Electric Motor Monitoring & Life Prediction in Mining Ben Nalbantof Supervisor – Galina Mirzaeva Cooperative Research Centre (CRC) for Mining

Objectives Existing methods of motor wellness diagnostic Determine physical conditions causing DC motor faults Identify excessive wearing & damage to their elements Diagnose any unreliable operations Recognise causes of lifetime reduction Modify existing operations and maintenance procedures

Motivation Mines desire an improvement in equipment performance & asset utilization Existing motor fleets are extensive

DC Motor Armature Brushes Commutator

Project Scope Insulation Commutation Switching Drive Interference

Insulation Insulation resistance Polarization Index Impulse Testing Insulation Testing DC coil resistance High Potential Partial Discharge Impulse Testing Most involved of the techniques Steep voltage front impulses test insulation

Commutation Armature Reaction Commutation Process Causes of Sparking Methods of mitigating sparking issues

Armature Reaction

Commutation Armature Reaction Commutation Process Causes of Sparking Methods of mitigating sparking issues

DC Machine Testing Achievements & Plans Efficiency Tests Armature Fault Tests Commutation Tests

Achievements & Plans Excitation of DC motor for testing

Switching Electronics Interference Thyristor Drive

Simoreg DC Drive Different switching frequencies Vary di/dt Other available options

Conclusions DC motors review Insulation tests DC motor testing DC motor testing with drive attached Results and recommendations

Questions?