Visual Object Tracking (VOT) remains challenging under adverse conditions such as illumination variations, motion blur, fast object dynamics, and background clutter. RGB-based trackers often degrade in low light or rapid motion due to reliance on appearance cues, while event-based trackers are robust to fast motion but lack semantic and contextual information for disambiguating targets in cluttered scenes. We propose RELTrack, a multi-modal tracker that integrates RGB, Event, and Language in a unified framework. RELTrack uses a three-level captioning strategy (object-, scene-, and video-level) to provide hierarchical textual guidance and a multi-branch fusion module to align and integrate RGB, event streams, and language embeddings for robust target localization. Experiments on four RGB–Event benchmarks, VisEvent (820 sequences), FE108 (108 sequences), COESOT (1354 videos), and FELT (742 videos), show that RELTrack achieves 63.1/80.5/73.3 (SR/PR/NPR) on VisEvent, 61.69/89.30 (SR/PR) on FE108, 66.7/79.3/77.6 (SR/PR/NPR) on COESOT, and 61.3/71.2/68.9 (SR/PR/NPR) on FELT, demonstrating state-of-the-art performance across datasets. Code and models are publicly available at: https://github.com/XXXXX/RELTrack .

Travel-time reduction is a primary objective for managing connected emergency vehicles (CEVs) to save people’s lives or put out a fire. With the integrity of internet of things (IoT) and connected autonomous vehicles (CAVs), it has been a research challenge to find a safe, reliable, and optimal strategy that not only minimizes the CEV’s travel time but also lessens the undesirable side-effects on other road users. This article introduces multiple intelligent control strategies in one framework to boost the potential of CEVs traveling via multiple traffic intersections. The framework includes a path-planning mechanism adapting to sudden traffic delays, traffic signal preemption controller adapting to the urgency level associated with the emergency event, and a deep-learning model for CAVs to predict the time required for giving way to the CEV. All modules are implemented through a microscopic traffic simulation environment (PTV-VISSIM). This article holds significant implications for various scenarios involving CEVs and intelligent transportation systems (ITS). The path planning approach showcased notable improvements, reducing average path travel time by 9% when compared to existing benchmarks. The regression error for predicting the merging time of CAVs is minimized to be 0.4 second. Furthermore, the signal preemption controller demonstrated an important trade-off analysis between the level of intrusive preemption signal control and the undesired impacts on the traffic network. This finding enables traffic management authorities to make informed decisions regarding signal preemption strategies, considering both the travel time optimization for CEVs and the potential network-wide traffic impacts.

In this article, we propose an improved high-boost-gain split-source inverter (SSI) for renewable energy generation. The proposed inverter retains the features of the existing SSIs, such as single-stage boost inversion with a reduced number of passive components and elimination of the inverse modulation–duty relationship constraint of the impedance-source inverters. It also provides additional features that include higher boost inversion ability than existing SSIs to connect low-voltage renewable energy sources to the grid, no voltage-source short-circuit issue, which increases the robustness of the proposed inverter and pulsewidth modulation dead times can be relieved, and the negative input dc-terminal and ac-neutral are electrically connected in the proposed inverter, resulting in a constant common-mode voltage and elimination of leakage ground currents for grid-interfaced PV power systems. A detailed circuit operation and analysis is provided, and experiments are performed on a 400-VA prototype inverter to confirm the working of the proposed topology.

A new type of filter/extractor named independent time-delay signal cancellation (itDSC) method is proposed in this article. Unlike conventional harmonic sequence filter (HSF) designs, the phase modifying and vector recovering stages of the proposed itDSC are separately set with single targets to make time-delays independent from the targeted HS indices and fundamental period. Consequently, the proposed HSF is more flexible in design, more robust and accurate in performance as well as faster in dynamic response compared to the conventional ones. A new phasor representation of an arbitrary order and sequence is first introduced for three-phase signals by using only a single integer-index-number (h). Then, a generalized principle of filtering/extracting arbitrary HS is proposed where the conventional time-dependent methods are specific cases. Last, new designs with independent time-delays are proposed to avoid the drawbacks of dependent time-delays and improve the filter performance in the applied systems. Comparative performance and extended applications on fundamental-frequency positive-sequence extraction used in power converter control areas are presented. The experiments show the superiority, application potentials, and challenges of the proposed method in the power converter control area.

