Anglia Components |
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New sinusoidal output filters increase motor life and system reliability
This effectively increases the service life of the motor by reducing the likelihood of failure, and the significant down-time costs associated with maintenance or replacement. In addition, the output filters convert the pulse width modulated output signal into a smooth sine wave with a low harmonic content, which offers many advantages. First, the system efficiency is improved by reducing eddy current losses and displacement currents in the motor. Second, leakage currents through the motor bearings to earth will be eliminated by the filter and the bearing's service life increased. Third, acoustic noise is also reduced, an important consideration in applications such as air-conditioning and ventilation systems, where air ducts can amplify the noise and distribute it to the whole building. Furthermore, lower pulse currents coupled with the shielded motor cables to earth result in lower semiconductor losses in the inverter and also produce a better overall EMC environment. Typical applications will be found wherever a motor needs to run at different speeds and therefore is controlled by a motor drive; from pumps and conveyors, to lifts and cranes, machine tools, alternative energy supply systems, robotics, medical, chemical and general industrial automation. The filters are designed to operate in common 400VAC supply grids and with current ratings from 2.5A to 610A, in small incremental steps. They allow switching frequencies from 4kHz to 16kHz and motor frequencies up to 60Hz (70Hz). A 690VAC version is also being developed. A technical data sheet providing more detailed information is available on request. For more information on the full range of Schaffner products available from Anglia please call +44 (0)1945 474747 or email info@anglia.com |
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This news article was published in November 2002.
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15/10/02