Patent ID: 7436686

Claim:
Voltage inverter provided with four switching cells (Q 1 to Q 4 ) to be connected to the terminals of a DC voltage source (Vdc), each comprising two semiconductor switches (I 11 , I 12 , I 21 , I 22 , I 31 , I 32 , I 41 , I 42 ) installed in series, these switches having a common point (A 0 ) to be connected to an AC current source (Mac) with three phases (p 1 , p 2 , p 3 ) and a neutral (n), the connection being made onto one phase (p 1 , p 2 , p 3 ) for three of the cells (Q 1 , Q 2 , Q 3 ) and onto the neutral (n) for the fourth cell (Q 4 ), wherein each of the four cells (Q 1 to Q 4 ) cooperates with a semiconductor electrical isolating device (S 1 , (S 2 . 1 and S 2 . 2 )) to be put into a turn-off state if the cell should fail, this isolating device (S 1 , (S 2 . 1 and S 2 . 2 )) being arranged either on the connection to the AC current source (Mac), or on connections to the terminals of the DC voltage source (Vdc).