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Terry Chandler Power Quality Thailand LTD PQsynergy 2011 Chiang Mai, Thailand Sept 2011WWW.powerquality.co.th1 Slide 2 Monitoring Technologies Motors Generators Switchgear Cables Transformers Motors Generators Switchgear Cables Transformers Slide 3 Electrical Power Grid 3 Slide 4 Transformers and Bushings Slide 5 Data-Information-Knowledge Knowledge Using the information Information (Trend graphs etc) Data (values of parameters) Sept 2011WWW.powerquality.co.th5 Slide 6 Basic System Capabilities (Data) Transformer Monitoring, Control & Communications Monitor Inputs: Analogue (temperatures, fan motor current, DGA, PD) Digital (switch positions, sensor outputs) IEDs (Intelligent External Devices) Digital data Provide Outputs: Analogue Digital Data Communications Visual Slide 7 Monitoring and control of transformers Control Functions if needed Cooling Control Voltage Control including paralleling Sept 2011WWW.powerquality.co.th7 Slide 8 Transmission Transformer Slide 9 FIBRE Optic TEMPERATURE SENSING Direct monitoring of temperatures occurring in winding hotspots, core and other locations where fibre optic probes are built in to transformer Sept 2011WWW.powerquality.co.th9 Slide 10 Bushing Health Monitor (BHM) Alarms on: Magnitude of the imbalance current Trend of the imbalance currents Temperature dependencies Can be used for PD Slide 11 Installation Core Ground Current RFCT Slide 12 Installation CT Slide 13 Bushing sensor and Flexible CT Sept 2011WWW.powerquality.co.th13 Slide 14 BUSHING HEALTH MONITOR Continuous on line monitoring of bushings real time information of bushing capacitance and power factor. early detection of possible failure.. Sept 2011WWW.powerquality.co.th14 Slide 15 On-line Tap Changer (OLTC) Monitoring OLTC Counter OLTC Contact Wear OLTC Hunting Reversing Switch Exercise OLTC Motor Current Monitoring Auto Cleaning of the Reversing Switch OLTC Delta T Monitoring Sept 2011WWW.powerquality.co.th15 Slide 16 ELECTRICAL PARTIAL DISCHARGE PD activity occurring in a transformer can be detected by monitoring from the bushing tap (which is commonly used in factory testing). Sept 2011WWW.powerquality.co.th16 Slide 17 OEM sensor monitor functions Auto-Recharging Breather OLTC Oil Filtration System OLTC Contact Wear Sensor Inert Air or N2 Generation System Fan current (verify fans running) Contact closures Other Sept 2011WWW.powerquality.co.th17 Slide 18 Typical Monitoring system Sept 2011WWW.powerquality.co.th18 To Scada if available Slide 19 Information real time Sept 2011WWW.powerquality.co.th19 Slide 20 Reliability Improvement With on-line condition based data, condition based alarms when problems originate early detection and action or intervention promptly Prevent unscheduled outages. The analytical software within the monitoring system automatically identify issues requiring maintenance attention. The recording of cooling system run times OLTC operations Sept 2011WWW.powerquality.co.th20 Slide 21 Realizing True Capacity of Transformer Real-Time measurement of operational parameters allows the user of the transformer to realize the true capacity based on existing conditions of weather, load etc. optimal performance can be realized Sept 2011WWW.powerquality.co.th21 Slide 22 Maintenance Savings for Transformers The advanced analytics within the monitoring system filters through the condition data to automatically identify issues requiring maintenance attention. The recording of cooling system run times and OLTC operations provide useful data on the moving parts components. This provides Operations and Maintenance personnel the appropriate information to schedule condition based maintenance using information provided directly by the asset. Sept 2011WWW.powerquality.co.th22 Slide 23 Information Case Studies Sept 2011WWW.powerquality.co.th23 Slide 24 Case Study 1 6.6 kV Motor Motor with continuous PD monitor This motor drives a large critical compressor for a international customer. This client has been using a continuous partial discharge monitor for several years. Recently there was a fast increase in PD levels from the one of the RTDs. Sept 2011WWW.powerquality.co.th24 Slide 25 Increase in Partial Discharge Sept 2011WWW.powerquality.co.th25 Slide 26 Increase in PD activity it was recommended that the motor be taken out of service for inspection. An outage was scheduled for May 2009. Once the motor was placed back into service, all PD levels dropped down to acceptable levels and have remained at those levels. Sept 2011WWW.powerquality.co.th26 Slide 27 The defect was easily discovered and field repairs were made. Sept 2011WWW.powerquality.co.th27 Slide 28 By proving this early warning, one can schedule a planned outage. Taking a planned outage, is far more cost effective than having an unexpected Sept 2011WWW.powerquality.co.th28 Slide 29 Economic return (knowledge) Prevented catastrophic failure By proving this early warning, one can schedule a planned outage. Taking a planned outage, is far more cost effective than having an unexpected Estimated Cost Savings: $91,000 Sept 2011WWW.powerquality.co.th29 Slide 30 Economic returns Reliability improvement Realizing true capacity of transformer Maintenance savings Documenting life of transformer Extend life of transformers Sept 2011WWW.powerquality.co.th30 Slide 31 Case 2 230 kV Bushing Data Sept 2011WWW.powerquality.co.th31 Scheduled maintainance Slide 32 Cost saving (Knowledge) Estimated Cost Savings: Several Million Dollars due to cost of a new transformer and lost production. Scheduled shut down and replacement of Bushing vs unexpected failure and damage. Sept 2011WWW.powerquality.co.th32 Slide 33 Summary Large transformer assets monitoring system provides near real time data, alarming and historical data on all transformer parameters. Eliminates the need for manual measurements. Alert the owner to do preventative repairs before a major failure. Lower the cost of transformer inspections and regular servicing. Sept 2011WWW.powerquality.co.th33 Slide 34 Thank You Contact for more information Terry Chandler Terryc@powerquality.org Sept 2011WWW.powerquality.co.th34 Slide 35 Sept 2011WWW.powerquality.co.th35 Slide 36 Sept 2011WWW.powerquality.co.th36