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关键词： 工程机械   变量柱塞泵   LQ优化控制   状态观测器  

摘要： 针对变量柱塞泵传统控制方法难以实现快速性、稳定性、鲁棒性的兼顾,也不能估计并利用泵的状态参数进行全生命周期内的性能优化等问题,提出了一种基于状态观测器的变量柱塞泵流量LQ最优控制(Linear Quadratic Optimal Control)方法,在改善泵控制性能的同时实现了泵不可测状态参数的在线估计。以A4VSO40柱塞泵为例,建立了变量柱塞泵的数学模型,以状态误差和控制输入的二次型约束为性能指标,设计了变量柱塞泵流量的LQ最优控制器,针对实际中因测量条件或成本限制难以测得全部状态参数以及测量噪声等问题,设计并引入了卡尔曼滤波状态观测器。仿真结果表明,所提出的基于状态观测器的LQ最优控制方法不仅可以实现状态参数的估计、减小噪声对状态参数估计的影响,而且相较于PID控制和LQ最优控制,流量阶跃响应的超调量分别下降了24%和5%,验证了所提控制方法的有效性。

关键词： 电力机车   矢量控制   直流电压控制   准恒速度控制   总效率  

摘要： 为解决当前大功率电力机车无法实现全速度范围之内对其稳定、安全控制的问题,在对大功率电力机车牵引系统简单概述的基础上,以HXD2C型电力机车为研究对象,为其匹配性设计了全速度范围之内的分段矢量控制策略;针对无电状态和传统准转矩控制劳动量大的问题,设计了直流电压控制策略和准恒速度控制策略。经试验表明,调制控制策略可实现对电力机车的稳定安全控制,且总效率可达86%。

关键词： TOPSIS   Reliability of power electronics   IGBT module   Finite element method   Thermal model  

摘要： This paper examines the impact of various packaging materials on the IGBT module's thermal characteristics. A 3D finite element method (FEM) model of the studied IGBT module is created and validated by experimental tests. The materials used in the baseplate and the insulation layer of the IGBT module are then replaced with various materials to investigate how different material combinations affect the thermal performance. The ob-tained thermal performance of different materials is placed next to other criteria (mechanical strengths, least square of CTE mismatches, cost, and weight) to be ranked by the TOPSIS multi-criteria decision-making method based on the given objective weights. The results showed that the three combinations of AlSiC/AlN, W/Si3N4 and AlSiC/Si3N4 have the best overall performance and are ranked first to third, respectively. The frequently used material pair Cu/Al2O3 achieved 14th place indicating that it performs poorly in comparison to the other alternatives.

关键词： IGBT   Power semiconductor   Hydrogen sulphide   H2S   Corrosive gas   Dendrites   DBC   Substrates   Packaging   Accelerated testing   High voltage  

摘要： In some applications or environments, power semiconductor devices are exposed to hydrogen sulphide (H2S). The degradation mechanisms triggered under these circumstances have been reported already, but the degradation dynamics, the acceleration factors and the impact on the service life of the affected devices are not yet fully understood. There are no standard test methods available for power semiconductor devices and therefore, a test campaign with highly corrosive climatic conditions was started to investigate the degradation mechanisms under high voltage.

关键词： Thermal network   PI control   IGBT module   Solder degradation   FEM model  

摘要： Under long-term thermal cycles, the solder layers in IGBT modules degrade inevitably, which affects their heat dissipation performance and eventually leads to the failure of IGBT modules. In order to monitor the degradation degree of the IGBT chip solder layers according to the junction temperature, a thermal network model for monitoring the IGBT chip solder degradation based on feedback PI control is proposed. Firstly, the finite element simulation model of the IGBT module is established and the degradation degrees of the chip solder layers are defined in the simulation model. Then the thermal network model is extracted according to the finite element simulation model and the thermal impedance functions are fitted from the different power loss and chip solder degradation degrees. Meanwhile, a control loop with PI controller is established to regulate the thermal impedances. Finally, the accuracy of the proposed thermal network based on feedback PI control for chip solder degradation monitoring and junction temperature calculation is verified under different chip solder degradation degrees.

