Wheel
Clutch
I
S
G
Engine
Transmission
Differential
Wheel
375
Hybrid Vehicles
Transmission
Clutch
Starter
Generator
Flywheel
Belt
Engine
Wheel
Differential
Wheel
Figure 12.10
Separated-starter-generator system for conventional ICEVs.
Figure 12.11
Integrated-starter-generator system for HEVs.
the definite advantages of high robustness and low inertia, but has the drawbacks of relatively lower efficiency and lower power density (Zhan, Chan,
and Chau 1999). The permanent-magnet (PM) brushless machines, including those PM brushless AC ones (Chau et al. 2006a; Cui et al. 2005) and PM
brushless DC ones (Gan et al. 2000; Wang et al. 2002), offer the advantages
of high efficiency and high-power density. However, they suffer from the
incapability of flux control (Bae and Sul 2003). A double-stator PM brushless
topology is proposed to tune the flux, but it needs a complicated mechanism to shift the spatial angle between two stators (Zhang et al. 2006). By
incorporating the advantageous features of both the PM brushless and SR
machines, the doubly salient PM (DSPM) machine offers the merits of high
efficiency, high-power density, high robustness, and low inertia (Chau et al.
2005; Cheng et al. 2003). But, it still has the drawback of inflexible flux control.
By replacing the PM materials with a DC field winding, a brushless doubly
fed doubly salient (BDFDS) machine (or specifically called the stator doubly