New trends in power quality measuring instruments

One of the challenges in all supply systems is the control of power quality (PQ). The assessment of PQ in distributed supply systems implies the synchronized measurement of a great deal of different parameters at different points and with different requirements. The choice of suitable parameters, sampling rates "aggregation operations" and periods to obtain data containing the maximum information on possible "quality faults", using minimum memory space and minimum processor resources is one of the major problems of PQ instrumentation. An additional problem in distributed systems is the synchronization of data acquisition at different points. This paper presents the design of an instrument for PQ measurement, based on a previous analysis of CPU and memory needs. The inclusion of a high resolution real time clock with GPS synchronization allows the comparison of measurements at different points of the grid. Software for transient capture, with a trigger based on wavelet transform is also presented.