Challenges of Precision Testing of EV Drives Future Powertrain Conference 2017 David Meek (M.Eng and Man) Chief Engineer 1 st March 2017
What We Do What We Do Everyday Where Which Economic Sectors Assurance Testing Inspection Certification 100+ countries 1,000+ laboratories 40,000+ people Products Trade Resources 2
Transportation Technologies ITT Electrification Testing Services Worldwide Today Hybrid powertrain emissions testing - UK EV traction motor testing - UK Electrical systems safety testing and certification UK, Germany, USA & China EMC immunity / radiation UK, Germany, USA & China Component environmental testing UK, Germany, USA & China EV Battery testing function, safety and durability Germany, USA & China EV Charger station testing UK, Germany, USA & China 3
Intertek United Kingdom Milton Keynes UK Powertrain Test & Development Laboratory Single site facility with 30 test cells emotor Performance, Efficiency, Thermal and Durability Testing 100kW and 300kW 18,000rpm 2 rigs Hybrid Powertrain and EV Driveline Testing Single and dual A/C driveline dynos to 800kW - 4 cells Engine Performance, Emissions and EMS Mapping Transient A/C dynos to 570kW / 1,200Nm - 5 cells Engine Durability Testing Eddy-current dynos to 900kW / 6,000Nm - 7 cells High voltage systems testing up to 1,000V Transmission Testing Catalyst, DPF, SCR and GPF Ageing - 5 cells Fuel & Lubricant Engine Testing - 7 cells plus Vehicle-based Fleet Trials Real Driving Emissions Testing 4
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Key Challenges Providing trustworthy, accurate and repeatable data from an electrically noisy environment Intertek has invested in equipment, software and methods to ensure it delivers accurate high bandwidth data for its clients in the following key areas Mechanical Power Measurement Electrical Power Measurement Thermal Control and Measurement ECE Reg. 85 Power Certification 6
Challenge Mechanical Power Measurement Providing accurate high bandwidth torque measurement Modern inverter driven electric machines can exhibit very high torque slew rates up to 50kNm/s Precision current control methods demand precision torque measurement Intertek Solutions: Rotor position synchronous trigger to allow data sources to be time and position synchronised achieves < 0.01 mechanical degree accuracy at 18,000rpm High bandwidth in-line HBM T40B torque sensor with UKAS torque calibration traceability to < 0.05% High frequency data acquisition 20kHz to 20MHz depending on channel 20kHz torque signal sampling recommended to prevent aliasing of torque signal Low windage / low loss link shaft system Torque offset nulling method integrated into rig control system Bi-directional zero speed crossing method eliminates influence of static cogging torque wind-up between DUT and load motor 7
Challenge Electrical Power Measurement Providing trustworthy, accurate and repeatable electrical current, voltage and power data Analysing PWM driven currents and voltages with fundamental frequencies up to 20kHz with analysis required up to 50 th harmonic Fast response electrical power analyser for transient power and efficiency measurement on cycle-by-cycle basis with reliable tracking of motor fundamental frequency Intertek Solution: Electrical Power Analyser Intertek has worked closely with Newton s 4 th to develop a customised power analyser solution to meet automotive requirements Suitable for fast transient cycle-by-cycle power measurement High 2.0MHz sampling rate enables harmonic analysis High bandwidth voltage sensors to avoid aliasing of voltage signal due to switch-on switch-off voltage overshoot in phase cables sometimes called ringing High bandwidth external current sensors high currents for EV applications prevent the use of internal shunts NPL traceable calibration of analyser and current sensors as a system with power accuracy < 0.05% 8
Challenge Thermal System Measurement Providing trustworthy thermal data from an electrically noisy environment Thermal limit testing is critical for optimum performance and machine robustness Temperature sensor signals are notoriously prone to electrical noise Temperature sensors are often embedded close to high voltage wires introducing a risk of high voltage cross-over Efficient electrical systems often generate insufficient heat to achieve target temperature set-points quickly Intertek Solution: Electrically Isolated Sensor Module Intertek has developed its own flexible and modular 3.0kV isolated instrumentation modules with noise rejection software Suitable for analogue, digital and temperature sensor inputs 16bit resolution and bandwidth up to 1.0 MHz Outputs on standard automotive CAN network or via analogue into ETAS INCA etc. Intertek Solution: Dual Channel Fluid Conditioning Rigs Intertek designed rig with heating, cooling and variable speed pump emachine and Inverter can be individually pre-conditioned to desired temperature set-points in the range -10 to +105 o C 9
Supporting ECE Reg. 85 Power Certification Working within the current ECE framework Intertek has worked with the VCA to understand how the current Regulations should be interpreted for modern inverter driven machines Intertek Solution: VCA Credited Facility for Reg. 85 Power Certification VCA Credited for pre-certification attribute setting (Various critical parameters must be pre-specified and submitted to the VCA for validation/approval before the actual certification occurs) UKAS traceable measurement for all test data sources. Intertek emachine test facility easily exceeds all certification accuracy requirements 10
Further information www.intertek.com david.meek@intertek.com Tel: +44 (0)1908 513018 11