The DC bus link, or connections, of the AKD drive can be used to connect the DC bus of one drive to the DC bus of another drive.  The connection is done in parallel between two or more drives, with the maximum number of drives being limited by the total sum of the current ratings, as specified in the drive manual.   This method is commonly used to help maintain the DC bus voltage within the allowable range in applications involving motor regenerative power (regen).  As a motor is back-driven (driven by the load, gravity, external forces, etc.), the motor produces power, causing the DC bus voltage in the drive to increase.  The voltage can be maintained at an appropriate level by dissipating power through a regen resistor. 

Connecting the DC bus of each drive in parallel allows the DC bus voltage to be equal in all of the drives.  This is useful in two ways.  If a single drive's regen capability can handle the regen requirement of all of the drives in the application, then it is possible to only use a single regen resistor connected to one of the drives.  That drive then handles all regen (dissipation) for all of the drives.  It is also possible that some drives will be using power while others are in regen.  This acts as a balance, so that the power generated by some motors can be directly used by other drives, and thus requiring less or no regen capability requirement. 

Connecting the DC bus of multiple drives requires that each of the drives use the same AC mains source at the same mains voltage level.

The KCM Capacitor Module can be used in parallel with a system of AKD drives with parallel DC bus links.  The KCM module is only for AKD's with 400/480V rated voltage and maximum rated current up to 24A.

This article is a single-source data for AKD.

• Digital current controller (670 ns)
• Digital speed controller  (62,5 µs)
• Digital position controller (250 µs)