Compared with traditional silicon (Si) power devices, silicon carbide (SiC) devices have attracted extensive attention due to their excellent characteristics. In recent years, the manufacturing process of SiC devices has become more mature, but the cost is still high. Therefore, replacing only some of the Si devices with SiC devices in a topology is a better choice to achieve higher system efficiency while considering costs. This paper studies the hybrid configuration schemes consisting of two SiC devices and four Si devices (2SiC&4Si) in ANPC three-level inverter. Two hybrid 2SiC&4Si topologies are proposed. In order to make full use of the low switching loss characteristics of SiC devices in hybrid topologies, specific modulation strategies are applied to concentrate switching losses on SiC devices. Based on the 2SiC&4Si hybrid ANPC topologies, three efficient SiC&Si hybrid configuration schemes are derived. In this paper, the theoretical comparison and experimental verification of the efficiency and loss distribution of the three hybrid schemes are carried out. INDEX TERMS SiC&Si hybrid configuration, ANPC, loss analysis.

Silicon carbide (SiC) devices have excellent performance, such as higher switching frequency and lower switching loss compared with traditional silicon (Si) devices. The application of SiC devices in inverters can achieve higher efficiency and power density. In recent years, the production process of SiC devices has become more mature, but the cost is still several times that of traditional Si devices. In order to balance cost and efficiency, replacing only some of the Si devices with SiC devices in a topology is a better choice. This paper proposed a high-efficiency hybrid active neutral point clamped (ANPC) three-level inverter which has only two SiC devices and the other devices are Si devices. A specific modulation strategy was applied to concentrate switching losses on the SiC devices and reduce the on-state loss through parallel operation during freewheeling intervals. Theoretical efficiency curves and experimental verification of the proposed hybrid scheme with Si-only and SiC-only schemes were carried out.

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In the optimized design of power converters, loss analysis of power devices is important. Compared with estimation methods, measuring the power device loss directly in the circuit under test is more accurate. The loss measurement method can be divided into two categories: electrical measurement and calorimetric measurement. The accuracy of the electrical measurement result is restricted to the accuracy of the measurement equipment and parasitic parameters, especially for fast switching devices like SiC devices. The results obtained from calorimetric measurement are more convincing. Based on the measurement principle, calorimetric measurement can be divided into four categories: flow density measurement, temperature equivalent measurement, double jacket measurement, and temperature sensor measurement. This paper proposes an optimized temperature sensor measurement method, which has shorter time consumption, a simpler setup, and lower cost. The principles of the optimized method are described and compared with the traditional ways in detail to show its advantages. The loss measurement and error analysis are carried out in a three-level ANPC (active neutral-point-clamped) topology experiment platform based on the SiC&Si hybrid module to prove the accuracy and practicability of this method.