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关键词： 矿井提升   高压变频   功率单元   级联H桥  

摘要： 针对目前矿井提升场合级联多电平H桥四象限高压变频设备的变压器绕组结构复杂、功率单元设计难度大、且需进线电抗器等问题,设计了一种新型CHB型四象限高压变频器,简化了高压变频设备的变压器结构,降低了功率单元的设计难度,取消了电抗器柜体,提高了高压变频系统的性价比和可靠性。

关键词： 绝缘栅双极型晶体管   开通失效   结构改进  

摘要： 对绝缘栅双极型晶体管(IGBT)在小电流开关测试失效进行了分析研究,对IGBT栅极和集电极的电压电流波形监测发现,IGBT在小电流开通时电压电流波形存在严重的振荡问题,电压幅值超过器件最大额定值,导致器件失效。分析了IGBT芯片电容和栅极电阻对小电流开通振荡的影响,通过对IGBT芯片结构进行改进,将小电流振荡抑制在安全值范围内,解决了IGBT小电流开通失效问题,改进后的IGBT器件性能参数和应用测试温升接近国外竞品。

关键词： 多电机   变频器   调速控制系统  

摘要： 多电机变频调速控制,可对电力输送状态进行调控,可有效解决电压不稳等问题。因此,变频调速控制,对电力控制效果提升有促进作用。在对多电机变频器调速控制系统进行研究中,充分利用变频技术以及微电子技术,针对变频器主流电机的调速控制方式、实践应用等展开讨论与研究,旨在实现变频器主流电机调速控制系统的实践应用效果提升。

关键词： 提升机   变频器   双三电平   防爆   矢量控制  

摘要： 在总结暗井提升系统存在重载启动时对电网和机械冲击大、功率因数低、调速困难以及电能浪费问题基础上,按照暗井提升机电控装置防爆要求,介绍了矿用防爆提升机变频电控装置的组成和关键技术。分析了主电路拓扑结构、矢量控制算法、热设计、功率无感母线以及电磁兼容性设计等内容,并将该电控装置应用于钱家营矿、平煤八矿等暗井提升系统。运行结果表明:该电控装置在调速、运行特性以及节能等方面优势明显,可以满足煤矿MW级暗井提升系统的使用要求。

关键词： 隔离型AC-DC变换器   调制策略   零矢量   移相控制   软开关  

摘要： 传统隔离型双向AC-DC变换器多为两级式结构,变换器效率低、控制系统复杂,现有的单级式解决方案通常依赖大量实时计算,难以兼具低电流应力、宽软开关范围和高功率传输能力特性。为此,该文设计基于双有源全桥的新型单级隔离型双向AC-DC谐振变换器,提出一种含有零矢量的复合频率调制策略。从高频开关周期入手,利用数学推导,证明所提方案在实现自动功率因数校正功能的同时,可降低开关器件的开关频率,免除附加吸收电路,实现交直流全桥的软开关,且几乎无功率回流,从而有效提升变换器的功率传输能力,所提单变量调节方法简化控制系统设计。最后,搭建额定功率为450W的仿真和实验平台,证明理论分析的正确性和调制策略的可行性。

关键词： 最优控制   伯克霍夫插值多项式   预处理  

摘要： 为改善传统伪谱法的收敛性与可靠性,针对高条件数伪谱微分矩阵,提出一种基于伯克霍夫预处理的良态伪谱法。首先,根据高阶勒让德正交多项式在配点的取值和权重,计算合适的伯克霍夫插值多项式,构建伯克霍夫左预处理算子;然后,对传统伪谱法线性微分系统两边同时左乘该算子,消除约束系统中病态微分矩阵。数值实验结果表明,相比于传统勒让德伪谱法,伯克霍夫预处理伪谱法在相同迭代步数下的计算精度更高,在相同性能指标下的计算效率更优,具有更广阔的应用前景。

关键词： DC circuit breaker   energy balancing   hybrid circuit breaker (HCB)   IGBT   metal-oxide varistor (MOV)   overvoltage   progressive switching   sequential tripping   staged turn-OFF   voltage overshoot  