The increased deployment of renewable energy in power networks makes it necessary to maintain equilibrium between generation and demand due to their intermittent behavior. However, numerous strategies, including load shedding, load shifting, and energy storage technologies, can also be utilized to meet the increasing demand for load. This article proposes a course of action based on demand response (DR), which prioritizes demand-side monitoring, within the automatic generation control paradigm. A rule-based fractional control scheme with a two-degree-of-freedom topology is developed for the frequency regulation of a deregulated identical hybrid two-area power system in a DR framework. A quasi-oppositional Harris Hawks optimization is investigated along with the proposed controller to tune the controller coefficients adaptively. A thorough examination of the preferred system, including the DR approach, significantly enhances the frequency regulation services and offers a significant improvement over conventional frequency regulation in terms of system dynamics. Research is further enhanced by considering natural random time delay in the DR framework to analyze the dynamic behavior of the system. An experimental evaluation using the OPAL-RT 5700 is presented to verify the practicality of the suggested technique for intermittent sources and loads.

This paper proposes a novel cascaded multilevel inverter (CMLI) structure based on switch capacitor (SC) tech-nology, which is capable of achieving up to 17 levels. The inverter is constructed by cascading two SC-based 9-level MLI basic modules, resulting in a 17-level SC-CMLI structure. The proposed inverter employs a reduced number of power switches, floating capacitors, gate drives, and dc sources, making it easy to implement. The Nearest level Control PWM technique is used to generate the switching pulses for the proposed 17-level CMLI. The proposed inverter is simulated under different modulation indices and dynamic load change conditions. The output voltage waveforms have significantly less total harmonic distortion (THD) content of 5.18%. The theoretical analysis of the proposed inverter is verified using MATLAB/Simulink software. Overall, the results demonstrate that the proposed 17-level SC-CMLI is an efficient and practical solution for high-power applications. This topology can be extended to higher voltage levels.

Single-phase dual-buck ac–ac (DBAC) converters are gaining attention due to their intrinsic protection from shoot-through and open-circuit problems of conventional ac–ac converters. However, research works on DBAC converters are mainly concentrated around unipolar topologies. In a few developed bipolar topologies to date, the inverting buck–boost operations (for series voltage injection and step-variable frequency outputs) are inefficient and burdened by large voltage and current stresses (${v}_{\text{in}} + {v}_o\ \text{and}\ {i}_{\text{in}} + {i}_o$) of switching devices and ripples of passive elements. In this article, an efficient dual-buck structured buck–boost ac–ac converter is proposed, with the following features: no voltage source shoot-through and inductor open-circuit problems, natural attainment of safe commutation without additional protection circuitry or complex control, no need for pulsewidth modulation dead times, and elimination of high-frequency conduction ofmosfet’s body diodes and related slow reverse recovery issues. The proposed converter provides distinct types of efficient inverting and noninverting buck and boost operations, with smaller switch voltage/current stresses (${v}_{\text{in}}/{v}_o$and$\ {i}_{\text{in}}/{i}_o$) and passive component ripples. Combined inverting and noninverting buck–boost operations are also proposed with separate tuning of buck and boost voltage transfer ratios. A simple adaptable switching strategy provides the switch control pulses for all circuit operations by modulating the buck and boost control reference signals. The proposed converter provides sustained input/output currents and performs well with nonresistive loads. Extensive theoretical analysis is presented followed by practical verifications on a 400-VA laboratory circuit.

