Analysis and Design of a Permanent Magnet Bi-Stable Electro-Magnetic Clutch Unit for In-Wheel Electric Vehicle Drives

2017

Teh. vjesn.

Pomoćni uređaj za pokretanje direktno pogonjenog električnog vozila s regulatorom brzine praznog hoda motora STARTING ASSISTANCE DEVICE FOR DIRECTLY-DRIVEN ELECTRIC VEHICLE WITH VARIABLE-IDLE SPEED CONTROL Ping Xiong, Chenglin GuOriginal scientific paper By introducing a novel permanent magnetic bi-stable electromagnetic clutch unit (PMBECU) in the driveline of directly-driven electric vehicle, a flexible connection between motor and hub is realized with characteristic of separated starting process of drive motor and wheel load. Firstly, the working principle and power supply scheme for the PMBECU is discussed. Then the assembly for the wheel-drive system with starting assistance device by the clutch is investigated. Considering the good dynamic performance of wheel motor, variable-idle speed scheme is presented and the simplified model for fast clutch engagement is built and analyzed. Finally, the proposed method for directly-driven electric vehicle launch is performed on the test rig. The experimental results indicate the shock intensity and electromagnetic impulsion during the starting process is decreased effectively by clutch-coupling startup, which results in good driving comfort and less heat in armature winding of drive motor. Keywords: clutch unit; directly-driven electric vehicle; driving comfort; starting assistance; variable-idle speed control Pomoćni uređaj za pokretanje direktno pogonjenog električnog vozila s regulatorom brzine praznog hoda motoraIzvorni znanstveni članak Uvođenjem nove trajne magnetski bi-stabilne elektromagnetske spojke (PMBECU) u transmisiju direktno pogonjenog električnog vozila, ostvarena je fleksibilna veza između motora i glavine karakteristična po odvojenom pokretanju pogonskog motora i osovinskog opterećenja. Najprije se raspravlja o načinu rada i shemi dovoda energije za PMBECU. Zatim se istražuje sklop za sustav pogona kotača s uređajem za pokretanje pomoću spojke. Razmatrajući dobre dinamičke karakteristike motora kotača, daje se shema promjenljivog praznog hoda te se gradi i analizira pojednostavljeni model za brzo ukapčanje spojke. Konačno se predložena metoda za pokretanje direktno pogonjenog električnog vozila primijenjuje na uređaju za ispitivanje. Eksperimentalni rezultati pokazuju da su jačina udara i elektromagnetski impuls tijekom pokretanja efikasno smanjeni pokretanjem zupčaste spojke, što rezultira udobnošću u vožnji i manjim zagrijavanjem namotaja armature pogonskog motora.Ključne riječi: direktno-pogonjeno električno vozilo; pomoć kod pokretanja; regulator brzine praznog hoda; sklop spojke; udobnost u vožnji

Section: New-type Clutch Unit and Its Working Principlementioning

confidence: 99%

Starting assistance device for directly-driven electric vehicle with variable-idle speed control

2017

Teh. vjesn.

“…clutch is introduced into the driveline of the direct-drive propulsion system for the purpose of achieving a flexible connection between the motor and the hub. In order to retain the distinguishing merits such as a compact powertrain and the independent control for each wheel motor, the new-type clutch is designed and its working principle is illustrated in [7]. The existing features (e.g.…”

Section: Introductionmentioning

confidence: 99%

Research on torque compensation with optimal pedal throttle for direct-drive electric vehicle start-up

2017

Teh. vjesn.

Original scientific paper The original rigid connection between the motor and the hub is replaced with a flexible one using the clutch to connect the driving and driven sides of the driveline system. Then the paper proposes a separable process of motor start-up and load operation, based on which the scheme of idle speed control is studied. Focusing on the contradiction between the extended torque capacity and the reduced vehicle jerk merely by tuning the idle speeds, an improved solution is proposed for toque compensation by throttle adjustment during the clutch engagement. Furthermore, the method for tracking the armature voltage of the driving motor is investigated and optimized, aiming at the balance between the demanded transmitted torque and the jerk level during the starting process. Finally, effectively enhanced torque capacity of the driving motor for the vehicle start-up on the premise of the improved comfort level has been demonstrated by experiments. Keywords: armature voltage compensation; direct-drive; flexible coupling; idle speed; vehicle jerkIstraživanje kompenzacije zakretnog momenta s optimalnom prigušnicom pedale za pokretanje električnog vozila izravnog stupnja prijenosa Izvorni znanstveni članak Originalna kruta veza između motora i glavine zamijenjena je fleksibilnom uporabom spojke za povezivanje pogonskog i gonjenog vratila sustava prijenosa. U radu se zatim predstavlja odvojeni proces pokretanja i opterećenja motora na osnovu kojega se analizira shema reguliranja rada motora u praznom hodu. Fokusiranjem na probleme koordinacije povećanog kapaciteta zakretnog momenta i smanjenja trzaja automobila samo regulacijom rada motora u praznom hodu, predlaže se poboljšano rješenje kompenzacije zakretnog momenta podešavanjem napona rotora dok se spojka aktivira gonjenom stranom. Nadalje, ispituje se i optimizira metoda za označavanje napona zakretnog momenta s ciljem stvaranja balansa između traženog prijenosnog mehanizma zakretnog momenta i jačine trzaja tijekom pokretanja vozila. Konačno, eksperimentima je demonstriran učinkovito poboljšani učinak zakretnog momenta pogonskog motora kod pokretanja vozila u svrhu povećane udobnosti.Ključne riječi: elastična spojka; izravni prijenos; kompenzacija napona rotora; rad motora u praznom hodu; trzaj vozila

“…Because the wheel speed starts from zero, its change in angular speed is defined by Equation (12). Substituting the wheel speed from Equation (12) into Equation (14), the equivalent angular acceleration of the wheel is obtained. Then, combining the definition of jerk, the transient jerk for preserving a good driving comfort at the starting time is expressed as…”

Section: Factors Influencing the Starting Performance Indicesmentioning

confidence: 99%

“…Ideally, the two rotating masses will turn into one linked mass once the speed difference between the motor and the wheel approaches zero, and driving with the locked clutch for t > t. a(t 0 ) is assumed to be the equivalent acceleration of the wheel by ideal coupling in the time interval [t 0 , t), whereas a(t) stands for the wheel acceleration at the clutch lockup time instant. Based on the ideal clutch model, the equivalent angular acceleration of the wheel is determined by Equation (14). The corresponding wheel acceleration when the clutch instantaneously engages is calculated as…”

Section: Optimal Principle Of the Idle Speed Control Strategymentioning

confidence: 99%

See 1 more Smart Citation

An improved startup mode using clutch coupling for in-wheel electric vehicle drives

2017

Automatika

Self Cite

By introducing a new type of clutch into the driveline system of an in-wheel drive electric vehicle, a flexible connection has been developed to replace the rigid one between the hub and the motor. The driving motor can realize variable idling, unlike the internal combustion engine, which needs a minimum rotational speed. This paper proposes a new startup method that utilizes the initial kinetic energy of the motor to achieve a smooth and fast acceleration of the wheel speed from zero to the expected motor speed. First, the powertrain system, including the driving motor, the clutch and the vehicle resistance, is modelled. Second, factors influencing the starting current and the jerk level during the starting process are investigated. In consequence, the idle speed can be interpreted as a tunable variable that determines the tradeoff between the torque capacity and the jerk level. Finally, simulation and experiments on a laboratory test rig are performed. The results validate that the proposed variable-idle speed control strategy has a lower jerk level and lower starting current when compared with those using a direct start under the same load condition.