Output reactors reduce the rate of voltage rise (dv/dt) and the height of the current peaks, and enable longer motor cables to be connected.
Owing to the high rates of voltage rise of the fast-switching IGBTs, the capacitance of long motor cables reverses polarity very quickly with every switching operation in the inverter. As a result, the inverter is loaded with additional current peaks of substantial magnitude.
Output reactors reduce the magnitude of these additional peaks because the cable capacitance reverses polarity more slowly across the reactor inductance, thereby attenuating the amplitudes of the current peaks.
When using output reactors, the following should be observed:
Max. permissible output frequency 150 Hz
Max. permissible pulse frequency 4 kHz
The output reactor must be installed as close as possible to the Power Module
Two output reactors are to be provided to increase the permissible cable lengths.
When connecting the Power Modules to IT networks, the use of an output reactor is recommended to avoid an overcurrent shutdown in the event of a ground fault.
1) On the rating plate of the reactor, the current is specified according to the duty cycle for high overload (HO). This is lower than the current specified according to the duty cycle for low overload (LO) of the Power Module.
