The special circumstances are considered of an induction motor driven submersible pump supplied from a variable frequency converter which is remote from the pump location, necessitating subsea cables which may be considerably longer than in normal practice. The principal objective of the series of practical tests is to investigate the performance of such systems to evaluate a complete electromechanical system model for use in the prediction of the current and torque requirements of the drive, and to assess the effect of converter switching patterns on the voltage profile of the transmission section. Results of computer studies are presented which are validated by comparison with measurements taken on an ESP system during precommissioning tests. The factors affecting the in-service operational characteristics of the drive are discussed and recommendations made.