Introduction
Generator Field Monitoring combines Premium Shaft Ground Monitoring (SGM) and Rotor Flux Monitoring (RFM) systems into one powerful controller. Plant personnel can achieve the benefits of both systems for better trend analysis and easier system management.
shaft ground monitoring
Monitoring the shaft grounding allows plants to reduce operation expenses, while optimizing capital. The system detects failures such as poor shaft contact, bearing faults, and stator issues.
Shaft Ground Monitoring Case Study
SGM measures 0 to peak, DC, and RMS levels at the ground current, shaft voltage, turbine and exciter shaft voltage to give a better and more complete picture.
The generator in Figure 2 is challenging, and has high peaks that aren’t picked up by handheld meters. The operator was alerted to the high peaks based on pre – determined alarms, and replaced the ropes.
Shortly thereafter, the voltage began to increase again in a steady fashion again alerting the team to a potential failure. The plant was able to fix the concern during an upcoming outage rather than the failure causing a costly forced outage in the future.
rotor flux monitoring
Advanced knowledge of insulation failure can prevent shorted winding turns, damaged insulation, and forced outages. Measuring the magnetic flux signal within the rotor alerts plants to early detection of potential failures.
Trending and Analyzing RFM Data
Figure 3 shows a breakdown of a RFM analysis:
- Image A is the asset tree showing all the items the system is measuring and calculating on one flux probe.
- Graph B indicates how the waveform is collected and analyzed. The dotted lines show which coil is at zero cross when the scan is taken.
- Table C calculates the percent difference between the lead and lag on each coil representing any potential shorted turns.
- Graph D conveys RMS calculations of the flux density waveform.
generator field monitoring return on investment
Shaft Ground Monitoring ROI
Rotor Flux Monitoring ROI
* Note: The results are estimates and illustrative only. Specific risks, costs, and prices will vary. This is not a guarantee of savings nor a guarantee of eliminating risk. Proper maintenance must be performed.
Future of predictive maintenance: monitoring initiatives
Companies with multiple monitoring systems are able to validate potential failures by measuring different electrical signals within various equipment throughout the plant. Abnormal waveforms found in one monitoring system are usually replicated in others, allowing personnel the confidence and knowledge that their equipment is either healthy or will need maintenance in an upcoming outage. Fewer surprise outages ultimately save plants money, and free up resources to be reallocated to other projects.
For more information on Generator Field Monitoring, click on the image below to watch the webinar:
