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In this paper, an offline evaluation method for the cooling capability of three-phase insulated-gate bipolar transistor (IGBT) inverters is presented, which can better emulate real working conditions. With a properly designed sudden-stop control sequence, the conventional junction temperature monitoring method at a low current is used to calculate the junction temperature before the sudden stop of an inverter. This can solve the challenging switching loss calculation issue in conventional methods. Finally, the feasibility, control sequence, and electrical behaviors of the proposed method are validated through experimental tests.

In this paper, an online junction temperature monitoring method based on the on-state voltage under high collector current density measurements for IGBT power modules is proposed. Unlike the conventional junction temperature monitoring method, the presented method can extract the junction temperature during operation without altering the modulation strategy or topology of the converter. The proposed method is verified by simulations and the JEDEC-51 standard recommended approach. To accurately extract the on-state voltage during operation, a measurement circuit that combines the advantages of both the active MOSFET clamp and the diode clamp is designed and tested. It has been shown to have good accuracy and a rapid response time. After the calibration results are obtained, the presented method is applied to a three-phase voltage source converter controlled by a closed-loop SVPWM modulation strategy.

A junction temperature monitoring method has been presented based on the on-state voltage at high currents. With a simplified physical model, this method mapped the relationship between junction temperature and on-state voltage. The tough calibration and signal sensing issues are solved. Verified by body-diode voltage detecting method, the presented method shows a good performance and high accuracy, in the meantime, it would not change the modulation strategy and topology of the converter.

The layout of power modules is a crucial design consideration, especially for silicon carbide devices. For electrical layout, optimizing the parasitic parameters can improving switching loss and dynamic behavior. For thermal layout, reducing the thermal resistance and controlling thermal capacitance can reduce the local hot point. Conventional layout design iterations are based on human knowledge and experience. But the major drawback of manual design methods is a limited choice of candidates, large time consumption and also the lack of consistency. With the introduce of automatic layout design, these challenges can be overcome which in the meanwhile alleviates current and temperature imbalance. By reviewing element representation, placement, routing, fitness evaluation, and the optimization algorithm approaches, a state-of-the-art power module layout design method for electric vehicle applications is introduced.

SiC Hybrid switch (HyS) combines low conduction loss of Si IGBT and low switching loss of SiC MOSFET, and the cost is closer to that of Si IGBT. The promising high performances of HyS will bring considerable achievement in terms of enhancing power density of a converter system. By reviewing the gate drive pattern, gate drive hardware, current sharing, module design, converter design, and cost, this paper introduces state-of-the-art SiC HyS.

With the increasing power density of IGBT module, the problem of reliability reduction caused by overheating has attracted more and more attention. It is an effective way to improve the reliability of IGBT module by using the fully-immersed liquid cooling technology. At the same time, the influence of the medium environment of the fully-immersed liquid cooling technology on the parasitic parameters of the IGBT module needs to be studied. In this paper, parasitic inductances and resistances of the IGBT module under air cooling and fully-immersed liquid cooling are extracted by simulation, and parasitic capacitances of the IGBT module under air cooling and fully-immersed liquid cooling are extracted by experiment respectively. The variation law of parasitic parameters of IGBT module under fully-immersed liquid cooling is obtained. The research results lay a foundation for the successful application of fully-immersed liquid cooling technology in the field of IGBT cooling.

SiC MOSFET and Si IGBT based hybrid switches (HyS) has low conduction loss and low switching loss. At the same time, HyS device costs are much less than pure SiC MOSFET device with the same power rating. The promising performance of HyS can help to design a high power design converter system with over 30 kHz and 50 kW applications. In this paper, a series of SiC/Si HyS modules are designed, and some of them were developed and tested.

Hybrid switch (HyS) combines low conduction loss of Si IGBT and low switching loss of SiC MOSFET. The cost of HyS is close to pure Si IGBT. The promising high performances of HyS will bring considerable achievement to enhance power density of a converter system. In this paper, a SiC/Si HyS based 1200 V/400 A three phase module was developed, and was tested in a motor drive.

In this paper, three hybrid switch (HyS) module consisting of the paralleled Silicon (Si) Insulated Gate Bipolar Transistor (IGBT) and Silicon Carbide (SiC) Metal-Oxide Semiconductor Field-Effect Transistor (MOSFET) are developed. From the double pulse evaluation results, they are promising for fast switching and low price. The fabricated 1200 V/200 A hybrid module was used for a motor drive, and it was tested to 30 kW, 30 kHz.

