Davide Tarsitano

Plug-In Hybrid Electric Vehicle: Modeling, Prototype Realization, and Inverter Losses Reduction Analysis

Nowadays, the greatest part of the effort to reduce pollution emissions is directed toward the hybridization of automotive drive trains. In particular, the design of hybrid vehicles requires a complete system analysis, including the optimization of the electric and electronic devices installed on the vehicle and the design of all the mechanical connections between the different power sources to reach the required performances. The aim of this paper is to describe the design and prototype realization of a plug-in hybrid electrical vehicle (PHEV). Specifically, an energetic model was developed in order to analyze and optimize the power flux between the different parts. This model was experimentally validated using a prototype PHEV. In addition, in order to improve the driving range in an all-electric model (all-electric range), a detailed analysis of the inverter control was performed, because this component is one of the key components of the power train. In order to reduce inverter losses and dimensions, several control methods can be adopted. In this paper, a direct self-control strategy for reducing the inverter losses is presented and validated.

Analysis of electrical interferences related to the current collection quality in pantograph–catenary interaction

The dynamic interaction between a pantograph and a catenary influences the quality of the current collection; in particular, when two pantographs are used to collect current, the second pantograph is subjected to the disturbances originated on the overhead line by the transit of the first pantograph, generally causing a deterioration of current collection quality. Under these conditions, the occurrence of continuous sparking, contact loss, and arcing cause an increase of wear for both contact wire and collector strips, but also cause variations of contact voltage and feed current that in turn produce interferences on the on-board electrical systems like drive motors and signalling system. In order to investigate the latter, a procedure for the correlation of the quality of current collection with the level of electrical interference is proposed in this article. The procedure is based on experimental and numerical models combining relationships obtained by means of laboratory tests with simulation tools. An application to a real case of double pantograph collection is presented.

Energy control strategies comparison for a city car Plug-In HEV

In the last few year many control strategies regarding the energy management in Hybrid Electrical Vehicle (HEV) have been discussed. This paper aims to compare different strategies with a particular attention to Plug-In-HEVs (P-HEV) energy management algorithms. In facts many control strategies have been developed and discussed on traditional parallel HEV in order to find out the most efficient energy management of the Electrical Motor (EM) and the Internal Combustion Engine (ICE). The adoption of these control strategies on a P-HEV, with an oversized on board energy storage system (vs. traditional HEV), do not lead to a significant improvement of the global vehicle efficiency because they use the Electrical Motor (EM) only for short operation time and they consider all the energy stored into the battery produced by the ICE. Control strategies developed for traditional parallel HEV have been taken into account and they have been opportunely adapted in order to utilize the extra amount of energy stored into the batteries. A full energetic simulation model has been used in order to compare the performances of different control strategies. The P-HEV model has been specialized for the vehicle realized at Mechanical Dept. of Politecnico di Milano and it has been validated using experimental data.

Inverter loss minimization for a plug-in hybrid veihcle traction drive using DSC control

Plug-in hybrid electric vehicle can be very useful to improve fuel economy and reduce the level of pollution especially in the urban area. This kind of vehicle needs a large battery stack to assure a good autonomy distance range in pure electric (zero emission) operating mode. To make this possible the dimension and the efficiency of the whole power train have to be optimized. The inverter in the electrical traction drive is one of the key component in the power train. In this paper a method for evaluating and reducing the inverter losses has been presented.

Full energetic model of a plug-in hybrid electrical vehicle

Nowadays the greatest part of the efforts to meet fuel economy and to reduce pollutant emissions are directed toward the hybridisation of automotive drive trains. In particular the design of hybrid vehicles requires a complete system analysis including the control of the energy given from the on board source, the optimisation of the electric and electronic devices installed on the vehicle and the design of all the mechanical connection between the different power sources to reach required performances. The aim of this paper is to develop an energetic model for analysis, design and control of a plug-in hybrid electrical vehicle (PHEV) with particular attention paid to energy and power flux between the different devices. The model described in the following paragraphs has been experimentally validated on a Plug-in HEV, realized, in prototypal version, at the Mechanical Department of the Politecnico di Milano.

Plug-In Hybrid Electrical commercial Vehicle: Modeling and prototype realization

Nowadays the greatest part of the efforts to reduce pollutant emissions is directed toward the hybridification of automotive drive trains. Such topic has a particular relevance while looking at vehicles that operate in urban environment, like light commercial vehicles. In particular the design of an hybrid vehicle requires a complete system analysis including the optimization of the electric and electronic devices installed on the vehicle and the design of all the mechanical connection between the different power sources to reach required performances. The aim of this paper is to develop an energetic model to develop optimized strategies able to reduce pollutions emissions, design and control of a Plug-In Hybrid Electrical commercial Vehicle (PHEV) with particular attention paid to energy and power fluxes between the different devices. The model described in the paper has been experimentally validated on a Plug-in HECV, realized, in prototypal version, at the Mechanical Department of the Politecnico di Milano. The proposed validated model would be then exploited in order to develop an optimized energy management strategy with the aim to reduce pollutant emission of commercial vehicles that are used to deliver goods in urban areas.

