Line Reactor for VFD
The functions of input line reactor
It can restrain harmonic current, improve power coefficient, weaken surge voltage in input circuit, the impact of current on VFD, the influences of power voltage, limit current surge caused by grid voltage change and switching surge, spike pulse or voltage defects in phase change of rectifying circuit, effectively protect VFD and improve power coefficient. Input line reactor not only can stop the disturbance from power grid but reduce the pollution of power grid by harmonic current produced by rectifying unit.
The functions of output line reactor
When the length of cable between VFD and motor is longer than the specified value of product, output line reactor should be added to offset the influences of charging and discharging of coupling capacity in the operation of cable of motor and avoid overcurrent of VFD. Output line reactors are divided into two types. One is iron core line reactor adopted when the rate of carrier wave is lower than 3kHz. The other one is ferrite line reactor adopted when the rate of carrier wave is lower than 6kHz. The installation of output line reactor on the output terminal of VFD aims to increase the distance between VFD and motor. Output line reactor can effectively restrain the instantaneous high voltage when turning on or off IGBT of VFD and reduce the adverse influences of voltage on cables and motor.
The functions of EC line reactor
FC VFD is installed between DC rectification link and inversion link and is mainly used to limit the AC component of DC in a range, keep rectified current continuous, reduce current pulse, make inversion link operate more stably and improve the power coefficient of VFD.