Parameter Descriptions 2-169
7000-TD002A-EN-P – September 2007
PWM Parameters
Rectifier Pulse Number [Rec Pulse Number]
Linear Number: 95
Minimum Value: 0
Maximum Value: 36
Access Level: Service
Read/Write: Read Only
This parameter indicates the number of pulses per cycle in the switching pattern for the rectifier on PWM
Rectifier drives.
Inverter Pulse Number [Inv Pulse Number]
Linear Number: 295
Minimum Value: 0
Maximum Value: 65535
Access Level: Service
Read/Write: Read Only
This parameter indicates the number of pulses per cycle in the switching pattern for the inverter.
Inverter Pulse-Width Modulation Pattern [Inv PWM Pattern]
Linear Number: 378
Access Level: Service
Read/Write: Read Only
This parameter specifies the PWM firing pattern that is being used by the inverter SGCTs. Depending on
the stator frequency and the switching frequency, the inverter will be firing in one of the three different
PWM patterns:
Synch Mod Synchronous Modulation
SHE Selective Harmonic Elimination
Asynch Mod Asynchronous Modulation
Pattern 3 Not Currently Used
Pattern 4 Not Currently Used
Pattern 5 Not Currently Used
The following table illustrates typically at what speeds each pattern is utilized:
Synchronous Modulation (Medium speed)
Selective Harmonic Elimination (High speed)
Asynchronous Modulation (Low Speed)
DC Current Reference 5 pulse to 3 pulse [Idc 3 Pulse]
Linear Number: 756
Minimum Value: 0.000 pu
Maximum Value: 10.000 pu
Access Level: Service
Read/Write: Read Only
This parameter indicates the dc link current value in per unit at which a PWM rectifier will switch from 5-
pulse firing to 3-pulse firing. If the dc link current is more than the parameter value and the dc link voltage
reference (Vdc Reference) is below Vdc Ref 5p to 3p (379), the drive will switch from 5-pulse to 3-pulse.
This value is calculated from the rated motor current, rectifier device current rating and the Idc Fac 5p to
3p (560).
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