This article proposes a new control scheme with a nonlinear quadratic regulator (NQR) associated with a hybrid switching stage for permanent magnet synchronous generator-based wind turbines (WTs). The proposed method shows a new approach combining a nonlinear optimal control method with a hybrid switching stage for WT generations (WTGs). As the WTG is a nonlinear system, NQR control design is directly employed to deal with the nonlinearity while a hybrid switching scheme can deal with constrained control inputs as discrete nonlinear characteristics of switch-mode power converters. A polynomial-based dynamic model is derived for the new NQR design. Unlike the previous state-dependent Riccatti equation (SDRE) technique where the solution of the nonlinear optimal controller is approximated, this technique finds the exact online solution of SDRE with nonlinear feedback gains flexibly depending on the tracking error. Then, the optimal control laws are implemented via a hybrid switching stage ensuring a smooth current regulation under a reduced switching frequency while avoiding any complicated modulator or finite state search. The proposed control design is investigated via comparative studies with linear quadratic regulator (LQR), direct switching, and space-vector pulse-width-modulation stages (SV-PWMs) implemented in both platforms of MATLAB/Simulink and real-time OPAL-RT. Comparative results exhibit flexible optimal performances via online hyper-parameter tuning to reduce the speed tracking error and low current ripples under a reduced switching frequency.

Dual Active Bridge converter is used widely in various applications due to its fast dynamic response. This paper proposes a control strategy that can suppress the load current disturbance and input voltage fluctuation simultaneously to enhance the output voltage recovery performance. A Model-based single-phase shift control is used here. The load current and input voltage is used as feed forward signal in the control loop to accomplish fast dynamic response. Detailed mathematical modeling and design of the proposed controller have been discussed. A brief study on controller performance is addressed under various operating conditions. Moreover, the performance of the proposed controller has been compared with the conventional controller in order to justify theoretical analysis. Typical experimental results are presented to verify the proposed method.

In the electric vehicle industry, multilevel inverters (MLIs) are widely used for power conversion in high-power-medium-voltage propulsion drives. The five-level ANPC topology with voltage boosting capability is a promising MLI topology for single-stage solar photovoltaic power conversion. The switching pulses for the MLIs are generated using various PWM techniques. The performance of the five-level boosted ANPC inverter is compared using four distinct unipolar PWM techniques: unipolar sine PWM, unipolar 60◦PWM, unipolar third harmonic injection (THI) PWM, and unipolar zero sequence injection (ZSI) PWM. The performance of these PWM schemes are tested on real-time OPAL-RT platform. Under unipolar THI PWM, the 5L-boosted ANPC outperforms in terms of %THD reduction and higher fundamental output voltage magnitude. Furthermore, the ZSI PWM balances the neutral point potential efficiently.

The output voltage of a photovoltaic panel is greatly affected by irradiance, temperature, shading, etc. A buck-boost type inverter is, therefore, required to accommodate the wide fluctuations in dc voltage. This article proposes a class of single-phase, single-stage buck-boost inverters employing five switches (implemented using power MOSFETs with external fast recovery diodes) to provide buck-boost operation for wide variations in photovoltaic (PV) output voltage. In this article, the proposed inverters are immune from current shoot-through problems associated with voltage source inverters, easing the requirement for PWM dead-times. They also provide a common-grounding feature between the grid-neutral and the negative-terminal of the PV panel, successfully suppressing the PV leakage current. In addition, they provide reactive power support. A simple input boost inductor-based buck-boost inverter is proposed with a wide gain range; other variants are also proposed based on the switched inductor, quadratic boost, and switched coupled-inductor, achieving higher boost voltage inversions with smaller values of duty ratio. Detailed circuit operations are presented based on proposed modulation strategies. Design guidelines/requirements of components and their comparisons are provided for all of the proposed inverters. The theoretical analysis and performance characteristics of all four topologies are experimentally validated using 400 VA laboratory prototype inverters.