摘要： During sequential tripping of dc hybrid circuit breakers (HCBs), the energy-absorbing metal-oxide varistors (MOVs) are inserted one after the other rather than simultaneously. This tripping scheme has been demonstrated to be effective in reducing the peak fault current and fault interruption time. However, the voltage overshoots during the sequential tripping process need to be suppressed and the fault energy among the MOVs needs to be balanced. Therefore, this article proposes, first, a simple overvoltage suppression method and second, a modified sequential tripping algorithm for HCBs. The former method is realized by increasing the turn- off gate resistance of the semiconductor devices, for which an analytical expression relating the HCB peak overvoltage and the semiconductor switch's gate resistance is provided. The latter algorithm is able to evenly distribute the MOV energy absorption under different grid conditions with the least number of switching events via a predefined tripping scheme and an energy feedback loop. Verification results from both time-domain simulation and a 1.2 kV circuit breaker hardware corroborate the efficacies of the proposed strategies, which will improve the performance of the sequentially tripped HCBs.

关键词： Accelerated aging experiment   bonding wire   condition monitoring   failure mechanism   insulated gate bipolar transistor (IGBT)   lifetime prediction model  

摘要： In the welding insulated gate bipolar transistor (IGBT) module, the module failure caused by bonding wire failure accounts for about 70% of the total module failure. Therefore, it is essential to improve the reliability of the IGBT module bonding wire. This article is devoted to a comprehensive review of the mechanism of IGBT bonding wire degradation and failure. The development and progress of related research methodologies on the reliability of the IGBT module bonding wire are introduced, including multiphysical field simulation technology, accelerated aging test (AAT), lifetime prediction model, and condition monitoring technology.

关键词： Gate drive circuit   high-voltage pulse generator   pulse discharging switch   semiconductor switch   series stacking   synchronized gate signal  

摘要： High-voltage switches composed of semiconductor switching components generally require a series stacked configuration, owing to limitations from the device voltage rating. In this configuration, isolated and synchronized gate signals should be applied to each of the switching devices for reliable operation. In this study, a high-voltage switch composed of a series stack of 12 semiconductor switches and a simple and low-cost gate drive circuit for the series stacked switch were designed. The proposed design can be applied to a low-power solid-state pulsed power modulator (SSPPM) without needing auxiliary circuits for the synchronized and isolated gate signal, by using a gate transformer with a single high-voltage cable loop on the primary side. Furthermore, the secondary side of the gate transformer has a simple circuit composed of two Zener diodes, a resistor, and a small storage capacitor. An insulated-gate bipolar transistor (IGBT) stack with 12 switches of 1200 V and 40 A rating each and a gate drive circuit were accordingly developed and proved to operate with a maximum pulse voltage and current of 10 kV and 100 A, respectively. The high-voltage switch with the IGBT-stack-based configuration was also verified to have compact dimensions of 10 x 10 cm.

关键词： void   maximum junction temperature   IGBT module   ANSYS finite element analysis   reliability  

摘要： Solder layer void is one of the main failure causes of power semiconductor devices, which will seriously affect the reliability of the devices. In this study, a 3D model of IGBT (Insulated Gate Bipolar Transistor) packaging was built by DesignModeler. Based on ANSYS Workbench, the influence of void size, location, solder layer type, and thickness on the temperature distribution of the IGBT module was simulated. The results show that the larger the void radius, the higher the temperature of the IGBT module. The closer the void is to the center of the solder layer, the higher the temperature of the module. The void on the top corner of the solder layer had the greatest impact on the junction temperature of the IGBT module, and the shape of the void is also one of the factors that affect the temperature of the module. The denser the void distribution, the higher the temperature of the module. The temperature of the IGBT module was reduced from 62.656 & DEG;C to 59.697 & DEG;C by using nanosilver solder paste, and the overall heat dissipation performance of the module was improved by 5%. The temperature of the module increased linearly with the increase in solder layer thickness, and the temperature increased by 0.8 & DEG;C for every 0.025 mm increase in solder layer thickness. The simulation results have a guiding significance for improving the thermal stability of IGBT modules.