J. J. A. Oliver

Learn More
The impedance-based stability-assessment method has turned out to be a very effective tool and its usage is rapidly growing in different applications ranging from the conventional interconnected dc/dc systems to the grid-connected renewable energy systems. The results are sometime given as a certain forbidden region in the complex plane out of which the(More)
System designers normally use commercial dc-dc converters to build the power system. Simulation plays an important role in the configuration, analysis and design of the system, but the lack of available models of commercial dc-dc converters is a major drawback. The aim of this work is to develop a generic model of dc-dc converters based on the information(More)
The combination of non-linear control and linear control proposed in [1] has a very fast transient response (voltage step from 1 V to 1.5 V in 2 ¿s). In order to achieve this fast transient response the non-linear scheme is based on measuring the current of the output capacitor of a Buck converter. The design of this current sensor is complex due to(More)
The objective of this work is to propose a whole solution for simulating power systems based on the use of behavioral DC/DC converter models. The proposed model is a generic model whose parameters can be obtained from datasheets (especially useful to model commercial converters) or equivalent tests. The model has configurable features which can be activated(More)
Hybrid vehicles need a high voltage DC bus to supply power to the motor. Architectures of these vehicles usually include a DC-DC bi-directional converter between this voltage bus and the conventional battery. When the DC bus is held by a big capacitor, the selection and design of the aforementioned converter has an additional difficulty since the converter(More)
The use of finite element analysis (FEA) solvers in order to explore the field distribution is a common practice for designing custom made magnetic components. However, the use of the field distribution information for the generation of a model valid to be simulated in a circuit simulator is not evident. There are several issues that need to be addressed in(More)
This paper presents a new modulation technique for the Bidirectional Dual Active Bridge Series Resonant Converter (DAB SRC). The main feature of the proposed modulation is the elimination of the switching losses of the active devices that allows operating the DAB SRC at high switching frequency (500 kHz, 1kW converter). Thus, the transformer design is more(More)
This work is related to the improvement of the output impedance of the Buck converter by means of introducing an additional power path that virtually increases the output capacitance during transients. It is well known that in VRM applications, with wide load steps, voltage overshoots and undershoots may lead to undesired performance of the load. To solve(More)
In recent years, many converters are being proposed to be used like bidirectional. Some applications of these DC-DC converters can be battery charger-dischargers, hybrid vehicles, and DC-UPS. In applications like hybrid vehicles a high voltage DC bus to supply power to the motor is usually required. When the DC bus in hybrid vehicle is held by a big(More)
In this paper a novel bidirectional multiple port dc/dc transformer topology is presented. The novel concept for dc/dc transformer is based on the Series Resonant Converter (SRC) topology operated at its resonant frequency point. This allows for higher switching frequency to be adopted and enables high efficiency/high power density operation. The(More)