Technical Presentations

Sub-Synchronous Resonance (SSR) Phenomena for Synchronous machine – Simulation & Analysis using EMTP and mitigation technique890

Abstract
Synchronous generators are exposed to oscillatory stresses due to their proximity to statcom devices and other power electronics devices, such as FSCs, HVDC controllers, and STATCOMs, which generate s... see moreub-harmonic frequencies. The interaction between sub-harmonic frequency components and mechanical mass can lead to Sub-Synchronous Resonance (SSR), an unstable and dangerous condition that causes torsional oscillation in the turbine generator shaft. This can reduce machine life, cause fatigue and damage to the shaft, and even result in its breakage. To avoid this, SSR detection/protection should be installed in generator units close to series compensated transmission lines. Different SSR modes can occur depending on the network condition and degree of compensation provided. Comprehensive Torsional Vibration Monitoring & Analysis systems are expensive, but there are cost-effective solutions to sense sub-harmonic quantities reliably at low amplitudes based on desired magnitude of sub-synchronous voltage and/or current. The offered solutions are supported by simulations, studies, modeling, and detailed analysis carried out in EMTP®.

Tag(s): Protection, Stability Studies, HVDC, STATCOM

Influence of HVDC Controls on Transient Stability of Synchronous Machines747

Abstract
<h2 class="title">EMTP Europe User Conference 2019 </h2> <p class="tagline"><b>The EMTP User Conference pres... see moreentations are now available online!</b></p> <p id="text-intro"><b>Influence of HVDC Controls on Transient Stability of Synchronous Machines</b><br> With the energy transition in France and in Europe, the transmission grid is strongly impacted by the forthcoming connection of power electronics devices, such as offshore wind farms and HVDC interconnections. These new devices use power electronics converters that generate transients which are usually more complex to analyzed than for standard AC devices, in particular during faults. These phenomena can have an impact on the grid stability.<br> The presentation will focus on the transient stability studies of synchronous generator influenced by power electronics devices. The objective is to compare the critical fault clearing time for different fault locations, fault conditions and different HVDC converter fault ride through control strategies. Generic test cases as well as real scenarios are considered. In this study, the critical time is obtained with bisection method thanks to the new parameter sweep toolbox.