Title: Evaluation of a Dedicated Power Electronic Converter and Associated Control Strategy for a Kinematically Linked Linear Compressor

Student thesis: Master's Thesis


Compressed gases are widely used in our modern-day industrial society. A particular requirement common to several sectors is gas purity, for applications such as healthcare, hydrogen (H2) and the semiconductor industry. To this very day, delivering gases of the highest purity at high discharge pressure remains a challenge with state-of-the-art technology. In order to do so, complex sealing and venting chambers are added to current-generation piston compressors. To tackle this issue, a kinematically linked linear compressor was developed in the PhD dissertation of dr. ir. Beckers in cooperation with Atlas Copco. Using linear electric motor technology and a simple control strategy, inspired by the workings of an internal combustion engine, allows smooth operation whilst reducing the mechanical loading of the most vital components. The novel compressor type seems promising to obtain an oil-free, compact and hermetic solution for high discharge pressures. Hence it is a potential candidate as a compressor for pure gases. Nonetheless, the control strategy and linear electric motor require the addition of a power electronic converter (PEC), which is not yet optimised for this particular application. This is the context where the research of this MSc. thesis picks up. The focus lies on the global efficiency improvement of the drivetrain, including the PEC and associated control strategy. To do so, different PEC and control strategies are evaluated in a multi-physics simulation tool, bringing together the mechanical, thermodynamic and electromagnetic subdomains of an existing 30 kW prototype. To this end, the electrical energy losses are studied and a novel improved control strategy is derived which better exploits the system’s resonance. Finally, the analysis shows that the requirements of the PEC can be greatly relaxed, reducing the peak apparent power rating by 62.6%.
Date of Award2023
Original languageEnglish


  • Power Electronic Converter
  • Linear Compressor
  • global efficiency improvement

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