Combined electric applications in transport

Maximizing the efficiency in transport vehicles will be a necessity. This may be realized by introducing a power electronic conversion between the Internal Combustion Engine (ICE) and the wheels. Hence the ICE may be used at its maximal efficiency point. One still can choose the kind of fuel: liquid or gas hydrocarbons, hydrogen, alcohol. The ICE delivers electrical power by means of a high efficiency generator and rectifier Further on one can recover electrical energy from the exhaust thermal power by means of a bottom cycle. A solution is to use an organic rankine cycle for this. The motion itself is done by high efficiency converters and permanent magnet motors. One can reduce gear losses while using direct drive wheel motors. In ships one can also optimise the propeller and the number of propellers

Light and ultralight electric vehicles

Today electrical vehicles are again considered seriously. However, one is not yet used to their performance. An overview is given in what one can expect from electric vehicles, ranging from electric bicycles to the electrical SUV. Special attention is given to the possibility of ultralight electric cars and the elbev concept, “Ecologic Low Budget Electric Vehicle”. Together with high efficiency power plants, a CO2 emissions of about 10gr/km could be obtained

Designing power inductors: practical solutions

An overview of losses and thermal aspects if power inductors is given. Most of the time core losses are given only for sine square wave, but users use it in square waves. Also bulk currents affect losses in larger inductors. Usually the transverse field is dominant for eddy current losses in conductors. Some heat drain improvements are proposed. Large power inductors could benefit of rectangular coil formers on demand

Influence of the amount of permanent-magnet material in fractional-slot permanent-magnet synchronous machines

The efficiency of permanent-magnet (PM) synchronous machines with outer rotor and concentrated windings is investigated as a function of the mass of magnets used, keeping the power, volume, and mechanical air-gap thickness constant. In order to be useful for electric vehicle motors and wind turbine generators, the efficiency is computed in wide speed and torque ranges, including overload. For a given type and amount of magnets, the geometry of the machine and the efficiency map are computed by analytical models and finite-element models, taken into account the iron loss, copper loss, magnet loss, and pulsewidth-modulation loss. The models are validated by experiments. Furthermore, the demagnetization risk and torque ripple are studied as functions of the mass of magnets in the machine. The effect of the mass of magnets is investigated for several soft magnetic materials, for several combinations of number of poles and number of stator slots, and for both rare earth (NdFeB) magnets and ferrite magnets. It is observed that the amount of PM material can vary in a wide range with a minor influence on the efficiency, torque density, and torque ripple and with a limited demagnetization risk

Eddy current based, contactless position transducer for a gas handle

In electric vehicles, it is normal to have an electronic set value for 'gas' and for 'brake'. Traditional potentiometers with sliding contacts are not reliable. Magnetoresistive sensors or hall effect sensors need a magnet on the moving part. The proposed sensor just needs iron on the moving part. It uses an oscillator circuit where the absorbed current is an indication of damping, so how close the iron is to the sensor. The component cost is low and the output has a soft gradual change with the displacement

Electric cars compared to ultra-light electric vehicles and global warming

Although some effort has been done, if the full global warming effect is considered, also the parasitic methane emissions should be taken in account and not only CO2 for electric vehicles. Not just -20% (2020), but big changes are needed to counter the global warming problem. Drastic solutions are ultralight electric vehicles instead of the actual heavy ones. If the technology is well developed, it can reduce CO2 emissions by a factor 5 compared to usual electric vehicles (2050 target). It has also effect on the indirect CH4 emissions in electricity, but also at tire dust, which might be even the biggest source of particulate matter PM10-PM2.5. A vehicle concept F2E for two electric is proposed, towards a very good compromise between energy, comfort, cost, global warming and pollution

Electric vehicle possibilities using low power and light weight range extenders

Electric cars have the disadvantage of a limited range, and drivers may experience a range anxiety. This range anxiety can be solved by adding a range extender. But, the range extender should be light so as not to significantly increase the weight of the original vehicle. In urban areas with dense traffic (usually developing countries), the average speed around cities is typically lower than 50km/h. This means, the rolling resistance losses are more important than aerodynamic losses, and a weight reduction results in a bigger electrical range. Therefore, smaller and lighter range extenders are of much interest. The contribution of this paper is to indicate the possibility of range extenders with less than 25 kg with a capacity of 150 to 200 cc to suit a condition where weight counts. In this paper, the cost, environmental and grid impacts of going electric are also discussed. The effect of high altitude and driving style on the performance of an electric vehicle is assessed. The challenges and opportunities of vehicle electrification between countries with decarbonated power generation and fossil fuel dominated power generation are highlighted. Throughout the article, the case of Ethiopia is taken as an example