Active filter and method for scheduling transistor bridge trigger times for each phase of power grid

摘要

A method for scheduling of periodic real time processes in an operating system, comprising the steps of defining a reference point in time for a periodic real time process, and scheduling the periodic real time process from the reference point in time. Preferably a future point in time is defined as the reference point in time at the start up of the operating system. The real time process is preferably a periodic control process during which a relative control point in time, counted from the beginning of the subsequent control cycle, is calculated during each cycle with absolute time correction counted from the reference point in time. The absolute time correction corresponds to the period of the periodic process multiplied with the number of passed control periods until the beginning of the subsequent control cycle, at which the absolute control point in time is calculated through an addition of the relative control point in time with the absolute time correction. In one embodiment the method according to the invention is applied in an active filter for compensation of variations in an apparatus current consumption from a power grid as a result of changes in the apparatus' electrical load.