Application of standard solutions for mesh corner delayed auto-reclose and autoswitching with numerical relay

For the Delayed Auto-Reclose (DAR) and Autoswitching (ASW) systems in Mesh Corner circuits, taking into consideration the desire to minimise the overall system cost by reducing hardwired connections and auxiliary relays, the advanced multifunctional numerical relays with GOOSE (Generic Object Oriented Sub-Station Event) Communication interface via UCA2 (Utility Communication Architecture) protocol have been developed and used to replace old electromechanical and numerical relays. The application of DAR and ASW of Mesh Corner requires interfacing to all the plant status, co-ordinated controls and a large amount of inputs and outputs. To replace the old relays and reduce massive traditional hardwire connections, using an advanced numerical relay (here called MCDAR) with the GOOSE Communication interface over an Ethernet link, aMCDAR relay standard scheme solution has been created and applied to provide the full control logic and input-output (I/O) required for DAR and ASW of a single Mesh Corner. Within the MCDAR relay standard scheme solutions, all interfaces to basic protection functions associated with Mesh Corner such as Feeder, Transformer and Mesh Corner circuits are catered for and control functions are provided such as automatic reclosure of Mesh Corner circuit breaker, Autoswitching of the disconnectors, and suppression of a Ferro-resonance condition. The control information for Mesh DAR and ASW can be passed and exchanged between the MCDAR relays with GOOSE mapping via Ethernet local network. The MCDAR relay scheme solution can be used for DAR and ASW applications from a single switch to an eightswitch mesh. The paper presents the application of the numerical relay MCDAR standard solution with UCA2 GOOSE interface at Mesh Corner sites on transmission and distribution networks, and highlights the benefits of the application of the numerical MCDAR relay standard scheme solutions.