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 chosen. Others are using epicyclic gears with a hydrodynamic superimposition drive.

Taking advantage of the condition of the artwork in electric motors and frequency converters, the driving program for the superimposition of the planet carrier is founded on a Permanent Magnet Synchronous Superimposition (SI) engine and a dynamic Front-End Cycle Converter. Therefore – E stands for Electric.
This is a high-speed gear drive system incorporating elements that allow the utilization of a low-cost constant-speed (electric) driver for a variable-speed application.

A lot 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 chosen. Others are employing epicyclic gears with a hydrodynamic superimposition drive.
It started with hydraulic liquid couplings producing slippage with results not much 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 cost of the shaft trains improved, and so did efficiency. The problem of THD (Total Harmonic grid Variable Speed Gearbox 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 planet carrier is founded on a Long term Magnet Synchronous Superimposition (SI) motor and an Active Front-End Cycle Converter. Therefore – E stands for 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 current to the electric motor. 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 normally of any concern. If, however, additional unexplained frequencies appear 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 discovered in DC drives and motors are shown.”
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, 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 several applications.