Driving schedule

On a transient driving schedule, this instaiitaneons fuel economy must be averaged over the distance driven. 

The shortcoming of a constant-speed test is that in traffic, nobody drives at constant speed. Consequently, with the onset of the federal fuel-economy standards that took effect in the United States in 1978, the Environmental Protection Agency (EPA) prescribed transient driving schedules deemed representative of both urban and highway driving. 

Automobiles vary enormously in their weight from 2500 to 5500 lb, which requires an engine displacement from below 100 to above 500 cu. in. In a similar driving schedule, a 5000 lb car will emit nearly twice the... 

As time and cost constraints make it impossible to use a fleet test as the test procedure in the development of emission control catalysts, several simplified durability tests have been developed. In order of decreasing complexity, these tests are a vehicle driven on the road according to a well defined driving schedule, a vehicle mounted on a vehicle dynamometer driven according to a well defined procedure by robots, tests with an engine mounted on an engine dynamometer, and tests in a laboratory furnace (Table 19). 

These DEF systems are generally mounted on the side of the frame of the vehicle. The fill point is generally under hood. The actual diesel emissions fluid is a 35% urea-water mixture. Because this mixture freezes at -11°C, a heated EPDM (ethylene-propylene diene monomer)/nylon 6,6 line is used to deliver the urea from the tank to the exhaust stream. A sensor controls the flow of the urea to obtain the NOx reduction. This system can reduce NOx emissions by up to 40%. The urea refill rate is about once every 3 months based on typical driving schedules. 

Many consortia and publications have proposed a number of standard drives to evaluate battery performance. Schedules such as the Federal Urban Drive Schedule (FUDS), the Highway Fuel Economy Test (HWFET), and the Dynamic Stress Test (DST) are used as yardsticks of performance on a comparative basis. As metrics for fuel economy or other corporate standards, they may be appropriate but these should not generally be used as the real-world test of battery performance. Where performance is to be measured, it is recommended here that a Kochis Stress Test (KST) be used, which is a test philosophy that states that the maximum loads (charge and discharge) that will be used in the vehicle should be used to establish performance traits. This implies two points (i) the test should be demonstrated and calibrated in a vehicle that is the intended application (ii) if vehicle calibrations are changed, the effect on battery performance must be re-evaluated. 

Figure 7. Dynamic response of the system on a portion of the FUDS. The fuel cell system s power generation lags behind the driving schedule s power demand during rapid power up-ramps.

FHDS Federal Highway Driving Schedule H2GC4S9 Dihydrogen Tetragermanium... 

FUDS Federal Urban Driving Schedule H2S04 Sulfuric Acid... 

This 1.6L has relatively cool exhaust and achieved converter light-off with the Pd Front Brick converters about 175 seconds into the ECE portion of the driving schedule. Converter ligh-tofF is defined when the front brick catalyst bed temperature reaches 350 C. 

European driving cycle (NEEXT), which is available on internet as value table, has been considered for this study. Other driving schedules have been considered for variation purposes (Fig. 27.6). 

A system analysis of different concepts with simulations was presented in [30]. Three hybridization concepts with supercapacitors or batteries were analyzed concepts 1.0, 1.1 (a), and 1.1 (b). They were all compared with a pure fuel-cell system. The simulations showed that hybridization with supercapacitors significantly load-leveled the fuel cell operation. Fuel economy for the FUDS (Federal Urban Driving Schedule) cycle was improved up to 28% in case of supercapacitors. Because of the higher losses in the batteries, the improvement in fuel economy was only 6% for batteries. The highest fuel economy improvement was achieved for concept 1.0 with supercapacitors directly coupled to the fuel cell, as there are no additional losses for the DC-DC converter. 

The micro-hybrid electric vehicles are the simplest versions that improve fuel efficiency. Burke et al. [2] used a small electric motor and a module of 18 commercial carbon-carbon double-layer-based ESs. They demonstrated a 40% improvement in fuel economy with the Federal Urban Driving Schedule (FUDS) and an increase in engine efficiency of 30% in comparison to an ICE of 19%. 

C.A. Papachristou and H. Konuk, A Linear Program Drive Scheduling and Allocation Method Followed by an Interconnect... 

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