Tsinghua University

Delta Electronics, Inc.

Yu-Hsing Chen

Po-Tai Cheng

Wen-Yin Tsai

Jen-Chung Liao

Disclosed is an uninterruptible power supply, including a rectifier for generating a DC voltage; an energy storage unit; an inverter for converting the DC voltage into a three-phase modulating voltage; a filter; a bypass switch circuit for selectively outputting a three-phase AC voltage or the three-phase modulating voltage as a three-phase load voltage; and a control circuit for controlling the operation of the uninterruptible power supply. The control circuit may use a flux compensation block with different operating modes to adjust the three-phase load voltage at the startup phase of a second inductive load and at the stable phase of the second inductive load, thereby compensating or correcting the flux of the second inductive load to prevent the flux distribution of the second inductive load from being saturated.

Uninterruptible power supply

The present invention discloses a flux linkage compensator, which applies to an UPS system and comprises a load transformer flux linkage observer, a compensation voltage command generator, and a flux linkage command generator. The load transformer flux linkage observer generates a load transformer flux linkage signal. The flux linkage command generator generates a flux linkage command signal. The difference between the load transformer flux linkage signal and the flux linkage command signal forms a flux linkage deviation signal. The compensation voltage command generator generates a voltage compensation signal to make the flux linkage deviation signal approach zero. Thereby, the flux linkage compensator can compensate for the flux linkage deviation occurring in starting the UPS system. Thus, the present invention can perform voltage compensation fast and reliably and inhibit the inrush current effectively.

Growing community of inventors

Hsinchu, Taiwan

Yu-Hsing Chen