 

Distributed Resources with Electric Power Systems, IEEE P1547.1, 

November 2003. 

[4] T.S. Basso and R. DeBlasio, "IEEE P1547 series of standards for 

interconnection: preprint," National Renewable Energy Laboratory, 

Golden, CO, NREL/CP-560-34003, May 2003. Available: 

http://www.nrel.gov/docs/fy03osti/34003.pdf. 

[5] IEEE Recommended Practice on Characterization of Surges in Low 

Voltage (1000 V and Less) AC Power Circuits, IEEE Standard C62.41.2-

2002. 

[6] IEEE Recommended Practice on Surge Testing for Equipment 

Connected to Low-Voltage (1000 V and Less) AC Power Circuits, IEEE 

Standard C62.45-1992 (R2002). 

[7] “NREL Distributed Energy Resources Test Facility: Advancing 

distributed power technology” fact sheet, National Renewable Energy 

Laboratory, Golden, CO, NREL/FS-560-35044, October 2003. 

Available: http://www.nrel.gov/docs/fy04osti/35044.pdf. 

[8] J.M. Daley and R.L. Siciliano, “Application of emergency and standby 

generation for distributed generation: Part 1,” presented at the Industrial 

and Commercial Power Systems Technical Conference 2002, pp. 138– 

150. 

[9] J.M. Daley and R.L. Siciliano, “Application of emergency and standby 

generation for distributed generation: Part 2,” presented at the Industrial 

and Commercial Power Systems Technical Conference 2002, pp. 151– 

157. 

[10] IEEE Recommended Practice for Utility Interface of Photovoltaic (PV) 

Systems, IEEE Standard 929-2000. 

[11] B. Kroposki, S. Englebretson, C. Pink, J. Daley, R. Siciliano, and D. 

Hinton, "Validation of IEEE P1547.1 Interconnection Test Procedures: 

ASCO 7000 Soft Load Transfer System," National Renewable Energy 

Laboratory, Golden, CO, NREL/TP-560-34870, September 2003. 

Available: http://www.nrel.gov/docs/fy04osti/34870.pdf. 

[12] Z. Ye, D. Finney, R. Zhou, M Dame, B. Premerlani, B. Kroposki, and S. 

Englebretson, "Testing of GE Universal Interconnection Device," 

National Renewable Energy Laboratory, Golden, CO, NREL/TP-560-

334676, August 2003. Available: 

http://www.nrel.gov/docs/fy03osti/34676.pdf 

[13] B. Kroposki, R. DeBlasio, J. Galdo, “Distributed Power Program DER 

pilot test at the Nevada Test Site,” National Renewable Energy 

Laboratory, Golden, CO, NREL/TP-560-32063, May 2002. Available: 

http://www.nrel.gov/docs/fy02osti/32063.pdf 

VIII. BIOGRAPHIES 

Benjamin Kroposki (S’90, M’93, SM’00) is a senior engineer at NREL 

and leader of the Distributed Power Systems Integration Team. His expertise is 

in the design and testing of distributed power systems, and he has produced more 

than 30 publications in this area. Kroposki also participates in the development 

of distributed power standards and codes for IEEE, the International 

Electrotechnical Commission (IEC), and the National Electrical Code. He serves 

as secretary for IEEE P1547.1. Mr. Kroposki received his bachelor’s and 

master’s degrees in electrical engineering from Virginia Tech and is a registered 

professional engineer. 

Thomas Basso (M’80) is a senior scientist working at NREL under the 

NREL Distribution and Interconnection R&D area of the NREL Distributed 

Energy and Electricity Reliability Program. Prior at NREL, he conducted 

outdoor accelerated weathering of photovoltaic (PV) modules and was NREL 

project leader for PV Management under the NREL/Department of Energy PV 

Advanced R&D Project. Before coming to NREL, he was a design engineer with 

a consulting engineering firm and worked for a manufacturer of air-cooled heat 

exchangers for the petrochecmical, refinery, and utility industries. He was also a 

standards engineer for the American Society of Mechanical Engineers and an 

instructor in the Mechanical Engineering Department of Northeastern University. 

He serves as secretary for IEEE SCC21, P1547, P1547.2, and P1547.3 and is a 

member of the IEC Joint Coordination Group for Decentralized Rural 

Electrification Systems, IEC TC8, the American Society of Mechanical 

Engineers, and the American Solar Energy Society. 

Richard DeBlasio (M’65, SM’83) is technology manager of the 

NREL/Department of Energy Distributed Energy and Electricity Reliability 

Program, which includes Distribution and Interconnection R&D at NREL. 

Before joining NREL in 1978, he was with the U.S. Atomic Energy 

Commission in Washington, D.C. (1974–1978), and Underwriters 

Laboratories (1972–1974). He was also a member of the technical staff at 

Stanford University (1965–1972). He is an electrical engineer; a senior 

member of IEEE; an IEEE SA Standards Board member; chair of IEEE SCC 

21 on Fuel Cells, Photovoltaics, Distributed Power, and Energy Storage; and 

chair of the international standards committees IEC TC82 and Joint 

Committee on Decentralized Rural Electrification Systems. 

6
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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 

February 2004 

3. REPORT TYPE AND DATES COVERED 

Conference Paper Preprint 

4. TITLE AND SUBTITLE 

Interconnection Testing of Distributed Resources: Preprint 5. FUNDING NUMBERS 

DP03.1001

6. AUTHOR(S) 

B. Kroposki, T. Basso, and R. DeBlasio 

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National Renewable Energy Laboratory 

1617 Cole Blvd. 

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13. ABSTRACT (Maximum 200 words) 

With the publication of IEEE 1547-2003TM Standard for Interconnecting Distributed Resources With Electric 

Power Systems, the electric power industry has a need to develop tests and procedures to verify that 

interconnection equipment meets 1547 technical requirements. A new standard, IEEE P1547.1TM, is being written 

to give detailed tests and procedures for confirming that equipment meets the interconnection requirements. The 

National Renewable Energy Laboratory has been validating test procedures being developed as part of IEEE 

P1547.1. As work progresses on the validation of those procedures, information and test reports are passed on to 

the working group of IEEE P1547.1 for future revisions. 

14. SUBJECT TERMS 

Standards; 1547; testing; distributed generation; distributed energy; distributed power; 

DG; DER; DP; Distribution and Interconnection R&D; National Renewable Energy 

Laboratory; NREL 

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