Affiliations: [a] Electrical Engineering Department, Purdue University, West Lafayette, IN, USA | [b] Standard Drives Division, Rockwell Automation, Mequon, WI, USA
Correspondence:
[*]
Corresponding author: Dr. R.J. Kerkman, Standard Drives Division, Rockwell Automation, Mequon, WI, USA. Tel.: +1 262 512 8263; Fax: +1 262 512 8300; E-mail: [email protected].
Abstract: This paper deals with the inclusion of frequency effects (skin effect) in an enhanced transport delay model for electric cables of arbitrary length connected to a PWM-IGBT-Variable Frequency Drive (VFD), to better predict overvoltage peaks in the line during transient. The problem and the importance of predicting peak overvoltages to determine the appropriate insulation to be used in cables is addressed. From the step response of the cable, and using Genetic Algorithms (GA), an impulse function for cables is characterized. The novelty of this characterization is the emulation of an infinite long cable. Such a function is used to predict frequency-dependent voltage and current in longer cables. Simulation and experimental results are provided. Finally, an extension of this model is made for the n-conductor cable.
Keywords: Electric cables, skin effect, VFD, reflected waveform
