Belt Starter Generator Research Articles

Integration of a Belt Starter Generator in a Flex-Fuel Vehicle

<div>The concern with global warming has led to the creation of legislation aimed at minimizing this phenomenon. As a result, the development of technologies to minimize vehicle emissions and reduce fuel consumption has gained market share. A promising alternative is the use of a belt starter generator (BSG): an electric machine to replace the vehicle’s alternator. This research analyzes the effects of introducing a 12 V BSG into a flex-fuel vehicle, specifically examining its impact on fuel economy and CO<sub>2</sub> emissions when using both gasoline and ethanol. The utilization of a low-voltage BSG in a flex-fuel vehicle has not been previously studied. Numerical simulations and experimental fuel consumption and CO<sub>2</sub> emissions tests were performed for the normal production flex-fuel baseline configuration and the vehicle with the 12 V BSG, following the standards ABNT NBR 6601 and ABNT NBR 7024. The use of the BSG led to a 10.06% reduction in CO<sub>2</sub> emission in the urban cycle for the vehicle running on gasoline and a 6.28% reduction in energy consumption in the combined cycle. The results demonstrated that the low-voltage BSG is a promising solution for reducing fuel consumption and GHG emissions in flex-fuel vehicles. The electrical machine installation required minimal modifications to the vehicle and had a low adaptation cost. The BSG can also improve vehicle performance and drivability.</div>

Software strategy for internal combustion engine and electric motor control on a hybrid electric vehicle equipped with belt starter generator and automated manual transmission

In order to fulfil the latest EU emission standards, the average amount of CO2 emissions for each vehicle sold has to be reduced to avoid fines for manufacturers. One of the simplest and cheapest ways of hybridization is the belt starter generator (BSG), which makes it suitable for an entry-level range of vehicles. This paper presents a software strategy developed for internal combustion engine (ICE) and belt starter generator (BSG) control on a vehicle equipped with automated manual transmission and also the drivability, comfort and emission performances improvements expected by using this strategy.

Internal Combustion Engine Starting and Torque Boosting Control System Design with Vibration Active Damping Features for a P0 Mild Hybrid Vehicle Configuration

In order to meet the increasingly stricter emissions’ regulations, road vehicles require additional technologies aimed at the reduction of emissions from the internal combustion engine (ICE). A favorable solution from the standpoint of costs and simplicity of integration is a 48-V electrical architecture utilizing a low-voltage/high-power induction machine, which operates as the so-called engine belt starter generator (BSG) coupled via a timing belt with the ICE crankshaft within a P0 mild hybrid power train and used for starting up and boosting of the ICE power output, as well as for recuperating kinetic energy during vehicle deceleration. The aim of this work was to design a vibration damping system for the belt transmission within the so-called front end accessory drive (FEAD), which couples the BSG with the ICE crankshaft and to test the control system by means of simulations for realistic operating regimes of the P0 mild hybrid power train in order to show the functionality of the proposed approach in terms of mild hybrid vehicle performance improvement. Simulation results have pointed out effective attenuation of belt compliance-related vibrations using the proposed active damping control, with vibration magnitude reduced between three and five times compared to the default case during engine start-up phase. They have indicated the realistic belt slippage effects during engine start-up phase and have illustrated the effectiveness of the FEAD torque boosting capability with 30% gain in acceleration during vehicle launch.

