Electric power converter for vehicle

An electric power converter for a vehicle comprising:

• an electric power conversion unit connected as a multi-phase bridge circuit configuration between a rotating electrical machine unit driven from the outside to generate multi-phase alternating current electric power, and a direct-current device, each phase arm of the multi-phase bridge circuit including a switching element having a parallel-connected diode;
• a synchronous rectification permission means which generates a diode ON signal corresponding to the energization state of the diode;
• and
• a synchronous rectification control means which generates a switching timing signal for a switching element corresponding to the diode ON signal on the basis of the diode ON signal, and
• performing switching control of the corresponding switching element on the basis of the switching timing signal from the synchronous commutation control means, thereby executing synchronous rectification,
• wherein the switching timing signal is obtained by subtracting a control allowance time from a synchronous commutation available time calculated on the basis of the ON time of at least one diode, and
• wherein the control allowance time is determined as a sum of a control delay time which is constant irrespective of the operating state of a generator, and a control allowance which is an allowance time which varies depending on the operating state of the generator.