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 Variable Speed Gearbox artwork in electric motors and frequency converters, the driving program for the superimposition of the planet carrier is founded on a Long term 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 elements that allow the usage 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. 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 liquid couplings generating 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.
Adjustable Frequency Drives (VFD) were developed and, at the same time, the expense of the shaft trains increased, therefore did efficiency. The issue of THD (Total Harmonic grid Distortion) rose and kept VFD out of several applications.
Taking advantage of the state of the artwork in electric powered motors and frequency converters, the driving system for the superimposition of the earth carrier is founded on a Long term Magnet Synchronous Superimposition (SI) electric 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 utilization 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 motor. In a normal scenario, the vibration will end up being monitored and stored on a periodic basis. If the 360 Hz signal is present in the vibration spectrum, it is not normally of any concern. If, however, additional unexplained frequencies come in the vibration spectra, then it might be advisable to have 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 provided.”
It started with hydraulic liquid couplings producing slippage with results very little 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 expense of the shaft trains increased, and so did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and held VFD out of several applications.
