PWM整流器中IGBT结温特性的研究

绝缘栅双极型晶体管(IGBT)是风电系统中PWM整流器的核心器件,而结温是影响IGBT使用寿命的主要因素,因此有必要对PWM整流器中IGBT工作状态下的结温特性进行研究。文章详细介绍了IGBT模块结构和SVPWM调制策略,设计了PWM整流器中IGBT测温系统的实验电路,搭建了实验平台。使用光纤对IGBT在工作状态下的结温进行了测量,获得了结温工作曲线,并分析了IGBT结温温升的曲线特征以及变化规律,为整流器中IGBT的可靠性研究提供了依据。     

双馈风电变流器IGBT模块损耗及结温的计算分析及变化规律研究

针对双馈风电变流器IGBT模块在交变热应力的长期作用下导致故障频发的问题,提出其损耗与结温的准确计算模型及不同工况下两者变化规律的研究。首先,建立了机侧及网侧变流器在整流或逆变模式下IGBT模块损耗及结温的计算模型;其次,对机组在不同运行工况下,其损耗和稳态结温进行分析。结果表明,随风速的增大,机侧与网侧变流器IGBT模块的损耗变化规律不同;机侧变流器IGBT模块的结温波动剧烈,尤其是在同步风速附近区域。     

基于IGBT模块饱和压降温度特性的结温探测研究

实验室条件下,IGBT模块的结温探测是瞬态热阻抗测试的关键。首先分别在热稳态和热瞬态下证明了饱和压降温度特性只与芯片有关,然后建立了IGBT模块结温探测模型,利用饱和压降值和集电极电流值来计算结温值,并将用模型计算出的结温与光纤实测的结温相比较,吻合性良好,证明了模型计算法能够准确探测结温。该方法可以用于恒流加热过程中瞬态热阻抗的测量,比起热敏参数法中冷却过程测量瞬态热阻抗相比,更具有实际意义。     

混合封装电力电子集成模块内功率电路对驱动保护电路的热影响

混合封装电力电子集成模块(IPEM)是目前中功率范围内电力电子集成的主要方式。IGBT器件与控制和驱动电路高密度地封装在一起,IGBT的发热对驱动保护电路会产生非常不利的影响,我们针对这个问题进行了研究。利用三维有限元法建立了模块内的传热模型,对不同发热功率下IGBT的结温以及驱动保护电路PCB的最高温度进行了计算和分析。另外,对功率电路与驱动保护电路PCB之间存在空气隙以及模块完全被密封后模块内的传热问题也进行了实验研究。     

IPOSIM-IGBT仿真工具在UPS设计中的应用

IPOSIM是一个功能强大的IGBT仿真工具,能够计算IGBT和续流二极管的开关损耗和导通损耗,仿真其温度分布和结温纹波,又增添一些灵活的负荷定义、比较等功能,因而更具价值。文中简单介绍了计算1GBT损耗的基本理论和相关热分析模型以及应用该工具的相关原则。同时,结合UPS的基本特点和负载特性,重点分析如何有效地利用这个工具来选择IGBT,以及掌握在不同设计和应用条件下1GBT的运行状态。最后以5kVA UPS的实际应用作为案例。     

采用动态差分模型表征脉冲驱动LED电热特性

为了研究不同驱动方式下LED结温的差异性,依据LED热结构模型,从功率传递角度构建了差分型LED电-热动态模型,利用相同平均功率、不同频率的注入电功率,计算脉冲驱动条件下的LED结温.同时,采用正向电压法测量实际结温,对模型预测结温的准确性进行了分析.研究表明,差分模型能够表征脉冲驱动方式下LED电热特性,其理论预测值与实测值误差约为4℃,基本能够满足工程应用要求.更有意义的是,采用差分模型,能够分析在特定驱动条件下,LED热容、热阻等参数对结温的影响,为不同驱动模式下LED个性化结构设计提供了理论基础.     

基于电热耦合模型的功率器件结温预测

结温预测对于功率器件的可靠性分析具有重要意义,基于此,提出了一种基于电热耦合模型的功率器件结温预测方法。首先通过Twin Builder软件建立了绝缘栅双极晶体管(IGBT)的行为模型,通过电路仿真的手段获取IGBT的平均功耗为324 W;然后将IGBT的功耗代入有限元仿真模型中得到了IGBT模块温度场分布,最高温度为99.58℃;最后搭建了IGBT模块结温测试平台,将仿真结果与实验数据进行对比,验证温度场计算模型的有效性;并实验对比了IGBT功耗分别为119 W和294 W下的最高结温,得到的温度场计算误差在10%以内,验证了IGBT有限元模型的有效性。     

