The latest family member of Power Diagnostix' fiber optic transmission systems, FOS4 offers high speed data acquisition via fiber optic cables on multiple channels in parallel. The scalable system allows the acquisition of acoustic PD signals or other measurement signals under AC, DC, or impulse testing in laboratories as well as on site. The modular system accepts up to twelve optical channels and comes with high-speed controller card to communicate with a notebook. Besides this, the FOS4 system has additional signal output on the rear side and can be used as a digital isolated amplifier without the use of any software.
PD localization by Acoustic Travel Time Analysis (ICMacoustic)
The system consists of FOT4 transmitter units and FOR4 receiver units. Each channel acts as an independent transient recorder with its own storage and settable acquisition speed and storage depth. The sampling rate is 20 Msample/sec. and, hence, sufficient to even acquire the pointing vector of the incoming acoustic wave, when using a two-dimensional three-sensor configuration.
For PD localization purposes the ICMacoustic software offers full control of the FOS4 system including averaging and trigger logic. It is designed for the acoustic localization of transformer partial discharge with the triangulation method. The basic idea is to reduce the localization to a “flat problem”. I. e., to horizontally position three sensors on a line to firstly get the horizontal position of the layer (see upper graph of the software’s measurement panel, left). Here, the position of the sensors are entered and assigned to their channel. In a second step the sensors are placed on a vertical line at the found vertical position. In the lower graphs the sensor positions are entered accordingly.