Aimed at the problem that the control modes of interconnecting power converters (IPCs) are complicated to assign and difficult to control when different types of power grids are connected, a novel grid-forming(GFM) control method for IPCs that interconnect high voltage direct current (HVDC) and high voltage alternating current (HVAC) sub-grids is proposed. This method uses modular multilevel converters (MMCs) to control AC and DC terminals simultaneously. In addition, two dual-port GFM MMC control strategies are put forward. Finally, a simulation comparison between single-port GFM control and the proposed two-port GFM control is performed. Results show that compared with the single-port GFM control, the two-port GFM control method is more flexible to emergencies(i.e., line and generator outage), and there is no need to choose the control mode of GFM or grid-following(GFL) for IPC ports in the power grid.

Accurately obtaining the electromagnetic characteristics of high-voltage and high-power switching devices is crucial for predicting the electromagnetic interference in a system in which the devices are located. Research is focused on an equivalent method of switch waveforms for analyzing the electromagnetic characteristics of high-voltage and high-power switching devices. Aimed at the problem that the existing equivalent waveforms are too ideal to reflect the complex spectral components in the switching transients of devices, an analytical model for the electromagnetic characteristics of devices considering their switching processes is proposed. Starting from the time-domain analytical formula for the analytical model and based on the Fourier transform theory, the frequency-domain analytical formula for the analytical model is derived, and the spectral envelope characteristic parameters are analyzed to obtain the spectral characteristics of the analytical model. The theoretical analysis was verified by using the measured switching waveforms of Si IGBT and SiC MOSFET devices.

As electronic devices continue to miniaturize and integrate, thermal simulation has become a critical factor during the design phase. The conventional finite element method(FEM) used for the thermal simulation of electronics packaging modules faces a trade-off between computational efficiency and accuracy, and it also encounters difficulties in handling problems of large deformation and grid distortion, which will cause errors in the results. In this paper, a thermal simulation system for electronics packaging modules based on the smoothed particle hydrodynamics (SPH) algorithm is proposed. The SPH algorithm is based on the meshless Lagrange numerical method, and it resolves the heat conduction equation by discretizing the simulation object into a set of particles, thus accurately predicting the heat conduction and heat dissipation in electronics packaging modules. Since it does not need to generate a large number of micro-meshes, there is no grid distortion. Compared with FEM, the SPH algorithm achieves an accuracy error between 1% and 2%, thereby improving the simulation efficiency by approximately 30 times. Therefore, this algorithm is highly suitable in simulating the thermal behavior of a dynamical system with a complex structure.

Owing to their advantages in switching speed, temperature characteristics and voltage withstand capability, silicon carbide (SiC) power modules are gradually applied in the motor controllers of electric vehicles. As a core component of electric vehicles, the motor controller demands high electro-thermal characteristics of power modules, posing a significant challenge to SiC packaging. In this paper, the mainstream HybridPACK Drive module packaging is taken as an example, the driver and direct bonded copper(DBC) layout are optimized, and the copper wire bonding technology is introduced to balance the module's electro-thermal performance and reliability. In addition, the response surface methodology is used to optimize the elliptical Pin-Fin heat sink, thereby enhancing the module's heat dissipation performance. Finally, prototypes of SiC power modules before and after optimization were fabricated for comparison, and a double-pulse test setup and a power back-to-back test setup were established respectively to evaluate the electro-thermal performance of the two approaches. Experimental results indicate that when the chip spacing was equal to half the die width, the optimized power module can achieve a superior thermal performance while maintaining the electrical characteristics.

A rapid solution method for the thyristor electro-thermal coupling model based on the conjugate gradient method is developed to address the limitations of traditional solution techniques in terms of processing efficiency and computational cost. By optimizing the iteration process and convergence criteria, the solution efficiency and accuracy are significantly improved. A novel parameter selection strategy is introduced to automatically adjust the algorithm's iteration step size, thus accelerating the convergence speed and reducing the computational resource consumption. Compared with the traditional solution methods, the optimization approach achieves an average reduction of 10% in solution time and an 8% increase in solution accuracy. This progress demonstrates the effectiveness of the adaptive conjugate gradient method in the rapid solution of electro-thermal coupling models, providing an efficient and reliable computational tool for the thermal management of power electronic devices. The proposed method exhibits significant efficiency improvement and good accuracy under various test conditions, offering an innovative solution for efficiently solving the thyristor electro-thermal coupling models. This method is also of practical significance for related research in the field of power electronics.

