This paper studies the interest of the integration of battery energy storage with Static Synchronous COMPENSATOR (STATCOM) for improving the low voltage ride through capability (LVRT) of a fixed speed wind turbine connected to the grid. For this reason and by applying a grid fault, a comparison is made between integrating the SSSC, the STATCOM and the STATCOM with battery energy storage.The system with the aforementioned flexible alternating current transmission system (FACTS) systems is simulated using MATLAB/SIMSCAPE and the results show that the STATCOM with a battery is most efficient in terms of improving the LVRT of a fixed speed wind turbine.

Encountering series-compensated transmission lines, sub-synchronous resonance (SSR) may strike the power system by jeopardizing its stability and mechanical facilities. This paper aims to verify the capability of static synchronous series COMPENSATOR (SSSC) in mitigating the mechanical and electrical oscillations such as SSR in wind farm integrations. A wind turbine with a self–excited induction generator (SEIG) represents the wind farm and it is connected to the system through a transmission line compensated by a series capacitor. Both the induction–generator (IG) effect and torsional interaction (TI) on SSR occurrence are examined. Simulations are carried out using EMTDC/ PSCAD on the IEEE first SSR benchmark model along with a SEIG based wind turbine. Also a Fast Fourier Transform (FFT) analysis is performed to determine the dominant torsional mode existing in the turbine generator system. The SSSC impact on SSR mitigation is interrogated in various case studies. A SSSC with a simple power flow control in its base case is first considered. It is shown that the SSSC can damp the SSR even without any specific auxiliary controller. In the following the same SSSC is shown to effectively damp SSR when equipped with an auxiliary SSR damping (SSRD) controller.

In this paper, the modified linearized Phillips-Heffron model is utilized to theoretically analyze a single-machine infinite-bus (SMIB) installed with SSSC. Then, the results of this analysis are used for assessing the potential of an SSSC supplementary controller to improve the dynamic stability of a power system. This is carried out by measuring the electromechanical controllability through singular value decomposition (SVD) analysis. This controller is tuned for simultaneously shifting the undamped electromechanical modes to a prespecifed area in the s-plane. The issue of designing a robustly SSSC- based controller is considered and formulated as an optimization problem according to the eigenvalue-based multi-objective function consisting of the damping ratio of the undamped electromechanical modes and the damping factor. Next, considering its high capability to find the most optimistic results, the Gravitational Search Algorithm (GSA) is used to solve this optimization problem. Wide ranges of operating conditions are considered in design process of the proposed damping controller in order to guarantee its robustness. The effectiveness of the proposed controller is demonstrated through eigenvalue analysis, controllability measure, nonlinear time-domain simulation and some performance indices studies. The results show that the tuned GSA based SSSC controller which is designed by using the proposed multi-objective function has an outstanding capability in damping power system low frequency oscillations, also it significantly improves the power systems dynamic stability.

Silicon carbide power devices are widely utilized in applications requiring high voltage and current. Due to the limited current capability of a single module, silicon carbide MOSFETs are frequently arranged in parallel to enhance the current capacity of the final product. However, variations in circuit parameters or inconsistencies in semiconductor manufacturing can cause imbalances in the current among the parallel modules, potentially resulting in performance and dependability challenges. To tackle the matter, this paper introduced the use of an active approach designed for paralleled SiC MOSFETs to resolve these unbalanced currents. The proposed method used a current transformer to detect the imbalance current. Further, an active COMPENSATOR is presented within a closed-loop control feedback that effectively eliminates the current imbalance among parallell modules in a master-slave configuration. Details of current transformer and stability of the closed-loop control are investigated. Experimental results are provided to showcase the viability and efficiency of the proposed approach.