The search for fossil fuels substitutes forces the use of new propulsion technologies applied to means of transportation. Already widespread, hybrid vehicles are beginning to share the market with hydrogen-powered propulsion systems. These systems are fuel cells or internal combustion engines powered by hydrogen fuel. In this context, road tests of a hydrogen fuel cell drive were conducted under typical traffic conditions according to the requirements of the RDE test. As a result of the carried-out work, energy flow conditions were presented for three driving phases (urban, rural and motorway). The different contributions to the vehicle propulsion of the hydrogen system and the electric system in each phase of the driving route are indicated. The characteristic interaction of power train components during varying driving conditions was presented. A wide variation in the contribution of the fuel cell and the battery to the vehicle’s propulsion was identified. In urban conditions, the share of the fuel cell in the vehicle’s propulsion is more than three times that contributed by the battery, suburban—7 times, highway—28 times. In the entire test, the ratio of FC/BATT use was more than seven, while the energy consumption was more than 22 kWh/100 km. The amounts of battery energy used and recovered were found to be very close to each other under RDE test conditions.

Hybrid vehicles allow an increase in the powertrain efficiency thanks to their design. One such factor is the use of increased voltage supplying electric motors to the voltage supplying the high voltage battery. The battery voltage is increased several times in the inverter (boost) system to increase the final electric power supplied to the electric motor. The article presents the possibilities of using such a voltage boost in urban and non-urban driving conditions. The tests were performed on the latest generations of parallel hybrid drive systems in Lexus NX 300h and Toyota RAV4 hybrid vehicles. It has been shown that the boost system is used in about 30–40% of the urban drive distance (up to 20% of the driving time). The power supply voltage boost of the electric motors of both vehicles is used throughout the entire engine speed range of these machines at high torque values. Research has shown that the maximum voltage gain – approximately three times (up to 650 V) – is within the maximum torque range of the electric motors and allows for doubling the torque generated by the drive.

The development of internal combustion engines is currently based around the ideas of downsizing and rightsizing. These trends, however, are not very widespread in vehicles with hybrid drive systems. Nevertheless, the authors analyzed the performance indicators of hybrid drives in downsized vehicles. Two generations of a vehicle model, equipped with hybrid drive systems, were used in the analysis in which not only the design of the internal combustion engine was changed, but also other hybrid drive systems (including the transmission, electric motors and high-voltage batteries). The paper analyzes the energy flow in two hybrid vehicles of different generations during tests in real road driving conditions in accordance with the requirements of the RDE (real driving emissions) tests. The authors have confirmed that newer vehicle designs extend the vehicle range by 38% in the electric mode under the conditions of road traffic (68% in the urban conditions). The application of a combustion engine with better operating indexes did not result in its greater load, but led to limitation of the maximum pressure-volume (PV) diagram. The change of the battery to Li-ion, despite its lower electric and energy capacity, led to an increase in vehicle’s working parameters (power and regenerative braking).

The portfolio of the automotive market appears more and more low-emission and zero-emission propulsions in vehicles. This is the result of measures taken to limit or even eliminate the emission of harmful substances into the atmosphere generated by vehicles. The article covers issues related to energy conversion in automotive drive systems currently offered by automotive manufacturers. Standard, hybrid, hybrid plug-in, electric and fuel cells drive system were analyzed. Attention was drawn to the chain of energy transformations related to each of the analyzed drive systems. The efficiency of the presented vehicle drive systems was analyzed. General conclusions were formulated regarding the method of analyzing energy changes related to the operation of automotive propulsion systems. The article reviews selected author's own works on hybrid and hydrogen propulsions.

The article presents the issues of energy recovery in the hybrid drive system of a vehicle Toyota Yaris 1,5 Hybrid. Road tests of a vehicle equipped with a hybrid drive system were carried out in accordance with the recommendations of the RDE test. In these studies, measurements of braking energy recovery were carried out in urban, rural and motorway traffic conditions. The analysis of the obtained test results may constitute a premise for the creation of an appropriate strategy for the operation of the hybrid drive system in terms of meeting the requirements of the currently prepared Euro 7 standard.

Monografia dotyczy rozwoju wybranych źródeł napędu pojazdów samochodowych, które mogą stanowić alternatywę dla standardowego, tłokowego silnika spalinowego. W pracy przedstawiono genezę powstania i zasadę działania różnego typu hybrydowych systemów napędowych oraz systemów elektrycznego napędu pojazdów wykorzystujących zasilane wodorem ogniwa paliwowe. Podkreślono rolę hybrydowych układów napędowych jako ogniwa pośredniego w rozwoju konstrukcji pojazdu w drodze do pełnej elektryfikacji systemów napędowych. W monografii dokonano wnikliwej analizy tego typu układu napędowego obejmującej zarówno opis rozwoju konstrukcji na przestrzeni ostatnich lat, jak i wyniki badań naukowych przeprowadzonych z udziałem autora opracowania. Ważnym elementem uzupełniającym pracę jest omówienie zagadnień związanych z produkcją wodoru, metodami jego oczyszczania, a także przechowywaniem na pokładzie pojazdu oraz transportem z zakładów produkcji do stacji dystrybucji. Istotną część opracowania stanowi ponadto dyskusja poświęcona bezpieczeństwu eksploatacji pojazdów wyposażonych w układy napędowe zasilane wodorem. Prezentowane w monografii treści w dużej mierze opierają się na doświadczeniu zawodowym autora, a także na wiedzy pozyskanej podczas udziału w badaniach naukowych tego typu pojazdów.