The Static Scherbius Drive provides the speed control of a wound rotor motor below

synchronous speed An alternator (or synchronous generator) is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with ...

. The portion of rotor AC power is converted into DC by a diode bridge. This

motor drive A motor drive is a physical system that includes a motor. An adjustable speed motor drive is a system that includes a motor that has multiple operating speeds. A variable speed motor drive is a system that includes a motor that is continuously v ...

has the ability of flow the power both in the positive as well as the negative direction of the injected voltage.What is Scherbius drive?
/ref> The Scherbius Drive is an electrical drive system invented by

Arthur Scherbius Arthur Scherbius (30 October 1878 – 13 May 1929) was a German electrical engineer who invented the mechanical cipher Enigma machine. He patented the invention and later sold the machine under the brand name Enigma. Scherbius offered une ...

, a German engineer known for his work in

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

and

cryptography Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logy, -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of Adversary (cryptography), ...

(he also invented the

Enigma machine The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the W ...

). This drive system is primarily associated with controlling the speed of

electric motors An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate Laplace force i ...

, particularly asynchronous (induction) motors. It is closely related to the static Kramer drive.

Key Features

Slip Power Recovery

The drive enables the recovery and reuse of slip power from the rotor circuit of a wound-rotor induction motor. Instead of wasting the slip power as heat, it redirects it back to the power supply or another part of the system, improving overall efficiency.

Use of Rotary Converters

In its original design, Scherbius Drive used rotary converters (essentially motor-generator sets) to modulate the slip power. Modern implementations often replace rotary converters with solid-state electronics like inverters.

Variable Speed Control

By managing the slip power, the Scherbius Drive allows for speed control of the motor. This makes it particularly useful in applications requiring variable-speed operation, such as cranes,

wind turbines A wind turbine is a device that converts the kinetic energy of wind into electrical energy. , hundreds of thousands of large turbines, in installations known as wind farms, were generating over 650 gigawatts of power, with 60 GW added each y ...

, and

pumps A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action, typically converted from electrical energy into hydraulic or pneumatic energy. Mechanical pumps serve in a wide range of applications such ...

Advantages

*Improved

efficiency Efficiency is the often measurable ability to avoid making mistakes or wasting materials, energy, efforts, money, and time while performing a task. In a more general sense, it is the ability to do things well, successfully, and without waste. ...

due to slip power recovery. *Smooth and reliable speed control. *Suitable for high-power industrial applications.

Modern Evolution

Modern systems inspired by the Scherbius Drive concept now use advanced

power electronics Power electronics is the application of electronics to the control and conversion of electric power. The first high-power electronic devices were made using mercury-arc valves. In modern systems, the conversion is performed with semiconduct ...

, such as static Scherbius drives, which incorporate converters and inverters to perform the same function with higher efficiency and flexibility.