含有源功率解耦的单相H桥逆变器综合可靠性评估

为抑制单相H桥变换器系统中直流侧低频纹波,近年来出现了许多功率解耦方法减小或消除DCLink电容,延长DC-Link寿命,提高其可靠性。然而,由于有源功率解耦引入了额外器件,且原有器件的应力也有所改变,因此,有必要对变换器级的可靠性进行综合评估。基于2 k W的单相H桥逆变器,通过器件级的电-热应力模型、寿命模型、Weibull分布得到器件级可靠性,并基于器件级可靠性,通过可靠性框图(RBD)得到变换器级可靠性,与传统无源解耦逆变器相比较,综合评估带两种不同有源功率解耦的单相H桥逆变器可靠性。

Reliability Evaluation of a Single-phase H-bridge Inverter with Integrated Active Power Decoupling

Various power decoupling methods have been proposed recently to replace the DC-link Electrolytic Capacitors (E-caps) in single-phase conversion system, in order to extend the lifetime and improve the reliability of the DC-link. However, it is still an open question whether the converter level reliability becomes better or not, since additional components are introduced and the loading of the existing components may be changed. This paper aims to study the converter level reliability of a single-phase full-bridge inverter with two kinds of active power decoupling module and to compare it with the traditional passive DC-link solution. The converter level reliability is obtained by component level electro-thermal stress modeling, lifetime model, Weibull distribution, and Reliability Block Diagram (RBD) method. The results are demostrated by a 2kW single-phase inverter application.