Line Loss Minimum Control of Loop Distribution Systems Using UPFC

This paper presents an elaborated mathematical analysis of the line loss minimum condition of loop distribution systems. In order to achieve this condition, the unified power flow controller (UPFC), a typical FACTS (flexible AC transmission systems) device that is capable of instantaneous control of transmission and distribution power flow, is used. Also, the available control schemes of the UPFC to minimize the total line loss of the loop distribution system are presented. The authors propose the line inductance compensation control and the line voltage compensation control which can be applied to the loop distribution system according to the line parameters. The effectiveness of the proposed control scheme, line inductance compensation control, has been verified experimentally using laboratory prototype in a 200 V, 6 kVA system.