Servotronix CDHD2S - Page 96

Drive Setup
—96—
Determine the energy that the bus module can absorb
)) (V- C(V
2
1
= E
2
NOM
2
MBUS
Where:
EBUS= Energy that the bus module can absorb (J)
C=Bus module capacitance (F); please refer to the Bus Specifications section
VM = Maximum bus voltage (v); please refer to the Bus Specifications section.
VNOM=Bus nominal voltage=√2Vmains（V）
Determine whether the regenerative resistor is needed.
If EBUS>EM, the regenerative resistor is not needed.
If EBUS<EM, the regenerative resistor is needed.
Determine the resistor value
The procedure for calculating regeneration requirements is twofold. The regenerative resistor value and
resistor power must be determined.
Determine the resistance value
3IV
V
= R
MB
M
Max
2
Where:
VB = Motor back-EMF - motor loss.
/2)(R IM - N K = V
MBB
3
VM = Maximum bus voltage (v); please refer to the Bus Specifications section.
KB=Back-EMF constant (VL-L/rpm)
N=Motor velocity before deceleration (rpm)
IM = Current during deceleration (ARMS/phase)
RM = Motor resistance (ΩL-L)
Determine the average power dissipated
t
) V- C(V
2
1
-E
= P
cycle
2
Low
2
HighM
AV
Where: