Title :
High-frequency measurements on three-phase 50 HZ power transformers
Author :
Rabinovici, Raul ; Zuckerberger, Adrian ; Reichman, Isar ; Bass, Simon ; Schwartzes, Moshe
Author_Institution :
Dept. of Electr. & Comput. Eng., Ben-Gurion Univ. of The Negev, Beer Sheva, Israel
Abstract :
The power transformers could face situations when a high frequency voltage of up to several MHz is superposed on the rated 50 Hz three-phase voltages. Examples could be power on-line communications, lightning strokes, or switching surges. The high frequency voltages are identical voltages (common mode) on all the three phases of the power transformer, i.e., they form a zero-sequence three-phase voltages system that is superimposed on the 50 Hz direct-sequence three-phase rated voltages system. The paper presents experimental results regarding the behavior of a three-phase transformer in a common mode connection and excited by zero sequence voltages in the frequency range 100 Hz-100 kHz. A principal conclusion is that both the `magnetizing¿ and leakage inductances are due to air magnetic fields. As a result, the `magnetizing¿ inductance and `core¿ losses are much lower than those of a three-phase transformer in a conventional connection and exited by three-phase direct sequence voltages.
Keywords :
frequency measurement; power transformers; air magnetic field; frequency 100 Hz to 100 kHz; frequency 50 Hz; high-frequency measurement; leakage inductance; lightning stroke; magnetizing inductance; power on-line communication; switching surge; three-phase power transformer; zero-sequence three-phase voltage system; Communication switching; Frequency; Inductance; Lightning; Magnetic fields; Phase transformers; Power measurement; Power transformers; Surges; Transformer cores; Power transformer testing; power system modeling; power system simulation;
Conference_Titel :
Electrical and Electronics Engineers in Israel, 2008. IEEEI 2008. IEEE 25th Convention of
Conference_Location :
Eilat
Print_ISBN :
978-1-4244-2481-8
Electronic_ISBN :
978-1-4244-2482-5
DOI :
10.1109/EEEI.2008.4736684
