68 5. MATHEMATICAL MODELING AND TV ANALYSIS OFHYBRID ELECTRIC VEHICLES
k
0
99
D k
S2b
r
2
b
C k
ab
r
2
b
(5.44)
k
0
10;1
D k
S2b
r
S2
r
b
(5.45)
k
0
10;7
D k
ab
r
a
r
b
(5.46)
k
0
10;10
D k
S2b
r
2
b
C k
ab
r
2
b
(5.47)
J
c
D J
0
c
C n.M
a
r
2
ca
C M
b
r
2
cb
/ (5.48)
r
ca
D r
S1
C r
a
(5.49)
r
cb
D r
S2
C r
b
(5.50)
where the moment of inertia of the carrier J
c
is defined as
J
c
D J
0
c
C n.M
a
r
2
ca
C M
b
r
2
cb
/; r
ca
D r
S1
C r
a
r
cb
D r
S2
C r
b
; (5.51)
where J
0
c
is the carrier moment of inertia, n is total number of planet gears a-b in the compound
planetary gear set, M
a
and M
b
are masses of planets a and b, r
ca
and r
cb
are radiuses of revolution
of the short and long planet gears. J
S1
is the moment of inertia of small sun gear, J
S2
is the
moment of inertia of big sun gear, J
a1
, J
a2
, and J
a3
is the moment of inertia for short planet
gears, and J
a1
D J
a2
D J
a3
J
b1
, J
b2
, and J
b3
is the moment of inertia for long planetary gears,
and J
b1
D J
b2
D J
b3
J
r
is the moment of inertia for ring gear.
5.2 THE TORSIONAL DYNAMIC MODEL OF THE
POWER-SPLIT HYBRID SYSTEM
e TV model for the power-split hybrid driveline system is presented in Fig. 5.2.
And the engine dynamics equation can be described by
J
e
R
e
C k
tc
.
e
c
/
D 0; (5.52)
where J
e
is the moment of inertia of the engine,
e
is the angular displacement of engine, and
c
is the angular displacement of planetary carrier. k
tc
D
k
t
k
c
k
t
C k
c
, k
t
, and k
c
are the CPGS of the
torsional damper and the planetary carrier. e dynamics equation of the TV can be described
by
J
m
R
m
C k
rm
r
m1
.
m
r
m1
r
r
r2
/ C k
md
r
r2
.
m
r
m2
d
r
d
/ D 0; (5.53)
where J
m
is the moment of inertia of the reducer, k
rm
is meshing stiffness between the ring and
the reducer, k
md
is meshing stiffness between the reducer and the differential. r
m1
and r
m2
are
base radiuses of reducer gears, r
r2
is the base radius of the outer ring, and
m
and
r
are angular
displacements of the reducer and ring, respectively.
e equilibrium equation of TV for the differential can be derived as follows:
J
d
R
d
C k
md
r
d
.
d
r
d
m
r
m2
/ C k
lh
.
d
lw
/ C k
rh
.
d
rw
/ D 0; (5.54)