Motors & Drives Information

Chorus Motors plc. -- Uses of traction motors can get five times as much power on start-up for the same sized frame by switching to the latest Chorus® Meshcon(TM) motor and drive system. In recent laboratory tests, a 20 horsepower Chorus Meshcon system achieved low-speed start-up torques in excess of five times those achieved in a conventional three-phase motor of the same size, using the same current.

One result is that Chorus Meshcon can provide a starter and generator system in the same motor. In a car, the starter, which gives high torque at low speed, cannot generate power at high speeds. The generator, or "alternator," provides electric power at high speeds but does not have enough torque to start the engine.

This basic limitation exists both for permanent magnet DC brushless motors, and inverter-fed AC induction machines.

Chorus Meshcon breaks this mould. Its new winding and drive connections allow the motor to act as both a low-speed, high-torque machine (suitable for starting an engine), and as a high-speed, low-torque machine (suitable for generating power from an engine). The change happens in a fraction of a second, allowing a motor to seamlessly switch from starting mode to generating mode.

The specific results from the latest 20hp Chorus Meshcon drive show that a motor and drive designed for high-speed, low-torque generation-type operation is able, without any additional loading on the power electronics, to deliver five times the torque at low speeds.

Chorus Meshcon is thus ideal for starter-generators, conveyors, locomotives, cargo handling equipment, hoists, printing presses, or any application requiring large start-up torques and smaller high-speed loads. Newly updated details can be found on the Chorus Motors plc web site at www.chorusmotors.gi including recent test results.

Integrated power assemblies for Chorus Meshcon continue to be designed and built by Semikron Limited on an exclusive basis. Chorus Motors plc is currently working with several motor suppliers to meet customer requirements for specific applications.

"With these superb results from testing, we are now designing motors and drives for specific applications that are clearly superior to any other motor and drive technology," said Isaiah Cox, President of Chorus Motors plc. "We are already tendering for contracts which, if we are successful, will put our business on a firm footing for many years to come."

Technical Notes:

The Chorus Star concept uses concentrated, high-phase order windings which allows the beneficial use of harmonics (temporal, spatial, and overload). Consequently, a Chorus machine can achieve much higher torque densities than a traditional three-phase motor, but with no cost penalty.

Conventional motor drives cannot output maximum current and voltage to a three-phase motor when it is operating at low speed, for example, when starting. The proprietary Chorus Meshcon system uses harmonic drive to simulate high-speed conditions, so that the motor then draws a higher current into the winding slots.

The result is that a very much smaller drive can be used for the same load, without hampering high-speed operation. The same motor could, for example, be used to start a car engine, and then efficiently produce electrical output as a generator once it is running.

About Chorus Motors

Chorus Motors plc (OTC: CHOMF) is a majority-owned subsidiary of Borealis Exploration Limited (OTC: BOREF). Chorus has developed the proprietary Chorus® Star and Chorus Meshcon(TM) electric motor technologies, which offer substantial cost and performance improvements over comparable motor and drive systems. The Chorus systems produces high torque at start-up speeds and are ideal for traction applications such as automobiles, trucks, locomotives, and ships. Its advantages enable several potentially innovative applications in aerospace.

# posted by Medical Information : 2:56 AM