Best Practices in Condition Monitoring and Risk Assessment for High-Voltage Motors and Generators
A best practice article for engineers and plant managers operating HV motors and generators.
By Ron Scollay, Technical Authority at machinemonitor® with over 30 years in the field.
Motors and generators are inherently reliable. The operational stresses at the shaft, load, and connection to the power supply are factors that contribute to ageing and developing failure mechanisms.
Matching the machine to the application to understand the normal working stress and how this affects the machine components is the first step in effecting a reliability-centred maintenance program.
Understanding Operational Stresses
As an example, a high-power rating at low voltage and low power rating at high voltage are design aspects that have different failure mechanisms. The method used for health monitoring of electrical machines requires an appreciation of the operational stress created by the power connection and mechanical coupling on the machine design.
Condition Monitoring Transducers
There are many condition monitoring transducers used to monitor electrical machines. Stator winding insulation health, partial discharge and tan delta, rotor bar integrity, rotor turn insulation, vibration levels, winding and bearing temperature etc, are all aspects that measure discrete components of the machine integrity. What condition monitoring aspects and how they are determined as appropriate to economically manage machine reliability is the question.
The requirement is therefore:
To understand the machine design and design stress raisers in the application.
To have a method to leverage from experience of operating and maintenance challenges of machines in operation in similar applications.
To identify the failure mechanisms from the design and application knowledge.
The RiskMonitor® Process
Riskmonitor® is a system that collates machine knowledge and provides the engineering diligence to understand the machine condition and operating risk by answering the questions;
What do the condition monitoring results mean in terms of risk, reliability, and longevity.
Where are gaps in the overall machine condition knowledge that require further qualification.
What condition monitoring is best to manage the most significant ageing stress parameter in the machine.
What techniques can cost effectively be conducted to determine whether intrusive maintenance inspection can be postponed by confidently applying accurate engineering knowledge?
The outcome is knowledge to effect condition-based reliability centred maintenance decisions.
RiskMonitor® was developed by machinemonitor® specifically to manage and analyse test results and monitoring data for electrical assets. The platform has been operating for over 22 years and has been improved based on customer needs and usage.
In 2023, an advanced addition was included by the OptMonitor® continuous monitoring solution.
