Research And Application Of Control Methodology For Gasoline Generator Based On Photoelectric Sensor

With the enhanced awareness of environmental protection,countries are tightening regulations for small gasoline engines,and the renovation of gasoline generators is imminent.It is necessary to reduce emission of tail gas pollutants and optimize design based on the function of generators.Conventional generator use load as an adjustment basis and do not consider the contribution of tail gas emission factors for throttle adjustment.The paper proposes using photoelectric exhaust sensor detection on the basis of traditional generators to improve generator throttle control precision and reduce emissions of pollutants.The paper focused on the design of photoelectric exhaust gas sensor,the hardware circuit and the software control method.The internal gas distribution was uneven in the traditional exhaust gas sensor,affecting the measurement accuracy.This paper added a reference channel to the principle of non-dispersive infrared detection,and auxiliary chambers were added to the gas chambers of the sensor to make the gas flow distribution of the exhaust gas sensor uniform and reduce measurement interference factors.The generator control system was based on the detection values of the load voltage,current and exhaust emission concentration to control the inverter link and throttle opening,so that the generator output a stable rated voltage to meet the workload requirements.In the hardware part of the generator system,the design principles of the circuits such as threephase rectifier,throttle control circuit,voltage/current and photoelectric exhaust gas detection circuit were introduced,as well as the analysis of the main device parameters;In the software part,the whole system adopted the dual-regulation mode of SPWM inverter control and throttle control.The SPWM inverter control was for the purpose of fast respond and stably power output when abruptly changing load.Throttle control speed was the system’s ability to match engine oil supply quickly,output-power and load.Due to the gasoline generator’s change in load,there was a tendency for the throttle to overshoot and the gasoline engine exhausts excessively.Based on traditional control methods,this system added feedback of photoelectric exhaust concentration detection.The system with FuzzyPID dual control strategies,joint multi-parameter adjustment of the throttle control to improve the accuracy and reduce the emissions,and the generator output was more stable.According to the above scheme,a 2kW gasoline generator prototype based on photoelectric exhaust sensor was completed,and the sensor was calibrated and tested the sample to prove its feasibility.The paper completed the test of the prototype and improved the test of the same model before.From the data analysis and comparison,the prototype output voltage,power,and frequency are stable.The exhaust emissions of the prototype are much lower than those before the improvement.The photoelectric feedback control system in this paper is not only suitable for 2kW gasoline engine,but also for larger power generators,diesel generators and agricultural machinery of the same type.It has certain applicability.