Application Notes:
Multi-Purpose Measurement Tools Help Utilities Increase Service and Protect Revenue |
|
 |
| |
|
|
| |
|
| |
Electric utilities are working harder than ever to stay competitive, manage capacity, and protect revenue. To differentiate themselves from competitors, many utilities are offering power quality and other efficiency-related services. As a result, new power quality measurement tools are reflecting this same multi-purpose field service ethic.
The three-phase analyzers that technicians already use to measure power factor and trend power quality now offer user-settable ratios for displaying readings as if measuring at the primary side of PTs and CTs. They also verify revenue meters.
Enough revenue meters are out of tolerance that a 2001 Electric Power Research Institute study estimated meter-related losses at $5 million to $20 million per year for a medium sized U.S. utility.
Using a multi-purpose analyzer such as the Fluke 430 Series allows utility technicians to offer more customer services in less time and quickly audit revenue meters during each site visit.
Power quality, power factor, and demand managementNew handheld three-phase power quality analyzers like the Fluke 430 Series are rated for use at the service entrance and will trend data easily, without setup.
To support detailed yet efficient assessments of substations and customers' power, new analyzers:
Measure voltage, current, frequency, power, power factor, power consumption (energy), unbalance and flicker, harmonics and inter-harmonics on all three phases and neutral
- Log events like dips, swells, and interruptions
- Trend all measurements onscreen, with automatic scaling
- Check conformity to EN50160 limits or to custom limits
- Capture 40 waveforms showing detailed dips, swells, interruptions or transients
- Meet 600 V CAT IV, 1000 V CAT III safety standard required for measurements at the service entrance
- Transfer stored measurements to the PC
Revenue meter verificationThe meter verification test is similar to a hand-switch verification and can quickly uncover tolerance problems. On new analyzers, technicians use a softkey to conduct the test, with no configuration or accessories needed. The verification can be performed on any electromechanical meter or electronic meter that has an indicator or rotating disk.
Figure 4 shows the Power and Energy display on the Fluke 430 Series. Technicians connect the analyzer and then press the softkey labeled "MANUAL COUNT +1" to increment the counter each time the marker passes on the revenue meter. Figure 4 shows the results after three revolutions of a meter (pulses). In this case, the value observed from the revenue meter was 4.9 % lower than the 3.148 kWh measurement on the Fluke 434.
Here's how the manual measurement works:
1. Set the scale factors
Set CT and PT scale factors on the analyzer, if necessary. (See Figure 3.) Under the FUNCTION PREFerences for the Power and Energy Function, set the pulse constant on the analyzer to match the pulse constant on the revenue meter (Kh). Use the down arrow button to see the pulse constant as shown in Figure 5. Connect the 430 in parallel with the revenue meter.
2. Setup the energy measurement
Select the Power & Energy mode from the main menu and press the Hold/Run softkey twice. Press the TIMED softkey, then specify the number of pulses to count before holding the results on the display. Press START to return to the Power and Energy Screen. Press the ENERGY softkey to open the Energy display. Make sure Pulse Counting is turned on.
3. Perform the verification
Press the RESET ENERGY softkey to reset the energy counter as the marker passes on the revenue meter. Press the MANUAL COUNT + 1 softkey each time the marker passes.
4. Read the results
After the number of rotations specified in step 2 above, the display will hold. Read the meter error, in percent, from the lower right part of the screen.
Some utilities make a practice of auditing large customer power meters once a month to safeguard revenue. New, multi-purpose power quality analyzers make this kind of personalized field service far more efficient, and feasible. They also provide more customer-friendly data, offering new ways to add value to customer service.
Click here to download the full pdf: Multi-purpose measurement tools help utilities increase service and protect revenue » |