Normally the windings connected to the inverter circuit are not grounded. The grounded electrostatic shield placed between the primary and secondary windings is placed to prevent capacitive coupling of these windings.<\/p>\n
The main advantage of this screen is to minimise the possible transfer of high frequency disturbances (harmonics, pulses, surges occurring in the inverter) from the primary winding (B.T.) to the secondary winding (A.T.) and into the power grid.<\/p>\n
The other advantage of the electrostatic screen is to reduce the transfer of high voltage transient overvoltages to the primary winding(s) (B.V.) and the inverter connected to this primary winding. Without the electrostatic screen a high percentage of high voltage transients in the secondary winding (A.T.) could be transferred to the primary winding (B.T.) of the transformer.<\/p>\n
In addition, the electrostatic screen acts as an additional filter dU\/dt. The electrostatic screen can be made of either aluminium or copper, and when fitted to transformers it must be grounded at only one point. At the customer’s request an insulator can be fitted to the cover with the screen connected internally to earth through this insulator, rather than internally.<\/p>\n<\/div><\/div><\/div>