Design method for timing system of secondary equipment considering rapid temperature change environment

The secondary equipment in the smart substation represented by the merging unit ensures the synchronization of bay-level sampling data through a time synchronization system. However, with the introduction of new functional requirements such as busbar dual cascading and emerging architectural demands including acquisition and execution units, the performance of the time synchronization system has been compromised. To address the impact of rapid temperature variations on devices, this paper proposes a design scheme for time synchronization systems. In terms of hardware, an OCXO utilizing dual-parameter frequency modulation compensation technology is adopted, integrated with a temperature variation prediction method to eliminate hysteresis effects; In terms of algorithm, a hybrid long-term and short-term time-keeping algorithm based on least squares fitting is developed, explicitly incorporating environmental temperature variation rates to enhance system adaptability in rapid thermal transients. Finally, comprehensive verifications are conducted on the thermal-frequency characteristics of OCXOs and the temporal performance of the synchronization system. Experimental results demonstrate that devices incorporating this innovative time synchronization design can satisfy industry testing standards under rapid temperature variation conditions.