Performance Analysis of a Novel Electronic Variable Valve Actuation System Developed for a Camless Engine

Variable valve actuation (VVA) technology has the potential to enhance the energy efficiency of internal combustion engines, and its development is relevant to the global shift towards sustainable power generation. In a conventional cam-based system, valve actuation is achieved with a fixed cam profile, and the valve events are tied up with the crankshaft’s rotation and, hence, are not flexible. However, an electronic VVA system enables flexible control of the engine valve events and valve lift profile as a function of time. The present article discusses the development and performance analysis of an in-house test facility for electro-pneumatic variable valve actuation (EPVVA) system. The EPVVA system utilizes high-frequency solenoid valves. The solenoid valves control the valve lift profile. The control is achieved by the modulation of the electrical pulses sent to the solenoid valves. The engine valve events of opening and closure are independently controlled by varying the time of activation of the inlet and exit solenoid valves. The valve actuation profile of the EPVVA system is characterized with the help of a Hall-effect based position sensor. The independent control of valve lift parameters, such as peak valve lift, area under valve lift profile, and the duration of valve opening, is demonstrated with a systematic variation of control parameters as well as the timing of their initiation. The repeatability of valve actuation is assessed by conducting multi-cycle experiments. The effect of the inherent characteristics of solenoid valves, the control unit, and the working fluid on the repeatability of valve operation is quantified through statistical analysis.