Hybrid electric vehicle ( hev ) is one of the main types that will be developed in the next twenty years because of its low fuel consumption , low emissions and comparatively easiness for being merchandized . however , as it has at least two sets of propulsion systems , the hardware structure and the energy management system is complex . the optimal match of various components and the optimal combination of a large number of control parameters are therefore required 混合动力电动车(简称hev )因其低油耗、低排放、商品化相对容易，是将来二十年内汽车开发的主要型式之一，但因其具有至少两套动力驱动系统，故硬件结构和能源管理系统都比较复杂，需要找到各类部件的最优匹配和大量控制参数的最佳组合。
With the development of multi - variable control technology and aero - propulsion technology , future excellent engine must have the character , which is high ratio in thrust and weight low fuel and long use life . therefore the control system of aero - engine has also been becoming more and more complicated . the precision of control system is also extra higher 随着高推重比、低油耗、长使用寿命、高机动性航空发动机的研制，现代航空发动机需要控制的变量越来越多、精度越来越高，因此，航空发动机控制系统变得越来越复杂，传统的航空发动机控制系统是采用机械液压控制。
By adjusting many variable geometry components of the engine , bypass ratio can be changed during large range ( the most 0 . 25 of military fighter ) . the high specific thrust characteristic of turbojet engine and the low specific fuel consumption characteristic of the turbofan engine can be realized during different flight phase by the usage of vce technology 变几何变循环发动机是应用于第四代多用途战斗机的理想动力装置，通过多个部件几何的调节在较大范围内改变涵道比，能够使发动机在不同航段分别实现涡喷发动机的高单位推力性能和涡扇发动机的低油耗性能。
