1.Many simulations and investigations about the adaptive ground distancerelay arerun in 110kV and 500kV system,and the simulations show that the adaptive grounddistance relay has excellent adaptability and selectivity not only in 110kV system butalso in 500kV system,and the effect turns up trumps.
2.By calculating the apparent impedance,the author analyses the operating behaviour of phase- and earth-fault distancerelay and shows that their performences vary with the amplitude of the double-feed emf and the inequality between the source impedance angle and that of the line impedance.
4.Making the compari- son between the time synchronism with TV and the method of Loran-C, the main time relay (5853.9~(μs)) was determined within distance from our observatory to the CCTV.
