20 Years of Experience in VSDs for High Power Compressors of Steam Crackers

The paper presents the history of Variable Speed Drives ( VSDs ) for high power compressors of steam crackers (20 to 40 MW) in operation for the last twenty years in a branch of major French company. The paper addresses issues such as experiences, performances and availability, maintenance and upgrades, debottlenecking, modernization. The paper covers the solutions implemented in terms of technology, power range, speed range and control philosophy for the application: High Speed synchronous motor, current source thyristor converter, transformer, cables, cooling, harmonics, inter-harmonics, power factor, redundancy. It recommends the technology choices for new projects. The presentation is illustrated with examples of units in operations in different plants within a branch of major French company.