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 system to compensate for a difference between an AC grid side frequency and an AC load side frequency. The electronic power system can comprise an electronic power inverter, such as one usable with an uninterruptible power supply. Cycles of signals indicative of the AC grid power and the AC load power are counted and compared to obtain a cycle error value. If the cycle error value exceeds a first value to indicate that AC load side frequency is too high or too low, then compensation is performed to change the AC load side frequency to be closer to the AC grid side frequency. If the cycle error value falls below a second value to indicate that the AC grid side frequency and AC load side frequency are sufficiently close to one another, then the compensation is deactivated.