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Power Quantities

View per-phase active, reactive, and apparent power with power factor.

What This Tab Does

The Power tab shows per-phase active, reactive, and apparent power with power factor gauges and power triangle visualizations. It pairs a voltage channel with a current channel to compute how much real power is being transferred, how much reactive power is oscillating, and what the overall power factor is at the current cursor time.

This tab requires sign-in. Once enabled, it updates in real time as you move the cursor or use the playback slider to animate through the recording.

1Power Analysist = 0.045s

2Channel Pairing3 pairs

456

Phase AVA → IA

P12.50kW

Q4.12kVAr

S13.16kVA

PF0.950 lagging

φ18.2°

Phase BVB → IB

P11.83kW

Q3.94kVAr

S12.47kVA

PF0.949 lagging

φ19.1°

Phase CVC → IC

P12.08kW

Q4.01kVAr

S12.73kVA

PF0.949 lagging

φ18.6°

73-Phase Totals

P₃φ

36.41 kW

Q₃φ

12.07 kVAr

S₃φ

38.36 kVA

PF0.949lagging

φ18.6°

Header — Zap icon with “Power Analysis” title and cursor timestamp display.

Channel pairing — Collapsible V–I channel mapping configuration. Auto-detected pairs can be manually overridden. Renders before phase cards.

Phase cards — 3-column grid, each card with a colored left-border accent matching the phase color (red/blue/green).

P/Q/S values — Active (P), reactive (Q), and apparent (S) power per phase with engineering units.

Power triangle — SVG triangle showing the P–Q–S relationship with angle arc and phase-colored strokes.

Power factor bar — Color-coded gauge — green (≥0.95), amber (≥0.85), red (below). Shows PF value and lead/lag.

Total system power — Sum of all phases: total P, Q, S with overall power factor and angle.

Time Playback

The playback slider at the top of the tab lets you animate the power display through time. Press Play to watch how active power, reactive power, and power factor change as the recording progresses — this reveals the transition from normal load conditions through fault inception to clearance.

Drag the slider thumb to scrub to any specific moment. When dual cursors (A/B) are placed on the waveform, their positions appear as draggable markers on the slider, and Jump to A/B buttons below the slider let you snap between the two points with one click.

The cursor is automatically placed at the start of the recording when a file is loaded, so power values are always available immediately.

Time Playback Slider

123

A4B

545 / 200 ms61x

7Jump to:AB

1Play / Pause — animate through the recording. Phasors, power, harmonics, and readout values update in real time during playback.

2Reset — jump back to the start of the recording.

3Slider track — drag the thumb to scrub to any point in the recording. The filled portion shows current position.

4A/B cursor markers — when dual cursors are placed on the waveform, their positions appear as draggable markers (blue for A, orange for B). Drag a marker to reposition that cursor.

5Time readout — current playback position and total recording duration in milliseconds.

6Speed control — click to cycle through presets (0.5×, 1×, 2×, 4×, 8×). Double-click to type a custom speed. At 1× speed, one power cycle takes one second of wall time.

7Jump to A / B — snap the slider position to cursor A or cursor B. Only visible when both dual cursors are placed.

Channel Pairing

Power quantities require both a voltage and a current channel. Detego automatically pairs channels based on their phase labels (e.g., Va with Ia, Vb with Ib). If the automatic pairing is not correct for your recording, expand the Channel Pairing section to manually configure the channels.

Voltage Mode

The Channel Pairing section includes a voltage mode toggle with two options:

Phase-to-Ground -- Use when your recording contains phase-to-neutral voltages (e.g., V_A, V_B, V_C). Pair each voltage directly with its corresponding phase current. You can add or remove pairs as needed.
Line-to-Line -- Use when your recording contains line-to-line voltages (e.g., V_AB, V_BC, V_CA). Select the available line-to-line voltage channels and phase currents. Detego automatically derives phase-to-neutral voltages from the line-to-line measurements before computing power.

Detego auto-detects which mode to use based on channel names and units. If auto-detection fails, you can switch modes manually.

