Impact of Different Driving Cycles and Operating Conditions on CO2 Emissions and Energy Management Strategies of a Euro-6 Hybrid Electric Vehicle

Abstract

Although Hybrid Electric Vehicles (HEVs) represent one of the key technologies to reduce CO 2 emissions, their effective potential in real world driving conditions strongly depends on the performance of their Energy Management System (EMS) and on its capability to maximize the efficiency of the powertrain in real life as well as during Type Approval (TA) tests. Attempting to close the gap between TA and real world CO 2 emissions, the European Commission has decided to introduce from September 2017 the Worldwide Harmonized Light duty Test Procedure (WLTP), replacing the previous procedure based on the New European Driving Cycle (NEDC). The aim of this work is the analysis of the impact of different driving cycles and operating conditions on CO 2 emissions and on energy management strategies of a Euro-6 HEV through the limited number of information available from the chassis dyno tests. The vehicle was tested considering different initial battery State of Charge (SOC), ranging from 40% to 65%, and engine coolant temperatures, from −7 • C to 70 • C. The change of test conditions from NEDC to WLTP was shown to lead to a significant reduction of the electric drive and to about a 30% increase of CO 2 emissions. However, since the specific energy demand of WLTP is about 50% higher than that of NEDC, these results demonstrate that the EMS strategies of the tested vehicle can achieve, in test conditions closer to real life, even higher efficiency levels than those that are currently evaluated on the NEDC, and prove the effectiveness of HEV technology to reduce CO 2 emissions.

Evaluation of the Effects of Biodiesel on Emissions and Performance by Comparing the Results of the New European Drive Cycle and Worldwide Harmonized Light Vehicles Test Cycle

“…Phase-1 version of the WLTP with the name of Global Technical Regulation was released in 2015 [18]. Although researchers have investigated exhaust emission and fuel consumption difference of the NEDC and the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) [19,20], very limited experimental data exists in the literature on the effects of biodiesel over the WLTC.…”

Driven Performance of Electric Vehicles in Edinburgh and Its Environs

“…The actual energy demand of BEVs when they are operating on the streets is usually different from the manufacturer's specifications of the efficiency [33]. Legal measures are commonly based on defined and laboratory-controlled driving cycles, which are available just as summarised values.…”

Powertrain Test Bench System

“…In order to respond to this problem a Worldwide Harmonized Light Duty Driving Test Cycle (WLTC), has been developed and used as a basis for certified tests procedures since 2014 [4]. In 2017, European commission decided to replace NEDC by WLTC [6], [7].…”