Servotronix CDHD2S - Page 98

Drive Setup
—98—
Calculation of current during deceleration
A
0.0181
261
1.188
0.0004840.001
t
ω-ω
k
)J+(J
I
d
21
t
LoadMotor
M
18=
+
==
Calculation of energy
J9lb67.57ft0)-)(261 0.000484(0.0015
2
1
)ω)(ωJ+(JE
22
2LMdec
63.1
2
1
2
1
==+=−=
J11.61 = 0.0181 )
2
1.32
( 18 3 = t 2)(R3I E
2
dM
2
Mmotor
= /
Jlbft0)-(261)tω-(ωTE
d21ffriction
8.454.30181.05.1
2
1
2
1
====
75.22J=4.8-11.611-91.633=E-E-E=E
frictionmotordecM
( )
J
2
1
)V- C(VE
2
NOM
2
MBUS
05.34340420001120.0
2
1
22
=−==
Since EM>EBUS, a regenerative resistor is needed.
Calculation of resistor specification
V 182.423 = )
2
1.32
( 18 3-25000.0812 = )
2
R
( I3-NK = V
M
MBB

Ω02.31
318423.182
420
2
=

==
3IV
V
R
MB
2
M
MAX
7.1W
5.03
)380(4000.001120
2
1
44.42
t
VC(V
2
1
E
P
22
cycle
2
LOW
2
HighM
AV
=
−−
=
−−
=
W.
R
V
genRe
M
655686
132
420
P
22
PK
===
4.11.3 Regenerative resistor overload protection
Motor energy regeneration in CDHD2S is always active.
The motor energy regeneration function has two modes:
⚫ Regeneration with resistor overload protection.
The regenerative resistor circuit requires overload protection to ensure reliable operation of
the resistor. In this mode, you can configure the CDHD2S regenerative resistor parameters for
protection.
⚫ Regeneration without resistor overload protection. This mode is also called bang-bang mode.
In bang-bang mode, the drive will activate the regenerative resistor when the upper threshold
is exceeded (400V for medium-voltage drives, 770V for high-voltage drives); when the bus voltage
drops to the lower threshold (400V for medium-voltage drives) 380V,