State-of-the-Art for Full Electric Driven Refrigeration Compressors Solutions Using Adjustable Speed Drive: Which Combination of Technology Platforms Leads to the Best CAPEX and OPEX Solution up to 100 MW?

During the last two decades, natural gas became a very important source of energy. Consequently, liquefaction of such gas became a mandatory process to allow shipping from production fields to customers. Very large liquefaction plants have been built and many more will be built in the next 10 years. The power of such plants is continuously increasing, and at the same time, environmental restrictions have become stricter and create a real challenge for the viability of new plants. Consequently, new approaches must be taken to overtake these challenges, and in particular, the driving solution for refrigeration compressors. In the last years, more and more projects have required full electric drives from 15 to 100 MW and different electrical solutions have been developed by various manufacturers in Europe and Asia, such as load-commutated inverter with a double-winding synchronous motor, voltage source inverter (VSI) with a standard synchronous motor, and VSI with a squirrel cage induction motor. Each of these solutions has their pros and cons and must be evaluated as a complete system from the grid to the compressor. The paper will study each component and then the complete system in order to present comparison tables of the three solutions, helping the engineers to choose the best one for their specific application.