Energy Production, Distribution and Storage - 2
There is a traditional approach of implementing the robust, reliable and critical systems with several separate redundant hardware modules, achieving the required level of readiness and fail safety. However, the modern era of digital everything shifted the focus to software implementation of all the complicated systems, including critical ones. This shift allows eliminating expensive hardware redundancy with independent software modules, running on fewer hardware pieces, making it easier to fix issues, upgrade functionality and introduce new features to the existing installations. In the Power Grid this shift can be seen broadly starting with consumer side, represented with devices basically known as Internet of Things (IoT), to the Power Stations and Substations, that use an implementation called Industrial Internet of Things (IIoT), particularly Digital Substation model. In terms of critical systems this means that for example a digital relay protection device may as well perform as commercial electricity meter, running an appropriate software module, while equipped with precise and reliable sensor. The following article describes the attempt of improving a Fiber-Optic Current Sensor technology to correspond the needs of all protection, control and electricity metering systems. This includes the sensitivity, dynamic and static range, response time, measurement accuracy, environmental operation conditions, safety and reliability.
Wide area monitoring system (WAMS) installed in HOPS control center collects and process synchrophasor data in real time. There are ongoing activities on continuous, incremental and gradual upgrading of existing WAMS with new protection functions and control algorithms towards WAMPAC system. This paper describes line differential protection based on synchrophasor data and implemented on PDC server running in control room. In the first phase, the algorithm was applied to historical synchrophasor data. That check revealed that estimation block in PMUs at both line ends must implement the same estimation technique. Because of this finding, only lines with the same PMU type on both ends were selected for real-time performance test in the second phase. Several months long performance test successfully confirmed a soundness of concept and its implementation. It was proven in practice that new algorithm can be used as an effective tool for validation of basic protection performance and a solid foundation for development and implementation of backup protection.
In the present paper, the influence of reactive current settings of converters on traditional distance protection schemes is investigated. Contemporary grid codes demand converter-based generation to inject additional reactive current during faults to support the grid voltage. Through steady state simulations, it is illustrated that the amount of reactive current, defined by a fixed gain factor, impacts the calculated fault impedance by distance protection. It is illustrated that with a fixed gain factor for reactive current contribution, correct operation of traditional distance protection schemes to protect lines connected to converter-based generation is not feasible.
The power system is an example of a nonlinear system with many different oscillation sources and accordingly many oscillation types, including electromechanical oscillations, oscillations caused by control elements, or sub-synchronous oscillations. The estimation of oscillation types in the power system gives a direct insight into the state of the system stability. The ability to estimate oscillations in real time is facilitated by installing a Wide Area Monitoring System (WAM), which enables accurate metering with accurate timestamps. The HOPS synchrophasor concentrator, in addition to its main role of collecting and processing synchrophasor measurements, has an electromechanical oscillation analysis module. This paper describes the oscillation detection tool for historical data with an aim to develop real time oscillation detection system for potentially unstable events in real-time.
Intelligent grids are key enablers of the energy transition towards a decarbonized sustainable energy infrastructure. The rapid development of these grids places many new challenges to the measurement support required to ensure a secure and high-quality electricity supply. With an active contribution from all participants, this workshop will discuss and determine the existing and future measurement challenges for the successful development of smart electricity grids. The basis for the discussion will be formed by the Strategic Research Agenda recently drafted by the European Metrology Network (EMN) on Smart Electricity Grids.
Damir Novosel, Quanta Technology, US Bas Kruimer, DNV, the Netherlands Shay Bahramirad, ComEd, US Vladimir Terzija, University of Manchester, UK