International Conference on Renewable Energies and Power Quality (ICREPQ’13) Bilbao (Spain), 20 th to 22 th March, 2013       (RE&PQJ) ISSN 2172-038 X, No.11, March 2013 Short Time Voltage Variations Analysis for the new Brazilian Distribution Procedures (PRODIST) and for the IEC 61000-4-30 G. S. Wojichowski 1 , C. D. P. Crovato 2 and R. C. Leborgne 1 1 Department of Electrical Engineering Universidade Federal do Rio Grande do Sul Av. Osvaldo Aranha 103, Porto Alegre - Rio Grande do Sul (Brazil) - CEP 90035-190 Phone number: +5551 99681929, e-mail: guilherme.wojichowski@ufrgs.br , rcl@ece.ufrgs.br 2 Feevale University ERS239, 2755, Novo Hamburgo - CEP: 93352-000 - Rio Grande do Sul (Brazil) Phone number: +5551 33584016, e-mail: cesarc@feevale.br Abstract. This paper presents the analysis of one important requirement of the new Brazilian regulation of Power Quality. The Electric Distribution Procedures (PRODIST), that includes power quality regulation, stipulates the references and methods of measurements to the Electrical Utilities that soon will become a standard that will have limits that must be achieved. The main target of this paper is to compare and propose a specific calculus methodology for a Power Quality Analyzer to precisely identify the amplitude and duration of Short Time Voltage Variations requested in the PRODIST. The PQ Analyzer complies PRODIST technical specifications and the International Standard IEC61000-4-30 for some aspects that PRODIST is not clear. The weak points that are not specified in the PRODIST are also analyzed, showing that they should be more precise, otherwise if different manufactures choose distinct methods, procedures and algorithms, they will not reach the same results. Therefore, power quality measurements could not be compared using equipment of different manufacturers. Key words Power Quality Analyzer, Brazilian Power Quality Standard (Prodist), Short Time Voltage Variation 1. Introduction The Power Quality (PQ) issues in Brazil are regulated by the Electrical Energy Regulation Agency (ANEEL). The Brazilian Electric Distribution Procedures (PRODIST) [1] is composed of eight modules, the one concerned about the PQ is Module 8, that states the parameters that should be measured such as: steady state voltage magnitude, power factor, voltage harmonics, voltage unbalance, voltage fluctuation (flicker), voltage variation and frequency variation. The problem is that PRODIST does not mention the calculus method for detection of short time voltage variation (STVV). The IEC 61000-4-30 [2] states a specific method to measure the STVV. The main objective of this paper is to present, analyse and compare several methods to measure STVV. The method that presents the best performance is proposed to be used by both standards, and by the manufactures of Power Quality Analyzers. 2. PRODIST and IEC 61000-4-30 Short Time Voltage Variations Analysis The PRODIST shows how to measure and characterize the disturbances and the reference values to the power quality compliance. The minimum hardware requirements for the measurement system according to the regulation are: Digital sampling of 16 samples per cycle; Analog to Digital converter of 12 bits; Precision: 1% of the reading value. The PQ disturbances according to PRODIST are: Steady State Voltage Magnitude; Power Factor; Voltage Harmonics; Voltage Unbalance; Flicker; Short Time Voltage Variations; and Frequency variation. Only the Short Time Voltage Variation will be analysed in this paper. The Short Time Voltage Variations are determined by the RMS voltage and the duration of the disturbances is between half cycle and 3 minutes [2]. They are classified by PRODIST in six types showed in Table I. 3. Analysis and Proposal of Calculus Methodology The methods described below show different ways of detecting and calculating the magnitude and duration of short time voltage variations. https://doi.org/10.24084/repqj11.379 593 RE&PQJ, Vol.1, No.11, March 2013