Study On Transmission Scheme And Control Strategy Of Series Heavy Hybrid Loader

Loader has high energy consumption, bad emission and low fuel efficiency, so it ismeaningful to study the energy saving technology of hybrid loading machine in today’senergy shortage and environmental deterioration is becoming more and more serious cases.Recently, research on the parallel hybrid loader technology has made a series of excellentachievements, which effectively improve the energy utilization rate of engine, but becauseof the traditional parallel program retains the hydraulic torque converter, it is impossible toimprove the system transmission efficiency in essence. This restricts the development ofparallel structure. this paper proposes scheme of petroleum-electric heavy hybridvehicle,cancelles the torque converter. According to the structure and working conditions ofloading machine, this paper studies on the control strategy about effectively energymanagemen and reasonable distribution of system power, which ensures each elements ofthe power system working in high efficiency to better effect to save energy and reduceemission.The main research contents and conclusions include the following1. This paper proposes scheme of heavy hybrid vehicle based on the powertransmission technology. Adopting the way of combination of theory analysis and empiricalformula and according to the loading motor mechanics theory, this paper establishes thehybrid loader power transmission system model. Taking genetic algorithm as a parametermatch method, this paper takes power system efficiency as objective function of theoptimization to meet the load demand and achieve parameters matching scheme in whichminimum installed power as constraint condition. Using this method to optimize the maincomponents of hybrid loader system with parameters match method.2. This paper studies the control strategy of series hybrid loader. This paper proposescontrol strategies based on the judgment type sectional working point more switching controlstrategy and fuzzy logic control strategy. Control strategy structure and control rules areestablished respectively. The results show that the two kinds of control strategy can guaranteethe stability of the super capacitor to achieve dynamic balance and make sure engine outputtorque is smooth and basically works in high efficient area. When the speed of engine is fixed,using the judge sectional type working point switch control strategy can save about12%fuelthan traditional loader and using fuzzy logic control strategy can save about14.03%fuel thantraditional loaders. When the speed of engine is changing, using the judge sectional type working point switch control strategy can save about15.05%fuel than traditional loader andusing fuzzy logic control strategy can save about17.27%fuel than traditional loaders.3. Put forward the real-time control strategy and quadratic programming to analyze andoptimize fuzzy logic control strategy. With the target of optimal overall efficiency,optimization model was built to optimize engine speed and power distribution from powersystems as well as to improve the effect of fuzzy logic control. Bench test shows thatreal-time control algorithm can further improve fuel economy and reduce fuel consumption,saving more fuel for18.18%than the traditional loaders. Using quadratic programming canfind the holistic optimal control path and control the engine to work near along the torquecurve of optimal efficiency, improving fuel economy.18.48%of energy is saved compared totraditional engineering loaders.4. Build the first domestic bench of heavy series petroleum-electric hybrid loader basedon electric drive technology. Eight groups of experiments are conducted using the bench.(1)Traditional experiment. The system works according to the driver’s intention.(2) Variablespeed experiment of parallel hybrid engine. Control system torque distribution using fuzzylogic.(3) Constant speed experiment of series hybrid engine. Control torque distributionusing logic gate.(4) Constant speed experiment of series hybrid engine. Control systemtorque distribution using fuzzy logic.(5) Variable speed experiment of series hybrid engine.Control system torque distribution using logic gate.(6) Variable speed experiment of serieshybrid engine. Control system torque distribution using fuzzy logic.(7) Variable speedexperiment of series hybrid engine. Control system torque distribution using fuzzy logicbased on real-time control.(8) Variable speed experiment of series hybrid engine. Controlsystem torque distribution using fuzzy logic based on quadratic programming. Search for theoverall optimal control path and verify correctness and viability of the energy control strategyby bench test.Theoretical and experimental studies have shown that heavy series petroleum-electrichybrid loader can improve the efficiency of system torque transmission by replacing thetraditional torque converter with electric power transmission technology. The proposedcontrol strategy achieved system energy management under different working conditions,combined a better match between power source and load, improved the efficiency of theloader and fuel economy.