Novel Current Measurement Concept for Half Bridge Topologies Based on Simple-to-implement Digital Current Observer

Konferenz: PCIM Europe 2019 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management
07.05.2019 - 09.05.2019 in Nürnberg, Deutschland

Tagungsband: PCIM Europe 2019

Seiten: 7Sprache: EnglischTyp: PDF

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Ahmad, Mohsin Ejaz; Schafmeister, Frank; Boecker, Joachim (University of Paderborn, Germany)

Measuring devices are required to ascertain voltage and current data in controlled power electronic converters. The voltage can be measured easily and cost-effectively with the suitable high impedance operational amplifier circuits, while the current determination is becoming more challenging due to the increase in the switching frequency of modern (GaN-) converters. This paper presents a novel and an efficient current sensing scheme with a simple-to-implement digital current observer that estimates the inductor current of a half bridge by using available signals from digital closed-loop control in combination with basic DSP peripherals. The practical implementation, based on a standard low-cost DSP, will have less negative influence on switching characteristics of the switches, reduces the inductance in commutation path, and decreases the size and cost of the overall system.