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The improved virtual flux–based direct power control (VF‐DPC) strategy for a grid‐connected power converters is proposed in this paper to eliminate current harmonics and mitigate voltage fluctuations during grid voltage faults without using voltage sensors. The proposed control strategy integrates VF‐DPC for static reactive power compensator (STATCOM) and active power filter (APF) into a single algorithm. The reference electrical quantities for each operating mode of the converter are selected based on the state of the electrical grid. Specifically, if the grid voltage variation remains within the limits defined by international standards, the APF operating mode is prioritized. However, if the voltage variation exceeds these standards, the STATCOM operating mode is given preference. The primary goal of the proposed control strategy is to enable a seamless transition between APF mode and STATCOM mode, while minimizing reactive power exchange with the electrical grid and reduces the number of sensors required. This control strategy gives priority to the reactive power injection during grid voltage faults to support voltage regulation. Under normal grid conditions, it enables the power converter to effectively eliminate current harmonics produced by nonlinear loads. Simulation results demonstrate that the proposed modified VF‐DPC technique has high performance in both of converter operation modes. Practical results plotted using a test bench based on a dSPACE 1104 card justify the validity and efficiency of the developed algorithm.

In the trajectory of carbon dioxide (CO 2 ) neutrality, wind and solar energies will be the key for the energy transition in the electricity sector; however, a massive integration of solar and wind farms into the electricity grid by 2050 will be carried out. For this end, powers control and powers management of these two renewable energies have taken the attention of several researchers since the last decades. This article presents a reactive energy management strategy for a power grid linked to a wind farm utilizing doubly fed induction generators (DFIG) and enhanced by a static reactive power compensator (STATCOM). This management strategy improves an electrical grid capability in the event of a low‐voltage ride through (LVRT) and aims to optimize the sizing of the STATCOM to be installed alongside the wind farm. The proposed oriented voltage control strategy (VOC) for the grid‐side converter and STATCOM facilitates effective reactive current injection into the grid during symmetrical faults with significant voltage sags. A maximum power point tracking (MPPT) approach combined with stator flux‐oriented control (FOC) applied to the rotor side converter enables effective control of the DFIG during an asymmetrical fault. Breaking down currents and voltages into positive and negative sequences expressed in the synchronous frame enhances DFIG and STATCOM control during grid voltage asymmetrical faults. The control algorithms are validated by simulation results using MATLAB‐SIMULINK.

This paper presents the design of optimum wideband compensator filters to improve the passband of comb-based filter classes composed of the cascade of different lengths of comb filters. More specifically, we consider three classes of comb-based functions modified from the literature proposed to increase the aliasing attenuation of comb filters. However, those functions exhibit a high passband droop, which should be compensated to avoid the deformation of a decimated signal. The magnitude characteristic of the filter is in sinusoidal form. The design parameters are amplitudes of the sinusoidal functions obtained using MATLAB Particle Swarm Optimization (PSO). As a result, a minimum of the maximum passband deviation is achieved. The examples of the optimum compensator designs for all three comb-based filter classes are presented. As a result, the proposed decimation filter is less complex compared with the classical Remez-designed decimation filter.

The work is devoted to the study of the possibility of developing an active vibration isolation system in which in order to compensate for the dynamic forces on the hull arising due to the oscillations of an elastically suspended vibroactive mass, the effect of inertial forces in antiphase is used. The vibroactive force compensator is an electrodynamic actuator. It is mounted on the hull close to vibroactive mass supports and produce an inertial force by controlling oscillations of the moving mass, which compensates the force on the hull from the vibroactive mass.

Under the environment of large temperature differences, the Sichuan-Chongqing UHV project is located at the high-altitude area, and the universal bellows compensator which cannot meet the requirements of large displacement is prone to instability. This paper proposes the design scheme of modified pantograph linkages bellows compensator by studying the instability mechanism of the bellows and improving the structure of the compensator. The overall size is reduced, the stress and the deformation of the flange are decreased, and the stability of the compensators are enhanced. According to mechanics theories, the corresponding relationship among displacement, spring rate and the spring rate force was discovered. The equations of lateral displacement of bellows with high accuracy was established. And the final experimental displacements were obtained after two steps of calculating.