Nonlinear Model Predictive Control of Mild Hybrid Powertrains With Electric Supercharging

Energy management plays a decisive role in the design of efficient 48V mild hybrid drives owing to the limited amounts of energy and power. In particular, strong nonlinearities of an electrified engine air path and the high interaction between the 48V mild hybrid powertrain and the electrical system pose a major challenge. Current research results show the fundamental potential of optimization-based energy management strategies. However there is a lack of optimization-based solutions that allow online direct control of the electrified air path and the electric motor. In this context, this study presents a nonlinear model predictive control (NMPC) approach for a 48V mild hybrid powertrain with an electric supercharger, which is able to simultaneously improve the response behavior and energy consumption. The control concept is developed on the basis of a detailed system description. The special features of optimization-based control for the degrees of freedom of the powertrain, i.e., the belt starter generator (BSG) and the electrified air path through a throttle, waste gate, and electric supercharger (eC), are addressed. After an analysis and verification of the control properties, the NMPC is evaluated in dynamic driving cycle simulations through a comparison with a state-of-the-art rule-based control strategy. The investigations show that the NMPC is able to control the system well even under transient situations with a high influence of disturbance variables. In addition, the NMPC allows a specific and fuel saving use of the 48V system while improving the driving dynamics at the same time.

Hybrid Power System Design for Multifunctional Mini-Loader Vehicles

This study presents the improvement of energy efficiency and operating time of mini-loader vehicles by integrating the power system of internal combustion engines (ICE) and electric motors (EM). The hybrid powertrain was developed based on the belt-starter generator (BSG). The BSG system enabled us to choose optionally the ICE or the EM mode according to the power demand in different usage scenarios. The required power specifications were evaluated. The equipment in conformity with specification was then tight-stacking installed in the limited space of the mini-loader. Therefore, the mini-loader ably passes across a 770 mm width door. In the situation of consumption of the same amount of gasoline, the hybrid power mode can increase the operating time by 30 min. In addition, its power output can be satisfied to override 140 mm high short steps, cross a 300 mm trench, and climbing a 30% slope. In particular, using electricity as a power source can reduce carbon emission.

Numerical Investigation of 48 V Electrification Potential in Terms of Fuel Economy and Vehicle Performance for a Lambda-1 Gasoline Passenger Car

Real Driving Emissions (RDE) regulations require the adoption of stoichiometric operation across the entire engine map for downsized turbocharged gasoline engines, which have been so far generally exploiting spark timing retard and mixture enrichment for knock mitigation. However, stoichiometric operation has a detrimental effect on engine and vehicle performances if no countermeasures are taken, such as alternative approaches for knock mitigation, as the exploitation of Miller cycle and/or powertrain electrification to improve vehicle acceleration performance. This research activity aims, therefore, to assess the potential of 48 V electrification and of the adoption of Miller cycle for a downsized and stoichiometric turbocharged gasoline engine. An integrated vehicle and powertrain model was developed for a reference passenger car, equipped with a EU5 gasoline turbocharged engine. Afterwards, two different 48 V electrified powertrain concepts, one featuring a Belt Starter Generator (BSG) mild-hybrid architecture, the other featuring, in addition to the BSG, a Miller cycle engine combined with an e-supercharger were developed and investigated. Vehicle performances were evaluated both in terms of elasticity maneuvers and of CO2 emissions for type approval and RDE driving cycles. Numerical simulations highlighted potential improvements up to 16% CO2 reduction on RDE driving cycle of a 48 V electrified vehicle featuring a high efficiency powertrain with respect to a EU5 engine and more than 10% of transient performance improvement.

Investigation on the performances of a twin arm tensioning device

In the present work, an experimental analysis of the performances of a twin arm tensioner is conducted. The investigated device is used in an automotive belt drive system mounting a belt starter generator. This configuration represents the latest trend of micro-hybrid technologies and is devoted to keep the tension of the belt within a reasonable range, while obtaining the highest possible efficiency in both motor and generator modes. At first, the functionality of a twin arm tensioner is investigated with a static model. Afterward, the performances of a real tensioner are experimentally assessed through a dedicated test rig in quasi-static conditions. The system is benchmarked in terms of angular displacement of the tensioner arms, belt tensions on the corresponding spans, and sliding arc in different operating conditions. Finally, experimental and simulation results are compared. It is shown that the proposed static model is able to capture the behavior of the real device and highlight its functionality.