This paper proposes a model-based identification method for online monitoring of a state of charge (SOC) and state of health (SOH) of lithium polymer (Li-Po) batteries, which allows a runtime prediction and improves a useful capacity of the aged battery by an internal voltage compensation. For this, the internal resistance of the battery model is frequently updated with the latest estimated data. The algorithm utilizes the measured input current and the battery terminal voltage, where the Sigma-point Kalman filter (SKF) is utilized as an estimation tool. As a result, this scheme offers robustness and high accuracy for estimation under varying operating conditions of the battery. The feasibility of the proposed scheme is validated by the simulation and experimental results. It is shown that the estimation error for the SOC is about 4%.

DC short-circuit fault ride through is one of the most important characteristics for the modular-multilevel converters (MMC) employed in high-voltage direct-current (HVdc) transmission systems. During the faults, for providing a fault-tolerant control with reactive power compensation to the grid, the MMC normally changes its structure, which requires a remarkable modification and burden computation for implementing the modulation technique in the MMC. This paper proposes an alternative submodule configuration of the MMC based on a carrier-phase-shift PWM scheme, which is easily implemented for switching the operation modes of the MMC from normal condition to fault-tolerant control. The arms of the proposed MMC are configured by typical half-bridge submodules (HBSM) and suggested series-connected triple SMs (SCTSM) in interleaving series, where the SCTSM is composed of three HBSMs connected in series through an additional IGBT and a clamp diode. With the additional IGBTs and diodes, the SCTSMs can produce bipolar output voltages and the MMC can be restructured to operate as three-phase cascaded multilevel converter during pole-to-pole short circuits to control the converter currents. In addition, the cost and power loss of the proposed MMC are lower than those of the existing MMCs based on full-bridge SMs (FBSM), a hybrid of HBSMs and FBSMs, and clamp-double SMs. PSIM simulation results for the 300 MW-300 kV HVdc system with the proposed MMCs are shown to verify the effectiveness of the scheme.

In this paper, a new configuration of modular-multilevel converter (MMC) is proposed, which is the modified structure of the alternative-arm converter (AAC) with the improvements in terms of cost, loss, footprint, and device count. The proposed MMC also operates through alternatively conducting and blocking the upper and lower arms in a leg as the AAC, where a common stack of full-bridge submodules (FBSM) is shared for the upper and lower arms. This results in a reduction of the SM number in the converter leg, consequently for the whole MMC, from which the number of DC capacitors of the SMs is also reduced resulting in a significant reduction in cost and volume of the converter and improving the reliability of the converter. Extra active switches are required to control the common stack to operate with either the upper or lower arms. Furthermore, the proposed MMC also provides the fault-handling capability and reactive power compensation to the electric grid under the DC-cable short circuits. Simulation results for a 17-level MMC modeled by PSIM have been shown to verify the feasibility of the proposed scheme under normal operation and DC-fault conditions.

Cascade H-bridge multilevel inverter is a best candidate for static VAr compensation in medium and high voltage applications. The topology consists of several capacitors to provide dc link voltage support for H-bridge inverters. Regulation of the dc link voltages at the required levels is a major research challenge in VAr compensated inverters. This paper presents a novel and simple control strategy for a five level cascade H-bridge multilevel STATCOM. The scheme realizes the required objectives with fewer PI controllers and produces accurate results. Rigorous simulation study is carried out in MATLAB SIMULINK to validate the control scheme and results are presented.

The dynamic behavior and stability analysis of a quadratic boost converter for high conversion ratio applications is addressed. After studying the stability of the system by using the monodromy matrix, a closed form stability condition is used for predicting the boundary of subharmonic oscillation in the system in terms of the duty cycle and the slope of the ramp modulator. The derived theoretical conditions are validated by numerical simulations using a system-level switched model obtaining a good matching between the results. This work provides a convenient means of stability boundary determination in the parameter space hence facilitating the design of quadratic boost converters.