METHOD AND APPARATUS FOR CYCLE ERROR CORRECTION FOR A POWER CONVERTER DEVICE, SUCH AS AN ELECTRONIC POWER INVERTER

摘要

Cycle error correction is performed in an electronic power systemto compensate for a difference between an AC grid side frequency and an ACload side frequency. The electronic power system can comprise an electronicpower inverter, such as one usable with an uninterruptible power supply.Cycles of signals indicative of the AC grid power and the AC load power arecounted and compared to obtain a cycle error value. If the cycle error valueexceeds a first value to indicate that AC load side frequency is too high ortoolow, then compensation is performed to change the AC load side frequency tobe closer to the AC grid side frequency. If the cycle error value fails belowasecond value to indicate that the AC grid side frequency and AC load sidefrequency are sufficiently close to one another, then the compensation isdeactivated.