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This paper presents a new non-isolated high-gain Buck-Boost Converter (BBC) that uses a switched- inductor (SL) voltage multiplier. This type of DC-DC converter can be very useful in renewable energy applications, especially PV, where the output DC voltage is stepped up to a higher voltage. The output voltage of the proposed switched-inductor BBC (SLBBC) is around 15 times the input voltage with positive polarity when a 0.75 duty cycle of the power switches is used. This is achieved without the use of a transformer or common-core coupled inductors, so the topology is simple to construct. This high output voltage is achieved by using the SL voltage multiplier, which consists of three diodes and two inductors. There are two power switches that operate synchronously, which is an advantage of the design. However, it is discovered that the voltage gain in the step-down mode of the proposed converter is less than that of the other converters. The proposed converter is analyzed in the Continuous Conduction Mode (CCM). The operating principles and steady-state analysis are presented in detail. MATLAB/Simulink was used to prove the effectiveness of the proposed SLBBC. [ABSTRACT FROM AUTHOR]

In the pursuit of a sustainable electric power system, the integration of renewable energy sources and distributed energy resources is gradually replacing traditional power generation. These new resources are integrated into the grid via inverters, which, despite their efficient performance, present dynamic challenges to the power grid when implemented on a large scale. To maintain grid stability and ensure effective regulation during abnormal operations, various modeling techniques are necessary; while the dynamics of inverter-based resources (IBRs) are traditionally modeled by transfer functions, this paper sheds light on differential-algebraic equations (DAEs) modeling and numerical integration methods. The inherent limitations of transfer function modeling stem from its restricted applicability, as it is exclusively suitable for linear and time-invariant systems. In contrast, the nonlinear DAEs of the IBR system can be converted into a state–space form, which offers a versatile framework for modeling, evaluating, and designing a diverse array of systems. In addition to being compatible with time-varying systems and multiple-input multiple-output systems, the state–space technique may incorporate saturation and dead zone characteristics into the dynamic model. Our research focuses on IBR modeling in a grid-following scheme, which is current-controlled and synchronized to the grid by a phase-locked loop (PLL). The presented state–space model consists of the inverter, grid, control, and designed PLL. Beyond the discussion of its application to IBRs, the presented method holds the potential to solve a wide range of DAEs. The proposed model is compared with a benchmarked system. [ABSTRACT FROM AUTHOR]

Among multilevel inverters (MLIs), two-level inverters are the most common. However, this inverter type cannot maintain total harmonic distortion (THD) due to its limited number of levels. Reductions in THD are inversely proportional to the number of levels where increased output occurs in diverse ways, and the use of fewer components with low harmonic distortion is necessary for such reductions. This work proposes a seven-level (7L) MLI design with a small number of components and low harmonic distortion. The proposed MLI is combined with switched capacitor (SC) cells to promote output levels and at the same time to boost the input voltage. The connections between the capacitor and the source are based on the series to parallel topology, where the charging and discharging of the SC cells are caused by fluctuations in their connection. The output of the SC cell is combined with an H-bridge inverter controlled by a proposed PWM controller. The simulation result of the SC 7L inverter was completed using LTspice software. A comparison of the proposed topology with that of other current MLI led to better validation results. The proposed design shows a reduction in the THD with fewer components. The cost and size of the proposed inverter is minimal due to the smaller number of components. Ohmic load and inductive ohmic load were used as loads for the system. [ABSTRACT FROM AUTHOR]

Due to their high power density and appropriateness for small circuits integration, switched-capacitor (SC) converters have gotten more interests. Applying the soft-charging technique effectively eliminates the current transient that results in a higher power density and a higher fundamental efficiency. Achieving the complete soft-charging operation is impossible by using the conventional control diagram for any SC converter topology. In this paper, we proposed a split-phase control to achieve the complete soft-charging operation in a power switched-capacitor (PSC) converter. The proposed control diagramwas designed for a 1-to-4 PSC converter (two-level of the PSC converter). The implemented split-phase diagram successfully controls eight switches to exhibit eight modes of operation. In addition to the current transient elimination, the complete soft-charging allows us to reduce capacitor sizes. However, reducing capacitor size negatively increases the output voltage ripple; hence, an output LC filter is needed. The complete soft-charging achievement accomplishes a 96% efficiency due to the lower output impedance and the dead time switching. LT-Spice software has been used to verify the proposed control and the results were compared with hard-charging and incomplete soft-charging operations. [ABSTRACT FROM AUTHOR]

This paper proposes a novel hybrid algorithm combining chaotic Jaya (CJaya) and sequential quadratic programming (SQP), namely CJaya-SQP, for solving the coordinated design problem of static var compensator (SVC) and power system stabilizers (PSSs). The CJaya serves as a global optimizer and the SQP as a local optimizer for fine-tuning the solution. In the proposed algorithm, chaotic maps are used to generate the initial solutions and control the search process. In order to prove the performance of the CJaya-SQP, a set of benchmark optimization problems is used where the results are compared with those of the basic Jaya and other recognized algorithms. The proposed optimization method is then applied for the optimal tuning of PSSs and SVC controllers in such a way that damping ratios and damping factors of the electromechanical modes are optimally improved. To illustrate the robustness of the CJaya-SQP-based coordinated PSSs and SVC controllers, the four-machine, two-area system is used. Eigenvalue analysis and nonlinear time-domain simulation vividly show that the CJaya-SQP-based coordinated controllers improve greatly the system's dynamic stability with a robust damping of local and inter-area power oscillations. [ABSTRACT FROM AUTHOR]

This paper presents a new approach for coordinated design of power system stabilizers (PSSs) and static VAR compensator (SVC)-based controller. For this purpose, the design problem is considered as an optimization problem whose decision variables are the controllers' parameters. Due to nonlinearities of large, interconnected power systems, methods capable of handling any nonlinearity of power networks are mostly preferable. In this regard, a nonlinear time domain based objective function is used. Then, the coyote optimization algorithm (COA) is employed for solving this optimization problem. In order to ensure the robustness and performance of the proposed controller (COA-PSS&SVC), the objective function is evaluated for various extreme loading conditions and system configurations. To show the contribution of the coordinated controllers on the improvement of the system stability, PSSs and SVC are optimally designed in individual and coordinated manners. Moreover, the effectiveness of the COA-PSS&SVC is assessed through comparison with other controllers. Nonlinear time domain simulation shows the superiority of the proposed controller and its ability in providing efficient damping of electromechanical oscillations. [ABSTRACT FROM AUTHOR]