2 hp (1.5 kW) VFD, 3 Phase 240V, 415V, 480V

2 hp variable frequency drive, three phase 240V, 415V, 480V for choice.

Specification:

Tips: Variable frequency drive harmonic wave problems and solutions
The devices that have switch effect in VFD main circuit will produce harmonics wave in the process of on-off circuit. The lower harmonics usually have large effect on the motor load, causing the torque ripple. And the higher harmonics increase the leakage current of the VFD output cable, causing low output. Harmonic wave interference can also lead to misoperation of the relay protection device, so that the electrical instrument measurement is not accurate, or even cannot work properly.
The treatment of harmonic wave problems is to cut off the interference route transmission and suppress high harmonic wave of interference source.
The methods of cutting off the interference route transmission:

1. Cut off the approach of common ground wire propagation interference. The ground connection of the power line and the ground connection of the control line should be separated, that is connecting the grounding terminal of the drive device to the earth wire, and the grounding terminal of the control device to its metal shell.
2. Set the signal line away from the interference source power wire. Wiring separation is effective in eliminating this interference, that is, to separate the high-voltage cables, power cables, control cables, instrument cables and computer cables wiring.

The methods to suppress higher harmonic wave on the interference source:

1. Increase the internal impedance of the VFD power supply. Usually the internal impedance of the power supply device has the function of buffering the reactive power of the DC filter capacitor. The larger the internal impedance, the fewer the harmonic wave content. The internal impedance is the short circuit impedance of the transformer. Therefore, when choosing variable frequency drive power supply, the best choice is large short circuit impedance ones.
2. Install the filter. In the front of VFD, install the LC-type passive filter can filter out 5 and 7 times of high harmonic wave.
3. Install the reactor. Install the line reactor in the front of VFD to suppress the overvoltage on the power supply.
4. Set the active filter. Active filtering can automatically generate a current that has the same amplitude and the opposite phase of the harmonic current, so that can effectively absorb the harmonic wave current.