| In the current, under the situation of energy and environment problem increasingly prominent, the development of new energy vehicle, which are energy conservation and environmental protection, has become a national strategic choice. Urban road sweeper, as a public service vehicle, is an important target of the national development of new energy vehicle. However, since the road sweeper is a kind of long-time operation and high energy consumption vehicle, the capacity requirement for the energy storage device is quite high. In the situation of restricted battery energy density and use cost, pure electric technology is difficult to make a big breakthrough in the field of sweepers in the short term. Range-extended electric vehicle, as a transition from traditional fuel vehicle to pure electric vehicle, can effectively reduce the consumption of fossil fuels on the premise of controlling vehicle cost and ensuring driving range. So it is a favorable and feasible energy conservation and emissions reduction approach in the current situation. Based on the above analysis, this paper carried out the study of power system of range-extended electric road sweeper. In this paper, the structure scheme had been designed, the parameters of main power system components had been matched, and the control strategy had been worked out. Finally, the performance of the vehicle had been validated by means of co-simulation, and an optimization had been made on the performance of the vehicle. The main work is as follows:(1)Based on the analysis of the system structure, operation characteristics and dynamic system structure of traditional road sweeper, pointed out its weaknesses in energy conservation and emissions reduction, noise, use cost and maintenance, etc. Combined with range-extended electric vehicle’s advantages in improving fuel economy and emissions performance, the power system structure scheme was designed. Then a comparison was made with prototypical twin-engine road sweeper, and it proved to be a good energy conservation and emissions reduction plan;(2)According to the analysis of the working characteristics and performance requirements of the sweeper, completed parameters matching and components selection of main components of power system such as driving system motor, fan’s motor, hydraulic system motor, transmission, power battery pack, auxiliary power unit(APU), to meet the dynamic performance requirements and improve fuel economy;(3)Through the analysis of the characteristics of power system, operation characteristics and energy flow characteristics, made the control strategy for APU system, braking energy recovery system and transmission shifting;(4)On the basis of power system structure and its control strategy, built vehicle’s simulation platform in Cruise. And built control strategy model in Matlab/Simulink. Then validated vehicle’s performance and control strategy by co-simulation in Cruise and Matlab/Simulink;(5)Used the engineering optimization software Isight to integrate Cruise, got a set of optimal scheme by optimizing the main parameters of the transmission system and control system. Under this set of optimal scheme, the vehicle’s fuel economy achieved relatively optimal.The simulation results showed that both of the parameters match and the control strategy of the power system could meet work requirements well in the simulation model. The range-extended electric road sweeper made a great improvement in fuel economy under the precondition of ensuring the normal working ability and good dynamic performance. |
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