
6.DETERMINING THE ACCELERATION TIME SPECIFICATIONS FOR THE αi SERIES B-65272EN/04
- 34 -
- Acceleration time (t1) in the constant-torque range (0 to Nb)
(JL+Jm) ×Nb
2
t1=0.10754× [sec]
Pf×1000
- Acceleration time (t2) in the constant-output range (Nb to Nf)
(JL+Jm) × (Nf
2
-Nb
2
)
t2=0.10754× [sec]
2×Pf×1000
- Acceleration time (t3) in the decreasing-output range (Nf to Nm)
(JL+Jm) × (Nm-Nf) Pf Nm-Pm Nf
t3=0.10754× × {(Nm-Nf) - ×Ln(Pm/Pf)} [sec]
(Pm-Pf) ×1000 Pm-Pf
The total time (t) required for acceleration in the range from 0 to N m
is t1+t2+t3 [sec]
Deceleration can be controlled so that the time required for
deceleration is nearly equal to that for acceleration. When the power
voltage is high, or the impedance of the power is high, the time
required for deceleration may not be made equal to that for
acceleration.
Calculation example
Model α8/8000i has the acceleration/deceleration output
characteristics shown below.
13.2
11
0
1500 6000
8000[min
-1
]
Speed
9
7.5
Output
kW
cceleration/deceleration output
30-minute rated output
In this case, the variables have the following values.
Jm : 0.0028 [kgf⋅m⋅sec
2
]
NOTE
The rotor inertia is 0.28 [kgf⋅cm⋅sec
2
] in the
α8/8000i specifications. When the unit is changed
for calculation, the rotor inertia is 0.28
[kgf⋅cm⋅sec
2
]/100 = 0.0028[kgf⋅m⋅sec
2
]