IEEE Test Feeders for

Advanced Inverter Analysis

JASON FULLER

Pacific Northwest National Laboratory

PV Distribution System Modeling Workshop

5/6/2014

A little background…

IEEE Distribution Test Feeder Working Group

Under Distribution Analysis Subcommittee

Informally started in 1991 with four radial test systems (fifth was added later)

Original models were designed to benchmark unbalanced power flow

solutions between tools

NOT designed to test optimization algorithms

NOT designed to test speed to solutions

NOT designed to test network systems

NOT designed to test “big” systems

etc.

New models were and are needed!

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New test systems are being added

8500 Node Test Feeder (2010)

Larger-scale to evaluate scalability of algorithms

Real system with multiple voltage control devices

Balanced and un-balanced versions

Includes service drops (120/240 V)

Courtesy of

EPRI’s OpenDSS

Comprehensive Test Feeder (2010)

Designed to test models of standard components

Cables, lines, transformers, regulators, induction

machines, substations, sources, parallel lines,

switches, triplex, quadraplex, etc.

Tests convergence, especially under various

switching schemes

Courtesy of W.H. Kersting

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New test systems are being added

Neutral-Earth-Voltage Test Feeder (2010)

Tests ability to determine NEV effects

Multi-phase system with

4 circuits, neutral, and 4 telecom circuits on a pole

Single- to three-phase laterals

Pole and load grounds

Substation neutral reactor

Solved in multiple frequencies (3rd harmonic)

Based on actual system near U.S. university

Test Feeder for DG Protection Analysis (2011)

Tests fault currents, voltages, etc. in presence

of distributed generation

With and without a utility source

Multiple reclosers and fuses

Based on actual 1.65 MW WT connected to a

12.47 kV feeder

Courtesy of T.E. McDermott

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New test systems are being added

Short-circuit test cases (2012)

Tests unbalanced short-circuit currents and voltages under given set of

assumptions (no sequence components!)

Results compared on original radial test feeders

Additional models are needed for distributed generation and inverters!

Network Test System (2014)

First case is a small, 390-node system (ideal)

Expanding to larger, more complicated ones

Tests the effectiveness of solvers and algorithms

on unbalanced, heavily meshed systems, including

Low-voltage meshes

Parallel transformers and cables

Spot networks

Normal and loss of primary feeder operations

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In the works

Time-series test case

One-second resolution over a short time scale

One-minute resolution over a longer time scale

Load shapes to replace static loads (to include DG sources)

Variety of voltage control modes

Low voltage test case

Large meshed network test case

Inverter-based DG test case

Microgrid test case

Integrated transmission and distribution test case

GridLAB-D simulation of 123-node

with 30-second load shapes

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Do we need an advanced

inverter test feeder?

The research community may be able to:

Evaluate the interaction of existing and potential voltage

control systems?

Test the interaction of current and future protection

schemes?

Investigate islanding and/or ride-through behaviors

during grid disturbances?

Understand interactions with other advanced

technologies (DR, VVO, etc.)?

Evaluate business models, revenue recovery, and rate

design to support investigation of alternatives?

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What’s needed for an

advanced inverter test case?

Real (or realistic) feeder model with high

penetrations

Multiple voltage control devices (and

settings / configurations)

Unbalanced and balanced loading and

generation

Time-series load and generation data

High- and low-resolution

Agreed upon inverter performance model(s)

and parameters

With multiple control types (e.g., static PF,

dispatched Q, local voltage control, etc.)

Multiple testing regimes (steady-state, quasi-

steady-state, transient / dynamic, etc.)

“Effects of distributed energy resources

on conservation voltage reduction”

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How do we make a useful model?

Hardware-in-the-loop?

Hardware-in-the-Loop

Two Advanced Inverters with PV located right

after line regulator (80 kW each)

Rest of system simulated

1-second synchronization / timesteps

Courtesy of joint PNNL / NREL HIL Project

Questions / Comments?

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