Controllers
Parameter manual b maXX BM3000
Document no.: 5.12001.07 Baumüller Nürnberg GmbH
470
of 820
4.7
4.7.2.3 Torque Current Limiting
The torque current limiting acts on the integral term of the speed controller and on the out-
put of the motor manager before the current is forwarded to the current controller.
There is no limiting at the output of the speed controller because a digital filter can be in-
serted between the speed controller and the motor manager, or an Isq can additionally
be fed into the motor manager.
The torque current limiting can be set separately for motor or generator operation
(
Z138.2–, Z138.3–). By adapting the "Mode of Iq limit " Z138.1– bit 0, the separate lim-
iting can alternatively be applied to Torque Direction 1 or Torque Direction 2. For "asym-
metric" limiting, operating quadrants 1 to 4 are evaluated using the present speed and
torque current. Hysteresis
Z138.4– can be set when determining the operating quad-
rants.
Two symmetrical limits Z138.14– and Z138.15– are available in addition to the limit de-
pendent on quadrants. The limiting Z138.14– is intended for a fast cyclic access via anal-
ogous input or fieldbus process data. Other limits of the torque current are the breakdown
limit (
Z138.18–, also refer to ZBreakdown torque– on page 498) or external limits (refer
to Z138.8–).
A torque current limit is set by the torque limit Z138.22– as well.
Furthermore, the torque current can be disabled due to a power failure (refer to Z130.10–
bit 1).
Always the less value of these limits is effective! The effective limit values are displayed
in
Z138.6– Iq upper limit and Z138.7– Iq lower limit.
The settable torque current limits Z138.2–, Z138.3–, Z138.14– and Z138.15– were
standardized by the "Max. torque current" Z19.8– and is the percentage set of this pa-
rameter. The parameters of ProDrive can be entered and displayed in ampere (as this
was demanded by the setting auxiliary) but the values can change in the operating pro
-
cess because the reference value could change due to field weakening or to external total
current limit. Refer to the parameter
Z19.8– and Z138.1–.
Dependent of the standardization modes (parameter "Mode lq limit" Z138.1– bit 1 and
bit 3) the calculation of the parameter Z19.8– can be changed. Consequently, the follow-
ing standardization or limit modes accordant to the motor type are available: Load mode
Standard, Load mode ASM-lsdMax and the current mode.
NOTE!
Up to firmware version V01.08: The dead time measurement must be repeated if the
PWM frequency is changed.
From Firmware version V01.09: If the correction table Z123.15– is measured from
firmware version V01.09 onwards and the adaption of the dead time compensation
according to the PWM frequency is active (
Z123.1– bit 3 = 1), the effective voltage
of the dead time compensation is corrected according to the effective PWM frequen-
cy. A new dead time measurement after a change of the PWM frequency is therefore
not necessary. However the best results are generally reached if the used PWM fre
-
quency corresponds to the PWM frequency at the moment of the dead time measure-
ment.