Starter Generator Research Articles

Modeling and Simulation of an Integrated Starter Generator Based on PMSM with SVPWM Strategy for Engine Starting and Battery Charging

The modelling and simulation of an integrated starter generator (ISG) system with 48 and 12-volt DC power setup for use in automotive applications is presented in this paper. The ISG system is a key component in these applications, providing both engine starting and battery charging capabilities. A mathematical model of the ISG system is developed using Simulink, and the system is simulated under various conditions with a 48- and 12-volt DC power setup. The results of the simulations are presented and discussed, highlighting the performance and efficiency of the ISG system. Key Words: Integrated Starter Generators, Flywheel mounted ISG, DC-DC 48V and 12V setup, Space Vector PWM, Permanent Magnet Synchronous Machine (PMSM), IC Engine starting and battery charging,

Component-Level Modeling of More Electric Auxiliary Power Units for Cooperative Control

Today, the more electric aircraft (MEA) concept is gaining tremendous popularity. As a key component of the MEA, a more electric auxiliary power unit (MEAPU) integrated model with high accuracy and real-time performance is essential when conducting cooperative control and hardware-in-the-loop (HIL) test research. This paper proposes a novel MEAPU integrated model consisting of a MEAPU component-level-model (CLM) and a starter-generator (SG) model. Firstly, a MEAPU CLM was built and a continuous scaling method for the component characteristic map in the CLM is proposed to improve the model’s accuracy. Then, a double winding induction starter-generator (DWISG) model based on the electromagnetic theory, which is quite time consuming, was simplified using the pulse width modulation (PWM) rectifier linearization method. Finally, considering the coupling relationship between the MEAPU CLM and DWISG, an accurate real-time MEAPU integrated model was built and its simulation results were analyzed. Compared with the test results, the error of the proposed model was less than 0.5%; meanwhile its single-step simulation time was less than 20 ms, which can meet the demands of cooperative control and HIL test research. Furthermore, the continuous scaling method and PWM rectifier linearization method were found to be effective for modeling other MEAPUs and more electric engines (MEE).

Multidisciplinary Designing and Ground Tests of a Starter Generator for Small Aircraft

Multidisciplinary Designing and Ground Tests of a Starter Generator for Small Aircraft

Choosing a Topology of an Integrated Starter–Generator for a Two-Circuit Turbojet Engine

Choosing a Topology of an Integrated Starter–Generator for a Two-Circuit Turbojet Engine

Dynamic Characteristic Improvement of Integrated On-Board Charger Using a Model Predictive Control

This paper proposes a dynamic characteristic improvement of an integrated on-board charger (OBC) using a model predictive control (MPC) method. The integrated OBC performs both battery charging and starter generator (SG) driving for engine starting in plug-in hybrid electric vehicles (PHEVs). If it performs battery charging, battery-side voltage and battery-side current are control objects which are usually controlled by using a proportional-integral (PI) controller. However, it has the disadvantage of undesirable dynamic characteristics, and gain tuning of the PI controller is necessary to properly control the voltage and current. Therefore, this paper proposes the MPC method for the dynamic characteristic improvement of integrated OBC. It can achieve not only dynamic characteristic improvement, but also robustness from the abrupt change of load impedance. By using the proposed MPC method for integrated OBC, the settling time to control the output voltage is decreased by 50% in the transient state compared to that by using the PI controller. The effectiveness of the proposed MPC method is verified by simulation and experimental results.

Rule-Based Time-Optimal Engine-Start Coordination Control With a Predesigned Vehicle Acceleration Trajectory in P2 Hybrid Electric Vehicles

