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

Taking benefit of the state of the artwork in electric motors and frequency converters, the driving system for the superimposition of the planet carrier is based on a Long term Magnet Synchronous Superimposition (SI) electric motor and a dynamic Front-End Cycle Converter. So – E means 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.

More than 50% of the compression and pumping systems over 3 MW need 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.
It started with hydraulic fluid couplings making slippage with results not much much better than the throttle.
The design 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 cost of the shaft trains increased, and so did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and held VFD out of many Variator Gearbox applications.

Taking benefit of the state of the art in electric motors and frequency converters, the driving program for the superimposition of the earth carrier is founded on a Long lasting Magnet Synchronous Superimposition (SI) electric motor and a dynamic Front-End Cycle Converter. So – E means Electric.
This is a high-speed gear drive system incorporating parts that allow the utilization of a low-cost constant-speed (electric) driver for a variable-speed application.

All of the above plots were taken by analyzing the current to the electric motor. In a normal scenario, the vibration will end up being monitored and kept on a periodic basis. If the 360 Hz signal is present in the vibration spectrum, it isn’t normally of any concern. If, however, other unexplained frequencies appear in the vibration spectra, after that it would be advisable to take a look at both the current waveform and the existing spectrum. In the pages that follow, a few examples of problems found out in DC drives and motors are presented.”
It started with hydraulic fluid couplings creating slippage with results not much much better than the throttle.
The design of hydraulic clutches then improved and included a torque converter and a superimposed epicyclic drive.
Adjustable Frequency Drives (VFD) were developed and, simultaneously, the price of the shaft trains improved, and so did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and kept VFD out of many applications.