Isolated MagI³C Power Module Mastering the 24V Industry Bus
Power Boost Feature
Author: Timur Uludag / Editor: Gerhard Stelzer
In the industrial environment, 24 V bus systems are widely used to supply a wide range of field devices. The article series so far explained selection criteria for power modules, typical voltage ranges, the issues with input voltage limits and especially the lower limit of the minimum input voltage and the upper limit of the maximum input voltage. Part 5 introduces the Power Boost feature.
In an industrial plant with its variety of applications, a lot of interaction between the supply, the loads and interference takes place. Many parameters are hard to calculate and hence can change during the implementation. One important point is the power that is needed to supply a load. Therefore, it is useful to have some kind of flexibility without changing the design.
A power boost feature is the ability of a power module to provide more than the nominal output power. There are two possible kinds of Power Boost functions: static and dynamic. Static power boost provides a durable extra power. Dynamic Power Boost even provides a multiple of the nominal power for a limited time. It needs periodic cool down cycles.
During the power boost event, the maximum ambient temperature rating is lower. This is related to the increased power dissipation of the power module. Thanks to the ability to deliver more than the nominal power, the following additional positive aspects enhance the application of a power module:
- Unforecasted increases in load demands are supported – see figure 1.
- Monotonic charging of capacitive loads is provided without voltage dips – see figure 1.
- Backup power for momentarily higher energy demands of the application.
- Tripping input fuses of downstream applications in case of an overload (ensures higher current for safe tripping) – see fuse tripping characteristic in figure 1.
Figure 1. Power boost abilities defuse issues with load fluctuations.