2.6 Accessories for frequency inverter
Inoréa offers a range of accessories for your three-phase and single-phase variable frequency drives. You can find braking units, a braking resistor for braking your inverter, cables and screen supports to put your inverter screen on a cabinet and anti-harmonic filters and EMC filters to prevent electromagnetic disturbances.
What is an anti-harmonic filter?
An anti-harmonic filter is an external module that prevents electromagnetic disturbances that could disturb the upstream network. The operation is simple, the incoming harmonics are filtered in the anti-harmonic filter before being sent back to the electrical network. They are mainly used in the industrial sector for installations that require a lot of electrical energy, particularly for asynchronous motors.
What is a brake unit and the drive's braking resistor?
The braking unit of a drive is a component (basically a transistor), internal for small models and external for powers above 15 kw, which allows to send back the power from the load when it becomes driving (a bit long sentence)
Technically, when the electric motor becomes a generator, due to the inertia of the load (e.g. balance wheel, crusher, flywheel, etc.), it sends power (current) back to the drive. The consequence is a rise in the drive's DC bus voltage, which can lead to the breakdown of the drive's IGBTs. The only way for the drive to protect itself is to shut down the switching, or to offload this excess energy to a braking resistor, via the braking unit.
What is a cable and screen support?
On some drives, it is possible to take the display out of the drive and put it on a cabinet, in particular to protect the frequency converter from environmental risks (dust, humidity, water). To do this, a screen support is used to place the inverter's screen on the cabinet and a cable to connect the inverter to the external screen.