Waveforms, Current Sensors and Their Bandwidth in Power Electronics

摘要

Over the last years, the switching frequencies of power electronic devices has constantly been rising. Can today's current sensors measure these higher frequencies? The existence of different types of sensors, current ratings, physical sizes and various bandwidth specifications render it difficult to select a current sensor, which performs accurate measurements. Two approaches are presented to help in selecting the probes's bandwidth based on the signal's waveform and the measurement error. One approach is based on a step signal with limited slope, the other one on the Fourier series. Last, lab measurements are presented to show the discrepancy between ideal and real behavior of current sensors.