Abstract Removing the integrated starter generator (ISG) in P2 hybrid electric vehicles (HEVs) reduces the overall cost of the powertrain, yet it comes with an additional control complexity of the engine-start process. An appropriate coordination control strategy between the internal combustion engine (ICE), drive motor, and clutch is necessary to reduce the time for the engine-start while constraining the vehicle jerk. A time-optimal coordination control strategy with a predesigned vehicle acceleration trajectory is proposed from results of nonlinear model predictive control (NMPC), which can reduce the time for the engine-start process and obtain a small vehicle jerk. A dynamic model for the engine-start process is first built. In this model, a cylinder-by-cylinder engine model (CCEM) is derived to describe the ICE dynamics. A Karnopp and Stribeck combined wet clutch model is proposed to handle effects of speed difference on the torque, and calculation problem of frequent switches when crossing zero speed point. Subsequently, the optimal control problem is formulated with selected states and solved with NMPC. Finally, a rule-based control strategy is extracted from results of NMPC. Simulation results show that the engine-start process can finish within 260 ms, 13.3% less than the previous study, with a predesigned vehicle acceleration to ensure the vehicle jerk within 10 m/s3 and the peak to peak vehicle acceleration within 0.2 m/s2 in the case study under investigation.

Analysis and remedies for factors responsible for time between overhaul: a case study of Do-228 aircraft starter generator

The starter generator is used for cranking the engine and to produce electricity for the aircraft system after a sustainable speed. A review of relevant literature reveals the time between the overhaul of the Do-228 aircraft starter generator but did not go in-depth to unravel the factors responsible. A survey research method is adopted to elicit information on the factors. Raosoft sample technique calculator: a software that primarily calculates or generates the sample size of a research or survey was used to obtain the minimum sample size from the study population with the nominal rolls of the technicians as the sampling frame. The questionnaire was vetted and validated by a professional focus group discussion team. The result shows that the factors responsible for the time between overhaul of the starter generator are Environmental Factors (10%), Mechanical Factors (20%), Poor Maintenance Factors (17%), Time Due (25%), Usage/Life Cycle (16%) and Aging (12%). 75% overhaul is unscheduled. It is recommended that the overhauling of the aircraft starter generators be done at 900 as against 1000 flight hour intervals to mitigate unscheduled maintenance.

A review of conventional and new-generation aircraft starter/generators in perspective of electric drive applications

PurposeMore electric aircraft (MEA) is defined as the extensive usage of electric power in aircraft. The demand for electric power in new generation aircraft rises due to environmental and economic considerations. Hence, efficient and reliable starter/generators (SGs) are trending nowadays. The conventional main engine starting system and power generation system can be replaced with an individual SG. The constraints of the SG should be investigated to handle the aviation requirements. Even though the SG is basically an electric machine, it requires a multidisciplinary study consisting of electromagnetic, thermal and mechanical works to cope with aviation demands. This study aims to review conventional and new-generation aircraft SGs from the perspective of electric drive applications.Design/methodology/approachFirst of all, the importance of the MEA concept has been briefly explained. Also, the historical development and the need for higher electrical power in aircraft have been indicated quantitatively. Considering aviation requirements, the candidate electrical machines for aircraft SG have been determined by the method of scoring. Those machines are compared over 14 criteria, and the most predominant of them are specified as efficiency, power density, rotor thermal tolerance, high-speed capability and machine complexity. The features of the most suitable electrical machine are pointed out with data gathered from empirical studies. Finally, the trending technologies related to efficient SG design have been explained with numeric datasets.FindingsThe induction motor, switched reluctance motor and permanent magnet synchronous motor (PMSM) are selected as the candidate machines for SGs. It has been seen that the PMSM is the most preferable machine type due to its efficient operation in a wide range of constant power and speed. It is computationally proven that the using amorphous magnetic alloys in SG cores increases the machine efficiency more. Also, the benefits of high voltage direct current (HVDC) use in aircraft have been explained by a comparison of different aircraft power generation standards. It is concluded that the HVDC use in aircraft decreases total cable weight and increases aircraft operation efficiency. The thermal and mechanical tolerance of the SG is also vital. It has been stated that the liquid cooling techniques are suitable for SGs.Originality/valueThe demand for electrical power in new generation aircraft is increasing. The SG can be used effectively and efficiently instead of conventional systems. To define requirements, constraints and suggestions, this study investigates the SGs from the perspective of electric drive applications.

