A protective relay voting scheme utilizing automation controllers

This paper explores utilizing a programmable automation controller (PAC) in a power system relay protection scheme. The adaptive voting scheme (AVS) uses a wide-area measurement system (WAMS) to classify the system operating state, and biases the protection scheme towards security or dependability based on stressed or normal conditions, respectively. The use of an automation controller to integrate with WAMS devices and perform voting logic is proved highly effective. The injected delays from the PAC in the protection scheme are taken into consideration, and minimized to a maximum value of 3.18 ms.