Abstract: A method is disclosed for controlling exhaust gas flow from a combustion engine to a turbocharger. The combustion engine includes a plurality of cylinders each with first and second exhaust valves, and the turbocharger includes first and second volutes with outlets that are separated by approximately 180°. The method includes: (i) directing exhaust flow from first and second cylinders into the first volute via a first exhaust channel by opening the first exhaust valve in the first and second cylinders; (ii) directing exhaust flow from third and fourth cylinders into the second volute via a second exhaust channel by opening the first exhaust valve in the third and fourth cylinders; and (iii) apportioning exhaust flow from each cylinder into the first and second volutes via the first and second exhaust channels by moving the second exhaust valve in each cylinder between a variety of positions.

Abstract: Polarity change of a feed-forward compensation signal for compensating for a dead-time voltage disturbance is synchronized with zero crossings of a load current reference. The load current reference is advanced in time by adding a fixed phase angle, scaled by the synchronous frequency, to the synchronous coordinates angle. The load current reference is time-advanced only for timing the polarity change of the feed-forward compensation signal and not for application to the current regulators; the current regulators still use the load current reference (unadvanced). For a converter, the load current would be an AC mains input current. For an inverter, the load current could, for example, be an induction motor stator current. The shape of the feed-forward compensation signal is approximately trapezoidal and is obtained from the limited, amplified, advanced load current reference.