In this paper, a modular three-phase multilevel inverter specially suited for electrical drive applications is proposed. Unlike the cascaded H-bridge inverter, this topology is based on power cells connected in cascade using two inverter legs in series. A detailed analysis of the structure and the development of design equations for the load voltage with n levels are carried out using pulsewidth-modulation phase-shifted multicarrier modulation. Simulations and experimental results for a 15-kW three-phase system, with nine voltage levels, validate the study presented.

Automotive embedded electronic systems have been increasing in power and complexity and, therefore, more advanced power electronic converters are necessary in these vehicles. Several dual-voltage (42 V/14 V) bidirectional converter architectures have been proposed for automotive systems in recent years. However, most of them have low efficiency or are based in series and parallel configurations with large number of semiconductors and magnetics devices. Therefore, in this paper, we propose a bidirectional high-efficiency converter with lower number of components. This converter was created by merging a switched-capacitor converter and a conventional bidirectional converter, resulting in a hybrid topology. The voltage across the semiconductors of the proposed converter is equal to half of the highest voltage source value. Furthermore, the topology is composed of only one inductor to control the power flow between the two voltage sources. To verify all the mentioned features, a prototype was implemented experimentally, reaching a maximum efficiency of 97.5%.

This article proposes a new high step-up DC-DC converter for fuel cell applications. Built-in transformers and voltage multiplier cells are integrated into the structure to step-up the voltage gain. The paper proposes a new topology with common ground. Two of them are connected using the dual boost concept. Thus, the final structure provides input current interleaved that reduces the current ripple, output-series connection that increases the voltage gain and floating ground on the output voltage, which can be a limitation for some applications. Additionally, on designing the built-in transformer with a leakage inductance value much less than the magnetizing inductance value (less than 0:5%), the proposed topology does not need a clamp circuit, which reduces the number of components and increases the efficiency. Operational steps, static gain analysis, and design guide of the new converter are described in details herein. Furthermore, a 1 kW, 48-800 V prototype was built to verify the theoretical analysis. Tests in laboratory reached 94:60% of maximum efficiency at 480 W and 93:00% of efficiency at 1.0 kW (rated power).

The success of electric vehicles (EVs) greatly depends on battery size, cost, lifetime, and capacity. The battery capacity of EVs has to contain enough energy to allow EV users to drive, at least, the minimum distance that internal combustion engine vehicles take. However, even with very efficient EVs and combining all the available highly efficient EV technologies, the battery capacity still needs to be large. Thus, one alternative to reduce the battery size is to improve the charging infrastructure by implementing sufficient public/private fast-charging locations, which will significantly increase the EV driving range with relatively low battery capacities. However, this kind of infrastructure requires charging with higher current capability, due to the high power levels involved in the fast-charging process. In this paper, a bidirectional dc/dc converter with six inverter legs connected to a three-phase output is proposed. The converter is similar to a three-phase dual-active-bridge (DAB) converter with more inverter legs in parallel. These additional inverter legs increase the converter current capability, without affecting the DAB main characteristics, preserving similar modulation techniques and DAB advantages. An accurate study about the proposed topology is carried out in this paper, and simulations and experimental results are shown for a 20-kW prototype, validating the theoretical analysis.

The availability of new electrical vehicle batteries with high current rating and capacity permits the realization of rapid charging. However, when using conventional methods, the charging process requires an expensive high-current grid interface. Therefore, a multiport converter with a stationary storage port to reduce the current required from the grid is proposed. The goal of this paper is to explore the fundamentals of the converters used in each port. Experimental results are shown to validate the study.

This article proposes a unidirectional high step-up dc–dc converter. The study approaches principle of operation, analysis, guide design, and experimental validation. The high-voltage gain is reached using coupled inductors and voltage multiplier cells (VMC). An interleaved structure of two phases is employed to provide a low-current ripple in the input side. The current balance between the phases occurs due to the insertion of a built-in transformer, which also contributes to increasing the voltage gain. The energy from the leakage inductances is reused, reducing voltage spikes across the semiconductors. Additionally, the proposed converter provides an input–output common ground, which is a requirement for many applications. To verify the proposed converter, a 1-kW prototype, 48–800 V, and 16.67 of voltage gain, was designed and tested. The maximum peak efficiency reached was 94.89% and the rated power efficiency was 93.86%.