The advancements in research on automotive power device packaging have significantly improved the dynamic performance and driving range of electric vehicles, making them more efficient and reliable. With the continuous optimization of automotive power device packaging, the electric vehicle industry is expected to embrace a broader market prospect and development space. In recent years, power device packaging modeling, packaging structure and optimization, thermal management and junction temperature monitoring, gate drive and applications, reliability analysis, and online monitoring have become current research hotspots and have received sustained attention from both the academic and industrial sectors. To promote discussions on the challenges and hot issues related to automotive power devices packaging and their applications, a special issue titled "High Reliability Power Device Packaging and Assistant Technology in EV Application" has been launched in the Journal of Power Supply.

Gate oxide degradation is a key reliability issue that limits the widespread applications of silicon carbide metal-oxide-semiconductor field-effect transistors(SiC MOSFETs), and online monitoring is an important means to improve the reliability of SiC MOSFETs as it can obtain the gate-oxide health status in real time. In this paper, an online monitoring method for SiC MOSFET gate-oxide health status based on gate reference voltage is proposed. The basic principle of using the gate reference voltage to monitor the gate-oxide health status is introduced in detail, and a gate reference voltage online extraction circuit is also put forward. The designed extraction circuit was verified by pulse tests, indicating that it can achieve online extraction. In addition, aging tests were conducted, and results verified that the proposed method can effectively monitor the gate oxide health status. The designed circuit can be integrated into gate driver without significantly increasing the system complexity.

With the rapid development of ultra high voltage direct current(DC) power transmission technology, the stability of valve base electronics (VBE) device is crucial for ensuring the reliability and efficiency of DC power transmission. The defects in VBE device circuit boards, such as short circuits and failed components, directly affect the system stability. However, the existing detection methods including manual microscopic inspection and automatic detection algorithms are often limited by their low efficiency and insufficient accuracy. In this paper, an automatic visual inspection method based on point pattern matching is proposed to address these challenges. This method significantly improves its detection accuracy and efficiency by generating point patterns that represent key areas and further matching them, which is particularly suitable for rapid quality control on production lines. Experimental validation shows that the proposed method significantly outperforms the traditional methods in terms of detection speed and accuracy, providing an effective technical solution for improving the quality of DC power transmission equipment and demonstrating important practical value.

In the burgeoning field of new energy vehicles, silicon carbide representing a new generation of semi-conductor power devices is progressively replacing silicon-based IGBTs, which also sets higher standards for the motor control performance within the corresponding innovative technological ecosystem. The precision of motor parameters is becoming increasingly critical for enhancing the performance of electric control systems as they evolve from the tradi-tional PI control and direct torque control to advanced algorithms such as model predictive control and neural network control. Aimed at the problem that the classic linear model for permanent magnet synchronous motors cannot adapt to complex and variable conditions due to nonlinear factors such as cross-saturation, a nonlinear magnetic flux identifica-tion method based on Gaussian process regression is proposed. By employing a second-order generalized integrator to acquire the magnetic flux data under dynamic conditions, the system identification is completed. Finally, the effective-ness of the proposed approach and the accuracy of parameter identification were verified through simulation and experi-mental results.

Aimed at problems such as the setup of an additional excitation source required by active magnetic shielding and the expensive magnetic shielding materials used in passive magnetic shielding, a wireless power transmis-sion (WPT) coupling mechanism with magnetic shielding based on Halbach effect is proposed on the basis of the tradi-tional DD coil structure. First, the topology of WPT coupling mechanism with magnetic shielding effect is proposed, and the principle for the magnetic shielding effect is analyzed theoretically based on the corresponding equivalent magnetic circuit model. Second, the expression for the magnetic field intensity of the coupling mechanism on any plane in the space is derived using the micro-element method. Finally, an experimental platform was built to verify the WPT perfor-mance and magnetic shielding effect of the proposed coupling mechanism. Results show that the Halbach effect coil can effectively weaken the magnetic field intensity outside the coupling mechanism and improve the magnetic shielding ef-fect while ensuring that the power transmission efficiency is basically the same as that of the DD coil.