Design of an Aviation Dual-Three-Phase High-Power High-Speed Permanent Magnet Assisted Synchronous Reluctance Starter-Generator With Antishort-Circuit Ability

This article proposes a novel dual-three-phase high-power high-speed permanent magnet assisted synchronous reluctance starter generator (PMaSynR SG) for aviation application, which has the characteristics of high efficiency, high power density, high reliability, and excellent antishort-circuit ability. The proposed PMaSynR SG can obtain higher efficiency and power density by embedding permanent magnet in the rotor topology compared with the synchronous reluctance generator, and has better antishort-circuit ability compared with the permanent magnet synchronous starter-generator. Moreover, design of dual-three-phase winding is adopted, which not only reduces the phase current, but also improves the reliability. In this article, the topological structure, characteristics and principle of PMaSynR SG are systematically studied at first. Second, a simplified <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis equivalent magnetic circuit model is established, and the expressions of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis inductance and permanent magnet flux linkage are derived on the basis of the basic parameter selection. Then, combined with parameter sensitivity analysis, the influence law of rotor structural parameters on antishort-circuit ability and electromagnetic performance is revealed. Finally, a 40 kW 24 000 r/min PMaSynR SG is designed and manufactured. The simulation and experimental results show that the proposed PMaSynR SG has excellent electromagnetic performance with the power density of 3.1 kW/kg and the efficiency of 94%, while the short-circuit current is only 59% of its rated value.

A new dual-ferrite–assisted hybrid reluctance machine with two-stage excitation for starter generator application

Reluctance machines with DC field coil in stator are a competitive candidate for starter generation application, due to the elimination of rare-earth permanent magnet (PM), robust structures, and controllable excitation. However, due to the poor excitation ability of DC field coils, the torque density is disadvantageous. Moreover, with the increase in the DC field current, it is exposed to the risk of extra DC saturation in stator teeth. As a consequence, the torque density and efficiency are both constrained. To solve the aforementioned problems, based on the comprehensive consideration of production cost and torque performance, this study proposed a novel type of hybrid reluctance machine with dual-ferrite–assisted in stator slots. The inner-layer ferrite PM is magnetized tangentially, which can effectively achieve the DC-saturation–relieving effect, while the outer-layer ferrite PM is magnetized radially to increase the machine torque density through the flux modulation effect. Based on finite element analysis, the machine torque density and efficiency can be improved by 20 and 5%, respectively. Furthermore, to simplify the excitation system of the DC terminal, a two-stage excitation method is proposed by splitting some turns of armature winding to feed DC field winding with passive rectifier. No power switching devices are needed for the excitation system in this way, making the system highly robust. The effectiveness of the proposed design is verified by time-stepping finite element analysis.

Design and Analysis of a Doubly Salient Wound Field Starter Generator for Cost-Effective Automobile Application

Doubly salient wound field machines exhibit the advantages of robust structure and controllable flux, and hence have been utilized as generators in applications of automobiles and renewable energy. However, the inherent unbalanced phase back-electromotive force (EMF) waveform caused by the asymmetric flux path brings difficulties for precise control and smooth operation. To solve the problem caused by unbalanced back-EMF waveform in conventional doubly salient machines, this paper presents a novel doubly salient wound field machine with balanced and symmetrical back-EMF waveform as starter generator in automobile application. The robust structure and the controllable flux are inherited, while the magnetless feature makes it promising for cost-sensitive applications. The proposed machine can be operated as an assistant motor for torque boosting at start-up stage, as well as a power recycling generator for battery charging at steady state. It is revealed that the proposed wound field machine exhibits similar cost, comparable torque density, improved torque ripple, and higher efficiency than the switched reluctance machine. Finally, the proposed prototype is fabricated, and dynamic experiment is conducted to validate the feasibility for automobile starter generator application.

Development of a 48V Integrated Starter Generator for Mild Hybrid Vehicles

Development of a 48V Integrated Starter Generator for Mild Hybrid Vehicles

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.

