168-169 2024 [추계학술대회]
| 제목 | 도그 클러치를 이용한 다중 모드 하이브리드 전기 자동차의 모드 전환 제어 |
|---|---|
| 분야 | 모빌리티 동력 및 구동시스템 |
| 언어 | English |
| 저자 | Toumadher Barhoumi(카이스트), 금동석(카이스트) |
| Key Words | Power-split hybrid electric vehicle(동력분기식 하이브리드 전기 자동차), Parallel hybrid electric vehicle(병렬형 하이브리드 전기 자동차), Dog clutch(도그 클러치), Mode shift(모드 전환), Real-time Simulator(실시간 시뮬레이터) |
| 초록 |
The shift to electrified powertrains is crucial to address growing environmental concerns and meet stricter emission regulations, with hybrid and plug-in hybrid vehicles emerging as the most viable solution due to the limitations of pure electric vehicles, such as range anxiety and battery technology constraints. Integrating multi-mode operating capabilities can improve hybrid vehicles’ performance but requires the use of clutches. While most vehicles employ friction clutches for smooth shifting, these are bulky, expensive, and inefficient due to slippage and viscous drag. In contrast, dog clutches, which couple shafts through interference, offer improved efficiency, compactness, and cost savings. Though impractical in conventional powertrains, dog clutches are well-suited for electrified systems where proper motor control can manage the speed synchronization, which makes them an effective alternative to friction clutches in multi-mode power-split hybrids. However, their use introduces additional control complexity, particularly during mode transitions, where two key challenges—speed discontinuity and torque hole—must be addressed. Therefore, the mode transient problem should be given special attention when considering using dog clutches. This study introduces a real-time forward simulator that considers mode shifts in a multi-mode power-split system utilizing dog clutches. The system under consideration integrates the Toyota Prius input-split architecture with fixed gear parallel modes using two dog clutches. An overview of the proposed methodology is shown in Fig. 1. First, fuel economy is assessed using the Equivalent Consumption Minimization Strategy (ECMS). Secondly, control strategies are derived to define the target mode according to specific driving conditions and operating strategies for the different modes are extracted. A stateflow diagram that visualizes the transition paths between modes is also created. Finally, a real-time forward simulator is developed, incorporating mode transient control strategies within its hybrid controller. The study's findings highlight the crucial role of the input-split mode in enabling smooth mode transitions when dog clutches are used. Torque hole and speed discontinuity issues are effectively mitigated as the clutches engagement and disengagement is managed through the control of the small motor/generator (MG) that is connected to the sun gear of the planetary gear set. During clutch engagement, the small MG synchronizes speeds by matching the engine's speed. On the other hand, during disengagement, it is controlled to cancel the clutch torque. Both engagement and disengagement processes rely on the input-split architecture, which demonstrates that the input-split architectures serves not only as an operational mode but also as a transitional mode. Thus, including a power-split mode in electrified powertrains is crucial when using dog clutches. |
| 원문(PDF) | 다운로드 |