Jesús Sallán

Optimal Design of ICPT Systems Applied to Electric Vehicle Battery Charge

Although the use of inductively coupled power transfer (ICPT) systems for electric vehicle battery charge presents numerous advantages, a detailed design method cannot be found in the literature. This paper shows the steps to follow in the optimized design of an ICPT system and the results obtained in their application to the four most common compensation topologies, pointing out the best one in terms of minimum copper mass and proper stability conditions. A new design factor K D is proposed to select the optimum configuration for each topology. Finally, the theoretical results are validated on a 2-kW prototype with a 15-cm air gap between coils.

High-Misalignment Tolerant Compensation Topology For ICPT Systems

Inductively coupled power transfer systems (ICPT) are an interesting alternative to conductive solutions for vehicle battery charge, particularly in electric public transport applications if operator-free fast charge is required along the route. To perform this task using ICPT systems, current solutions require an almost perfect alignment between coils in order to have optimal power transfer. This condition makes necessary a precise positioning maneuver from the driver or an electromechanic alignment system for the secondary winding, causing the process to be slow. This paper shows that it is possible to transfer rated power even with high misalignment if a suitable compensation topology is selected. The performance of the four basic compensation topologies is analyzed, and a series-parallel-series (SPS) topology is proposed, showing a suitable behavior for both the load and the power source. The theoretical results are validated in two series-series and SPS 2-kW prototypes with a 15-cm air gap between coils.

Practical Development of a 5 kW ICPT System SS Compensated with a Large Air gap

A 5 kW ICPT system with a large air gap of 20 cm has been developed and built for a battery charger of electric vehicles. The practical sizing, the best compensation topology and the operational frequency have been studied in order to get the maximum efficiency of the system. The study has been focused in showing the process of the prototypes implementation, validating the theoretical results and analyzing the influence of the frequency deviation with respect to the resonant frequency and the variation of the distance between the two coils in the behaviour of the system.

Development of a new connection scheme for variable-speed wind turbines using squirrel-cage generators

Nowadays it is mandatory for wind generation facilities to meet grid requirements much higher than the ones they had to comply with in the past, due mainly to the desire for an increase in the penetration of this type of energy source (S.A. Papathanassiou and N.D. Hatziargyriou, 2001). These requirements, along with the desire of variable speed operation, makes necessary the use of power electronics in the connection to the grid, by means of different topologies depending mainly on the type of generator used (induction, both doubly-fed or squirrel cage, or synchronous). The paper presents the development of a new connection scheme applied to a variable speed generation system using a squirrel cage machine, whose main goal is to increase the effective switching frequency in the grid side, in order to reduce the harmonic content of the injected currents

FABRIC's approach towards the estimation of energy storage system requirements for grid impact reduction

In recent years there has been a significant turn towards the research and development of electric vehicles. There are several government incentives towards decarbonizing the transport sector which is a major atmospheric pollutant via greenhouse gases that conventional ICE gasoline and petrol-fueled vehicles produce during their operation. In parallel, major vehicle manufacturers have introduced hybrid and fully electric vehicles to the market trying to reach the critical mass of buyers that will result to large penetration of electromobility in the transportation sector. EVs are expected to have a significant impact on future energy supply and distribution systems since the energy required for the propulsion of millions of vehicles will be shifted from fossil fuel to electricity provided by the grid. The increased demand and the characteristics of the load, especially for new FEV charging modes such as stationary and dynamic dictate big investments towards the enlargement of grid capacity, the increased integration of ICT towards the creation of smart grids and installation of technical solutions that will reduce the impact FEVs will have on the grid stability. This paper presents the concept of FEV dynamic charging which is the focus of FABRIC IP, makes an initial assessment on the foreseen impact this charging mode will have on the grid and proposes technical solutions for increasing grid stability.

Efficiency improvement in wind turbines by increasing speed range using a tandem connection scheme

The paper describes the use of a tandem power electronic configuration in variable speed wind turbines to improve efficiency by allowing an increase in both rotational speed and maximum power sent to the grid. First, the possible increment in power is determined, limiting both current and losses in the machine to their rated values, but allowing an increase in terminal voltage. Next, the increment in captured energy for different wind distributions is assessed. Finally, the required power rating of the converters in the secondary system is estimated, taking into account that in the proposed system they have the extra task of extracting from the generator and sending to the utility the extra generated power.