The SAVI version shown in Figure is identical to the classic vacuum interrupter as far as insulator, arc control and shielding is concerned, but instead of the bellows and moving contact stem, there is a permanent magnetic actuator fitted within the interrupter, together with a guide and flexible conductors.
The interrupter operates by means of signals sent from
the control unit to the coil inside the actuator, this makes
the contact move to the open position by overcoming the effect of the permanent magnet. To close the contacts, the field in the coil is reversed.
The concept includes two main variants. The first variant the entire magnetic actuator contained within the vacuum envelope. This gives a very compact design, with simple external circuit connections.
The second variant has the magnetic circuit external to the vacuum wall, with the magnetic field acting through the end cap material.This allows us to build the VI without the magnetic actuator magnet or coil , and for these to be added after the VI is sealed off, together with a combined Rogowski coil and voltage sensor if required.
