400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-0790 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2006-01-3570 King County Metro – Al lison Hybrid Electric Transit Bus Testing R. Robert Hayes, Aaron Williams, John Ireland, Kevin Walkowicz and Stuart Black National Renewable Energy Laboratory Commercial Vehicle Engineering Congress and Exhibition Chicago, Illinois October 31-November 2, 2006Downloaded from SAE International by Imperial College London, Saturday, September 08, 2018ISSN 0148-7191 Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is publ ished in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 3 00 word abstract to Secretary, Engineering Meetings Board, SAE. Printed in USA For multiple print copies contact: SAE Customer Service Tel: 877-606-7323 (in side USA and Canada) Tel: 724-776-4970 (outside USA)Fax: 724-776-1615Email: [email protected] permission and licen sing requests contact: SAE Permissions 400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: [email protected] : 724-772-4028 : 724-772-4891 Tel Fax Downloaded from SAE International by Imperial College London, Saturday, September 08, 20182006-01-3570 King County Metro – Allison Hybrid Electric Transit Bus Testing R. Robert Hayes, Aaron Williams, John Ireland, Kevin Walkowicz and Stuart Black National Renewable Energy Laboratory ABSTRACT Chassis dynamometer testing of two 60 foot articulated transit busses, one conventional and one hybrid, was conducted at the National Renewable Energy Laboratory’s, ReFUEL facility. Both test vehicles were 2004 New Flyer busses powered by Caterpillar C9 8.8L engines, with the hybrid vehicle incorporating a GM-Allison advanced hybrid electric drivetrain. Both vehicles also incorporated an oxidizing diesel particulate filter. The fuel economy and emissions benefits of the hybrid vehicle were evaluated over four driving cycles; Central Business District (CBD), Orange County (OCTA), Manhattan (MAN) and a cust om test cycle dev eloped from in-use data of the King County Metro (KCM) fleet operation. The hybrid vehicle demonstrated the highest improvement in fuel economy (mpg basis) over the low speed, heavy stop-and-go driving conditions of the Manhattan test cycle (74.6%) followed by the OCTA (50.6%), CBD (48.3%) and KCM (30.3%). With similar trends to fuel economy improvements the hybrid showed improvement in NOx emissi ons over the Manhattan cycle (38.7%), the OCTA (28.6%), CBD (26.6%) and KCM (17.8%). Effects of air conditioning loads and grade were also studied. OBJECTIVES This work comprises chassis dynamometer testing of two 60 foot articulated transit busses, one baseline and one hybrid, from King County Metro fleet operations in Seattle, Washington. Testing was performed to evaluate the emissions and fuel economy benefits of the Allison hybrid-electric powertrain in a transit bus application. Testing was conducted over f our driving cycles; Central Business District (CBD), Orange County (OCTA), Manhattan (MAN) and a cust om test cycle dev eloped from in-use data of the King County Metro (KCM) fleet operation. In order to evaluate the effects of additional engine and vehicle loading due to air conditioning and grade, select cycles were repeated with and without these added loads. Vehicle exhaust emissions, fuel consumption and state of charge of the energy storage system were measured for r epeated test conditions. The remainder of this document includes the experimental setup, test procedures, results, and conclusions from vehicle testing performed at the NREL ReFUEL laboratory. EXPERIMENTAL SETUP The vehicles were tested at th