Critical Review of Mitigation Solutions for SSO in Modern Transmission Grids

Abstract

<jats:p>The replacement of conventional generation by power electronics-based generation changes the dynamic characteristics of the power system. This results in, among other things, the increased susceptibility to subsynchronous oscillations (SSO). First, this paper discusses three recently emerging SSO phenomena, which arise due to the interactions between (1) a doubly-fed induction generator and a series compensated transmission system; (2) a voltage source converter (VSC) and a weak grid; and (3) nearby VSCs. A fundamental review of these phenomena resulted in the requirement for a reclassification of the existing SSO phenomena. This reclassification is proposed in this work and is based on interacting components identified using participation factor analysis for the distinct phenomena. Second, a critical review of the existing mitigation measures is performed for these phenomena, highlighting the advantages and disadvantages of the solutions. The influence of the wind speed, grid strength, number of wind turbines, and several converter controller parameters are also discussed. To assist equipment manufacturers, control design engineers, and system operators in selecting and designing effective mitigation measures, the existing solutions are categorized in control solutions, hardware solutions, and solutions based on system level coordination. Finally, perspectives on open issues conclude this paper.</jats:p>

Evaluation of Phase Imbalance Compensation for Mitigating DFIG-Series Capacitor Interaction

“…Solutions for mitigating DFIG-SSR can be based on (i) modifications in existing control algorithms of the DFIG (i.e., control solutions), (ii) installation of new hardware equipment or modification of existing hardware equipment (i.e., hardware solutions), and (iii) coordination between the power system state and existing or new controls (i.e., system level coordination) [1]. Control solutions are implemented in the power electronics interfaced device under consideration (in this case, the DFIG).…”

“…On the other hand, when the goal is to mitigate DFIG-SSR by means of any other FACTS device, it will have to be equipped with a supplementary damping controller (SDC). Several of such cases are reported in Reference [1]. Installing a FACTS device (except for TCSC) for mitigating DFIG-SSR is only cost-effective when additional power system support, such as voltage control, is required.…”

“…The sub-synchronous resonance (SSR) between a doubly fed induction generator (DFIG) and a series capacitor is a form of self-excitation and is defined as DFIG-SSR in Reference [1]. This phenomenon was observed in a practical power system for the first time in 2009, where the interactions between a DFIG-based wind farm and a series compensation transmission line in the power system of Texas resulted in a system disturbance [2].…”

“…In Reference [1], the authors presented a critical review of the existing mitigation solutions for DFIG-SSR. In this review, the solutions were categorised in control solutions, hardware solutions, and solutions based on system level coordination.…”

Electrical Damping Assessment and Sensitivity Analysis of a Liquefied Natural Gas Plant: Experimental Validation

“…Some previous studies such as [9,10] have shown that the synchronization system parameters affect the power system stability in the case of weak grids. Besides the impact of the Power System Stabilizer (PSS) on the SSR damping has been previously demonstrated in [11][12][13][14].…”