Switching the Neutral Conductor and its Effect on UPS Performance and the Countermeasure

Konferenz: Intelec 2013 - 35th International Telecommunications Energy Conference, SMART POWER AND EFFICIENCY
13.10.2013 - 17.10.2013 in Hamburg, Deutschland

Tagungsband: Intelec 2013

Seiten: 6Sprache: EnglischTyp: PDF

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Autoren:
Li, Xiyu; Zhu, Qingfeng; Wang, Wei; Liu, Baoqing (China Information Technology Designing and Consulting Institute co., Ltd., Beijing China)

Inhalt:
In order to meet the needs of ground fault protection (GFP) for low voltage distribution system, the 4 pole automatic transfer switch (4 pole ATS) must be used for the transfer switch circuit between commercial power (utility power) and standby generator set. But some of the 4 pole ATS use “break before make” neutral pole switching mode which can cause the neutral line interruption during the changeover of power supply. The interruption of neutral line has serious impact on the UPS performance and even causes critical load power down, which has attracted more and more attention at present. This is an urgent problem to be solved. This paper describes some transfer switch circuits used in telecommunication and data centers, analyses their performance and the effect on GFP and UPS performance. Some practical engineering solutions, including correctly choosing ATS, addition of isolated transformer and suitable bonding and earthing etc., are also proposed.