Design of integrated starter generators for dual-circuit turbojet engines

Design of integrated starter generators for dual-circuit turbojet engines

On the choice of the topology of an integrated starter generator for a two-circuit turbojet engine

On the choice of the topology of an integrated starter generator for a two-circuit turbojet engine

Development and Design of a Starter-Generator for a Turbofan Engine

The purpose of this article is to develop a starter-generator (STG) with reduced supply voltage of 27 V for a turbofan engine. The analysis has showed that the existing design schemes of the STG are mainly designed for high voltage, due to the complexity of the implementation of the power converter. As a result of the conducted research, a method for increasing efficiency has been proposed by modifying the phase commutation control method, and a power converter topology that allows all the operating modes of the designed STG has been developed. In addition, in this article, a comparison of two methods of phase commutation, traditional and with a modified angle has been presented and its result shows the difference and the prospects, as well as the effectiveness of the chosen solution. Thermal calculations have confirmed the possibility of providing all the necessary operating modes, in which the temperature of the active elements has not exceeded the permissible values. The resulting technical solution of the STG has a mass of the active part of no more than 6.09 kg, and it allows providing an output power of up to 40 kW in all the operating modes, at frequencies from 1000 rpm to 12367 rpm.

Development of a Starter-Generator for a Turbocharger Engine

The purpose of this article is to develop a Starter-Generator (SG) based on a synchronous electric machine with permanent magnets for spinning the rotor of a turbocharger engine. At the same time, there is a comparative analysis of the parameters of starter-generators with supply voltages of 27 V and 270 V. The analysis has showed that the existing design schemes of the SG are mainly designed for high voltage, due to the complexity of the implementation of the power converter. As a result of a comparative study of starter-generators with supply voltages of 27 V and 270 V, it has been found out that, in order to provide an output voltage of 27 V at a reduced speed, it will be necessary to use a step-up converter. Changing the configuration of the starter-generator to meet the value of 27 V is not possible because increasing the induced voltage in the generator mode will not allow achieving the desired value of the torque in the starter mode. Thermal calculations of the starter-generators at supply voltages of 27 V and 270 V have confirmed the possibility of providing all the necessary operating modes, in which the temperature of the active elements has not exceeded the permissible values. The total weight of the developed starter-generator with a supply voltage of 270 V has been 12 kg, while the total weight of the starter-generator with a supply voltage of 27 V has been no more than 11 kg. Thus, the conducted studies have shown the possibility of creating a starter-generator with supply voltages of 27 V, 270 V and minimum weight and size indicators for use in a turbocharger engine.

Architecture of Distributed Control System for Gearbox-Free More Electric Turbofan Engine

This article presents the development of the electric turbofan engine in distributed architecture with a design thrust in the range of 3 to 7.5 and from 7.5 to 30 kN for small and medium-sized unmanned aerial vehicles. The engine subsystems are considered as separate smart modules with a built-in control system, exchanging data via a digital channel with the central engine control and diagnostics unit. The key smart engine units are combined in the following subsystems: starter and turbine generators, oil pumps, actuator of guide vanes, fuel pumps, fuel metering unit, control and diagnostic unit. All pumps and guide vane actuator are electrically driven. Control and monitoring signals are transmitted via a digital bus. Functional and reliability analysis and the technical configuration design of each subsystem are presented. Based on analysis of the architecture of distributed control systems for a gearbox-free electric engine, different configurations of described subsystems are proposed.

Control Methods for Performance Improvement of an Integrated On-Board Battery Charger in Hybrid Electric Vehicles

This paper presents control methods for performance improvement of an integrated on-board battery charger (OBC) in hybrid electric vehicles (HEVs). HEVs generally consist of an OBC and a starter generator system (SGS). Since these each have a power conversion device for independent operation, such as battery charging and starter generator driving for engine starting, it necessarily increases the number of components, weight, and volume of the HEV. In order to overcome these disadvantages, recent research concerning the integrated OBC has progressed. Although it demands installation of power relays and an additional circuit, the integrated OBC is effectively operated for battery charging and starter generator driving. This paper proposes not only a harmonic reduction method of grid current, but also a feed-forward control method for performance improvement of the integrated OBC in HEVs. The effectiveness of the proposed control methods is verified by simulation and experimental results.