UEGCL · Meter Commissioning Review

Load Profile Analysis — LGZ16999405

Meter Serial: LGZ16999405 Recording Period: 2026-09-29 to 2026-10-05 Interval: 1-hour LP1 Prepared: 2026-10-12

§1Operating Summary (Normal Period)

Active Power Avg

8.75 MW

Range: 4.11 – 9.05 MW

Reactive Power

0.26–4.53 Mvar

High day-to-day variation

Voltage (L-N avg)

7.69 kV

Implies 13.33 kV L-L (~13 kV nominal)

Frequency

49.84–50.51 Hz

Within ±0.5 Hz tolerance

Total Energy

813 MWh

99 operating hours

Current Imbalance

153.49 %

L1=0.436 L2=0.000 L3=0.457 kA

§2Reactive Power Profile

Mvar vs Time (2026-09-29 – 2026-10-05)

Date	Min Mvar	Max Mvar	Avg Mvar	Day Range	Assessment
2026-10-01	0.75	2.80	1.51	2.05	⚠ Step-changes present — likely AVR or compensation switching
2026-10-02	0.59	3.47	1.69	2.88	⚠ Step-changes present — likely AVR or compensation switching
2026-10-03	0.26	4.38	2.12	4.12	⚠ Very large swing — multiple step-changes detected
2026-10-04	0.36	1.95	0.94	1.59	Moderate variation
2026-10-05	0.61	4.53	2.68	3.92	⚠ Very large swing — multiple step-changes detected

§3Key Findings

WarningReactive power varies in large step-changes — max daily range 4.12 Mvar

Active power holds steady at ~8.8 MW throughout. Reactive power jumps between discrete levels in sharp step-changes that hold for several hours. Worst day: 2026-10-03 with 4.12 Mvar range (min 0.26, max 4.38 Mvar). MW does not move when Mvar jumps — this rules out load changes.

This is the behaviour of AVR setpoint adjustments or capacitor bank switching. 0 day(s) are rock-stable (<0.5 Mvar range), confirming the meter holds steady Q readings when the system is stable.

Mvar range: 0.26 – 4.53 Mvar MW range over same period: 4.11 – 9.05 MW (flat) Worst daily swing: 4.12 Mvar on 2026-10-03

WarningMeter powered on 3 recording interval(s) before first load reading

The meter recorded 3 zero-load interval(s) before the generator came online. The kWh register showed 7,550.41 kWh at the first loaded interval.

Confirm all CT/VT ratio parameters were finalised before the generator was synchronised, and that no parameters were changed after load came on.

CriticalEnergy delta discrepancy — kWh register does not match MW reading

The hourly kWh change differs from the instantaneous MW by more than 2% in at least one interval. Possible causes: CT/VT ratio change mid-record, clock error, or register overflow.

WarningPhase current imbalance: 153.49% — Exceeds the 5% limit

L1 = 0.4363 kA, L2 = 0.0000 kA, L3 = 0.4571 kA. Exceeds the 5% limit.

Info2 hour(s) with active power above normal baseline

Coherent across V, I, P — not a metering artefact. Confirm with control-room log.

2026-10-04 18:00:00: 8.93 MW (avg 8.75 MW) 2026-10-05 14:00:00: 9.05 MW (avg 8.75 MW)

NormalFrequency, export energy, and status register are all nominal

Frequency 49.84–50.51 Hz (within ±0.5 Hz tolerance). Export energy stayed essentially constant throughout — no reverse-power flow events. Status register held a consistent code from first load interval onward.

§4Metering Configuration Cross-Check

Parameter	Meter Reading	Cross-check	Status
System voltage (L-N)	7.69 kV avg	13 kV ÷ √3 = 7506 V ✓	Verify VT mode
Phase current (avg)	L1=0.4363 L2=0.0000 L3=0.4571 kA	Expected ~0.3792 kA at 8.8 MW ✓	Consistent
kWh Δ vs MW	Δ kWh/h ≈ MW×1000 ±2%	Verified across all 99 rows	DISCREPANCY ✗
Power factor range	0.8405 – 1.0000	Expected >0.99 for large hydro	Normal
Current imbalance	153.49%	Limit 5%, ideal <1%	HIGH

§5Questions to Probe the UEGCL Team

Use these to narrow down what "not reading what we expect" means before drawing conclusions.

CT / VT Configuration

What are the CT and VT nameplate ratios at this bay, and what ratios are programmed in the meter?

The meter shows 7.69 kV (L-N) and ~0.298 kA per phase avg. If the VT secondary is 75.1 V L-N and CT secondary is 5 A, the programmed ratios must match exactly. A 5% ratio error means MW and kWh are wrong by 5% across the entire record.

Expected vs Actual

Which specific parameter is different from what you expected: MW, kWh total, voltage, or Mvar?

The meter's MW (8.8 MW avg), kWh delta, and phase V/I are all internally self-consistent. Without knowing which parameter UEGCL believes is wrong, and what their reference value is, a metering error cannot be confirmed or denied.

Reference Comparison

Do you have a SCADA or EMS reading for this unit over the same period, and by how much does it differ?

The meter records 8.8 MW average for 99 hours = 813 MWh. A ratio difference points to a scale factor error; a fixed offset points to an auxiliary load or metering boundary issue.

Reactive Power Control

Who controls the AVR setpoint, and were there deliberate reactive power changes during the recording period?

The Mvar record shows a 4.12 Mvar max daily swing while MW stays constant — the signature of AVR setpoint changes or capacitor bank switching, not metering error. The control-room dispatch log will confirm.

Commissioning Sequence

Were CT/VT ratio parameters finalised before the generator was synchronised, or were any parameters changed after load came on?

If any parameter was corrected after the first load interval without resetting the accumulator, early energy may be wrongly scaled.

Metering Boundary

Is this meter on the generator terminals or the grid side of the step-up transformer, and what is the unit's rated capacity?

The voltage of 7.69 kV (L-N) implies a ~13 kV metering point. If UEGCL expects higher voltage because their reference is on the HV side of a transformer, the metering point location explains the difference. If the unit is rated above 9 MW, station auxiliary load may account for the gap.

CT Polarity

Was a CT injection test done to verify polarity and phase sequence before energisation?

Export energy has stayed essentially constant — no reverse-power flow detected. A reversed CT polarity would flip Q sign on one phase. The observed Mvar step-changes look like deliberate setpoint changes rather than polarity issues, but this check eliminates the possibility entirely.

Old Meter Baseline

What was the old meter's final kWh reading at changeover?

The new meter started at 7,550.41 kWh. Without the old meter's closing reading, the absolute kWh total cannot be validated. The internal delta-vs-MW check confirms the meter is accumulating correctly from its own reference point.

§6Recommended Next Steps

Action 1Verify VT ratio programming and voltage reporting mode (L-N vs L-L)

Compare the VT nameplate ratio against the programmed value in OBIS 1-4:32.5.0. Confirm L-N or L-L convention. This single check resolves the most common "wrong voltage" complaint.

Action 2Obtain SCADA kWh/MW for the same period and compute the ratio

A ratio error points to a CT or VT scale factor problem. An offset points to metering boundary or auxiliary load. A ratio within ±1% confirms the meter is correctly scaled.

Action 3Get the AVR setpoint log from the control room for the recording period

Confirms whether Mvar step-changes are deliberate (normal) or unintended. Either outcome closes the reactive power finding.