Potential fuel saving in a powertrain derived from the recovery of the main energy losses for a long haul European mission

The reduction of automotive fuel consumption and emissions remains one of the main challenges. This paper presents the potential fuel saving in a CNG-powertrain derived from the recovery of the main energy losses. The analysis includes the kinetic energy recovery by a belt starter generator (BSG), the exhaust gas waste heat recuperation by using in a cascade approach, a thermoelectric generator (TEG) and a turbo-generator (TBG)- and the electrification of the main auxiliaries. An additional 48V board net as well as the addition of a storage system are also included in the study. To support on the design phase of the project and in the operation strategy, a dynamic model in Matlab/Simulink® has been used. The model includes all the new components/major changes required in the vehicle- experimentally validated-. It has been used on backward simulations for the ACEA long haul mission in order to maximize the vehicle’s efficiency.Estimations at rating point (600Nm and 1200rpm) result in an electric production up to 4kWh and a fuel saving of 7.5%. The most convenient technologies in the ACEA cycle turns out to be the KERs followed by the TBG.

Intelligent Belt Drive Systems in Hybrid Powertrains: a Multipurpose Test Rig

Abstract: In traditional engine setups Belt Drive Systems (BDS) are in charge of power transmission from the crankshaft to the accessories. They are complex and critical dynamic mechanisms, involving contact mechanics and vibration phenomena. The hybridization of vehicles has increased the severity of the operating conditions of these systems that have become even more critical. The traditional alternator was substituted by a Belt-Starter Generator (BSG), an electric machine that can power the BDS in particular operating conditions to improve the Internal Combustion Engine (ICE) performance or to allow regenerative braking. The aim of the present work is to describe the design and the main characteristic of a test rig conceived to investigate in laboratory environment on the behaviour of belt drive systems in dynamic conditions. Two permanent magnet electric motors are used to replicate the dynamic behavior of crankshaft and BSG in a realistic, though controlled and repaetable, manner.

Concept Layout and System Simulation of a 48-V Diesel Hybrid

In order to take the next step in CO2 reduction for diesel drivetrains, further electrification is a viable option. This raises the question: How much electrification — defined here in terms of system voltage — is necessary? To answer this question, a simulation was performed on theoretical recuperation potential with different e-motor power ratings. Here the NEDC was used as it represents the currently defined requirement. Boundaries of the simulation were a belt-starter-generator (BSG) architecture and no limitation due to energy storage capacity. The result of this simulation is shown in ➊. 100 % would mean that all the potential resulting from the deceleration phases could be used. Based on a current 12-V system, a certain limitation of about 20 to 30 % recuperation potential is experienced. Installing an electric motor in the range of 10 kW opens further recuperation potential of up to 80 % as well as further CO2 reduction. However, this exceeds the limits of the standard 12-V electrical system and requires a higher voltage level of 48 V. Open image in new window ➊ NEDC recuperation potential With a 48-V electrical system available a further step can be taken with the integration of an electric supercharger in order to increase low-end torque performance and dynamic response. Increased costs needs to result in further customer benefits besides the reduction in fuel consumption in order to create an attractive product for the market. Therefore, it was decided to additionally increase the power rating of the internal combustion engine while keeping single stage boosting. In ➋ the general strategy to reach the goal in terms of CO2 reduction by 20 % and increased fun to drive is described. Starting with the base engine definition as available on the market, the fuel consumption can be reduced by downsizing, and/or downspeeding; which compromises fun to drive. By replacing the standard turbocharger with a larger one the rated power was increased by 25 %. The further adaptation of a BSG with approximately 10 kW improves the performance from standstill significantly and the additional implementation of an electric supercharger assists in transient conditions, providing a level of fun to drive comparable or even better than the base engine. Open image in new window ➋ Generic roadmap towards improved fuel effi ciency and fun to drive The figures above serve as a general starting point for the considerations to follow. Finally, the realistic CO2 potential will be discussed after going through the system definition step-by-step.