Line-to-Line Configuration

In Line-to-Line mode, you assign up to three line-to-line voltage channels ( $V_{AB}$ , $V_{BC}$ , $V_{CA}$ ) and three phase currents ( $I_A$ , $I_B$ , $I_C$ ).

Only two of the three line-to-line voltages are required. The third is automatically derived using the identity $V_{AB} + V_{BC} + V_{CA} = 0$ .
Any of the three can be the derived one -- not just $V_{CA}$ . When two channels are assigned, the dropdown for the third shows “derive from others”.
If all three line-to-line channels are available in the recording, you can assign all three for maximum accuracy.

How derivation works

Detego derives phase-to-neutral voltages from line-to-line using complex phasor arithmetic. The derived voltages contain positive-sequence and negative-sequence components but not zero-sequence, which is inherently absent from line-to-line measurements. See Theory: Line-to-Line Derivation for the full mathematical treatment.

Saving Your Configuration

Channel pairing configuration is saved automatically per recording. When you reopen a recording, the voltage mode, channel assignments, and any manual pairs are restored exactly as you left them.

Reading the Results

The Power tab displays the following quantities for each voltage-current pair:

Quantity	Unit	What It Tells You
Active Power (P)	W	Real power doing useful work. Positive means power flows from source to load.
Reactive Power (Q)	VAR	Power oscillating between source and load. Positive Q means inductive (lagging); negative Q means capacitive (leading).
Apparent Power (S)	VA	Total power combining active and reactive. This is what determines equipment sizing (transformer ratings, cable ampacity).
Power Factor (PF)	0 to 1	Ratio of useful power to total power. PF = 1 means purely resistive; PF = 0 means purely reactive.

Power Factor Gauge

The power factor gauge provides a visual indicator of power factor quality. The gauge ranges from 0 to 1, with the indicator color shifting from red (poor power factor) through yellow to green (good power factor, close to unity). The gauge also shows whether the power factor is lagging (inductive load -- motors, transformers) or leading (capacitive load -- capacitor banks, cables).

Power Triangle

The power triangle visualization shows the geometric relationship between P, Q, and S. Apparent power (S) is the hypotenuse, active power (P) is the horizontal side, and reactive power (Q) is the vertical side. The angle between P and S is the power factor angle. A narrow triangle (small Q relative to P) indicates a good power factor; a tall triangle indicates a poor power factor with significant reactive power.

Tips

Use the playback slider to animate through the recording and watch how power quantities change from normal load through fault inception to clearance.
Use the Jump to A/B buttons to compare power at two specific points — for example, pre-fault load power (A) versus fault power (B).
A power factor near 1.0 during a fault suggests a predominantly resistive fault path (e.g., a ground fault through resistance).
Negative active power indicates power flowing from load to source, which occurs during generator reverse power conditions or with distributed generation.

How it works

For the mathematical definitions of P, Q, S, and power factor, see Theory: Power Quantities.

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Power Quantities

View per-phase active, reactive, and apparent power with power factor.

What This Tab Does

This tab requires sign-in. Once enabled, it updates in real time as you move the cursor or use the playback slider to animate through the recording.

1Power Analysist = 0.045s

2Channel Pairing3 pairs

456

Phase AVA → IA

P12.50kW

Q4.12kVAr

S13.16kVA

PF0.950 lagging

φ18.2°

Phase BVB → IB

P11.83kW

Q3.94kVAr

S12.47kVA

PF0.949 lagging

φ19.1°

Phase CVC → IC

P12.08kW

Q4.01kVAr

S12.73kVA

PF0.949 lagging

φ18.6°

73-Phase Totals

P₃φ

36.41 kW

Q₃φ

12.07 kVAr

S₃φ

38.36 kVA

PF0.949lagging

φ18.6°

Header — Zap icon with “Power Analysis” title and cursor timestamp display.

Channel pairing — Collapsible V–I channel mapping configuration. Auto-detected pairs can be manually overridden. Renders before phase cards.

Phase cards — 3-column grid, each card with a colored left-border accent matching the phase color (red/blue/green).

