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A Systematic Approach to the Development of the Automotive Electrical Power System Architectures
Abstract and Figures
Throughout the automotive industry, the average electrical load on the electrical power supply system has been growing rapidly over the last decade. The main reason for this trend is the drive to replace the existing hydraulic, pneumatic and other mechanical systems with electrically powered systems to improve fuel economy. Such systems require more electrical power and it is anticipated that future passenger cars will require alternators operating at high power levels in the range of 4kW to 5kW by 2010.
To overcome the problem, a 42V/14V automotive electrical power system is necessary to meet these requirements. Moreover, through modelling and simulation of sub-systems and then the whole system, automotive manufactures can reduce manufacturing costs in terms of reduced delivery time of products, improved engineering development processes and gain a competitive advantage.
In this thesis a novel and an attractive complete centralised dual-voltage system architecture with a single battery, which incorporates a new 42V alternator and a six-cell interleaved dc/dc converter, has been developed. A detailed list and a thorough examination have been made of the automotive electrical loads that are present on the passenger cars and those expected to be introduced in the future. Modelling and simulation of the new 42V alternator system which substantially improves the present Lundell alternator design has been developed. Inherent load-dump transient suppression has also been achieved. Detailed modelling and simulation based on a six-cell interleaved dc/dc converter has been developed.
The simulation results demonstrated the high performance features of the dc-dc based architecture system in meeting the future predicated load demand and it also leads to a reduction in weight and volume of wire harness components as well as fuel saving while at the same fulfilling the standards regarding dual-voltage automotive electrical power system specifications.
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... The generated energy is used for the on-board electrical network in the cars. Because of new electricity demands in cars, such as entertainment and telecommunication, the energy consumption of the on-board electric network in the car is increasing [29], [31]- [33]. ...
... The load scenarios are depicted in Fig. 8. Buses 4,7,8,14,24,25,29,30,31, and 32 are capable of controlling their loads. These buses can only perform load shedding. ...
The severe impact of natural disasters on distribution system (DS) infrastructure highlights the importance of enhancing the resiliency of such systems. The loss of critical loads, one of the worst results of these events, increases the significance of resilient restoration approaches. In addition to distributed generators (DGs), which are common resources in restoration schemes, internal combustion engines (ICE) cars can considerably affect DS resiliency. This paper first introduces an idea for using ICE vehicle as energy resources in a DS to enhance the system’s flexibility during restoration efforts after natural disasters. The amount of electrical consumption of modern cars and the availability of home inverters makes this idea practical. In addition, a novel comprehensive method is proposed based on the optimal formation of dynamic microgrids (MGs) that satisfies operational constraints and considers the ICE vehicles and is not based on path-based or children-parent nodes concepts. Moreover, the proposed method considers the integration of DGs in one microgrid. The proposed method is based on two-stage stochastic mixed-integer linear programming (MILP), and considers uncertain load consumption and demand response (DR). Finally, the effectiveness of the proposed method is evaluated using a modified 33-bus IEEE test system. The results show that integration of DGs leads to restoring more loads. Moreover, distribution and selection of the buses corresponding to ICE cars affect directly on the amount of restored load. Budget limitation is also considered in this paper. Evaluation of the proposed method shows the considerable effectiveness in increasing the resiliency of DS.
... A detailed list of the electrical loads, with their typical power and current requirements at various voltages are analytically analyses using Excel software with an attempt to forecast the power requirement for the immediate future demand, is to be found in [9]. ...
... The transient is induced by disconnecting the 36V battery to initiate the load dump transient at time t=0.01s. The peak transient voltage on the 42V bus seen in Figure 7is approximately 54.46V which is less than the 74.8V peak voltage observed with single 42V power system architecture [9]. The reason for the relative stability is due to the remaining of the 14V loads. ...
This paper presents the technical development, modelling, analysis and simulation of a 42V/14V dc/dc converter based architecture for dual/high voltage automotive electrical power system. It overcomes some of the limitations of traditional automotive electrical power system topology that use 14V power net. The proposed system simulation model composed of a 4kW/42V power generation system buffered by a 36V energy storage battery and a 1kW/14V interleaved six-phase buck converter. The effectiveness of the developed model of the complete dc/dc converter-based centralised system architecture is verified through simulation results using control-oriented simulator, MatLab/Simulink.
