Line and load friendly drive solutions for long length cable applications in electrical submersible pump applications

Long cable lengths (1,000 ft to 15,000 ft) associated with submersible pump equipment have limited the effectiveness of using modern variable speed drives (VSD) due to reflected wave voltage spikes associated with the drive switching voltage transitions. In the past, drives used external filters, inductors and conditioners to keep from damaging cable and motor insulation. Extra costs associated with this equipment, as well as the custom use, limit the overall effectiveness. Variable sine-wave generation (VSG) technology has been developed to overcome these load-side limitations, as well as providing the user all the flexibility that initially attracted them to VSDs. The paper first discusses load-side friendly features of the technology and shows how the sinusoid waveform with lower total harmonic distortion (THD) benefits ESP motor operation, such as increased insulation life expectancy, reduced motor heating and increased motor efficiency. Field application results showing comparisons of VSG technology to conventional drive technology is provided as well as computer simulation results. Secondly, the paper discusses new optional line-side friendly converter technology that can obtain near sinusoid current waveforms of lower THD to the utility grid. This technology has the benefit of minimizing line-side harmonic currents, which may be an emerging problem as the proliferation of oil field drives rapidly increases.