Parallel hybrid vehicles

The fuel economy of series and parallel hybrid vehicles are compared in Table 3 for both the com-... 

Comparisons of the Fuel Economy for Series and Parallel Hybrid Vehicles (1) Fuel economy shown lor diesel engines is gasoline equivalent... 

Michel, S., and Frank, A. (1998). Design of a Control Strategy for the Contiimously Variable Transmission for the UC Davis Future Car (Parallel Hybrid Vehicle). Department of Mechanical Engineering Report (September). Davis, University of California. 

The degree of hybridization is a useful parameter characterizing parallel hybrid vehicles. The value of this parameter is defined as the total power of the electric motor divided by the sum of the total power of electric motor and IC engine, according to the following equation ... 

The control strategies for dual mode hybrid vehicles are a combination of those used for series and parallel hybrids. There are so many possible hardware arrangements and associated control strategies, it is not possible to summarize them in a simple manner as was the case for series and parallel hybrids. The objective of the dual mode operation is to use the... 

A car company wants to design a battery for their hybrid vehicle. The battery requirement for this system is 300 V with a nominal capacity of 3.0 kW hr. Suppose they have a 5 A hr cell at 2.0 V. (a) How many cells will be required to make the required battery (b) How many cells will be in series and how many in parallel (Bhardwaj)... 

There is a large number of possible variations for the parallel hybrid configuration, besides that shown in Fig. 5.18, proposed by most of the major automobile companies. Some of them, for example, have a small electric machine in line with the crankshaft, where is usually located the flywheel in a IC engine vehicle. Another parallel hybrid configuration has the IC engine and the electric drive connected to different axles, as shown in Fig. 5.19, in particular in this case the IC engine drives the front wheels, the electric system the rear wheels and the road... 

Hybrid thermal vehicles are more expensive than traditional vehicles, because they include more than one energy source on board. However, there are some components of traditional vehicles which are not required for hybrid vehicles and can be made some savings. For instance, in the series conhguration there is no need for the gear box because the electric drive regulates the motor speed electronically, transmission is simplihed and differential is useless if the motors are directly connected to the wheels. The starter can be eliminated in both series and parallel conhguration since electric machines do not need any specihc devices to start. Many hybrid vehicles are currently on the market and this sector is growing rapidly worldwide. 

As part of an interdisciplinary study we are working on emission control catalysis for an extended parallel hybrid concept [1-5]. The main elements of the experimental car developed at the Swiss Federal Institute of Technology are the combustion engine, operating in a fixed cycle mode, a flywheel as a short term energy storage device, an electrical machine and a continuous variable transmission. One of the features of this hybrid vehicle is the so called intermittent... 

General requirements. The attributes in Table 11.20 are typical for parallel hybrid applications, and the attributes in Table 11.21 are typical for series hybrid vehicles. 

Controls and diagnostics for parallel-series hybrid vehicles. A typical set of control messages for hybrid vehicles is listed in Table 11.19. Although the variables are the same as those used in soft hybrids, the higher criticality of function implies that the calculated values, such as maximum source and sink currents, must be of even higher reliability if unexpected function fade or failure is to be avoided. 

High-voltage safety considerations require that the architecture of parallel- and series-hybrid vehicles include an integral BMM such that the battery can be controlled from within the pack. This assumes that the battery will be of an advanced design, such as Ni-MH, where safety requires fast, reliable, and self-contained communication with the contactor and charger. 

The cost dependency on a minimized cell size for Ni-MH and VRLA batteries is shown in Fig. 11.21. In these cases, VRLA is limited by life and Ni-MH is limited by power. At the energy levels required for parallel-series hybrid vehicles, it can be shown that the watt-hour life cost of Ni-MH would have to exceed 33 times that of VRLA, which is not the case even today with prototype batteries. The initial cost consideration that tipped the favour to VRLA for soft hybrids is far less impressive with parallel or series hybrids, since it can be further demonstrated that, even on an initial cost basis, VRLA is about 60% of the cost of the equivalent Ni-MH battery for the parallel-series application, well outside of the bounds where trade-off to initial cost could be considered. 

In a parallel-hybrid [Figure 7.2(b)], there are dual transmission systems a mechanical one driven directly by the engine and an electrical one driven by the electric motor. A parallel-hybrid corresponds to a conventional vehicle with a smaller engine and a larger battery. To date, most automotive manufacturers... 

Fuel cell hydrogen cars are not ready for the market but they represent another element in favor of electrification, that makes its future marketing possible as an alternative or in parallel with hybrid electric vehicles (HEVs) and battery-powered EVs. Therefore, at least three large families of products should be considered hybrid vehicles with internal combustion engines (ICEs) onboard, EVs powered by batteries recharged from outlets, and fuel cell hydrogen vehicles. 

The power-split hybrid configuration combines both serial and parallel hybrid structures, for example, by means of a planetary gear set. The power provided by an ICE is spht into a mechanical path driving the vehicle via the gearbox and an electrical path via an electric generator, a battery, and one or more electric machines... 

Figure J6.4 Series hybrid (a) and parallel hybrid (b) for fuel-cell hybrid vehicle. Reproduced from [14].

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