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 using epicyclic gears with a hydrodynamic superimposition drive.
Taking benefit of the condition of the artwork in electric powered motors 
and frequency converters, the driving system for the superimposition of the earth carrier is founded on a Permanent Magnet Synchronous Superimposition (SI) engine and a dynamic Front-End Cycle Converter. Therefore – E means Electric.
That is a high-speed gear drive system incorporating parts that allow the usage of a low-cost constant-speed (electric) driver for a variable-speed Variable Speed Gearbox 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 using epicyclic gears with a hydrodynamic superimposition drive.
It started with hydraulic liquid couplings creating 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.
Adjustable Frequency Drives (VFD) were developed and, simultaneously, the expense of the shaft trains improved, therefore did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and kept VFD out of many applications.
Taking benefit of the condition of the artwork in electric motors and frequency converters, the driving system for the superimposition of the earth carrier is founded on a Long lasting Magnet Synchronous Superimposition (SI) motor and an Active Front-End Cycle Converter. Therefore – E means Electric.
This 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.
All of the over plots were taken by analyzing the current to the motor. In a normal situation, 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 is not normally of any concern. If, however, other unexplained frequencies come in the vibration spectra, after that it might be advisable to check out both current waveform and the current spectrum. In the webpages that follow, a few examples of problems discovered in DC drives and motors are shown.”
It started with hydraulic liquid couplings making slippage with results very little 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, 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 several applications.