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Due to the existence of the neutral point (NP) voltage, controlling the three-level inverters has essentially become a multiobjective optimization problem (MOOP) that needs to provide stable output voltages for the load and maintain the NP voltage simultaneously. Traditionally, this MOOP is converted into a single-objective optimization problem by weighting factors. However, since the physical dimensions of the two control objectives are usually different, it is challenging to choose proper weighting factors to obtain a satisfactory performance according to a specific theory. To address this issue, a tolerant sequential model predictive control (TSMPC) utilizing a lexicographic optimization method is proposed in this article. This method establishes two distinct layers for the output voltage and NP voltage, arranging them in sequence according to the importance of control objectives to evaluate all voltage vectors. By using an explainable tolerance value rather than conventional weighting factors, the proposed TSMPC algorithm presents superior performance over traditional MPC approaches. Finally, the feasibility and effectiveness of the proposed TSMPC algorithm have been verified through relevant experiments and the stability of this algorithm has also been analyzed.

This work demonstrates the robust single-event irradiation hardness in 650-V E-mode p-GaN HEMTs with source-connected buried metal structure. Such device design notably contributes to the removal of irradiation-induced holes accumulated in the reverse-biased p-GaN/ AlGaN/GaN (p-i-n) junction region, thereby improving irradiation robustness against single-event burnout (SEB). The resulting device exhibits significantly improved SEB voltages of 558 and 467 V under heavy ion linear energy transfer ( $LET_{\text {ion}}$ ) conditions of 75.7 and 86.3 MeV $\cdot $ cm2/mg, respectively, setting a new performance record for GaN-based power devices. Moreover, based on pulsed laser equivalent heavy ion irradiation system configured with a power switching circuit, a high power conversion efficiency of 95% is demonstrated under 77.6 LET PL, 300 W/500 kHz conditions. This work thus makes a significant step toward reaching the promise of GaN devices for radiation applications.

We report high-performance Al0.1Ga0.9N p-i-n ultraviolet (UV) avalanche photodiodes (APDs) based on sapphire substrates with the employment of negative bevel edge terminations. An ultra-low slope angle of 2° was achieved through the optimization of photoresist reflow and inductively coupled plasma (ICP) etching processes. The devices present stable breakdown voltages ( ${V}_{\text {BR}}{)}$ around 115.9 V, low dark current densities ( ${J}_{\text {BR}}{)}$ below $5\times 10^{-{4}}$ A/cm2 and a record-high avalanche gain over $7\times 10^{{6}}$ . The electroluminescence (EL) during the avalanche multiplication process assembles in the device center, which is in good agreement with the TCAD simulations, indicating that the electric field crowding effect along the device periphery is significantly suppressed. Additionally, the tapered sidewall profile ameliorates the UV absorption loss in the p-GaN layer and leads to a high external quantum efficiency (EQE) of 29.74% under zero bias. Finally, through the exponential fitting of the dark current density versus the electric field strength, variable-range hopping (VRH) conduction is found to be the dominant leakage mechanism for Al0.1Ga0.9N APDs for the first time.

Voltage equalizers (VEs) are essential for partially shaded photovoltaic (PV) modules by equalizing the voltage of PV modules and preventing anti-paralleled diodes from bypassing the shaded PV modules, resulting in improved power yield under partial shading conditions (PSCs). Recently, different topologies for VEs have been discussed based on the distributed maximum power point tracking (DMPPT) principle at the module level. Considering that the power flow distribution, operation modes, and actual performance of these VEs show distinct differences, it becomes increasingly important for the performance quantification and comparative assessment of various topologies both theoretically and experimentally. Here, three typical differential-power-processing-based VEs are selected, including series-resonant-voltage-multiplier (SRVM), flyback-based PV-to-IP (Flyback-PV-IP), and flyback-based PV-to-Bus (Flyback-PV-Bus). Key performance indexes for VEs have been defined, including the processed power, power losses, and overall system efficiency. To quantify the performance of different topologies of VEs, an algorithm is developed in MATLAB with daily irradiation and temperature under various PSCs. Moreover, three experimental prototypes for the selected topologies have been built and main tests under different mismatching conditions have been conducted. With a systematic performance quantification and a fair comparison of typical VEs, this article will propose a systematic evaluation method for VE schemes. Meanwhile, the optimal VE topology with its control for typical PSC cases will be identified.

In mission-critical Internet of Things (IoT)-enabled wireless sensor networks (WSNs), the demand for reliable sensing data is significantly increasing. Meanwhile, the major challenge of maximizing network lifetime is energy dissipation optimization, whereas the existing major clustering protocols are proposed to reduce energy consumption without considering the malicious nodes in the network. This article proposes an improved stochastic fractal search (SFS) based on the multitrust fusion model for energy-efficient and secure clustering in IoT-enabled WSNs. The multitrust fusion model based on the entropy weight method (EWM) is established to calculate the integrated trust of sensors. After trust evaluation, an improved SFS using differential mutation and adaptive mutation factor is introduced to clustering. During clustering, the selection strategy of cluster heads adopts a new fitness function, which considers five parameters: integrated trust, residual energy, spatial density, the distance to the base station, and the dissipated energy for the next round. Experimental results reveal that the proposed protocol outperforms other existing protocols in all scenarios.