GE Industrial Solutions DV-300 DC Drive Users Manual - Manual (Page 309)

DV-300 Adjustable Speed Drives
——— FUNCTION DESCRIPTION ———
6
181
6.17.2 Torque calculation
The torque calculator is made of three blocks:
1.
Torque calculation according to the winder/unwinder ray and to the set tension: C = T x r
2. Calculation of the static, dynamic and inertial compensations
3. If the Taper function is enabled, the calculation of the tension curve is made according to the ray.
The tension and Taper reduction references can be sent via an analog input, serial line or field bus. The calculation
of the angular acceleration, necessary to the inertial compensations, can be carried out through asuitable internal
function or by stating via three digital inputs the acceleration, deceleration and fast deceleration conditions.
The connection to the PID function belongs to the compensation block. Such connection is necessary when a
closed loop tension control with loading cell is carried out.
The calculation result is sent directly to the drive current limits and can be monitored in the parameters In use
Tcur lim + and In use Tcur lim – of the LIMITS menu.
The standard parameters T current lim +/- and the limits set by the programmable overload function are anyway
active in order to protect both the inverter and the motor; the setting with the lowest value is always the most
important. It is also possible to set a specific current limit for the coil “launching” function during an automatic
switching. The outcoming tension value and that of the calculated torque current can be monitored on the analog
outputs.
OPTIONS
Torque winder
Torque calculat
[1180] Tension ref [%]
[1181] Tension scale [%]
[1194] Act tension ref [%]
[1193] Torque current [%]
Parameter description No.
Value
Standard
Configuration min max
Factory
American
Factory
European
Tension ref [%] 1180 0.00 199.99 0 0 *
Tension scale [%] 1181 0 200 100 100
Act tension ref [%] 1194 0.00 199.99
Torque current [%] 1193 0.00 200.00 **
* This parameter can be set on a programmable analog input.
** This parameter can be set on a programmable analog output.
Tension ref Per cent tension reference.
Tension scale Scale factor of the torque current in %.
This parameter is used when the value of the maximum winding torque has to be limited
or when a closed loop control is used in order to adjust the torque current value to the
real tension on the material measured by the loading cell.
As for tuning refer to paragraph Application example.
Act tension ref Monitor of the % tension reference less the Taper percentage set via Tension red; if the
Taper function is not enabled, it corresponds to Tension ref.
Torque current Monitor for the requirement of the torque current in %.