Our previous study showed that glycyrrhizin (GLY) inhibited porcine epidemic diarrhea virus (PEDV) infection, but the mechanisms of GLY anti-PEDV action remain unclear. In this study, we focused on the anti-PEDV and anti-proinflammatory cytokine secretion mechanisms of GLY. We found that PEDV infection had no effect on toll-like receptor 4 (TLR4) protein and mRNA levels, but that TLR4 regulated PEDV infection and the mRNA levels of proinflammatory cytokines. In addition, we demonstrated that TLR4 regulated p38 phosphorylation but not extracellular regulated protein kinases1/2 (Erk1/2) and c-Jun N-terminal kinases (JNK) phosphorylation, and that GLY inhibited p38 phosphorylation but not Erk1/2 and JNK phosphorylation. Therefore, we further explored the relationship between high mobility group box-1 (HMGB1) and p38. We demonstrated that inhibition of HMGB1 using an antibody, mutation, or knockdown decreased p38 phosphorylation. Thus, HMGB1 participated in activation of p38 through TLR4. Collectively, our data indicated that GLY inhibited PEDV infection and decreased proinflammatory cytokine secretion via the HMGB1/TLR4-mitogen-activated protein kinase (MAPK) p38 pathway.

With the increasing power density and application of IGBT modules, heat dissipation technology has become the key to IGBT module research. Institute of Electrical Engineering, Chinese Academy of Sciences proposed to apply evaporative cooling technology to IGBT modules. Evaporative cooling technology can better solve the problem of heat dissipation of IGBT modules. In an evaporative cooling environment, changes in the operating environment of the IGBT module may affect parasitic parameters within the module. Parasitic parameters are one of the factors that affect the operating state of the IGBT module. The presence of parasitic inductance inside the module can cause the module to generate a large number of voltage spikes during the switching process. Overvoltage can increase the collector current of the module and increase the internal temperature, which may cause device failure. This paper first uses SolidWorks software to model the IGBT, and then extracts the internal parasitic inductance and parasitic resistance of the module through the finite element software ANSYS Q3D Extractor. By setting the background material, the parasitic parameters inside the module under air cooling and evaporative cooling conditions are obtained. The comparison data obtains the influence of the cooling method on the parasitic parameters of the IGBT module, which provides a basis for further application of the evaporative cooling technology to the IGBT module.

Atomization parameters of liquid droplets in the spray cooling system-droplets velocity, droplets diameter, droplets distribution and others influence significantly on the heat exchange efficiency. This paper uses Phase Doppler Particle Analyser(PDPA) to make a precise measurement on atomization parameters on the spray cooling system used pressure atomizing spray nozzle. Then described the distribution of atomization parameters and summarized its regularity. Through the fitting on large quantities of data obtained in test, it's practicable to get the correlation formula between atomization parameters and pressure. Quantitative links between flow and atomization parameters will have an important reference to quantitative design of spray cooling system.

Nitrogen (N) and phosphorus (P) are key factors that limit phytoplankton growth in freshwater lakes. Controlling external P loading is a widely recognized measure for reducing eutrophication, but the usefulness of limiting N inputs remains under debate. Shallow lakes with frequent sediment resuspension events exacerbate internal P loading and limit the potential for in-lake P reduction. A two-way factorial mesocosm experiment was carried out using two levels of N inputs (with and without addition of potassium nitrate as N source) and sediment resuspension (with and without resuspension) for 35 days in order to examine the effect of N inputs on phytoplankton growth during sediment resuspension events. N addition alone did not affect phytoplankton biomass in mesocosms in treatments without sediment resuspension, likely due to the P limitation. However, internal P loading, via sediment resuspension, shifted mesocosms from P- to N-limited systems in which N addition significantly boosted phytoplankton biomass. Our results suggested that external loading comprising N alone may enhance phytoplankton growth in shallow, eutrophic lakes with frequent resuspension events like Lake Taihu, China. In such lakes, P-only management is unlikely to usefully reduce eutrophication, and a strategy to reduce both N and P is needed.

While considerable research has addressed the influence of sediment resuspension on shallow lake ecosystems, little attention has been paid to its potential impact on phytoplankton responses to nutrient loading. A factorial experiment was designed using field mesocosms to investigate the impacts of resuspension, nutrient loading and the interactions between them on standing crops of phytoplankton and community structure dynamics. Results showed that phytoplankton biomass increased with nutrient loading when no sediment resuspension occurred, but there was no significant biomass response to nutrient loading in treatments with strong sediment resuspension. The results also showed both sediment resuspension and nutrient loading to have significant effects on the structural dynamics of phytoplankton communities. Our results suggest that strong sediment resuspension can dampen the response of phytoplankton to nutrient loading in lakes such as Lake Taihu which experiences strong sediment resuspension due to wind action. These findings also suggest that in shallow eutrophic lakes with high nutrient concentrations or external loadings, measures aimed at reducing sediment resuspension are unlikely to be effective in aiding the re-establishment of macrophytes, because of the side effect of enhanced phytoplankton growth.