Can I upgrade LV VFD to MV VFD by changing dc choke rate?
Absolutely no, because from the terminal connections to control cards are rated for certain voltage level and PCB are have the EEPROM which is programmed for 380 V if the variable frequency drive is manufactured for 380V because the controls are incorporated to monitor the DC link circuit, if the supply voltage is increased, the DC link voltage will also be increased hence the VFD drive will trip on DC over volt. If the voltage is increased the amount of heat dissipation increases thus it requires big heat sink and ventilation fans thus requires the enclosure size to be increased better take a new variable frequency drive from a reputed brand.
To the best of my knowledge, MV VFDs have different pads on the IGBT than LV VFDs. The IGBT is rated at a higher voltage as a result. MV VFDs start at 4160 and go typically to 12,470 so the IGBT should be rated for a minimum of 30,000 whereas the IGBT for LV VFD would be rated at about 1,600. There is a much farther minimum live clearance for MV.
While at a conceptual level, there are similarities between the LV and the MV options, it is not practical to take a LV VFD and convert it to MV. If you wish to use an LV drive on MV, the only practical way is to use a step down transformer on the input of the VFD and a step up transformer on the output.
To the best of my knowledge, MV VFDs have different pads on the IGBT than LV VFDs. The IGBT is rated at a higher voltage as a result. MV VFDs start at 4160 and go typically to 12,470 so the IGBT should be rated for a minimum of 30,000 whereas the IGBT for LV VFD would be rated at about 1,600. There is a much farther minimum live clearance for MV.
While at a conceptual level, there are similarities between the LV and the MV options, it is not practical to take a LV VFD and convert it to MV. If you wish to use an LV drive on MV, the only practical way is to use a step down transformer on the input of the VFD and a step up transformer on the output.
