Biblio

With the ever-increasing energy demand and enormous development of generation capacity, modern bulk power systems are mostly pushed to operate with narrower security boundaries. Therefore, timely and reliable assessment of power system security is an inevitable necessity to prevent widespread blackouts and cascading outages. In this paper, a new white-box decision tree-based preventive strategy is presented to evaluate and enhance the power system dynamic security versus the credible N-K contingencies originating from transient instabilities. As well, a competent operating measure is expertly defined to detect and identify the islanding and non-islanding conditions with the aid of a wide-area phasor measurement system. The newly developed strategy is outlined by a three-level simulation with the aim of guaranteeing the power system dynamic security. In the first-level, six hundred islanding and non-islanding scenarios are generated using an enhanced version of the ID3 algorithm, referred to as the C4.5 algorithms. In the second-level, optimal C4.5 decision trees are offline trained based on operating parameters achieved by the reduction error pruning method. In the third level, however, all trained decision trees are rigorously investigated offline and online; and then, the most accurate and reliable decision tree is selected. The newly developed strategy is examined on the IEEE New England 39-bus test system, and its effectiveness is assured by simulation studies.

This paper shows the benefits of synchrophasor technology for islanding detection and resynchronization in the control room at Empresa de Transmisión Eléctrica Dominicana (ETED) in the Dominican Republic. EPG's Real Time Dynamics Monitoring System (RTDMS®) deployed at ETED was tested during operator training with the event data after an islanding event occurred on October 26, 2019, which caused the ETED System to split into two islands. RTDMS's islanding detection algorithm quickly detected and identified the event. The islanding situation was not clear for operators during the time of the event with the use of traditional SCADA tools. The use of synchophasor technology also provides valuable information for a quick and safe resynchronization. By monitoring the system frequency in each island and voltage angle differences between islands, operators can know the exact time of circuit breaker closure for a successful resynchronization. Synchrophasors allow the resynchronization in a relatively short time, avoiding the risk of additional load loss, generator outages or even a wider system blackout.

Microgrids are a promising alternative to the traditional distribution systems due to their highly desirable features, such as, reliability, resiliency, and efficiency. This paper covers the design, simulation, and economic analysis of a theoretically designed modern, mixed-use commercial and residential building on a feeder in Charleston, SC, USA. The designed system is simulated in PSCAD/EMTDC. The system combines a natural gas CHP turbine and generator block set, solar photovoltaics (PV), and a battery energy storage system (BESS). It is planned to provide power through a DC lighting bus and an AC to several different commercial load profiles as well as 40 apartments of varying sizes. Additionally, a comprehensive economic analysis is completed with available or estimated pricing to prove the feasibility of such a project.

Harmonic distortions come into existence in the power system not only due to nonlinear loads of consumers but also due to custom power devices used by power utilities. These distortions are harmful to the power networks as these produce over heating of appliances, reduction in their life expectancy, increment in electricity bill, false tripping, etc. This paper presents an effective, simple and direct approach to identify the problematic cause either consumer load or utility source or both responsible for harmonics injection in the power system. This technique does not require mathematical model, historical data and expert knowledge. The online methodology is developed in the laboratory and tested for different polluted loads and source conditions. Experimental results are found satisfactory. This proposed technique has substantial potential to determine the problematic cause without any power interruption by plug and play operation just like CCTV.