P/Q/S values — Active (P), reactive (Q), and apparent (S) power per phase with engineering units.

Power triangle — SVG triangle showing the P–Q–S relationship with angle arc and phase-colored strokes.

Power factor bar — Color-coded gauge — green (≥0.95), amber (≥0.85), red (below). Shows PF value and lead/lag.

Total system power — Sum of all phases: total P, Q, S with overall power factor and angle.

Time Playback

The cursor is automatically placed at the start of the recording when a file is loaded, so power values are always available immediately.

Time Playback Slider

123

A4B

545 / 200 ms61x

7Jump to:AB

1Play / Pause — animate through the recording. Phasors, power, harmonics, and readout values update in real time during playback.

2Reset — jump back to the start of the recording.

3Slider track — drag the thumb to scrub to any point in the recording. The filled portion shows current position.

4A/B cursor markers — when dual cursors are placed on the waveform, their positions appear as draggable markers (blue for A, orange for B). Drag a marker to reposition that cursor.

5Time readout — current playback position and total recording duration in milliseconds.

6Speed control — click to cycle through presets (0.5×, 1×, 2×, 4×, 8×). Double-click to type a custom speed. At 1× speed, one power cycle takes one second of wall time.

7Jump to A / B — snap the slider position to cursor A or cursor B. Only visible when both dual cursors are placed.

Channel Pairing

Voltage Mode

The Channel Pairing section includes a voltage mode toggle with two options:

Phase-to-Ground -- Use when your recording contains phase-to-neutral voltages (e.g., V_A, V_B, V_C). Pair each voltage directly with its corresponding phase current. You can add or remove pairs as needed.
Line-to-Line -- Use when your recording contains line-to-line voltages (e.g., V_AB, V_BC, V_CA). Select the available line-to-line voltage channels and phase currents. Detego automatically derives phase-to-neutral voltages from the line-to-line measurements before computing power.

Detego auto-detects which mode to use based on channel names and units. If auto-detection fails, you can switch modes manually.

Line-to-Line Configuration

In Line-to-Line mode, you assign up to three line-to-line voltage channels ( $V_{AB}$ , $V_{BC}$ , $V_{CA}$ ) and three phase currents ( $I_A$ , $I_B$ , $I_C$ ).

Only two of the three line-to-line voltages are required. The third is automatically derived using the identity $V_{AB} + V_{BC} + V_{CA} = 0$ .
Any of the three can be the derived one -- not just $V_{CA}$ . When two channels are assigned, the dropdown for the third shows “derive from others”.
If all three line-to-line channels are available in the recording, you can assign all three for maximum accuracy.

How derivation works

Saving Your Configuration

Channel pairing configuration is saved automatically per recording. When you reopen a recording, the voltage mode, channel assignments, and any manual pairs are restored exactly as you left them.

Reading the Results

The Power tab displays the following quantities for each voltage-current pair:

Quantity	Unit	What It Tells You
Active Power (P)	W	Real power doing useful work. Positive means power flows from source to load.
Reactive Power (Q)	VAR	Power oscillating between source and load. Positive Q means inductive (lagging); negative Q means capacitive (leading).
Apparent Power (S)	VA	Total power combining active and reactive. This is what determines equipment sizing (transformer ratings, cable ampacity).
Power Factor (PF)	0 to 1	Ratio of useful power to total power. PF = 1 means purely resistive; PF = 0 means purely reactive.

Power Factor Gauge

Power Triangle

Tips

Use the playback slider to animate through the recording and watch how power quantities change from normal load through fault inception to clearance.
Use the Jump to A/B buttons to compare power at two specific points — for example, pre-fault load power (A) versus fault power (B).
A power factor near 1.0 during a fault suggests a predominantly resistive fault path (e.g., a ground fault through resistance).
Negative active power indicates power flowing from load to source, which occurs during generator reverse power conditions or with distributed generation.

How it works

For the mathematical definitions of P, Q, S, and power factor, see Theory: Power Quantities.

PreviousCompute Tab NextDirectional