Monitoring the power quality of power supply system is an effective method for ensuring the safe operation of power system and user-side equipment. To ensure the power quality of power supply system, a monitoring method for its power quality stability is studied. Based on the Hilbert-Huang transform (HHT) algorithm, the harmonic frequency and amplitude of the power quality signal frame of power supply system are monitored, and the disturbance time amplitude and frequency of the power quality disturbance signal are detected, so as to realize the power quality stability of monitoring system. The frame loss rate, accuracy and transmission delay of the monitored power quality signals under different pressures (with different numbers of power quality signal frames) were tested by experiments, and results show that the proposed method can realize the monitoring of power quality.

The advantages of a Boost-APFC circuit operating in critical conduction mode are introduced. Aimed at the disadvantages of the traditional single-phase CRM-Boost APFC voltage mode control method, such as a long PI parameter debugging time, a poor adjustment effect and increasing unstable factors, a single-phase CRM-Boost APFC voltage mode control method with a static operating point is proposed, and the advantages of this method are verified by PSIM simulations. Considering the shortcomings of the novel interleaved control method, such as a long PI parameter debugging time, increasing unstable factors and the need to use an additional voltage-controlled current source, an improved two-phase interleaved parallel CRM-Boost APFC voltage mode control method is put forward, and the PSIM simulations are completed, with a power factor as high as 99.96%. A 4 kW two-phase interleaved parallel CRM-Boost APFC experimental prototype was made, and it was experimentally debugged, with a power factor of 99.66% and an efficiency of 98.02%.

Aimed at the problem that the power quality control equipment in distribution network is lack of collaborative allocation, an optimal allocation strategy for the control equipment of harmonics, reactive power and three-phase imbalance is proposed, which is based on the multi-objective particle swarm optimization (MOPSO) algorithm. The active power filter (APF) is used to suppress harmonics, the intelligent capacitor is used to compensate reactive power, and the phase-change switch is used to reduce three-phase imbalance. The control effect and operating cost about each power quality issue are taken as optimization objects, and the relevant power quality standards are considered as constraints. Through the MOPSO algorithm, an optimal allocation scheme for the allocation nodes and relevant access capacity of control equipment can be obtained. Furthermore, a power quality assessment model is built, and a simulation model based on an improved IEEE 18-node distribution system is also constructed. The harmonics, reactive power and three-phase imbalance loads are separately connected to simulate power quality issues, and simulation results verify the feasibility of the proposed strategy and its advantages compared with the traditional scheme for power quality control equipment.

The influence of ash deposition on the output characteristics of photovoltaic (PV) modules and the deposition rule of pollution particles on the modules' surface are studied, which are helpful for formulating an ash removal scheme and improving the efficiency of photoelectric conversion. The PV array on the roof of a fan hall in North China Electric Power University is taken as the research object, and an artificial ash distribution experiment was carried out to explore the influence of different ash deposition amounts on the output power, current and voltage of modules. To determine the influence of one single factor on the deposition of pollution particles, a numerical model of particle deposition is established using COMSOL under the same conditions as those in the natural deposition test of PV modules, and the influences of wind speed, humidity, particle size and pollution concentration on the deposition of pollution particles on the surface of PV modules are simulated and analyzed. Test results show that ash deposition has little influence on the working voltage, but a great influence on the output power and working current. When the ash deposition density is 5.07 g/m², the changing rates of output power, current and voltage are 8.71%, 6.48% and 0.40%, respectively. Simulation results show that when other conditions are the same, the deposition amount of particles decreases first and then increases with the growing wind speed and particle size, and the minimum value is reached at the wind speed of 3 m/s and particle size of 15 µm. Under the same conditions, the particle deposition amount increases with the growing humidity and pollution concentration.

Building a complete spacecraft electrical power and distribution standard system is an important tool for improving the design of spacecraft electrical power and distribution system and ensuring the safety and reliability of satellite energy. In this paper, the electrical power and distribution standard systems published by European Cooperation for Space Standardization (ECSS), National Aeronautics and Space Administration (NASA), Japan Aerospace Exploration Agency (JAXA), International Standard Organization (ISO) and American Institute of Aeronautics and Astronautics (A-IAA) were investigated. The focuses of their respective standard specialties were analyzed, the corresponding content was discussed, and the standard systems of various organizations were summarized. Combined with the actual situation in China, the suggestion and reference for the spacecraft electrical power and distribution standard system are put forward.