... Based on the switching frequency, input/output voltages and the duty ratio, the inductance value to guarantee that the converter cells would run in the continuous conduction mode over the entire operating range can be calculated using (1) [14] o o i max s Simulation time (s) ...
This paper focuses on modeling, analysis and simulation of a 42V/14V dc/dc converter based architecture.
This architecture is considered to be technically a viable solution for automotive dual-voltage power system for passenger car in the near further. An interleaved dc/dc converter system ischosen for the automotive converter topology due to its advantages regarding filter reduction, dynamic response, and
power management. Presented herein, is a model based on one kilowatt interleaved two-phase buck converter designed to operate in a Continuous Conduction Mode (CCM). The control strategy of the converter is based on a voltage-mode-controlled Pulse Width Modulation (PWM) with a Proportional-Integral-
Derivative (PID). The effectiveness of the interleaved step-down converter is verified through simulation results using control oriented simulator, MatLab/Simulink.
... During each of the six intervals, only two diodes conduct with the assumption that the amount of the short period of the "overlap" is zero. The mathematical model for operational characteristics of the circuit model of the synchronous generator connected to the full-bridge diode rectifier driving a constant-voltage load [3,4] and its equivalent circuit model is shown in fig. 3. Where Vg is the internally generated voltage and Zg the total synchronous impedance and given by (2). ...
The increasing demand for more fuel efficiency and environmentally friendly cars coupled with the consumers' drive for more comfort, safety and luxury has led to the introduction of more electrical and electronic systems in the passenger car. This is further impacted by the current trend in automotive industry to replace mechanical and hydraulic systems with their electrical counterparts. The handling capability of the current 14 V DC system is getting very close to reaching its limits. To meet the new growing electrical power demands with minimum fuel consumption and minimum environmental effects, the automobile industry is looking into increasing the present voltage threefold, from 14 V to 42 V for future cars. In this paper, a detailed mathematical model for a 3-phase bridge rectifier, 4 kW/42 V power system, Lundell alternator average electrical equivalent circuit will be presented along with the alternator performance curves and analyse of the effect of the converter commutation on the supply current characteristics. The developed 42 V automotive power system is implemented using control-oriented simulators (MatlabSimulink) modelling techniques to assess the effectiveness of the model and its transient behaviour. The dynamic behaviour of the alternator in terms power, voltage, load/supply currents to sudden load changes is presented. In addition, the design of a voltage limit circuit to minimize the load-dump and supply current transients will be discussed.
An optimization approach for automotive power semiconductor switch module with shunt resistor using an inlay printed circuit board (PCB) is proposed in this study to analyze electrical and thermal characteristics under a given maximum temperature rise constraint. The final module with a shunt resistor and current measurement block is designed and manufactured by adopting the optimization results. The performance is measured and compared with a conventional module without a shunt resistor, which was manufactured before optimizing. The number of MOSFETs used in the module decreased from six to four while satisfying a maximum temperature rise of 20 °C. Therefore, optimization increases the price competitiveness of the power module.
In the near future a significant increase in electric power consumption in vehicles is to be expected. To limit the associated increase in fuel consumption (and CO2 emission), smart strategies for the generation, storage/retrieval, distribution and consumption of the electric power can be used. This paper presents a preliminary case study based on a Model Predictive Control-based strategy that uses a prediction of the future driving pattern and load request in order to minimize fuel use by generating only at the most efficient moments. The strategy is tested in a simulation environment, showing a decrease in fuel consumption compared to a baseline strategy.
Throughout the history of the automotive industry, the average load on the electrical system has been increasing model year by model year. The main driver of this trend has been the increasing use of electric power due to the increasing level of equipment on the average vehicle. The electric power system of a modern vehicle has to supply enough electrical energy to drive numerous electrical and electronic systems and components. Usually, the electric power system of a vehicle consists of two major components, an alternator and a battery, with supplementary control systems sometimes used to aid system operation. For vehicle power supply analysis, a detailed understanding of the operational characteristics of the major components and how they interact as a part of the electric power system, including environmental and road conditions, is essential if the analysis is to aid system optimization.
In this study, a simulation tool has been developed using SABERA ® to enhance the process of vehicle electrical power system design, development, and optimization, which is becoming important as more electrical features are added to future vehicles.