Energy Recovering from Vibrations in Road Vehicle Suspensions

Over the last years, energy saving has become a very important issue. One possibility for limiting energy consumption is recovering it from systems where it is dissipated (energy harvesting). One of the most effective methods for implementing energy harvesting is to convert kinetic energy produced by mechanical vibrations into useful electric energy which can be stored in accumulators and then used to power sensors and/or active systems and/or on board auxiliary electrical loads. The application of an energy harvesting device to a road vehicle suspension system is presented in this paper. The device consists in a mass damper excited in resonance, a linear permanent magnet alternator and a power factor controlled rectifier (electromagnetic vibration driven generator). In a first stage of the research, the capability of the device of recovering energy from road induced vibrations of the suspension unsprung mass has been explored. The parameters of the device have then been tuned in order to optimize energy harvesting, taking into account the physical constraints concerned with the application (suspension geometry, electromagnetic vibration driven generator mass, etc.).

Modeling of the Internal Combustion Engine by Means of Willans Line Approach for the Study of Hybrid Electric Powertrain

The use of road vehicles has always represented a major contribution to the growth of modern society: it facilitates goods and people mobility, meeting most of the daily needs and it represents a backbone for the development of world economy, (i.e. the industrial field). Nowadays, this mean of transportation, however, given the high number of vehicles on the roads, has a negative impact both on the environment and on the quality of human life. Moreover it leads to an increase in additional costs (i.e. the costs related to environment pollution, global warming and depletion of resources). Such a negative aspect is due to the fact that the drive systems are often characterized by high variability of the load, hence the propulsion system works in areas with low efficiencies and high pollutant emissions. In order to overcome these problems, and to allow the compliance of the road transport system with new European guidelines (i.e White paper, and Horizon 2020), it is necessary to develop innovative technologies able to:- increase the overall powertrain efficiency;- introduce a sustainable alternative fuels strategy including also the appropriate infrastructure;- reduce carbon emission through a decarbonisation approach;In this perspective, in recent years, the technology of electric and hybrid vehicles has been developed, and nowadays it has become a feasible solution in the context of means of transportation. Car/truck-makers and operators look at further developments and innovation in this field in order to optimise the existing solutions and reduce the production costs.The current solution for hybrid vehicles aims to couple a conventional engine with an electrical motor; these two propulsion system are coordinated by an opportune algorithm in order to let the conventional engine operate in its higher efficiency range. Hence the technology foresees the action of endothermic and electrical motors. It is then pivotal for the success of this transport the optimisation of the whole system (electrical and endothermic) in terms of efficiency, sizing and of the control algorithm that coordinate the two propulsion systems. For the modeling of the internal combustion engine conventional approaches, based on the numerical simulation of the combustion process, cannot be used because of their complexity in term of time needed for computing activity. For hybrid power train the general approach to simulated a drive cycle, that usually last at least a few minutes, is based on engine map approach [1–2]. The main burden to the described process is the identifications of maps of torque and consumption for the internal combustion engine, which are normally not predictable in detail, nor are provided by the manufacturers, but they can only be determined by means of experimental tests. Such a process can become extremely expensive and time consuming. Hence in this work the concept of virtual optimisation is introduced basing on the identification of torque and fuel consumption maps for internal combustion engines on analytical methods considering the similarities with engine of the same class. In this regard, a model of the system is developed based on the “Willans Line Method” approach, subsequently to a theoretical definition of the model, the identification of maps is carried out for two different engines (one diesel heavy-duty engine and one spark ignition engine) in order to consider the existing configurations of hybrid vehicles. Eventually the calculated maps are validated considering experimental data from existing experimental campaign. Providing the validity of the method and its usefulness in the hybrid vehicle design.Copyright

A Study of Urban Electric Bus With Hybrid Energy Storage System Based on Battery and Supercapacitors

Nowadays considerable resources have been invested on low emission passenger vehicle both for private and public transportation. A feasible solution for urban buses is a full electrical traction system fed by supercapacitor that can be recharged at each bus stop while people are getting on and off. Such vehicle covers a short distance between consecutive stops, usually less than half a kilometer. An energy storage system able to provide high power peaks and small amount of energy is required. For these reasons, supercapacitors, which are capable of fast charging during bus stops, appear the most appropriate storage devices [1]. In order to consider the worst operating condition for the bus (like traffic jam of higher distance to be covered), a conventional battery is also installed, getting an hybrid energy storage system. An energy management function, able to manage the energy storage system, has been developed and validated by means of a numerical simulation model.Copyright

Torque Vectoring control for IWM vehicles

In recent years, the environmental concern generates an high improvement in hybrid and electrical mobility technology. Several layouts are available for the electric powertrain; the most interesting is the one with four electric motors, one per each wheel. The main interesting feature of this layout is the possibility of independently applying driving or braking torques on each wheel, i.e., torque vectoring control strategies can be fully exploited. An innovative control strategy for in-wheel motor (IWM) vehicles is developed and compared with a state-of-the-art control logic by means of numerical simulations. The proposed controller can increase vehicle performance and safety in cornering both on high and low friction conditions. The controller is made of two contributions: one, for steady-state cornering, is based on optimal control theory; the second, mainly for stability control, is based on a yaw index that does not need any vehicle model or estimation.