Study On Control Strategy Of Increasing Enthalpy Air-condition System For Electric Bus

Owing to the serious energy and environmental problems,developing electric passenger cars becomes the future trend,which therefore promoted the rapid development for its general utilization and application.However,due to the limitation of on-board energy storage,driving mileage is still the key problem to be solved.Especially under low temperature environment,the high heating energy consumption significantly limited the driving distance.Consequently,developing air-conditioning system with high efficiency and low energy cost becomes an important topic for electric bus.In this paper,based on the 12 m large electric buses,we successfully designed a set of enthalpy-adding heat pump air-conditioning system,which can adapt to highly variable condition of temperature.Afterwards,the control strategy was studied and optimized.The following contents are intensively researched.Based on the quasi-second level compression theory of air-supplying enthalpy adding,a heat pump air-conditioning system was designed to match the electric bus,and its control strategy was studied in order to save energy and achieve the comfort temperature.According to analyzing cold/hot load and air-conditioning system parameters,the design scheme for the air-conditioning system and the fuzzy PID control strategy were set.The corresponding application results were checked out through simulation analysis and experimental testing.In terms of the control strategy,fuzzy PID control was designed and employed,during which the key parameters were determined by calculating and simulating.Compared to traditional control strategy,fuzzy PID control significantly improved the temperature controlling accuracy of air-conditioning system and the stability under different working condition of volatility,presenting better ability for resisting disturbance.Bench and vehicle performance experiments of enthalpy-adding heat pump air conditioning system were then conducted.Under refrigeration working condition,using air-supplying enthalpy adding can improve the system refrigerating capacity.Under heating working condition,it can sharply increase heating capacity and COP performance.Our air-conditioning system can sharply improve the system efficiency,and the energy saving ratio can reach more than 50% under typical working conditions,showing widely application prospect.