The electric power system of a modern vehicle has to supply enough electrical energy to drive numerous electrical and electronic systems and components. The electric power system of a vehicle consists of two major components: an alternator and a battery. A detailed understanding of the characteristics of the electric power system, electrical load demands and the operating environment, such as road conditions and vehicle laden weight, is required when the capacities of the generator and the battery are to be determined for a vehicle. In this study, a battery-alternator system has been developed and simulated in MATLAB/Simulink, and data obtained from vehicle tests have been used as a basis for validating the models. This is considered to be a necessary first step in the design and development of a new 42 V power supply system.
The electrical power system is the vital lifeline to most of the control systems on modern automobiles. The following general trends are observed. (a) increased use of electrically actuated systems, (b) increased use of electronic control, (c) increasing requirements for high-integrity power supplies for safety critical systems, (d) increased average electrical power consumption (heating, actuation, control systems), (e) increased electrical demand at engine idle combined with reducing idling speeds, (f) increased interest in higher voltage systems, (g) electrical system problems a major cause of roadside breakdowns. These trends clearly indicate major changes in the requirements of vehicle electrical power supply systems and will demand considerable activity from the vehicle industry in the next decade. An important aim of this paper is to illustrate and promote a systems view of electrical power while considering existing and future problems and opportunities.
Such additional electronics results in a need for more electrical energy in automobiles and other vehicles. Because of this increase in electrical load, higher power demands are being placed on automotive alternator systems. It would, therefore, be desirable to provide a means by which the power output capability of an alternator can be increased. In this paper the author presents several solutions for improving the performances of power equipment, and mainly, of power sources from automotive. Still, considering the broad spectrum of the problem and the complexity of the domain, the solutions proposed by the author represent just a small part of the multitude of possible approaches of this theme and a starting point for further developments of these solutions because the present, high-reactance Lundell-type alternators with diode rectifiers and field control are widely used in the automotive industry
Electric engineering has been applied to the automobile since the 19th century when the automobile was invented. It was first for the ignition system, then a variety of electrical facilities such as for the starter, headlights, wipers, etc., were developed. At present, the battery has become indispensable for the automobile. The invention of the transistor, in 1948, brought about rapid progress of microelectronics technology, involving IC, LSI, and the microcomputer. Such technologies are now widely adopted for various functions of the automobile. This paper discusses (i) the role of electronics in the automobile, especially current and future automotive electronic systems; (ii) the electric power-supply and starter; (iii) the electrical needs of the battery.
This paper concerns the development of a full dynamic model for a integrated starter alternator (ISA) employing an induction generator, for potential use in the future automobiles. The model includes a direct rotor flux oriented controlled (DFOC) induction machine drive, which is operated in both motoring and generating modes (i.e. starter and alternator modes). During the starting, the induction machine cranks the engine with high starting torque against the engine restoring torque. When the speed of the engine is increased to a certain value that ensures the complete starting of the engine, the control system changes the induction machine into the generation mode. In the generation mode, the power is input to the machine from the automotive engine which is modeled as an infinite source of torque. The DC bus voltage is maintained at 42 V. The operating speed of the modeled ISA can be varied, with field weakening starting at the machine base speed. The model successfully allows many operational aspects of the proposed ISA to be predicted, in particular the regulated DC voltage developed by the ISA during conditions of load dump step speed increase.
This paper describes the concept, design, modeling, simulation and performance of an innovative fast field regulator developed for a high-power 42 V automotive generator, to minimize the load-dump energy and improve its reliability. In laboratory tests, a 3 kW 42 V Lundell generator, with conventional field regulator, failed the load-dump transient test. This research analyzed the root cause of the failure by analyzing the load-dump energy, using SABER modeling and simulation, which have been verified by tests. Various concept alternatives for minimizing the load-dump energy have been identified and an innovative and cost-effective solution based on fast field control was selected for development of the proof-of-concept hardware. The proposed technique reduced the load-dump transient duration by more than a factor of 5, resulting in a reduction of load-dump energy by more than 75%. This eliminated the need for paralleling multiple avalanche diodes in the alternator rectifier bridge to handle the transient energy, resulting in a smaller package and increased reliability at a lower cost. The proposed fast field control can be further applied to minimize the load-dump transients in all belted alternator starters (BAS) that use a wound-field machine.