When it comes to the question of whether it is worth while
modernizing an existing DC drive or less expensive to replace
it entirely with an AC drive, there are also various arguments
which need to be assessed:
Basically, there are several options available for a modernization job:
1. Replace the entire DC drive (converter and motor) by a new
DC drive.
2. Replace only the converter cubicle, if the motor is still in
good condition.
3. Replace the converter module by a modern digital unit.
4. Replace the old, analog drive electronics by new, digital
electronics while continuing to use the power section
(recommended only for ratings above 1 MW).
5. Replace the entire drive system with a new AC drive.
When answering the question of what approach constitutes
the optimum solution in a particular case, the following main
criteria are important:
Will the requirements for the drive change in future (load
requirements, environmental conditions)?
In what condition are the individual components of the
system (reliability, age, maintenance outlay)?
How far will the supply conditions change in future?
Before a decision is made to modify a drive from DC to AC
design, the following points should be taken into consideration:
Outlay for new power cabling.
Space requirements for converter cubicles.
Dissipation of energy losses from the switchroom sufficient?
Foundations, mounting for motor sufficient?
Space requirement for new motor.
Duration of conversion work.
modernizing an existing DC drive or less expensive to replace
it entirely with an AC drive, there are also various arguments
which need to be assessed:
Basically, there are several options available for a modernization job:
1. Replace the entire DC drive (converter and motor) by a new
DC drive.
2. Replace only the converter cubicle, if the motor is still in
good condition.
3. Replace the converter module by a modern digital unit.
4. Replace the old, analog drive electronics by new, digital
electronics while continuing to use the power section
(recommended only for ratings above 1 MW).
5. Replace the entire drive system with a new AC drive.
When answering the question of what approach constitutes
the optimum solution in a particular case, the following main
criteria are important:
Will the requirements for the drive change in future (load
requirements, environmental conditions)?
In what condition are the individual components of the
system (reliability, age, maintenance outlay)?
How far will the supply conditions change in future?
Before a decision is made to modify a drive from DC to AC
design, the following points should be taken into consideration:
Outlay for new power cabling.
Space requirements for converter cubicles.
Dissipation of energy losses from the switchroom sufficient?
Foundations, mounting for motor sufficient?
Space requirement for new motor.
Duration of conversion work.
