Summary
This work aims to develop a method to determine the asymmetry of currents and voltages in power transmission as well as to study the impact of the transmitted power, parameters of transmission lines, and adjacent systems on the asymmetry of currents and voltages in a power transmission. The calculation devised herein is based on quadripole equations in a matrix form and a method to achieve symmetrical components. The analysis of asymmetry is conducted on an example 500 kV power transmission that includes a transmission line with horizontal arrangement of phase conductors as well as sending and receiving systems. It is shown that, asymmetry of negative sequence currents for the untransposed transmission line can be up to 10% under small transmitted power and up to 2% for negative sequence voltage under transmitted power, more than the natural power. These values are higher than the permissible values, specified by regulations. Implementation of a full cycle of phase transposition allows for significant reduction in the asymmetry ratio of currents and voltages. It is also revealed that, except transmitted power, significant impact on asymmetry values lengthens the transmission line and impedances of the adjacent systems. The impact of the earthing scheme and number of grounded wires is negligible. Finally, a comparison of the obtained results with results of ATP EMTP software is conducted.
Additional informations
| Publication type | ISH Collection |
|---|---|
| Reference | ISH2015_229 |
| Publication year | 2015 |
| Publisher | ISH |
| File size | 509 KB |
| Price for non member | Free |
| Price for member | Free |
Authors
Walfridsson Lars, Källstrand Birgitta, Umemoto Takahiro