基于有限元仿真的IGBT混合模块的可靠性分析

集成化与微型化是当今电子信息产业发展的特点,其中电子元件的结温与热应力是影响其可靠性的重要因素。硅基IGBT和SiC基续流二极管组成的混合模块广泛应用于城市轨道交通等领域,其可靠性直接影响轨道交通车辆的运行性能。本文建立IGBT混合模块的仿真模型,随着各层材料厚度、焊料空洞大小和位置的变化,计算分析IGBT混合模块的温度与应变变化规律,对模块封装结构进行优化设计。将高热导率石墨烯应用在IGBT混合模块中,仿真分析应用位置不同对模块可靠性的影响,从而进一步优化混合模块的封装结构。通过仿真计算,优化后的IGBT混合模块可将最高结温降低近3℃,最大热应力下降超过30 MPa。     

工业级FPGA器件空间应用散热设计

建立了工业级FPGA的热分析模型,采用先模块后器件两步分析方法,研究了在热传导和辐射条件下模块盒体、导热衬垫热传导系数、厚度及压力对FPGA散热性能的影响。分析了FPGA芯片内部热分布的状态,提出了工业级FPGA空间应用的散热设计方案。研究表明,通过增加模块盖板厚度、优化器件布局、采用高导热系数导热衬垫,可以使工业级FPGA芯片结温满足一级降额要求。     

IGBT模块的并联从最坏情况模拟到完全统计方法

利用并联IGBT模块的蒙特卡罗模拟方法,可以基于器件中的随机模块参数和系统不平衡度计算出电流不平衡、开关损耗及结温.     

IGBT模块焊料老化状态监测方法及热网络模型优化

焊料老化是绝缘栅双极型晶体管(IGBT)模块内部传热能力退化和结温估计偏离的主要诱因。利用壳温与焊料老化程度间的对应规律构建了两者的量化关系,提出了焊料老化状态监测方法。采用与功率损耗无关的参数对恶化Cauer热网络(CTN)有效传热面积进行表征,提出了焊料裂纹诱导的结温低估补偿机制;考虑温度相关的异质材料导热系数及比热容参量,抑制了温升引起的材料传热特性退化影响。在此基础上,通过对传统CTN模型的优化,克服了传热路径无法自适应配置问题。仿真结果表明,所提方法可有效减小传热退化对模型计算结果的影响,实现对IGBT模块热行为动态变化的精确模拟,且结温估计结果相较传统CTN模型的更为精确。     

TLM method for thermal investigation of IGBT modules in PWM mode

The insulated gate bipolar transistor (IGBT) is popularly used in high power, high frequency power-electronic applications such as motor control and inverters. These applications require well designed thermal management system to ensure the protection of IGBTs. Choice simulation tools for accurate prediction of device power dissipation and junction temperature become important in achieving optimised designs.In this paper, thermal analysis of a 1200 A, 3.3 kV IGBT module was investigated and analysed using the three-dimensional transmission line matrix (3D-TLM) method. The results show a three-dimensional visualisation of self-heating phenomena in the device. Since the comparison TLM results with the analytical solutions do not exist for this IGBT module, we use the MSC.NASTRAN tool to find the similar range of the temperatures. Results are compared.Typically, IGBT is used in a three-phase inverter leg where the control signals are generated via PWM scheme so, the prediction of the temperature rise is important in the pulse operation conditions for the IGBT device. A view of the dynamic thermal temperature rise is obtained with 100 W-step pulse dissipation applied at IGBT chips. The temperature rises are calculated using TLM method during the PWM load cycles. Simulations give clear indications of the importance of the spreader material and are helpful in selecting the proper one.TLM has been successful in modelling heat diffusion problems and has proven to be efficient in terms of stability and complex geometry. The three-dimensional results show that method has a considerable potential in power devices thermal analysis and design.     

Thermo-fluid simulation for the thermal design of the IGBT module in the power conversion system

The junction temperature of the insulated-gate bipolar transistor (IGBT) module, which belongs to power semiconductor devices, directly impacts on the system performance of the power conversion system (PCS), and therefore, the accurate prediction of the airflow rate passing the heat sink block of the IGBT module is very important at the thermal design stage. In this paper, the thermo-fluid simulation was developed with the T–Q characteristic curve to predict the junction temperature of the IGBT module and the airflow rate of the heat sink block. The porous media model was adopted in the heat sink block with fins and the filled air between fins of the heat sink block in the PCS to remove the heavily concentrated mesh problems in the heat sink block. The proposed simulation model was compared to the experimental value for the hot spot temperature on the heat sink block and the differences were within the average 4.0% margin of error in the comparison. This simulation model can be used to evaluate the suitability of the cooling design according to various operating conditions of the fan and IGBT module with benefits of the reduction in the mesh generation and the computation time. Also, this simulation model increases the flexibility of predicting the airflow rates in the PCS due to the change of the airflow passage structure in the PCS or the capacity of the fan.     

