Improved estimation of iron losses for non-sinusoidal voltages. Issue 5 (10th August 2018)

• Record Type: Journal Article
• Authors: Ionita, Valentin; Petrescu, Lucian; Cazacu, Emil
• Is Part Of: Compel. Volume 37:Issue 5(2018)
• Page Start: 1698
• Page End: 1706
• Publication Date: 2018-08-10
• Subjects: Iron losses -- Fe-Si sheet -- Inverse Preisach hysteresis model -- Losses separation -- Non-sinusoidal voltage -- Numerical Everett function; Electrical engineering -- Data Processing -- Periodicals; Electrical engineering -- Mathematics -- Periodicals; Electrical engineering -- Periodicals; Electronics -- Data Processing -- Periodicals; Electronics -- Mathematics -- Periodicals; 621.3
• DOI: 10.1108/COMPEL-12-2017-0527
• Languages: English
• ISSNs: 0332-1649

Abstract

Abstract : Purpose: The electrical machines connected to modern electric power grids are non-sinusoidal excited, and their augmented losses, including iron losses, limit their working characteristics. This paper aims to propose a prediction method for iron losses in non-oriented grains (NO) FeSi sheets under non-sinusoidal voltage, involving an inverse classical Preisach hysteresis model and the time-integration of each loss component. Design/methodology/approach: The magnetic history management in inverse Preisach model is optimized and a numerical Everett function is identified from measured symmetrical hysteresis cycles. The experimental data for sinusoidal waveforms obtained by a single sheet tester were also used to identify the parameters involved in Bertotti' losses separation method. The non-sinusoidal magnetic induction waveform, corresponding to a measured voltage in an industrial electrical grid, was the input for Preisach model, the output magnetic field being accurately computed. The hysteresis, classical and excess losses are calculated by time-integration and the total losses are compared with those obtained for sinusoidal excitation. Findings: The proposed method allows to estimate the iron losses for non-sinusoidal magnetic induction, using carefully identified parameters of FeSi NO sheets, using experimental data from sinusoidal regimes. Originality/value: The method accuracy is assured by using a numerical Everett function, a variable Preisach grid step (adapted for the high non-linearity of FeSi sheets) and high-order fitting polynomials for the microscopic parameters involved in the excess loss estimation. The procedure allows a better design of magnetic cores and an improved estimation of the electric machine derating for non-sinusoidal voltages.