Hybrid vehicle characterization - Propulsion Systems for Hybrid Vehicles - page 430

1
ð MWP hwy FCT hwy = 33 : 44 Þþ½ð 1 MWP hwy Þ= PCT hwy

FEMWP hwy ¼ ð mpeg Þ

ð 9 : 6 Þ

1
ð 0 : 55 = FEMWP city Þþð 0 : 45 = FEMWP hwy Þ

FEMWP comb ¼ ð mpeg Þ ð 9 : 7 Þ

SAE J1711 UF weighted
SAE has developed a weighting factor to calculate combined mode fuel economy in
mpeg [10]:

2
ð 1 = UF city Þþð 1 = PCT city Þ

FEJ1711 city ¼ ð mpeg Þ ð 9 : 8 Þ

2
ð 1 = UF hwy Þþð 1 = PCT hwy Þ

FEJ1711 hwy ¼ ð mpeg Þ ð 9 : 9 Þ

1
ð 0 : 55 = FEJ1711 city Þþð 0 : 45 = FEJ1711 hwy Þ

FEMWP comb ¼ ð mpeg Þ 9 : 10 Þ

9.4 European NEDC

The New European Drive Cycle (NEDC) has a higher top speed than the US
Highway cycle (120 kph versus 96.2 kph) but an average speed of 32.2 kph that is
more consistent with the US FTP city cycle at 34 kph [8]. Figure 9.11 is a chart
showing the second-by-second speed in mph.

80

60

40

20

0

0 500 1,000 1,500

Time (s)

Figure 9.11 European NEDC drive cycle

This drive cycle is typically used by independent emissions testing laboratories
to characterize hybrid vehicle economy and emissions. Figure 9.12 is representative
of the NEDC cycle used for dynamometer characterization tests. It should also be
noted that the old style Clayton twin roller dynamometers have been replaced with
4 ft diameter single rolls with appropriate dynamometer settings for inertia and
rolling resistance.