High Speed Generator / Starter
This article gives a short overview of electrical machines used as high speed generators and motors, their advantages and some application fields. Furthermore, the challenges of developing and manufacturing high speed generators and motors are explained. With e+a located in Switzerland, there is a competent partner with more than 28 years of experience in designing and producing customized asynchronous and synchronous high speed generator elements for various application areas.
Introduction
Various requirements are actually leading to a growing demand for high speed generators. First of all, the continuous need for an increased power density. Due to the quasi linear relation between rotational speed and shaft power of an electrical machine, increasing the rated speed is an effective way to boost power density and efficiency. Hence this approach takes advantage of increasing shaft power without changing the size of the machine. On the other hand, the same performance can be provided in a smaller volume.
For generator applications, the main idea of using high speed generators is to directly apply an energy conversion unit to a given fast rotating mechanical system. Examples are turbine driven generators or Cryo applications, which actually experience a very similar revolution of its drive technology. Directly driven motor elements replace a set of a gear box and a 50/60Hz standard motor. Efficiency can be increased, the needed space is by far downsized and maintenance costs are reduced. Hence energy recovery systems e.g. become more and more interesting from a financial and an ecological point of view. Thus high speed motor elements contribute partly to the ongoing development of green energy applications.
High Speed Generator / Starter with air-foil bearing 25kwh 7kg
MovEnergy uses High Speed Generator / Starter (25,000 rpm) power from 25kWh to 65kwh with High power density, up to 5 kw / kg.
At start the engine drives the turbocharger until the fuel burns then the reverse is true and the electronic control optimizes the arrival of oil drip so that the generator maintains a constant speed (25,000 rpm).
F1 uses High Speed Generator / Starter
The experience acquired with KERS – the electro-mechanical system for the recovery of kinetic energy used for the first time in 2008 in Formula1 and today fitted on racing vehicles — led to the development of the Magneti Marelli electric engines. This technological revolution benefits greatly from the long-term knowledge gained by Magneti Marelli in the field of electrical machinery combined with the most advanced FEM design, simulation and analysis systems.
The optimization achieved in the design phases has made it possible to obtain state-of-the-art results with regards to development and production flexibility, for an optimal match to customer needs.
The ability to obtain a product with compact size, designed for the races, makes it possible to manufacture components that can also be installed in the reduced spaces available on vehicles already in production, consequently not conceived for hybrid systems.
The consequent weight reduction also proves to be an advantage in terms of the reduction in CO2 emissions.
Engines are developed with the goal of maximum performance optimization, also thanks to the joint use of Magneti Marelli control electronics. In fact, one of the peculiar features of Magneti Marelli’s hybrid systems is the fact that the development of the mechanical part goes hand in hand with the development of the electronic part by the same work team, which is unique in the market of components for electric engines.
High power density, up to 5 kw/kg (in mass-produced products)
High speed (25,000 rpm)
Compact size (up to 15 kw/l): easy to install