关键词： Condition monitoring  

摘要： The insulated gate bipolar transistor (IGBT) is one of the weakest components in the converter. Therefore, high reliability is very important in terms of price. However, it is very difficult to monitor IGBT's condition because it is not easy to directly measure the junction temperature in practice. And cooling system also important element of converter, but additional method should be used to monitor cooling system. This paper proposes a method of monitoring the condition of IGBT module and cooling system at once by heatsink temperature that is easy to measure. Advantage of proposed method is very easy to implement without interfering operation of IGBT. Simulation tests were conducted to verify the effectiveness and accuracy of this proposed method. The results show that the proposed method can improve accuracy of the reliability of power converter. Copyright © The Korean Institute of Electrical Engineers.

关键词： Modular multilevel converter   Fault diagnosis   Modified cuckoo search   Elman neural network   Data-driven  

摘要： Modular multilevel converter is widely used in electrical energy with many advantages, its safety and reliability has become a research hotspot. Since the structure of MMC is composed of multiple cascaded sub-modules, including a large number of IGBTs and capacitors. Therefore, fault diagnosis measures must be taken to quickly eliminate the faults. In order to solve this problem, a data-driven method is proposed based on a modified Elman neural network. By comparing the distance E-k between the predicted and true value of bridge arm current, this method can quickly realize fault detection. The original contribution of this paper is using the modified cuckoo search (MCS) to optimize the parameters of Elman model, so as to achieve the optimal balance between fault diagnosis accuracy and diagnosis speed. The simulation results proved that it can quickly detect the open-circuit fault of IGBT by data-driven, and the detection time is about 20 ms. (c) 2022 The Author(s). Published by Elsevier Ltd.

关键词： Computational modeling   Semiconductor device modeling   Semiconductor diodes   Mathematical models   Integrated circuit modeling   Insulated gate bipolar transistors   Junctions   Circuit simulation   dc-dc power converters   insulated gate bipolar transistors   power semiconductor devices   semiconductor device modeling   thermal resistance  

摘要： In this article, an electrothermal model of a diode-insulated gate bipolar transistor switch for modeling dc-dc converters is proposed. The formulated model has the form of a subcircuit for the simulation program with integrated circuits emphasis (SPICE) program and enables computations of both electrical characteristics of the converter and junction temperatures of the semiconductor devices. The equations used in the formulated model allow modeling the operation of the converter in both continuous conduction mode and discontinuous conduction mode. The correctness of the formulated model is experimentally verified for the boost converter. Good accuracy of modeling the characteristics of the converter is obtained. A .cir file based on the formulated model for an analysis in the SPICE program is attached to the article as the active content.

关键词： FEM   EBSD   Crack   IGBT   Power cycling  

摘要： This paper focuses on the thermomechanical behaviour and the consecutive damage of the bond-wire contacts in power semiconductors. Electro-thermal-mechanical finite element analysis of power cycle loads was used to model realistic transient temperature loadings as well as mechanical stresses. Mechanical damage modelling using the cohesive zone approach was used in conjunction with coupled finite element analysis. Parallel to the theoretical research, a pulse width modulation power cycling test bench was realized, and thermal cycles tests were carried out on power modules with temperature swing Delta T-j = 30 degrees C and minimal temperature T-j,T-min = 55 degrees C. Electron Back Scatter Diffraction was used to investigate crack early-stage crack propagation and crack propagation of the samples. Fatigue cracks were found to be always initiated from the interface wire -metallization and propagate exactly at the contact.

关键词： Sn58Bi   IMC   AlN nanoparticles   Phase field simulation  

摘要： The IMC (interfacial intermetallic compound) produced by the metallurgical reaction between the solder and the Cu plate enables the packaging of IGBT (insulated gate bipolar transistor) modules. In this paper, the growth behavior of IMCs of Sn58Bi/Cu and Sn58Bi0.05AlN/Cu at different times (10, 30 and 60 min) and temperatures (200, 250 and 300 degrees C) was investigated, which can provide a reference for the connection of IGBT. It was shown that the interfacial IMC thickness of both solders increased with time and temperature, but the growth of interfacial IMC was suppressed for Sn58Bi solder containing 0.05 wt% AlN. The effect of AlN on the inhibition of grain growth was also observed by EBSD testing. Because of the adsorption effect of AlN nanoparticles, they can adhere to the surface of IMC layer and decrease the effective the diffusion path of unreacted Cu atoms, thereby inhibiting the growth of interfacial IMC. And the effect of AlN particles on interfacial IMC was analyzed via phase field simulation. In addition, under the heating conditions with high temperature and long time, there were fewer cracks in the solder joints containing AlN particles, compared to the Sn58Bi solder. Therefore, AlN nanoparticles can enhance the reliability of Sn58Bi/Cu solder joints. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).