A 
lot 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 chosen. Others are employing epicyclic gears with a hydrodynamic superimposition drive.
Taking benefit of the state of the art in electric powered motors and frequency converters, the driving program for the superimposition of the planet carrier is founded on a Long lasting 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 parts 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 require 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.
It started with hydraulic fluid couplings creating 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, simultaneously, the cost of the shaft trains increased, therefore did efficiency. The issue of THD (Total Harmonic grid Distortion) rose and held VFD out of many applications.
Taking advantage of the state of the artwork in electrical 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. So – E means Electric.
This 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 over plots were taken by analyzing the existing to the engine. In a normal scenario, the vibration will become monitored and kept on a periodic basis. If the 360 Hz signal exists in the vibration spectrum, it is not Variable Speed Gearbox normally of any concern. If, however, various other unexplained frequencies appear in the vibration spectra, after that it would be advisable to take a look at both current waveform and the existing spectrum. In the pages that follow, a few examples of problems uncovered in DC drives and motors are presented.”
It started with hydraulic fluid couplings making 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.
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 several applications.