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

Taking advantage of the condition of the art in electric motors and frequency converters, the driving system for the superimposition of the planet carrier is based on a Long lasting Magnet Synchronous Superimposition (SI) motor and an Active Front-End Cycle Converter. So – E means Electric.
This is a high-speed gear drive system incorporating components that allow the utilization 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 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.
It started with hydraulic fluid couplings creating slippage with results very little 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 improved, therefore did efficiency. The issue of THD (Total Harmonic grid Distortion) rose and kept VFD out of many applications.

Taking advantage of the state of the art in electric motors and frequency converters, the driving program for the superimposition of the earth carrier is based on a Long term 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 parts 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 engine. In a normal scenario, the vibration will end up being monitored and kept on a periodic basis. If the 360 Hz signal exists in the vibration spectrum, it isn’t normally of any concern. If, however, various other unexplained frequencies come in the vibration spectra, then it might be advisable to take a look at both the current waveform and the current spectrum. In the webpages that follow, some examples of problems uncovered in DC drives and motors are presented.”
It started with hydraulic fluid couplings generating slippage with results very little 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, simultaneously, the cost of the shaft trains Variable Speed Gearbox increased, and so did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and held VFD out of several applications.