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 Variable Speed Gearbox electrical motors and frequency converters, the driving system for the superimposition of the planet carrier is founded on a Permanent Magnet Synchronous Superimposition (SI) motor and a dynamic Front-End Cycle Converter. Therefore – E stands for Electric.
This 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 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 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.
Variable Frequency Drives (VFD) were developed and, simultaneously, the cost of the shaft trains improved, therefore did efficiency. The issue of THD (Total Harmonic grid Distortion) rose and held 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 planet carrier is based on a Permanent Magnet Synchronous Superimposition (SI) electric motor and a dynamic 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.

All of the above plots were taken by analyzing the current to the motor. In a normal circumstance, 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, additional unexplained frequencies appear in the vibration spectra, after that it would be advisable to have a look at both current waveform and the current spectrum. In the pages that follow, a few examples of problems discovered in DC drives and motors are offered.”
It started with hydraulic liquid couplings making slippage with results not 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, at the same time, the expense 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.