Characterization of Input Current Interharmonics in Adjustable Speed Drives

Abstract

This paper investigates the interharmonic generation process in the input current of double-stage Adjustable Speed Drives (ASDs) based on voltage source inverters and front-end diode rectifiers. The effects of the inverter output-side low order harmonics, caused by implementing the double-edge symmetrical regularly sampled Space Vector Modulation (SVM) technique, on the input current interharmonic components are presented and discussed. Particular attention is also given to the influence of the asymmetrical regularly sampled modulation technique on the drive input current interharmonics. The developed theoretical analysis predicts the drive interharmonic frequency locations with respect to the selected sampling strategies. Simulation and experimental results on a 2.5 kW ASD system verify the effectiveness of the theoretical analysis.

Number of Levels, Arm Inductance and Modulation Trade-offs for High Power Medium Voltage Grid-Connected Modular Multilevel Converters

“…I 1,max is the maximum demand current and H = 50. It can be inferred that the straightforward interpretation of (1) may not take into account the harmonic components that appear at frequencies that are non-integer multiple of the fundamental, referred to as 'interharmonics' in [26]- [28]. In the case of the MMC, interharmonic distortion might be especially important because f sw is typically selected as a non-integer multiple of the fundamental (Section III).…”

Effects of Modulation Techniques on the Input Current Interharmonics of Adjustable Speed Drives

“…Characterization of the interharmonics in the ASDs normally needs to be considered with respect to their frequencies and amplitudes, and it needs to be analyzed during all operating conditions. Meanwhile, a precise mapping of the ASD's input current interharmonic frequencies within normal operating condition of the drive was introduced in [23], where a symmetrical regularly sampled fixed-frequency modulation technique is selected for the drive.…”

“…4. It is worth to mention that with the adopted modulation strategy, the DC-link inverter-side current oscillation frequencies f h dc can be obtained as [23]…”

Accurate Analysis of Harmonic Transmission of Line Commutated Converter Considering Firing Angle Fluctuation

“…The letter [24] proposed a method to determine the existence of interharmonics in the discrete Fourier transform (DFT) results. The interharmonic generation process in motor drive applications is investigated in [25], and the effects of modulation techniques are also taken into account [26]. However, the mechanism of interharmonic transmission in LCC has not been addressed in previous researches.…”