In order to solve the dependence on the relay protection system in the network sampling mode

the process of direct sourcing layer and sampling mode synchronous network is analyzed to find out why the synchronization goes wrong with network sampling technology. An improved clock system is then proposed in the network sampling mode. A redundant configuration scheme is presented for the main clock system architecture and the gradual adjustment scheme for the time adjusting mechanism is also proposed. The switch boundary clock scheme is put forward for IEEE-1588 technology. Actual engineering tests have validated that the scheme proposed is up to requirement with respect to relay protection of synchronization reliability

synchronization precision and long-time operation error. Application of the synchronization scheme is able to increase the independence and reliability of relay protection in the network sampling mode while making further improvement on the synchronization system of process level network sampling.