DG-IRMCK203 Datasheet, PDF (20/67 Pages) International Rectifier – Application Developer’s Guide

IRMCK203 Application Developer’s Guide
Nominal Vdc
Nominal DC bus voltage (in volts). For use with the IRMCS2031 development
platform, the nominal dc bus voltage should be set to 1.414 * ac input voltage ( ac
input voltage: USA 110V, JAP 100V, UK 220V etc.).
Max overload current
This is the anticipated maximum current in per unit drawn by the motor at the
motor’s rated speed. Setting this parameter to 1 pu means that the system drives
100% rated current at the rated speed.
Speed Regulator BW
Speed regulator bandwidth (in rad/sec). The system may not tolerate high speed
regulator bandwidth (due to mechanical coupling, gear box etc.), resulting in load
mechanical resonance. If the correct setting for this parameter is not known,
start with a value of 10 rad/sec and raise it gradually as the system is tuned.
Typical values would range between 10 and 25 rad/sec.
Acceleration Rate
This parameter defines the number of seconds required for the motor to accelerate
from 0 speed to the motor’s rated speed.
Deceleration Rate
This parameter defines the number of seconds required for the motor to decelerate
from rated speed to 0 speed.
Motoring Limit
Positive torque current limit (in percentage of rate current). Motoring power is
energy transferred from the inverter to the motor while the motor is running.
Regen Limit
Negative torque current limit (in percentage of rate current). Regenerative
energy is transferred from the motor to the inverter when the motor decelerates.
If the system does not contain a breaking resistor to absorb the regenerative
energy, an increase in DC bus voltage (and potential trip fault) results. This
parameter should be set to zero if the system cannot absorb regenerative power,
which is the case for the IRMCS2031 development platform as shipped.
Drive start current limit
Drive start-up current. During initial drive start-up, this current limit will be
applied to ensure robust start-up. Input as percentage of rated motor current.
Minimum running speed This is the minimum allowable operating speed for the Sensorless drive. Typical
values range between 5% and 10% of rated motor speed.
Pwm carrier freq
PWM carrier frequency. 10 KHz is the default setting for the IRMCS2031 product.
The setting of this parameter is a tradeoff between current ripple, inverter loss and
EMI noise.
Drive peak amps
This parameter defines the anticipated maximum drive current. This parameter
should be chosen to accommodate the anticipated full current range. The current
feedback resolution will degrade as a consequence of using a higher drive peak
amps value. Therefore, it is best to choose the minimum value that satisfies the
requirements of the application. It may be necessary to change the current
feedback shunt resistor on the IRMCS2031 development platform to conform to
the setting of this parameter. A shunt value calculated and displayed on the
worksheet to the right of the Drive peak amps entry (column F) shows the
recommended resistor value. It may be necessary to adjust the setting of the
Drive peak amps parameter slightly to obtain a shunt recommendation that
corresponds to a commercially available resistor value (1% or less tolerance
recommended).
This document is the property of International Rectifier and may not be copied or distributed without expressed consent.
20