Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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A Compensator for Lateral Current Reduction Applied to Autonomously Controlled UPSs Connected in Parallel

  • Sato Kazuhide Kazuhide (Department of Electrical and Computer Engineering., Yokohama National University) ;
  • Kawamura Atsuo (Department of Electrical and Computer Engineering., Yokohama National University)
  • Published : 2005.10.01
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Abstract

This paper presents a compensator for reduction of the reactive lateral current in multiple autonomously controlled uninterruptible power supplies (UPS) connected in parallel. This compensator acts directly on the control equation for voltage amplitude and it provides an improved current distribution especially in the case of parallel connection of UPSs with different output power ratings. Observations show that the original control equation for output voltage amplitude is efficient for voltage regulation but it causes great variation of voltage levels. A compensator with the same structure is added to counterbalance the variation caused by the original control equation. Simulations show promising results with the employment of the proposed compensator. Our simulations are confirmed by experimental results using three UPSs with different output ratings and voltage limiters ($1\%$) connected in parallel under various conditions.

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References

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