HV Test and Overspeed Facility Technical Challenges Emery | Engineering | May 16th, 2018 AEMT – Scottish Meeting May 2018
Agenda 1. Introduction 2. Motor Testing 3. High Speed Rotor Testing AEMT – Scottish Meeting May 2018
Introduction ◼ Richard Emery ◼ Engineering Manager - Sulzer EMS UK Ltd ◼ Engineering team based in Birmingham ◼ 16 service centres ◼ High Voltage Coil Manufacture ◼ Talk about technology behind two developments AEMT – Scottish Meeting 17 May 2018
Agenda 1. Introduction 2. Motor Testing 3. High Speed Rotor Testing AEMT – Scottish Meeting May 2018
Why Test a Motor? ◼ Ensure performance…. ◼ Temperature ◼ Vibration ◼ Balanced currents ◼ Eliminate risk… ◼ Expense of trouble shooting ◼ Cost of returning from site ◼ Delay in correcting issues ◼ Reasons for not testing… ◼ Cost ◼ Time ◼ Lack of suitable test plant AEMT – Scottish Meeting 19 May 2018
What Tests to Perform? ◼ Static tests - always performed ◼ Phase resistances ◼ Insulation Resistances (&PI) ◼ Interturn surge tests ◼ These prove windings are ok or otherwise ◼ Suitable for minor overhauls, small machines and site checks ◼ Let’s consider running tests AEMT – Scottish Meeting 20 May 2018
Benefits of Running Tests No-load run allows checks of: Loaded run checks: ◼ No load currents ◼ Full load currents ◼ Magnitude ◼ Magnitude ◼ Balance ◼ Balance ◼ Vibration ◼ Vibration ◼ Almost sync speed ◼ Slip speed ◼ Cold rotor only ◼ Hot rotor ◼ Noise ◼ Loaded noise ◼ Bearing condition ◼ Rotor currents on load ◼ Cooling performance ◼ Oil flow, temperatures ◼ Load test can be left until motor arrives at site……………….. AEMT – Scottish Meeting 21 May 2018
Difficulty of Load testing at Site ◼ Availability of constant load ◼ Machine under test needs to be at constant load for 4-6 hours ◼ Availability of full load ◼ Process doesn’t always allow full load ◼ Shut down time ◼ Need to measure hot winding resistances as soon as possible after shutdown ◼ RTD temperatures don’t tell complete story ◼ Flexibility of testing in Service Centre ◼ Can stop, start or change load at will ◼ Can start at 9:00 and finish at 17:00 ◼ Set up, reconfigure and start quickly ◼ Known test bed stiffness ◼ Repeatable vibration levels AEMT – Scottish Meeting 22 May 2018
Proposed Test System Topologies New test bed gives opportunities: ◼ To modernise from existing ◼ Increase flexibility Systems reviewed: ◼ Gearbox systems ◼ Variable frequency ◼ AC Generator AEMT – Scottish Meeting 23 May 2018
Motor Testing Challenges ◼ Frequency 50Hz and 60Hz required ◼ Voltage 400V up to 13800kV ◼ Speed 2 pole to 8 pole Power supply ◼ Induction motors 50Hz 50Hz ? 49Hz 1485rpm M G Tx 50Hz AEMT – Scottish Meeting 24 May 2018
Variable Frequency Solution ◼ Variable speed drive would solve some of the issues ◼ However has technical issues ◼ Harmonics ◼ Switching spikes ◼ Single phase testing ◼ Transformer testing PWM Waveform Voltage spikes AEMT – Scottish Meeting May 2018
Diesel Generator Test Facility ◼ Decision made to go with Diesel Generator driven system ◼ One large, one small for flexibility (2500kW and 700kW) ◼ Similar technology to old test plant ◼ Benefits of Fixed Frequency Supply ◼ Sine wave on stator winding - No dv/dt spikes or harmonics ◼ No harmonic heating, noise, vibration ◼ Allows momentarily overload ◼ Motor starts asynchronously – higher starting currents – Higher rotor currents AEMT – Scottish Meeting 26 May 2018
How to Determine a Motor Temperature Rise ◼ There are a number of accepted ways of testing a motor described in: ◼ IEC60034-29 ◼ IEEE 112 ◼ Run at full rated load ◼ Or perform equivalent tests: ◼ Extrapolation – Needs a load of some sort ◼ Mixed frequency – Needs 2 power supplies ◼ Forward short circuit – Needs 2 power supplies ◼ Equivalent tests need explanation AEMT – Scottish Meeting 27 May 2018
Sulzer System Layout Consider: G1 100A Motor G2 Starting current 600A 2500kW 700kW No load current 35A 0 – 415V 50-60Hz Transformer M 3.3, 6.6, Dyno 11&13.8kV AEMT – Scottish Meeting 28 May 2018
Agenda 1. Introduction 2. Motor Testing 3. High Speed Rotor Testing AEMT – Scottish Meeting May 2018
Turbo-Generator Service and Repair After any inspection or repair ◼ Balance checked (in shop or at site) ◼ Site runs often difficult to manage ◼ Access to all balance locations difficult ◼ In-house balancing quicker and better results AEMT – Scottish Meeting May 2018
Rotor Running Tests ◼ Balance below first critical speed ◼ Then above critical speed ◼ Then overspeed for 2 mins ◼ Check vibration levels before/after AEMT – Scottish Meeting May 2018
High Speed Balance Results Before After AEMT – Scottish Meeting May 2018
Overspeed Video https://www.youtube.com/watch?v=1C2pyTtbkjo AEMT – Scottish Meeting May 2018
High Speed Balance Pit Upgrade The HSB facility was installed in 2002 and operates between 20-30 times a year. It is used to test in-house repairs and plus test third party rotors. Risk assessments Improved quality Process improvements Repeatability Cost savings Investment in Technology AEMT – Scottish Meeting May 2018
High Speed Balance - Improvements ◼ Training ◼ Installing ◼ High speed balancing ◼ 5S of test area ◼ Safety risk assessments ◼ Lone worker ◼ Evacuation procedures ◼ Standard test paperwork ◼ Investment in new software AEMT – Scottish Meeting May 2018
New Balancing System ◼ More accurate sensors ◼ Fast Modelling ◼ Simulations possible = Faster process AEMT – Scottish Meeting 36 May 2018
Case Study ◼ Replacement of glass banding ◼ 4 pole generator ◼ Initial run shows need for balance AEMT – Scottish Meeting 37 May 2018
Case Study – Final Run ◼ After a few runs ◼ Balance weights added AEMT – Scottish Meeting 38 May 2018
Case Study – Final Run AEMT – Scottish Meeting 39 May 2018
High Speed Balance- Phase 2 ◼ Upgrade Drive system ◼ Old drive: ◼ New drive: ◼ DC Starter ◼ AC Variable frequency drive ◼ Ward Leonard Set ◼ Direct drive Motor (5000rpm) ◼ 11kV Synchronising panel ◼ Smaller lube system ◼ DC Motor (700rpm) ◼ Gearbox ◼ Large lube system ◼ Emergency gen set ◼ Highly skilled operators AEMT – Scottish Meeting 40 May 2018
Comparison Old drive system New system AEMT – Scottish Meeting 41 May 2018
Final Thoughts Customers expecting: ◼ More testing ◼ More comprehensive reports ◼ Better information Requires smart investments and new technologies AEMT – Scottish Meeting May 2018
Any Questions? AEMT – Scottish Meeting 43 May 2018
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