Power Quality

Measurement Capabilities

in Smart Revenue Meters

Thomas Cooke

1

Overview

• Benefits of PQ Measurements in Smart

Revenue Meters

• Barriers

• Assessment of Meter Measurements

• Standardizing PQ Measurements for Smart

Revenue Meters

• Questions / Discussions

Continuous Disturbance Monitoring Gap

Edge of the Grid

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?Courtesy OpenDSS

Electric Power Distribution System Simulator

Voltage Sag Severity from a Fault

20%

30%

40%

50%

60%

70%

80%

90%

100%

VSag

Use with Data Visualization - Quick and Interpretable PQ Info

1

2

3

4

5

6

7

8

9

VTHD

Barriers

• Current communications infrastructure cannot accommodate bandwidth

• Current data storage systems are not configured for long-term storage

• The cost of enabling PQ functions is too high

• Limited or no PQ capabilities in existing meter model.

• Limit “high-end” Meters to strategic locations (Bellwether Meters)

• Parameter based meters use less communication bandwidth and storage

• PQ and Smart Meter Standards

• IEEE 1159 (Recommend Practice for PQ Monitoring)

• IEC 61000-4-30 (correct PQ measurement algorithms )

• ANSI C12.19 (Utility Industry End Device [Smart Meter] Data Tables)

• ANSI 12.22 (Specification for Interfacing to Data Communication Networks)

Barriers to Implementation Potential Solutions

EPRI Meter Test Laboratory

• GE (KV2c, i210+c)• Itron (Sentinel, Centron)• Elster (A3 Alpha, Rex2)• Landis & Gyr (E330, E650)• Echelon (ANSI 2S)

Power System Simulations

• Replicate Daily Feeder Trends

• Simulate System Faults

• Generate Various Load Profiles

Single Phase Example Results

Example of Three

Phase Meter Results

Event Capture Assessment (Voltage Sags)

$800, $150, $300, $100, $400, $2200, $2000, $300, $450, $4400

Parameter Trending Concern

Sustained Interruption Test (Outage / Restoration)

Parameter Measurements Summary

Descriptions of ANSI C12.19 PQ Tables

The meter must have the capability to perform these functions and store them in this table.

Conclusions from Testing

• Present PQ capabilities are limited in smart meters

– Need to adopt parts of PQ Standards (keep cost low)

– Parameter trends below three seconds (simple change?)

– Ride-through capability during events. (mitigation?)

• ANSI PQ data tables are not being fully utilized.

• Beware of Claims and Terminology

– “Measures Fundamental and Harmonic Frequencies”

– “Waveform Capture”

• Benefits

– Single-phase did well with Outage / Restoration

– Three-phase meters exceed single-phase with PQ measurement capabilities —

especially from traditional PQ manufacturers.

– Strategic location of each (deliver max benefit for the cost)

Requirements of PQ Capabilities in Smart

Revenue Meters – Draft for Review• Intended to give minimal measurement

requirements for each PQ phenomena

• Tier levels are designed to give meter

manufactures some flexibility in choosing

methods that may work with existing

meter infrastructure or budget.

• To be reviewed by industry experts, electric

service providers, and meter

manufacturers.

• Feedback to tcooke@epri.com

Sample Requirement Voltage Interruptions, Sags, Swells

•Tier 1• Voltage Waveform recording at the beginning and end of the event, with least

32 samples per cycle, and pre and post event recording of at least 3 cycles.• Voltage RMS plot with 0.5 cycle resolution during the whole duration of the

event, with pre and post event recording of at least 1 second.•Tier 2

• Voltage RMS plot with 0.5 cycle resolution during the whole duration of the event, with pre and post event recording of at least 1 second.

• RMS is calculated from a waveform sampling at least 16 points per cycle.•Tier 3

• Log report or tabular data with minimum, average, and maximum RMS voltage amplitude recordings during an event, as well as the duration of the event.

• Statistical RMS recordings are derived from a 1 cycle RMS of a waveform sampled at least 16 points per cycle.

•Tier 4• Log report or tabular data with minimum, average, and maximum RMS voltage

amplitude recordings during an event, as well as the duration of the event• Statistical RMS recordings are derived from a 12 cycle RMS of a waveform

sampled at least 8 points per cycle

Requirements

Document

Summary of Tier

Requirements

Bandwidth and Storage: Event

Reporting Format

2,000 - 20,000 bytes 36 bytes 17 bytes

Sampling Resolution

Calculation Envelope Waveform Sampling

Requirements

DocumentManufacturers

Cost versus Needs

Guidance

1. Interruptions

2. Sags/Swells3. Parameters

Limits

15. Flicker

14. Ind. Harm.

13. Transients

9. THD

Requirements Document Download

EPRI.com

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