This study presents a new nonlinear model-based predictive control scheme using fractional-order calculus and interval type-3 (IT3) fuzzy logic systems (FLSs) for Micro-Electro-Mechanical-System gyroscopes (MEMS-Gs). The dynamics of MEMS-G are unknown and perturbed by actuator faults and disturbances. Two IT3-FLSs are used for online modeling of uncertainties and predicting of tracking error. The IT3-FLSs are online optimized by Lyapunov adaptation rules such that the stability and robustness to be guaranteed. Also, the designed compensators adaptively tackle the effects of perturbations and estimation errors. In various conditions such as dynamic perturbations, actuator nonlinearities, tracking of a chaotic system, and tracking of a pulse signal with sharp rising and falling, we examine the capability of the suggested controller and compare with new controllers and other type of FLSs. We show that a well tracking accuracy with the desired transient performance and least overshoot is obtained.

In this paper, the operating principle and control scheme in the CCM mode of the front-end totem pole PFC are analyzed. Based on the operating characteristics of the circuit topology, a PR controller is used to control the input current. When the grid voltage contains harmonic signals, a low harmonic compensator is cascaded in the original PR controller to reduce the impact of harmonics in the grid voltage on the control effect. Then input current distortion is analyzed when the AC input voltage crosses zero point, and the corresponding optimization method is proposed. Finally, different experiments are carried out to verify the effectiveness of the proposed method.

In some areas with sparse populations and dispersed power loads, the construction investment of distribution network lines cannot keep up, and the phenomenon of low voltage at the end of the power distribution network is particularly serious, even causing some household appliances to be unable to start. This article aims to provide some solutions to alleviate the low voltage of distribution network lines in certain regions. It introduces a method based on distributed series compensation for long lines with low voltage of the line terminal. In the same distribution network line, it is installed two or more sets of series compensators to alleviate the low voltage problem at the end of the long line of the distribution network based on a decentralized arrangement. The technical scheme is based on a 10 kV feeder for simulation to verify the correctness and effectiveness of the proposed method.

Multimessenger constraints tightly bound the gravitational-wave speed to be luminal, posing a strong filter for modified gravity. This paper develops a symmetry-selected Palatini framework with torsion in which exact luminality at quadratic order is achieved by construction rather than by parameter tuning. Two ingredients shape the observable sector: (i) a scalar PT projector that keeps scalar densities real and parity-even, and (ii) projective invariance implemented via a non-dynamical Stueckelberg compensator that enters only through its gradient. Under an explicit posture (A1–A6), we establish three structural results: (C1) algebraic uniqueness of torsion to a pure-trace form aligned with the compensator gradient; (C2) bulk equivalence, modulo improvements, among a rank-one determinant route, a closed-metric deformation, and a PT-even CS/Nieh–Yan route; and (C3) a coefficient-locking identity that enforces K=G for tensor modes on admissible domains; hence, cT=1 with two propagating polarizations. Beyond leading order, the framework yields a distinctive, falsifiable next-to-leading correction δcT2(k)=bk2/Λ2 (for k≪Λ), predicting slope 2 in log–log fits across frequency bands (PTA/LISA/LVK). The analysis is formulated to be reproducible, with a public repository providing figure generators, coefficients, and tests that directly validate (C1)–(C3).

Due to the recent rapid development of wind power generation, people have higher requirements for the stability of wind power systems. The randomness and intermittency of wind farms are strong. When the system is disturbed, or the line fails, it is easy to cause voltage instability. In order to ensure the stable operation of the power system, it is necessary to set up a static reactive power compensation device (STATCOM) to provide reactive power in the power system. This paper simulates and analyzes the wind power generation system with a STATCOM device. The results show that the operation process of the wind power system with STATCOM is more stable.