Research And Design Of Control System For Pemfc Electric Bicycle

With the continuous development of society and increasing global energy consumption, energy shortage and environmental pollution are more and more serious. All the worlds are trying to find alternative clean energy to solve this problem. The use of hydrogen can help to solve the energy shortage and environment pollution problems. So gradually replace oil with hydrogen is one of the solutions in the future. Hydrogen manufactured from fossil fuels, but also solar, wind, hydro and other renewable energy conversion. Proton exchange membrane(PEM) Fuel cells are the ideal conversion device for hydrogen. PEM fuel cells have widespread concerned for its low operating temperature, high current density, no environmental pollution, fast startup characteristics and so on.PEM fuel cells are considered to be the ideal substitute of conventional batteries, particularly in portable power source and new energy vehicles field. In China, there are a considerable number of battery scooters, gas scooters, etc. Battery scooters have to charge for a long time after each traveling. Gas scooters would consume fossil energy and emit exhaust polluting the environment. If PEM fuel cells used as the power source of scooters, it not only do not need to charge, and no environment pollution. Research in PEM fuel cells application and developed a control system of PEM fuel cells scooters is done in this paper.The history of fuel cells, research and applicated prospects in domestic and international introduced in this paper first,, then basic principles and classification of fuel cells introduced in this paper, this paper focus on that the structure, working principle and basic electrical characteristics of PEM fuel cells. The main factors which affected the running state of PEM fuel cells are reaction gas concentration and gas emissions. The system used air as the reaction oxidant, compressed air into the PEM fuel cells gas channel directly by a fan, provided hydrogen by metal hydride hydrogen storage bottle. The stack uses an air fan at the edge of cathode to provide air and cool the fuel cells stack. Second, the basic structure and working principle of the brushless DC motor, derived mathematical models and operating characteristics described in this paper, this paper also described the brushless DC motor PWM control principle in detail, we Proposed a PEM fuel cells scooters control system, developed a controller based on PIC18F4520, the controller’s function included1:1auxiliary power scooters, motor stall protection, smooth brake, startup, speed regulation, current limiting protection, overvoltage protection, undervoltage protection, real-time display the voltage, current and remaining hydrogen. Finally, after repeated experiments, we further improved and optimized the performance of PEM fuel cells scooters, made sure safe and stable operation.