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PCC Estimation

Synchronized High-Voltage PCC Estimation via Secondary Sensing

The Point of Common Coupling (PCC) is the point where the ESP installation electrically connects to the upstream supply network. For power-quality work, it is the reference point used to judge voltage distortion, harmonic contribution, dips, swells, and other utility-side events.

ESP-GUARDX can estimate synchronized high-voltage (HV) PCC and low-voltage (LV) readings from the same secondary-side sensing stream. Instead of requiring a separate high-voltage sensing chain at the PCC, the system uses the measured secondary signals and the configured transformer model to reconstruct what the corresponding HV-side harmonic behavior should be.

PCC values are reconstructed estimates

ESP-GUARDX does not need to physically inject a high-voltage sensor at the PCC for this feature. The PCC harmonic values are reconstructed from secondary-side measurements and transformer configuration data. Accuracy depends on correct transformer parameters, vector group, winding topology, impedance data, and site calibration.

How It Works

Traditional PCC monitoring often uses one sensing chain on the primary high-voltage side and another on the secondary low-voltage side. That can introduce three practical problems:

  • Extra high-voltage PT hardware, wiring, installation work, and maintenance points.
  • Timing mismatch between separate primary and secondary measurement chains.
  • Phase-shift and vector-group errors when comparing measurements across complex transformers.

ESP-GUARDX avoids that split by capturing harmonics directly from the secondary or rectifier-side inputs, then applying inverse mathematical reconstruction. The processing engine accounts for:

  • Winding impedance.
  • Transformer vector group.
  • Phase-shift angle.
  • Multi-pulse rectifier arrangement.
  • Site-specific transformer configuration.

From that single synchronized data stream, ESP-GUARDX estimates the HV-side PCC harmonic distortion and keeps the LV and reconstructed HV readings aligned to the same timestamp.

Why Synchronization Matters

When HV and LV readings are sampled by separate devices, even a small timing offset can corrupt harmonic comparison. A fast transient, VFD switching artifact, or short dip may appear in one data stream before the other, making the event look like a transformer or load problem when it is really a measurement-timing problem.

Because ESP-GUARDX derives the estimated HV PCC values from the same acquisition stream used for the LV reading, both states share the same timing reference. This removes temporal drift between the two views and makes PCC-to-secondary comparison cleaner during event review.

Supported Transformer Topologies

The reconstruction model is intended for heavy industrial ESP installations, including phase-shifting transformer arrangements used to reduce harmonic distortion. It can be configured for complex winding topologies such as:

  • Polygon or squashed-delta windings.
  • Zig-zag transformers.
  • Multi-pulse arrangements up to 30-pulse.
  • Phase-shifting transformer groups with non-standard angular displacement.

The important point for the operator is that PCC estimation is not a generic voltage-ratio calculation. The algorithm must know the actual transformer topology so it can reverse the phase angles, impedance effects, and vector-group behavior correctly.

Operational Benefits

Benefit What It Means on Site
Synchronized HV/LV comparison Estimated PCC harmonics and measured LV harmonics are aligned to the same timestamp.
Reduced HV hardware The site can avoid adding a dedicated PCC-side PT chain for this specific estimation workflow.
Fewer installation points Less high-voltage wiring, fewer panels, and fewer devices to maintain.
Better event interpretation Harmonic and transient behavior can be compared across the transformer without primary/secondary timestamp drift.
Support for complex transformers Phase-shifting and multi-pulse systems can be modeled instead of treated as simple turns-ratio devices.

Where You See It

PCC values appear in the power-quality and electrical-equipment views where ESP-GUARDX compares harmonic behavior across the surface power train. Use the PCC readings together with:

  • Power Quality for EN 50160-style event counts, risk scoring, and harmonic recommendations.
  • Power Measurements for live voltage, current, power, THD/TDD, and unbalance.
  • Harmonics Analysis for detailed harmonic-order inspection.
  • ESP Configurator for transformer vector group, impedance, pulse configuration, and related model inputs.

Configuration Dependency

PCC estimation is only as reliable as the transformer model behind it. Before relying on reconstructed PCC harmonics, verify the configured transformer data:

  • Step-down and step-up transformer vector groups.
  • Transformer impedance and rated values.
  • Pulse configuration.
  • Phase-shift angles.
  • VT/CT ratios and channel assignments.
  • Rectifier-side sensing connections.

If those values are wrong, the system may still produce a synchronized estimate, but the estimate will not represent the real high-voltage PCC accurately.