Non-exhaust emissions have become an increasingly important issue as their levels continue to rise and the health effects of particulate matter (PM) are more widely discussed. To address this issue, a vehicle demonstrator with integrated emission reduction of tires and brakes was developed as part of the Zero Emission Drive Unit Generation-1 (ZEDU-1) project. This novel concept includes the removal of tire road wear particles (TRWP) with a strong ventilation/filtering system and an enclosed multi-disk brake, making it a suitable tool for the investigation of non-exhaust emissions. Particle number (PN) and particle size distribution (PSD) measurements down to 2.5 nm were performed on a chassis dynamometer and on a test track. Due to the low background concentrations on the chassis dynamometer, it is possible to distinguish between tire and brake wear and to characterize even a small number of particle emissions. It could be shown that about 30

Although traffic exhaust emissions in Europe have been drastically reduced, airborne particle emissions caused by brakes and tires are still increasing with the number of vehicles. The measurement of non-exhaust emissions is an emerging technological challenge. We present a custom measurement setup to investigate the brake- and tire-wear emissions of an in-use battery electric vehicle. A separate brake housing and HEPA ventilation enabled airborne brake wear emissions to be measured under realistic conditions without external influences. The emission tests on a chassis dynamometer included particle number concentrations and particle size distribution for diameters of 4 nm to 10 μm. Emission indices were determined for three driving cycles: WLTC Class 3b, WLTC Brake Part 10, and a real driving cycle. Further investigations focused on emission control through regenerative braking and brake coating. Driving with regenerative braking reduced emissions by up to 89.9%, which related to the concentration of particles in the ultrafine/fine size range. Hard-metal brake coating led to a further significant reduction in emissions of up to 78.9%. The results point the way to future RDE measurement of non-exhaust emissions and show the potential of regenerative braking and brake coating to reduce airborne brake wear emissions.

Plug-in hybrid electric vehicles (PHEVs) show a high pollutant emission variability that strongly depends on the operating conditions of the internal combustion engine. Additionally, studies indicate that driving situations outside of the real driving emissions boundary conditions can lead to substantial pollutant emission increases. The objective of this study is to measure and analyze the particulate number (PN) and nitrogen oxides (NOx) emissions of a Euro 6 PHEV for a selected real-world driving test route in the Stuttgart metropolitan area. For this purpose, the vehicle is set out with multiple measurement devices to monitor vehicle internal and external parameters. Particle distribution results show an overall uniform pattern, which allows a comparative analysis of the different test scenarios on the basis of the PN concentration. While the trip-average PN emissions are in good agreement, transient effects during highway driving can substantially increase emissions, whereas the fuel consumption does not necessarily increase in such situations. PN measurements including ultrafine particles (UFP) show a significant increase in urban emissions due to higher cold start emission peaks. Additionally, low ambient temperatures raise the uncertainty of NOx and PN cold start emissions. With regard to future emission regulations, which claim that vehicles need to be as clean as possible in all driving situations, PHEV emission investigations for further situations outside of the current legislations are required.

A common approach to enhance the overall efficiency of an electric driven vehicle is to use a double motor concept. In the hereby presented research project TIOM (Two In One Motor) two different electric motors are used for traction, the compressor of the air conditioning (AC) system and the air compressor for the pneumatic systems in a public bus used in urban and suburban traffic. The main research questions in the following paper are first how the TIOM concept can be adapted to urban busses and second if the developed operation strategy leads to higher efficiencies. For this purpose a use case was defined and modelled with Dymola. A typical driving cycle was defined as use scenario. The model contains an operation strategy that can select between 16 different operation modes for the two motors based on the efficiencies of the motors, the torque requirements, the rotation speed of the wheel and the rotation speed range of the compressors. As a result, the energy consumption for the use case is evaluated and compared to a bus with a conventional motor concept with one large motor.

A common approach to enhance the overall efficiency of an electric driven vehicle is to use a double motor concept. In the hereby presented research project TIOM (Two in one motor) two different electric motors are used for traction and the pump of the hydraulic system. The main research questions in the following paper are first which motor concept fits best for this system and second if the developed operation strategy leads to higher efficiencies. For this purpose a simulation model of the vehicle including the hydraulic system was built in Dymola. As a use case a reference vehicle and a typical driving cycle were defined. The model contains a strategy that can select between five different operation modes for the two motors based on the efficiencies of the motors, the torque requirements and the rotation speed of the wheels. As a result the energy consumption in the different variations is evaluated and compared to a vehicle with a conventional motor concept with one large motor for the traction and hydraulic system.

Based on previous work [1, 2] a two-in-one-motor concept (TIOM) including an air conditioning compressor may increase the efficiency of electric driven cars by simultaneously reducing the total number of parts. The total energy saving results from two effects, switching between the two motors and operating them in its each best working point in addition of leading a part of the kinetic energy of the vehicle directly to the air conditioning compressor during recuperation events. The paper describes the development of such a double motor system coming from the drive concept design which depends on a chosen urban vehicle concept and leading over simulation to the design of the drive components and finally to the test of the total system.

In this paper, a Fuel Cell based Energy Storage System (FC-ESS) was investigated for enhancing the range of a electrical commuter vehicle. While using a special High Temperature Polymer Electrolyte Membrane (HTPEM) fuel cell with a nominal stack output power of 6 kW, the FC-ESS must be heated up to 120°C. A Fuel Cell Control Unit (FCCU) was created to fulfil the stack working conditions on anode and cathode. To evaluate the system concept a test bench including all required components to run the FC-ESS was built up. Results about the thermal heat up process e.g. a thermal heat up gradient of 2 K/min using a 1.3 kW electric heater integrated in the Tri Ethylene Glycol filled thermal system were obtained. The fuel cell stack polarization curve was measured making a ramp measurement from 10 A to 50 A. Hydrogen purge loss was disclosed between 3...12 % on constant stack electric power set points varying between 1...3 kW leading to an overall measured electric efficiency higher than 46 %. Referring on real traction power demand measurements of a demonstrator car for NEDC, WLTP and a specific commuter cycle between Stuttgart (ST) and Lampoldshausen (LA), the requested hydrogen storage capacity for different working conditions of the FC-ESS was calculated using different power set points. It was shown that a 6 kW FC-ESS with 0.5 kg stored hydrogen mass could extend the range of an FC-ESS equipped electric car up to 200 kilometres on NEDC and 196 km on WLTP. While using different fuel cell power set points commuter test cycle between ST-LA-ST can be driven either driven on the motorway or the freeway using the same hydrogen storage.