This paper proposes an analytical methodology that allows to assess rapidly the comparison of DC-DC converters. It was applied to evaluate two modular DC-DC structures, one isolated circuit and one non isolated circuit, focusing in the variation of the operating frequency for different DC voltage transformation ratios.

he paper describes the development of a power converter small scale mock-up and a real time model of an off-shore wind farm. A Power Hardware In-the-Loop validation is proposed for a demonstration of grid architecture and control principles. The paper presents the design methodology of the PHIL test bench and underlines the contribution of PHIL in the design flow of power converter development for DC grid application. Experimental results of preliminary PHIL tests are presented.

In this article, we focus on the condenser of a loop thermosiphon designed to cool power electronic component. The objective here is to condense Novec 649, our chosen working fluid for this loop. It is a fluid recently developed by 3M, which is known for having low environmental impact and non-flammable. We first present a theoretical analysis with the calculation and the hypotheses leading to the design of the multi-tubular condenser. Then we present a full size thermosiphon built for experimental validation. A discussion then addresses some of the design hypotheses. Three main parameters are studied : the tilting angle of the condenser (from horizontal to vertical orientations), the temperature of the coolant and finally the mass flow effect at different saturation temperatures. In our setup, we dissipate up to 2.4 kW at the evaporator level. The produced vapor is then condensed in the heat exchanger using cold water flowing at countercurrent. A number of measurements are made via thermocouples and pressure sensors located at both ends of the condenser to measure the average heat exchange coefficient.

This article presents the topology for non-isolated MMC-based DC-DC converter. The initial design study illustrates that such DC/DC converter will have overall semiconductor count comparable to a MMC AC-DC (used with HVDC transmission) converter of similar rating. A full controller schematic is presented and operating principles are discussed.

This paper proposes an in-depth analysis from the control point of view of dynamic models of a Modular Multilevel Converter (MMC) for high-voltage direct current (HVDC) application.