Yu Qiuping, Zhao Zhibin, Sun Peng, Zhao Bin, Cai Yumeng
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China.
Sensors (Basel). 2021 Jun 23;21(13):4285. doi: 10.3390/s21134285.
Power electronic devices are essential components of high-capacity industrial converters. Accurate assessment of their power loss, including switching loss and conduction loss, is essential to improving electrothermal stability. To accurately calculate the conduction loss, a drain-source voltage clamp circuit is required to measure the on-state voltage. In this paper, the conventional drain-source voltage clamp circuit based on a transistor is comprehensively investigated by theoretical analysis, simulations, and experiments. It is demonstrated that the anti-parallel diodes and the gate-shunt capacitance of the conventional drain-source voltage clamp circuit have adverse impacts on the accuracy and security of the conduction loss measurement. Based on the above analysis, an improved drain-source voltage clamp circuit, derived from the conventional drain-source voltage clamp circuit, is proposed to solve the above problems. The operational advantages, physical structure, and design guidelines of the improved circuit are fully presented. In addition, to evaluate the influence of component parameters on circuit performance, this article comprehensively extracts three electrical quantities as judgment indicators. Based on the working mechanism of the improved circuit and the indicators mentioned above, general mathematical analysis and derivation are carried out to give guidelines for component selection. Finally, extensive experiments and detailed analyses are presented to validate the effectiveness of the proposed drain-source voltage clamp circuit. Compared with the conventional drain-source voltage clamp circuit, the improved drain-source voltage clamp circuit has higher measurement accuracy and working security when measuring conduction loss, and the proposed component selection method is verified to be reasonable and effective for better utilizing the clamp circuit.
电力电子器件是高容量工业变流器的关键部件。准确评估其功率损耗，包括开关损耗和导通损耗，对于提高电热稳定性至关重要。为了精确计算导通损耗，需要一个漏源极电压钳位电路来测量导通状态下的电压。本文通过理论分析、仿真和实验对基于晶体管的传统漏源极电压钳位电路进行了全面研究。结果表明，传统漏源极电压钳位电路中的反并联二极管和栅极并联电容对导通损耗测量的准确性和安全性有不利影响。基于上述分析，提出了一种由传统漏源极电压钳位电路衍生而来的改进型漏源极电压钳位电路，以解决上述问题。详细介绍了改进电路的工作优势、物理结构和设计准则。此外，为了评估元件参数对电路性能的影响，本文综合提取了三个电量作为判断指标。基于改进电路的工作机理和上述指标，进行了一般数学分析和推导，为元件选择提供指导。最后，通过大量实验和详细分析验证了所提出的漏源极电压钳位电路的有效性。与传统漏源极电压钳位电路相比，改进后的漏源极电压钳位电路在测量导通损耗时具有更高的测量精度和工作安全性，并且所提出的元件选择方法被验证为合理有效，能够更好地利用钳位电路。
