SMES based unified power quality conditioner and its design

This paper presents a SMES based power quality conditioner.This device employs only one current source commuter and SMES (superconducting magnetic energy storage) coil as storage component,which can realize multiple functions such as load voltage regulation and active filtering.In this paper,the structure and operation principle of the system are described.Two modes of power adjustment are proposed,i.e.the load voltage is maintained by only adjusting reactive power of inverter under slight voltage sag,whereas by adjusting the active power as well as reactive power under deep voltage sag condition.The effectiveness of the system structure and control is verified by experimental results.The design method of main circuit parameters is analyzed.