Application of modelling and computer simulation for the development of a test setup for calibration of power quality measurement transducers for high voltage networks HÉDIO TATIZAWA 1 , ERASMO SILVEIRA NETO 2 , GERALDO F. BURANI 1 , ANTÔNIO A. C. ARRUDA 1 , KLEIBER T. SOLETTO 1 , NELSON M. MATSUO 1 2 Companhia de Transmissão de Energia Elétrica Paulista – ISA CTEEP 1 Instituto de Eletrotécnica e Energia da USP – IEE/USP Av. Prof. Luciano Gualberto, 1289 – São Paulo BRAZIL hedio@iee.usp.br http://www.iee.usp.br Abstract: - The term power quality is, in general, closely related to the quality of the voltage. Considering the widespread presence of sensitive loads in the electric grid, and the increasing awareness of the consumers concerning the quality of the power supply, the control and measurement of power quality parameters, for instance, harmonics, interharmonics, sags, swells, etc., are increasingly becoming much more important [1, 2, 3, 4]. Most of the necessary calibration procedures for power quality monitors and power quality analyzers are already defined in the international standards, mainly in the IEC 61000 series [5] and ANSI/IEEE Standards. This paper presents results of a research intended to develop a methodology for the calibration of high voltage transducers for power quality measurements in high voltage networks, considering that such kind of procedures are not yet established in the pertinent standards. In this research it is also considered that the conventional high voltage laboratory is not suitable for power quality tests, so some improvements are necessary on this subject. In this development, modelling and computer simulation using ATP – Alternative Transients Program [6] were used for to assess the frequency response of the test setup, and the design of the reactive compensation of the test circuit. Key-Words: - high voltage transducers, capacitive voltage dividers, power quality measurements, harmonics, IEC 61000 series, high voltage. 1 Introduction The control of power quality parameters in transmission and distribution networks demands qualified personnel, measurement equipment and suitable transducers for the power quality measurements. Considering the voltage transducers, the bibliographic survey performed shows that there is not enough consensus defining the calibration procedures for high voltage levels typically found in transmission and distribution networks [7, 8]. This paper summarizes the analysis performed and the main results of the research, aiming to develop a calibration test setup for high voltage transducers aiming to power quality measurements in power systems high voltage networks. 2 Test Setup Development Capacitive voltage dividers (CVD) are in common use for the measurement of power quality parameters in power systems networks [9], thanks to its modularity and easy installation in transmission and distribution substations’ environment. Fig. 1 shows a typical installation at field, in a 345kV transmission substation. In this Fig. 1 the high voltage branch of the CVD is shown, composed by six 500pF modular capacitances, nominal voltage 50kV. Referring to Fig. 2, all the capacitances of the high voltage branch (C1) are identical with nominal value of 500pF. For the measurements, the number of 500pF capacitances can be changed according to the expected voltage to be measured, in order to limit the voltage on the C2 capacitance of the secondary low voltage branch. This paper shows the development of the test circuit for the calibration of voltage transducers, aiming to measurements of power quality disturbances in power systems high voltage networks. This kind of development faces many levels of difficulties, considering that the generation of stabilized and well defined power quality disturbances, in the high voltage range (for example, over 1kV), for calibration purposes, requires the adaptation of the conventional high voltage laboratory equipment. The conventional high voltage laboratory, in general, is equipped only with high voltage sources for generating power frequency (60Hz or 50Hz) and impulse (atmospheric WSEAS TRANSACTIONS on SYSTEMS Hédio Tatizawa, Erasmo Silveira Neto, Geraldo F. Burani, Antônio A. C. Arruda, Kleiber T. Soletto, Nelson M. Matsuo ISSN: 1109-2777 880 Issue 9, Volume 7, September 2008