Enhancing the power density of vehicle-grade power modules is of significance for the performance of electric vehicles. The two-dimensional layout used in conventional power modules results in large parasitic inductance, which limits the switching speed and bus voltage and further affects the increase in power density. To solve this problem, an IGBT power module with EconoDUAL packaging was taken as the research object, and a three-dimensional layout was designed using the stacked DBC method to develop a 1 200 V/1 200 A IGBT power module. The layout structure of the proposed power module was introduced in detail. Compared with those obtained using the conventional two-dimensional layout methods, the parasitic inductance decreased by 58%. Additionally, electrical performance tests including a double-pulse test with pulse current of 1 200 A under bus voltage of 800 V were conducted on the power module, thereby verifying the improved power density of the module. To maintain the heat dissipation performance while increasing the power density,

Silicon carbide(SiC) MOSFETs are widely used in high-voltage, high-frequency and high-power-density applications for new energy electric vehicles owing to their superior material properties. During the process of double-sided cooling, the effect of chip layout spacing on heat dissipation and chip temperature uniformity was usually ignored, and the effect of chip temperature uniformity on the parallel current uniformity of multiple chips was not taken into account. A double-sided cooling package structure was designed, the effect on chip temperature uniformity due to chip layout spacing was analyzed, and the influences of different junction temperatures and different chip layouts on parasitic parameters and switching characteristics were also discussed. Aimed at different chip layout spacings and different cooling conditions, the effectiveness of the proposed method was verified through a large number of simulations and the response face analysis and comparison, providing technical method guidance and quantitative analysis for the influences of SiC power module packaging on chip temperature uniformity and switching characteristics.

Owing to its advantages including lower switching stress, harmonic components and a better anti-interference capability, the diode neutral point clamped (NPC) three-level inverter has become a prominent topology for DC-AC converters used in new energy fields such as photovoltaic and energy storage. The NPC three-level insulated gate bipolar transistor(IGBT) power semiconductor module which is widely used in high-power applications is studied. The commutation circuit in the NPC three-level power module is analyzed, and a precise simulation and evaluation method for the corresponding parasitic parameters is given. According to the principle of minimizing the parasitic parameters of the commutation circuit, a dynamic characteristic test circuit suitable for the NPC three-level power semiconductor module is designed. Based on the commutation circuit and the operating principle of circuit, a drive circuit for the NPC three-level power module is designed, and a driving scheme that enhances drive current, prevents shoot-through and allows for adjustable dead time is formulated. Finally, through dynamic testing of the NPC three-level IGBT module, a comprehensive assessment of the dynamic loss in power devices under various operating conditions is conducted.

Press-pack insulated gate bipolar transistor (PP-IGBT) modules are widely used in high-power applications such as flexible DC converter valves owing to their superior electrical performance and reliability. Therefore, an accurate observation of the junction temperature of a IGBT chip is important for monitoring its operating status and evaluating its remaining lifetime. The existing junction temperature observation methods are mostly designed for bonded-lead IGBTs, which cannot be applied directly because the characteristics of PP modules are not taken into account. Aimed at the PP IGBTs in large-capacity converter valves, a practical method for calibrating the on-state voltage drop and junction temperature of modules is proposed, and the online estimation error of junction temperature is comprehensively analyzed. Then, a junction temperature calibration scheme is designed based on a 5SNA 3000K452300 PP IGBT module(4 500 V, 3 000 A) produced by ABB, including experimental circuits, temperature calibration range selection, junction temperature control method, measurement circuits and calibration experimental procedure. Finally, based on a pulse test platform, the proposed method was verified. Experimental results show that the junction temperature calibration and observation scheme proposed was effective, the junction temperature observation error was within ±5 °C, and it can be applied to the case of differences in PP IGBT modules.

LLC resonant converters are widely applied in on-board power supplies owing to their high power density, high efficiency and small size, and their reliability is critical to the driving safety and passenger experiences. However, the complicated working conditions and harsh environment under which vehicles operate have become a huge challenge to power devices. When a switch failure occurs, the resonant converter cannot maintain a stable output voltage while operating at a resonant point, and both efficiency and output capability of the system will decrease substantially. To make the converter more compatible with fault occasions, an improved LLC topology and its control strategy are proposed in this paper, which can ensure that the output voltage remains unaffected when a switch failure occurs and the converter operates near the resonant frequency. Additionally, an optimized Burst control strategy is designed to suppress the overvoltage of the resonant capacitor during the fault tolerance transition and guarantee a smooth fault tolerance process. Finally, simulation and experimental results verified the effectiveness of the proposed method.