Search results for "Energy efficient transformer"
showing 2 items of 2 documents
A DC current transformer for large bandwidth and high common-mode rejection
1999
A review of known magnetic-coupled current-sensing techniques is presented, Subsequently, a novel technique is introduced, based on a configuration discussed in a previous paper. The previous technique made use of a galvanomagnetic device (Hall effect sensor) to sense the magnetization of a current transformer core, so that the sum of the Hall voltage and the voltage across the secondary shunt resistor would yield a faithful copy of the input current. The technique described in this paper makes use of the same principle to obtain a high bandwidth (from DC to 1 MHz) and very high common-mode rejection current transformer, without the need for a Hall effect probe. This is achieved by subtract…
A back to back method for the temperature rise test of prefabricated substations: A case study
2015
In this work a back to back method is presented which allows to develop heating tests of prefabricated secondary substations with a limited number of supplying equipment (an induction regulator and a capacitor bank). The proposed method makes use of the transformer tap changers to create a voltage difference on the medium voltage side. In this way, only an adjunctive low voltage supply is needed. With the proposed test system, the heating tests are developed on a 1000 kVA prefabricated substation. Thanks to the experimental tests, the class of enclosure of the substation and the operating temperature and resistance of the power transformers are determined, according to the recommendations o…