Minjae Kim

Hybrid Thermostat Strategy for Enhancing Fuel Economy of Series Hybrid Intracity Bus

The recently developed power distribution strategies in hybrid electric vehicles (HEVs) are often hard to apply, or the mathematical backgrounds are burdened by very complicated calculations. In this paper, a new control strategy, referred to as a hybrid thermostat strategy, is proposed for a series-type HEV (SHEV). The proposed strategy has its foundation in the thermostat strategy and incorporates merits from the power follower strategy such that it overcomes those strategy weaknesses and accomplishes increased efficiency with a practical concept. The development of the proposed strategy is based on AMESim and Simulink cosimulation with Simplex method optimization.

Series-Type Hybrid Electric Bus Fuel Economy Increase with Optimal Component Sizing and Real-Time Control Strategy

Key Words: Series Hybrid Electric Vehicle(직렬형 하이브리드 자동차), Optimization(최적화), Dynamic Programming(동적계획법), HILS(하드웨어 인 더 루프 시뮬레이션) 초록: 직렬형 하이브리드 자동차는 구조가 간단하고 단품들의 효율이 높기 때문에 연비성능이 우수하며, 병렬형과 비교하여 배터리, 엔진, 모터의 용량이 상대적으로 고용량인 특징을 가진다. 본 연구에서는 직렬형 하이브리드 자동차의 최적용량매칭을 통해 최적의 연비를 도출하고, 실시간 시뮬레이션 환경에서 사용될 알고리즘을 개발한다. 연구에서 진행된 용량매칭은 모터, 엔진/발전기 및 배터리를 대상으로 13개 주행 사이클에 대하여 순차적으로 이루어 졌으며, 이를 위해 Matlab 환경에서 최적화 기법인 DP(Dynamic Programming)을 사용하였다. 실시간 성능검증을 위한 차량모델은 Simulink 및AMEsim을 기반으로 개발되었고 실시간 제어로직이 구현된RCP(Rapid Control Proto-typing)와 연동하여 그 성능을 확인할 수 있었다. Abstract: The interest in reducing the emissions and increasing the fuel economy of ICE vehicles has prompted research on hybrid vehicles, which come in the series, parallel, and power-split types. This study focuses on the series-type hybrid electric vehicle, which has a simple structure. Because each component of a series hybrid vehicle is larger than the corresponding component of the parallel type, the sizing of the vehicle is very important. This is because the performance may be greater or less than what is required. Thus, in this research, the optimal fuel economy was determined and simulated in a real-world system. The optimal sizing was achieved based on the motor, engine/generator, and battery for 13 cycles, where DP was used. The model was developed using ASCET or a Simulink-Amisim Co-simulation platform on the rapid controller prototype, ES-1000.

Study of Energy Management Strategy Considering Various Working Modes of Plug-in Hybrid Electric Tractor

In recent years, eco-friendliness and high fuel economy have become important issues for commercial tractors. Electric tractors are often required for operation in a greenhouse. However, the battery capacity limits the available operation time. To overcome this problem, a plug-in hybrid electric tractor is considered a reasonable alternative. This tractor has a basic driving ability and can operate in various working modes such as mower, rotary, loader, and trailing. This study focuses on the energy management strategy by considering various working modes.

Study on the Development of Control Strategy for Series Hybrid Electric Bus based on HILS

In recent days, the study on hybridization of the heavy-duty is going on, actively. Especially, the improvement of fuel economy can be maximized in the intra-city bus because it drives the fixed route. For developing the hybrid electric intra-city bus, optimized control strategy which is possible to be applied with real vehicle is necessary. If the real-time control strategy is developed based on the HILS, it is possible to verify the real-time ability and fail-safety function which has the vehicle stay in safe state when the functional errors are occurred. In this study, the HILS system of series hybrid electric intra-city bus is developed to verify the real time control strategy and the fail-safety functions. The main objective of the paper is to build the HILS system for verifying the control strategy (rule-based control) which is implemented to reflect the Dynamic Programming results and fail-safety functions.

Optimal torque distribution strategy for dual traction motors in a series hybrid electric intra-city bus

In hybrid vehicles, the focus in optimisation methodologies to improve the fuel economy has generally been on the energy flows between the engine motor and battery, but the energy distributions in the traction motor unit have received little attention. Thus, the energy flow from the engine/generator unit to the traction motors that is determined by optimal control strategies may not be transferred to the wheels in the most efficient manner. To address such problems, this research studies an optimal torque distribution for the traction motors where an optimal torque distribution map is used that contains information for the most efficient distribution at all operating points. The optimal power distribution, apart from the energy flow from the engine to the traction motor unit, could be achieved for all operating regions with realistic bus speed profiles. As a result, the favourable type for the proposed strategy could be defined. The proposed strategy was demonstrated through simulations using AMEsim and Simulink co-simulation.