More than 50% of the compression and pumping systems over 3 MW require a variable-speed drive. Often medium-voltage motors fed by frequency converters and parallel shaft gears are chosen. Others are employing epicyclic gears with a hydrodynamic superimposition drive.

Taking advantage of the state of the art in electrical motors and frequency converters, the driving program for the superimposition of the planet Variable Speed Gearbox carrier is founded on a Long lasting Magnet Synchronous Superimposition (SI) electric motor and a dynamic Front-End Cycle Converter. So – E stands for Electric.
That is a high-speed gear drive system incorporating elements that allow the use of a low-cost constant-speed (electric) driver for a variable-speed application.

More than 50% of the compression and pumping systems above 3 MW need a variable-speed drive. Frequently medium-voltage motors fed by frequency converters and parallel shaft gears are chosen. Others are employing epicyclic gears with a hydrodynamic superimposition drive.
It started with hydraulic liquid couplings making slippage with results not much better than the throttle.
The look of hydraulic clutches then improved and included a torque converter and a superimposed epicyclic drive.
Variable Frequency Drives (VFD) were developed and, at the same time, the price of the shaft trains improved, therefore did efficiency. The issue of THD (Total Harmonic grid Distortion) rose and held VFD out of many applications.

Taking benefit of the condition of the art in electric motors and frequency converters, the driving program for the superimposition of the earth carrier is founded on a Long term Magnet Synchronous Superimposition (SI) motor and an Active Front-End Cycle Converter. Therefore – E stands for Electric.
That is a high-speed gear drive system incorporating components that allow the use of a low-cost constant-speed (electric) driver for a variable-speed application.

All of the above plots were taken by analyzing the existing to the electric motor. In a normal situation, the vibration will end up being monitored and stored on a periodic basis. If the 360 Hz signal exists in the vibration spectrum, it isn’t normally of any concern. If, however, additional unexplained frequencies appear in the vibration spectra, then it would be advisable to check out both the current waveform and the existing spectrum. In the pages that follow, a few examples of problems uncovered in DC drives and motors are shown.”
It started with hydraulic liquid couplings producing slippage with results not much much better than the throttle.
The look of hydraulic clutches then improved and included a torque converter and a superimposed epicyclic drive.
Adjustable Frequency Drives (VFD) were developed and, at the same time, the cost of the shaft trains improved, therefore did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and held VFD out of several applications.