View Full Document

12 views

Unformatted text preview:

Active Damping for Electromagnetic Transients in Superconducting Systems B K Johnson and H L Hess University of Idaho Moscow ID 83844 1023 Abstract The use of superconductors for power transmission has been studied for decades The lossless nature of the superconducting cables makes the system less stable operationally since the damping normally provided by resistive losses is eliminated Breaker actions during routine system operations or in response to faults can trigger high frequency oscillations between the inductances and capacitances in the system These capacitances are either power factor correction capacitors or parasitic phase to phase or phase to ground capacitances in the lines or cables The resulting transients are referred to as electromagnetic transients and can often see 100 or greater over voltages In a system using conventional conductors the series resistance will damp these oscillations within a number of 60 Hz cycles In a superconducting system these oscillations will persist with only the light damping from the frequency dependent resistance of the superconductors creating a longlasting distortion on voltage and current Many of the traditional methods to damp transient oscillations can be used but they won t cover every situation effectively Power electronic converters could also be used to damp these oscillations Either a shunt or a series connected converter could be used However the series connected converter would need to carry the full line current at all times but a shunt connected converter need be used to damp oscillations only when they occur Key issues are rating the converter and reducing energy losses The lossless nature of the superconducting cables creates new problems because eliminating losses also eliminates the damping normally provided by resistive elements Breaker actions during routine system operations or in response to faults can trigger high frequency oscillations between the line and transformer inductances and



Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Active Damping and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Active Damping and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?