【目的】由第一代和第二代半导体材料构成的功率器件,各方面性能都已经达到自身极限,在更为复杂的电路拓扑中难以应用。第三代新型半导体材料碳化硅(SiC)逐步成为研究焦点,相应的碳化硅器件也成为研究前沿。相比于传统硅(Si)基器件,碳化硅金属-氧化物-半导体场效应晶体管(SiC MOSFET)以其更为优异的特性在高压、高频和高功率密度领域广泛应用。受到载流能力限制,往往需要多个器件并联使用。不成熟的制作工艺和不对称的电路布局,会导致器件自身参数和外部电路参数存在差异,产生不平衡电流问题。针对该问题,本文提出一种均流控制策略。【方法】本文首先分析和总结了并联均流影响因素,确定了各个参数的影响程度。并以器件自身开通和关断特性为基础,通过理论公式推导,总结了电流变化规律。其次,设计了对应的电流检测电路,准确获取电流差异情况。最后,提出了一种调节驱动电阻的均流控制策略,通过调节多级驱动电阻,逐步调节不平衡电流。【结果】仿真结果验证了所提控制策略的有效性,电流不平衡度显著减小。【结论】结果表明,设置合理的驱动电阻,所提出的控制策略能有效实现双管并联均流。

[Objective] Power devices composed of first- and second-generation semiconductor materials have reached their performance limits, making them unsuitable for more complex circuit topologies. Silicon carbide (SiC), the third-generation semiconductor material, has gradually become a research focus, and corresponding SiC devices are now at the forefront of research. Compared to traditional silicon (Si)-based devices, silicon carbide metal-oxide-semiconductor field-effect transistor (SiC MOSFET) offer superior characteristics and are widely used in high-voltage, high-frequency, and high-power-density applications. However, due to the limited current-carrying capacity of a single device, multiple devices are often used in parallel. Immature manufacturing processes and asymmetric circuit layouts cause differences in device parameters and external circuit parameters, leading to unbalanced current issues. To address this problem, this paper proposes a current-sharing control strategy. [Methods] This paper first analyzed and summarized the factors affecting parallel current sharing and determined the influence of each parameter. Based on the devices’ switching characteristics, theoretical formulas were derived to summarize the current variation patterns. Then, a corresponding current detection circuit was designed to accurately capture current differences. Finally, a current-sharing control strategy based on adjusting multi-level driving resistance was proposed to gradually regulate unbalanced currents. [Results] Simulation results validated the effectiveness of the proposed control strategy, significantly reducing current imbalance. [Conclusion] The results show that by setting an appropriate driving resistance, the proposed control strategy can effectively achieve current sharing in dual-device parallel configurations.

国家重点研发计划项目(2021YFB2601403)