Vicruns 2S-0.4G-B, Руководство пользователя

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 The resistance of the resistor that over 2500W and the power are the
total amount of resistance and power. The power of the resistor is get
from parallel connection based on 2500W. For example, to get a
25000W 6
Ω
IS, ten 2500W 60
Ω
resistors are needed to be connected in
parallel.
The calculation of braking resistor: When the braking current IB flowing
through the energy consumption circuit is equal to half of the rated current
of the motor, the braking torque of the motor is approximately equal to its
rated torque:
IB=IMN/ 2 TB≈TMN or IB=2UB/ IMN
Notes：
IB—braking current，A； IMN—the motor rated current，A；
Tb—braking torque，N
▪
m； TMN—rated load torque of motor，N▪m。
As a general rule, the range of choice of braking torque is：
TMN＜TB＜2TMN IMN＜IB＜21MN
According to specific situation，users can decide the braking current according
to the formula(3-12) and (3-13).
After that，it is easy to calculate the braking resistance：
RB= UB/ IB RBmin= UB/ IMN
Notes：
UB is the braking threshold voltage；RB is braking resistor value .
UB is 1. 1times as that of the rated voltage of bus. RBmin is the minimum
braking resistance the common braking threshold voltage：
AC220V: DC380V AC380V: DC680V AC660V: DC1140V
When get IB and RB, the power of resistance will be known.
λ：Actual resistance value/calculated value ED%: Braking efficiency
Suppose that there is a 7. 5KW motor，rated current is 18A and rated input
voltage is 380V and：
RB=680V/ 9A=75Ω RBmin=680/18=38Ω
Empirically, the value is 75Ω
The power of braking resistor=1*6802/75*0.1=616W The power can be approp-
riately enlarged in actual use.
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Chapter 10 Appendix