Install at the control cabinet.
Three-phase voltage and current from the generator's CTs, and its PTs above 690 V. Nothing is mounted on the generator, the engine or the turbine.
HOW IT WORKS
Read from the generator's
own current and voltage.
Faults in the generator, and mechanical conditions in its drivetrain, change the current and voltage at its terminals. e-PCM measures those signals at the control cabinet and compares them with the model it has learned for that generator.
Learn the generator.
e-PCM builds a model of the machine from its own electrical behaviour across its operating conditions. Comparing similar units across a fleet adds context.
Watch and report.
Persistent deviations are flagged by fault category, with what to inspect. Results show on the unit and go to plant systems. In OmniSight, Artesis Insight AI writes them up.
WHICH GENERATORS
Fit depends on the
machine family.
Synchronous, induction and DFIG generators carry different signatures at their terminals. This is where e-PCM gives the most, and where it does not apply.
Hydro units
Salient-pole generators on a direct grid connection. Eccentricity, stator and excitation behaviour. Findings are checked against operating data, because hydraulic effects can resemble some rotor patterns.
Diesel and gas gensets
Continuous and standby duty. Generator condition, plus prime-mover effects that show up in the generator's current, from one measurement. These machines often have little other monitoring.
Wind turbines (DFIG)
Generator stator condition at the grid terminals. With an encoder speed reference, the gearbox and bearings are monitored too.
Steam and gas turbine generators
Generator condition and mechanical faults such as unbalance and misalignment. Turbine torque is smooth, so prime-mover faults are harder to place.
WIND TURBINES · DFIG
Generator, gearbox and bearings.
Read from the control cabinet.
On DFIG wind turbines, e-PCM measures at the turbine's control cabinet, with no sensors added to the generator or gearbox. The turbine's encoder gives the speed reference for gearbox and bearing analysis. Select a component to see what e-PCM reports.
COVERED
Generator
Stator condition with the affected phase identified, rotor indications, and the generator's output and power quality at the terminals.
INSPECTStator winding and connections on the flagged phase.
COVERED
Gearbox
Gear mesh patterns in the generator current, placed against shaft speed from the encoder.
INSPECTGear mesh and gearbox bearings.
COVERED
Bearings
Developing defects in the main, gearbox and generator bearings, placed against shaft speed. Where bearing geometry is known, it points to the bearing.
INSPECTThe flagged bearing, lubrication and mounting.
COVERED
Shaft and coupling
Unbalance, misalignment and coupling condition in the drivetrain.
INSPECTShaft alignment, the coupling and mounting bolts.
INPUT, NOT MONITORED
Encoder
The turbine's own encoder gives e-PCM the shaft speed. That speed is what lets gearbox and bearing patterns be placed.
SETUPEncoder signal wired to the e-PCM unit at the control cabinet.
NOT COVERED
Blades, pitch and yaw
Blade, pitch and yaw conditions are not covered by e-PCM.
INSTEADUse the turbine's own blade, pitch and yaw monitoring.
WHAT IT FINDS
Fault categories,
with what to inspect.
Findings are reported by category. The recommended check confirms the cause on the machine.
MECHANICAL
Unbalance, alignment, looseness.
Unbalance, misalignment, loose foundation and components, coupling. Inspection of balance, alignment, bolts and soft foot confirms the cause.
BEARINGS
Bearings and gearbox.
Developing bearing defects, placed against shaft speed and, where known, the bearing geometry. On wind turbines, an encoder speed reference extends this to the gearbox.
STATOR
Stator indication and phase.
Current asymmetry judged against voltage asymmetry, and stator-related patterns in the spectrum, with the affected phase identified. Inspection confirms the specific cause.
ROTOR
Rotor and eccentricity.
Rotor category indication consistent with eccentricity, corroborated with operating data, especially on hydro units. Rotor bar patterns on induction and DFIG generators.
EXCITATION
Excitation and voltage behaviour.
Loss of excitation, abnormal power factor or reactive power at constant load, and voltage and reactive power oscillation.
POWER
Power quality and output.
Voltage and current imbalance, harmonic distortion, active and reactive power, power factor and frequency.
IN THE FIELD
A 350 kW diesel generator.
An alarm that went unanswered.
A 350 kW, 380 V, 1500 rpm diesel generator on a farm in Germany was fitted with Artesis monitoring alongside its existing monitoring system. Shortly after the learning period, its mechanical and electrical parameters began to rise.
ALARM → WHAT HAPPENED
The mechanical parameters raised an alarm, then escalated to the examine level. The report pointed to the unbalance, eccentricity and coupling family.
The electrical parameters changed at the same time, corroborating a developing fault.
The generator's existing monitoring system gave no warning, so the generator stayed in service.
The generator failed. The examination found unbalance, which had progressed to contact between rotor and stator.
Shown as a record of what the electrical signature carried. The alarm was not acted on.
MORE FROM THE FIELD
MECHANICAL · TURBINE GENERATOR
95 MW steam turbine generator.
Confirmed by orbit plots.
At a power plant supplying a US steel operation, the spectrum of a 95 MW steam turbine generator showed a raised peak at twice running speed, an unbalance and misalignment indication. The plant's proximity-probe orbit plots at the generator free-end bearing showed the same condition.
HYDRO · FLEET COMPARISON
Six hydro units,
compared side by side.
Six generators at two hydro plants in Türkiye were assessed together. Five were in good condition. One showed loose foundation patterns, and two showed stator-related patterns below alarm level, marked for trending.
Case data from Artesis installations. Findings are shown by category, as e-PCM reports them. The hydro example is a fleet assessment, not a confirmed finding on the machine.
BEFORE YOU INSTALL
Requirements
and boundaries.
What an installation needs, and where generator monitoring from the terminals stops.
WHAT YOU NEED ON SITE
- Three-phase voltage and current at the generator control cabinet: current through CTs, voltage direct up to 690 V or through PTs above that.
- Control power for the unit: 100 to 240 V AC, or DC.
- Nameplate data and the machine family: synchronous, induction or DFIG.
- For wind gearbox and bearing monitoring: an encoder speed reference.
- For OmniSight and plant system integration: a network connection.
- A learning period at the generator's normal operating conditions before findings are reported.
WHAT IT DOES NOT DO
- Insulation aging: use offline IR, tan delta or PD testing.
- Partial discharge: use online or offline PD monitoring.
- Core lamination shorts: use thermography or core loss testing.
- Early field winding shorts: use flux probes or field current measurement.
- Blade and yaw conditions are not covered.
- It reports fault categories, not a severity scale.
e-PCM AND e-MCM
e-PCM for generators. e-MCM for motors.
Each product has its own analysis, built for its machine. Monitor your generators with e-PCM and your motor-driven equipment with e-MCM, and see both in OmniSight.
e-PCM · GENERATOR MONITORING
Start with the generators
you rely on.
Tell us the machine family, rating and duty. We will look at what e-PCM can see on it and what an installation needs.
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