Technical Challenges Emery | Engineering | May 16th, 2018 AEMT - - PowerPoint PPT Presentation

AEMT – Scottish Meeting May 2018

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

◼ 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

Introduction

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AEMT – Scottish Meeting May 2018

Agenda

• 1. Introduction
• 2. Motor Testing
• 3. High Speed Rotor Testing

AEMT – Scottish Meeting May 2018

◼ Reasons for not testing…

◼ Cost ◼ Time ◼ Lack of suitable test plant

◼ Eliminate risk…

◼ Expense of trouble shooting ◼ Cost of returning from site ◼ Delay in correcting issues

◼ Ensure performance….

◼ Temperature ◼ Vibration ◼ Balanced currents

Why Test a Motor?

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AEMT – Scottish Meeting May 2018

◼ 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

What Tests to Perform?

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AEMT – Scottish Meeting May 2018

No-load run allows checks of: ◼ No load currents

◼ Magnitude ◼ Balance

◼ Vibration

◼ Almost sync speed ◼ Cold rotor only

◼ Noise ◼ Bearing condition

◼ Oil flow, temperatures

◼ Load test can be left until motor arrives at site………………..

Benefits of Running Tests

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Loaded run checks: ◼ Full load currents

◼ Magnitude ◼ Balance

◼ Vibration

◼ Slip speed ◼ Hot rotor

◼ Loaded noise ◼ Rotor currents on load ◼ Cooling performance

AEMT – Scottish Meeting May 2018

◼ 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

Difficulty of Load testing at Site

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AEMT – Scottish Meeting May 2018

New test bed gives opportunities:

◼ To modernise from existing ◼ Increase flexibility

Systems reviewed:

◼ Gearbox systems ◼ Variable frequency ◼ AC Generator

Proposed Test System Topologies

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AEMT – Scottish Meeting May 2018

◼ Frequency 50Hz and 60Hz required ◼ Voltage 400V up to 13800kV ◼ Speed 2 pole to 8 pole ◼ Induction motors

Motor Testing Challenges

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50Hz M G 1485rpm 49Hz Power supply 50Hz Tx ? 50Hz

AEMT – Scottish Meeting May 2018

◼ Variable speed drive would solve some of the issues ◼ However has technical issues

◼ Harmonics ◼ Switching spikes ◼ Single phase testing ◼ Transformer testing

Variable Frequency Solution

Voltage spikes PWM Waveform

AEMT – Scottish Meeting May 2018

◼ 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

Diesel Generator Test Facility

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AEMT – Scottish Meeting May 2018

◼ 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

How to Determine a Motor Temperature Rise

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AEMT – Scottish Meeting May 2018

Sulzer System Layout

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0 – 415V 50-60Hz M G1 Dyno Transformer G2 3.3, 6.6, 11&13.8kV 2500kW 700kW Consider: 100A Motor Starting current 600A No load current 35A

AEMT – Scottish Meeting 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

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.

High Speed Balance Pit Upgrade

Risk assessments Process improvements Investment in Technology Improved quality Repeatability Cost savings

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

◼ More accurate sensors ◼ Fast Modelling ◼ Simulations possible = Faster process

New Balancing System

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AEMT – Scottish Meeting May 2018

◼ Replacement of glass banding ◼ 4 pole generator ◼ Initial run shows need for balance

Case Study

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AEMT – Scottish Meeting May 2018

◼ After a few runs ◼ Balance weights added

Case Study – Final Run

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AEMT – Scottish Meeting May 2018

Case Study – Final Run

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AEMT – Scottish Meeting May 2018

◼ Upgrade Drive system ◼ Old drive:

◼ DC Starter ◼ Ward Leonard Set ◼ 11kV Synchronising panel ◼ DC Motor (700rpm) ◼ Gearbox ◼ Large lube system ◼ Emergency gen set ◼ Highly skilled operators

High Speed Balance- Phase 2

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◼ New drive:

◼ AC Variable frequency drive ◼ Direct drive Motor (5000rpm) ◼ Smaller lube system

AEMT – Scottish Meeting May 2018

Old drive system

Comparison

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New system

AEMT – Scottish Meeting May 2018

Final Thoughts

Customers expecting: ◼ More testing ◼ More comprehensive reports ◼ Better information Requires smart investments and new technologies

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Any Questions?