Magnetics Business & Technology - Fall 2012 - (Page 4)

EDITOR’S CHOICE GE Scientists Successfully Test Traction Motor for Advanced Simulator Speeds Implementation of Hybrid and Electric Vehicles Direct-Drive Electric Motors Engineers at GE Global Research are advancing motor technology that could have a substantial impact on hybrid and electric vehicles (EVs) of the future. GE recently tested a prototype Interior Permanent Magnet traction motor, developed as part of a $5.6 million US Dept. of Energy (DoE) project, that could help extend the range EVs and hybrids can travel before recharging or needing gasoline. Traction motors are the key part of the propulsion system that converts electrical energy into motion to drive hybrid and electric vehicles. Not only is the GEdesigned motor less costly to make, lab testing revealed that it is more powerful and more efficient than what is on the market today. Combined, the additional power output and efficiency will help extend the range of EVs and delay the point at which hybrids switch to gasoline. GE’s prototype traction motor operates at a peak power level of 55 kW and exceeds state-of-the-art motors in the same class in several key areas including nearly twice the power density (acceleration), 3 to 5 percent more efficient, required torque achieved using much lower DC bus voltage, as low as 200 volts versus 650 volts, and operates continuously at a higher temperature; no need for dedicated cooling loop. Widespread adoption of hybrid and EVs will benefit from advancements, like this, in motor technology. Unlike conventional traction motors, which run at 65ºC and require their own dedicated cooling loop, GE’s motor operates continuously at 105ºC over a wide speed range (2,800 to 14,000 rpm at 30 kW) and can be cooled with engine coolant. Without the need for additional cooling lines, a hybrid will be lighter and cost less. GE has built several prototypes of this new motor. It’s been fully tested in the lab and demonstrated for DoE, but further testing must be done for reliability before commercial production is considered. Another important accomplishment of this project was the development of high-resistivity (3X) permanent magnets. This high resistivity will significantly lessen magnet losses and reduce or eliminate the need to segment the magnets. This will help keep costs down even more. A four-year project will follow-up on this work, as GE engineers set out to build a comparably performing motor with no rare-Earth magnets. An electromagnetic simulation tool is speeding the commercialization of a breakthrough direct-drive technology for electric vehicles by Magnomatics. The Opera simulator has been used by Magnomatics, a company that was set up to develop new forms of magnetic power transmission, to design a novel direct drive system that integrates a permanent magnet motor with non-contact magnetic gearing. Called the Pseudo Direct Drive, this new form of traction motor offers such an improved torque density that it can even be packaged within a vehicle’s wheel. The technology has already been demonstrated on a 22-inch city-bus wheel where it generated a continuous rated torque of 4,000 Nm and speeds of up to 750 RPM, which equates to a top speed of around 80 km/hour. Magnomatics is now engaged in several other Pseudo Direct Drive design projects in areas including marine propulsion, defence vehicles and direct-drive electricity generators for wind turbines. The design concepts behind Pseudo Direct Drive have emerged from a major design exercise by Magnomatics’ design team, which evaluated thousands of design variations with the aid of automated simulation provided by Cobham Technical Services’ Opera software. Opera’s finite element modeling, simulation, post-processing and optimization toolchain features a scripting language that allows users to automate their virtual design processes. Using this feature, Magnomatics has built up an extensive library of magnetic gear and motor/generator design utilities that allow its engineers to rapidly investigate new powertrain concepts. These tools provide easy-to-modify design shapes for the component parts of its magnetic gearing and motor/generator systems, such as stators and rotors, as well as special post-processing routines that provide proprietary analyses of the resulting performance. Typically, Magnomatics uses Opera scripts to evaluate hundreds of design variations, before homing in on shapes and geometries that offer the best performance. These initial design exercises are performed using Opera in a two-dimensional mode, where the simulations only take a few seconds each. Then, once the most promising design concepts have been identified, Magnomatics switches to Opera’s 3D simulation mode to evaluate a small number of potential design solutions in depth. This simulation phase is critical for Magnomatics as its major design goals, such as the need to reduce the amounts of magnetic material while optimizing torque, compete strongly against each other. During the final virtual 3D prototyping phase, Opera’s speed of execution is critical, as the complete drive system has to be simulated. However, Magnomatics’ magnetic gearing designs have little or no symmetry that allow the scale of the computation to be reduced. www.MagneticsMagazine.com 4 Magnetics Business & Technology • Fall 2012 http://www.MagneticsMagazine.com

Table of Contents for the Digital Edition of Magnetics Business & Technology - Fall 2012

Magnetics Business & Technology - Fall 2012
Contents
Editor's Choice
Permanent Magnet Motors in Application
Three-Axis Magnetic Field Measurement: From Nanoteslas to 14 Tesla
Characterizing Permanent Magnet Materials with a Vibrating Sample Magnetometer
Research & Development
Magnets • Materials • Measurement
Application • Component Developments
Industry News
Marketplace
Advertising Index
Spontaneous Thoughts: And the Wisdom to Know the Difference

Magnetics Business & Technology - Fall 2012