Centralised system for overfrequency real-time dynamic settings for generators

Abstract

The European Union (EU) network code "Requirements for Generators" regulates the Limited Frequency Sensitive Mode – Overfrequency (LFSM-O). This mode is the basis for overfrequency protection (OFP) and refers to the effect achieved through turbine generator at certain over-frequencies to reduce active power of production units, according to the given droop settings. On the other hand, the network code "Emergency and Restoration" allows for the OFP to be introduced alternatively by an automatic overfrequency control scheme.The problem arises with transmission system operators (TSOs) having generators without installed LFSM-O systems. Such an example was highlighted in the framework of the European project H2020 CROSSBOW in the Serbian TSO. In this project, Elektromreža Srbije proposed possible technical solutions for overfrequency protection system which meet the above network code requirements on emergency and restoration.This paper presents the concept of a system for centralized overfrequency protection dynamic setting for generators, which was proposed and implemented within the CROSSBOW project. The system is based on information from PMUs/WAMS and SCADA systems. The proposed technical solution is implemented in the WAProtector™ system and has been in operation since April 2021.The purpose of generator overfrequency dynamic settings is ensuring the stable operation of the power system in case of power frequency over the permissible limits with solutions requiring small financial investments and implementation based on existing systems.