Modules & capacitor assemblies

When the capacitance requirement is slightly higher or when the physical space creates constraints, larger single large-can capacitors may have to be replaced by multiple smaller ones. On such occasions, we talk about modules and capacitor pack solutions, where we simply connect the number of capacitors that are required to meet the specification.

Connecting capacitors in a capacitor bank also has other benefits for your application – mechanically, thermally and electrically.

Mechanically more durable as the single large-can capacitors are better secured. (Modules are usually used when the single large-can capacitors are quite large, from approx. 5x10 cm and up). There is also less risk of moisture or oxygen penetrating and causing corrosion.

Thermally more resilient, as a capacitor has the greatest heat dissipation axially. It is difficult to remove heat through conduction on the underside, where the connections are located, so this needs to be done from the top. In a module, the single large-can capacitors have smaller height differences compared to stand-alone large-can capacitors. This ensures that all are equally well cooled and maintain the same temperature. The difference in service life will be smaller between each single large-can capacitor, and thus the service life of the entire module will be longer.

Better from an electrical perspective, as modules are made of copper/aluminium sheet, which makes it easy to achieve a large conductor area. This reduces the resistance in the conductor. You can also achieve low inductances, as the various conductors come very close to one another. The low impedance types are particularly good when using high switch frequencies. In some cases, it is also possible to have shorter internal conductors in the single large-can capacitor, which in turn also results in less heat generation. 

The difference between a module and a pack is actually simply how many connections are required to connect the capacitors to your other electronics. The connections can be achieved via cables, PCBs or busbar solutions.