利用电容放电现场测量变流器IGBT模块损耗

On-site Measurement of IGBT Module Lossesin Power Converter System by Discharging DC Capacitor

为克服传统方法存在误差较大或工程实施困难的不足,提出一种变流器IGBT模块损耗现场测量的新方法。该方法利用直流电容放电过程现场对变流器IGBT功率模块的损耗特性进行测试,以验证变流器性能或诊断功率模块早期故障;通过适当控制变流器内各个IGBT导通与关断,构成直流电容Buck放电电路实施损耗测试。采用英飞凌1200 V/50 A功率模块FF50R12RT4搭建的380 V/10 k W变频器进行了实验研究,实验结果验证了该方法的可行性与有效性。现场测试方法充分利用变流器停机间隙和电容储能对负载电感放电进行测试,无需额外增加硬件,具有经济、方便、安全等优点。

This paper presents a new on-site testing method for IGBT power loss in order to overcome the short-comings of traditional method with large error or difficulty in engineering implementation. The method can be applied to verify the performances of converter or diagnosethe early fault of power modules by measuring the losses characteristic of IGBT module on-site by discharging DC capacitor. During the test, a DC capacitor discharging circuit is constructed by proper control of IGBTs inside the converter. Experimental study is carried out on a 380 V/10 kW variable frequency drive （VFD）with Infineon IGBT module FF50R12RT4 in this paper and the results prove the feasibility and effectiveness of the method. The proposed method take use of the existing DC capacitor and load inductance to perform the on-site losses testing when system is shutdown, so that it has advantages of no hardware modification, safe, simple and cost-effective.