多电平单元串联高压变频器功率单元的热设计

多电平单元串联电压源型高压变频揣的核心——变顿器的通用系统是功率单元，功率单元的热稳定性是高压变频器热发全的核心。在对兆瓦级高压变频器研发中，根据IGBT和DOIDE的参数特性，计算其热损耗功率。结合热分析公式研发变频器功率单元的热沉系统．并利用相关的热分析行业软件，完成300A电流等级的通用功率单元的热设计。     

应用于车载变流器的RC-IGBT工作特性

逆导型IGBT (RC-IGBT)是将IGBT功能与续流二极管功能集成在一个芯片上,实现了在相同封装体积下,可获得更大的功率密度,由于IGBT与二极管紧密的移相热耦合,在相同散热条件下,RC-IGBT允许的工作结温更高.同时,RC-IGBT的本征二极管还受到栅极电压控制,通过栅极电压控制策略,可以降低器件损耗,优化系统特性.介绍了RC-IGBT的基本工作原理和二极管退饱和控制特性,研究了RC-IGBT应用于变流器系统的损耗优化控制策略,分析了应用RC-IGBT的单相脉宽调制(PWM)整流器的工作特性与损耗特性.通过一个具体的应用工况运行仿真,分析对比了RC-IGBT和普通IGBT在PWM整流器应用中的损耗特性.结果显示,应用RC-IGBT后总体损耗有所降低,验证了RC-IGBT退饱和脉冲控制的有效性.     

IGBT junction and coolant temperature estimation by thermal model

The capability of IGBT (Insulated Gate Bipolar Transistor) to handle heat is one of its main limitations of high power application. This paper aims to study an IGBT thermal model under flow cooling condition and estimate the IGBT module junction and coolant temperature. Firstly, this paper studies the IGBT module internal sandwich structure and calculates the thermal resistance and thermal capacitor for each layer using a 1D physical model. Then a Cauer electric model is built for the IGBT module to evaluate the thermal constant time of the model. The liquid cooling method is applied in this project for fast cooling and the thermal parameters are studied and measured since this cooling method involves both solid and liquid. In order to estimate the junction temperature, the sensing temperature from NTC (Negative temperature coefficient) resistor inside the module is used as reference temperature. The equivalent thermal models, also named Foster model, from both junction to NTC and NTC to coolant are built, respectively. With these thermal models, the junction and coolant temperature estimation methods are derived. For the purpose of making the estimation accurate, the thermal coupling effect is carefully studied. Finally, the thermal model is verified by inverter application with current steps sweeping; the estimated temperature is compared with thermal camera measurement result which demonstrates good accuracy of the thermal model. The estimated coolant temperature is also well matched with thermocouple measurement result.     

Design optimization of an integrated liquid-cooled IGBT powermodule using CFD technique

This paper presents a novel approach to optimize pin array design of an integrated, liquid-cooled, insulated gate bipolar transistor (IGBT) power module. With the aid of a computational fluid dynamics (CFD) code, the fluid field and heat transfer inside the module were analyzed, and several design options on pin arrays were examined. For IGBT die circuitry, the uniformity of temperature distribution among dies is as critical as the magnitude of the die temperature. A noticeable variation in temperature among dies can accelerate the thermal runaway and reduce the reliability of the devices. With geometrically-optimized-pin designs located both upstream and downstream of the channel, a total power dissipation of 1200 W was achieved. The maximum junction temperature was maintained at 100°C and the maximum variation among dies was controlled within 1°C. The results from this study indicated that the device junction temperatures were not only reduced in magnitude but were equalized as well. In addition, the maximum power dissipation of the module was enhanced. Comparison with other direct- (pool boiling) and indirect- (cold plate) liquid cooling techniques was also discussed     

压力对换流阀用压接型IGBT器件功率损耗的影响

功率损耗一直是功率半导体器件应用时备受关注的问题.压接型绝缘栅双极型晶体管(IGBT)器件靠外部压力使内部各个组件保持电气和机械连接,因此压力直接或间接地影响着压接型IGBT器件的功率损耗.将压接型IGBT器件工作时产生的结温作为耦合变量引入,基于此建立了IGBT器件应用于调制脉宽(PWM)换流设备时的功率损耗计算模型,并详细分析了影响功率损耗的各种因素,包括机械压力、开关频率等.以换流阀用3 300 V/1 500 A压接型IGBT器件为例,采用有限元法研究了压力对压接型IGBT器件功率损耗的影响,重点探讨了器件内部各芯片功率损耗的变化情况.结果表明,增加压力一定程度上可以降低压接型IGBT器件的功率损耗,改善器件内部芯片结温分布不均的问题.     

大功率LED典型热沉结构散热性能分析

设计了三种大功率LED照明装置,并对其二次热沉散热进行了散热原理比较、实验性能分析,建立了热阻网络模型,对其进行了结温计算和寿命预测,发现微热管、薄肋片、风扇可以很好地实现散热.利用正交试验法对LED照明装置结温的影响因素进行了模拟分析,发现自然对流条件下,对流换热系数的影响可忽略不计,而需尽量提高导热环节的热导率并结合其散热能力进行功率的控制.为微热管散热技术提供了技术参考,为大功率LED器件的二次热沉散热提供了有效的实现途径.