Increased adoption of electric vehicles, photovoltaic, and battery energy storage systems is driving the need for high-current SiC power modules. The state-of-the-art multichip module is substantially more expensive than the IGBT module. This article proposes a cost-effective packaging methodology for high-power SiC intelligent power modules (IPMs) with discrete SiC devices. The proposed IPM integrates the gate drivers, decoupling capacitors, snubbers, discrete SiC devices, direct bond copper, base plate, temperature sensors, and overcurrent protection circuits, achieving very low loop inductance and thermal resistance, and more than 50% cost reduction. A 1200 V/480 A/2.15 mΩ half-bridge IPM is presented for comparison with commercial counterparts. A 1200 V/240 A/4.3 mΩ six-phase IPM is developed, and its performance is experimentally verified.

The inherent neutral-point (NP) voltage fluctuation of Vienna rectifier could have side effects on the input current quality. However, such effects have not been thoroughly analyzed in the literature yet. In this paper, based on the three-level to two-level space vector modulation (SVM) transformation, a novel method to evaluate the influence of the NP voltage fluctuation on the input current quality is introduced, which could optimize the NP control parameters. The proposed method superimposes the NP voltage fluctuation on the basis vectors, thereby establishing the correlation between the NP voltage fluctuation and the square root mean square (S-RMS) of the input current ripple. The detailed model of the NP oscillation under two-level coordinates is presented. By combining the two-level modulation, NP voltage hysteresis control is adopted to simplify neutral point voltage control and suppress NP low-frequency oscillation. Comprehensive influence of the NP compensation coefficient on the input current quality under NP hysteresis control is obtained, and the hysteresis control parameters are optimized by using the proposed evaluation method. Simulation and experimental results verify the correctness and effectiveness of the proposed evaluation method.

Three-level boost (TLB) converters are a promising interface of bipolar DC microgrids. With different power of the positive and negative DC buses, the conventional modulation method used in TLB converters fails to have zero voltage switching (ZVS) for all switches, and the peak current is also high, leading to the risk of inductor saturation. In this article, an optimized modulation (OM) method is proposed to achieve ZVS for all switches even under unbalanced loads. The OM method features the same valley current at both the high and low output power sides, contributing to wider ZVS range as well as smaller peak-to-peak current. The modulation degree of freedom in TLB converters under unbalanced-load conditions is analyzed in detail for the first time, and the advantages of the proposed OM method are compared with its counterparts in terms of the ZVS range, the peak and valley current, and the efficiency. The effectiveness and advantages of the proposed OM method are finally validated by experiment.

Busbars are critical components that connect high-current and high-voltage subcomponents in high-power converters. This paper reviews the latest busbar design methodologies and offers design recommendations for both laminated and PCB-based busbars. Silicon Carbide (SiC) power devices switch at much higher speeds compared to traditional silicon devices, making them more susceptible to parasitic elements within the busbar. In high-frequency SiC converters, using thicker copper offers limited improvement in high-frequency current handling due to the reduced skin depth at such frequencies. PCB busbars, however, provide several advantages, including reduced loop inductance, enhanced high-frequency current capacity, simplified assembly, and lower costs. Additionally, they enable the integration of components such as sensors, capacitors, and resistors, which can further optimize overall system performance. This paper also presents optimized busbar designs for both module-based and discrete device-based SiC high-power converters, comparing various SiC power module packages and offering design insights. Finally, this paper showcases a 75 kW three-phase inverter utilizing a PCB busbar, demonstrating its potential for achieving high power density and cost-effectiveness in discrete SiC device-based high-power converters.

Wide bandgap (WBG) power semiconductor devices are increasingly replacing silicon IGBTs in high-power and high-voltage power electronics applications. However, there is a significant gap in the literature regarding efficient testing methodologies for high-power and high-voltage converters under constrained laboratory resources. This paper addresses this gap by presenting comprehensive, hardware-focused testing methodologies for high-power and high-voltage WBG power semiconductor-based converter bring-up before the control validation phase steps in. The proposed methods enable thorough evaluation and validation of converter hardware, including device switching characteristics, driving circuit functionality, thermal management performance, insulation integrity, and sustained operation at full power. We utilized the double pulse test (DPT) to characterize switching performance in a two-level phase leg configuration, extract circuit parasitics, and validate magnetic components. The DPT was further applied to optimize gate driving circuits, validate overcurrent protection mechanisms, and measure device on-resistance. Additionally, a multicycle test was introduced to rapidly assess steady-state converter performance and estimate efficiency. Recognizing the critical role of thermal management in high-power converters, our methodologies extend to the experimental extraction of key thermal parameters—such as junction-to-ambient thermal resistance and thermal capacitance—via a heat loss injection method. A correlation method between temperature sensor measurements and junction temperature is presented to enhance the accuracy of device temperature monitoring during tests. To ensure reliability and safety, dielectric withstand tests and partial discharge measurements were conducted at both component and converter levels under conventional 60 Hz sinusoidal and high-frequency PWM waveforms. Finally, we highlight the importance of testing converters under full voltage, current, and thermal conditions through power circulating tests with minimal power consumption, applicable to both non-isolated and isolated high-power converters. Practical examples are provided to demonstrate the effectiveness and applicability of these hardware testing methodologies.