High power density inverter (i)

Abstract

The present invention relates to a single phase, non-insulated, miniaturized DC/AC power inverter () having an output power density higher than 3000 W/dm, wherein said first (S_H), second (S_L), third (S_H) and fourth (S_L) switches are made of wide-band semiconductors and preferably of gallium nitride or GaN semiconductors; and wherein said DC/AC power inverter () further comprises: a ripple-compensating active filter comprising a third half-bridge () having a fifth switch (S_H) in series with a sixth switch (S_L), said fifth switch (S_H) being connected at one end to the positive terminal (L+) of the DC input, said sixth switch (S_L) being connected at one end to the negative terminal (L−) of the DC input,the other end of the fifth switch (S_H) being connected to the other end of the sixth switch (S_L), defining a third common end, said third common end being connected to a first end of a LC filter, made of at least one inductor (L) and one storage capacitor (C), a second end of the LC filter being connected to the negative terminal (L−); modulation control means of said first (S_H), second (S_L), third (S_H), fourth (S_L), fifth (S_H) and sixth (S_L) switches for providing a switch frequency comprised between 20 and 500 kHz and allowing variable phase shifts between any two of said first (), second () and third () half-bridges and allowing dead time modulation of the switches of said half-bridges (), so that to obtain a switching approaching ZVS switching, in particular to obtain switching when current crosses through zero and further to cancel switching losses and so that to allow high peak-to-peak voltage variations in the active filter, while storing corresponding energy in the storage capacitors (C), wherein the Y-capacitors of the common mode noise filter (), are referenced to a shielding being at a reference potential, said shielding being insulated from earth, said Y-capacitors having a value comprised between 100 nF and several μF.