Functional safety analysis and promotion for relay protection device platform

Based on the IEC-61508 safety-related standards, this paper analyzes the current status of the functional safety for the typical relay protection devices. From the point that the device platform of the relay protection, the principle and the fault tree of the key circuit module of the device platform is described in detail. According to the functional safety standards, specific measures are put forward to improve the safety integrity level (SIL) of the module function, which make relay protection device up to a higher level of safety integrity. And meanwhile, this paper also interprets the additional requirements for the EMC immunity of the safety-related systems.