The authenticated broadcast is simulated in the bounded-degree networks to provide efficient broadcast primitives for building efficient higher-layer Byzantine protocols. A general abstraction of the relay-based broadcast system is introduced, in which the properties of the relay-based broadcast primitives are generalized. With this, fault-tolerant propagation is proposed as a building block of the broadcast primitives. Meanwhile, complementary systems are proposed in complementing fault-tolerant propagation and localized communication. Analysis shows that efficient fault-tolerant propagation can be built with sufficient initiation areas. Meanwhile, by integrating fault-tolerant propagation and localized communication, efficient broadcast primitives can be built in bounded-degree networks.

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.

The efficiency improvements offered by adopting Silicon Carbide (SiC) devices in Electric Vehicle (EV) inverters has been widely reported in various studies. However, it has still not been established whether or when the efficiency benefits can counteract the high price of SiC devices, especially for the scenario of urban electric buses. In this paper, the potential impact of installing SiC devices on electric buses is analyzed from the perspective of economic benefits. The SiC inverter used in the drive system is based on a discrete MOSFET in parallel. For comparison, an Si inverter based on a sixthgeneration IGBT produced by Infineon is also evaluated. A vehicle simulation platform is established in Simulink for an evaluation of energy consumption for different scenarios. It is shown that significant energy savings can be gained when the vehicle operates mostly in the partial load area. While in the nominal load area, energy savings are very limited. Based on the analysis, the conditions for offsetting the cost premium of SiC devices to realize system-level advantages are discussed using a multi-dimensional analysis considering the change in battery and device prices, driving range, vehicle mass, and driving cycles.INDEX TERMS SiC devices, electric bus, energy consumption, system-level advantages, driving cycles.

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