A method for transient air-fuel ratio control of high-power gas engines

Abstract

The invention relates to a method for controlling a transient air-fuel ratio of a high-power gas engine. The method comprises the following steps: (1) constructing a transient air-fuel ratio control system of the high-power gas engine; (2) outputting the amount of compensated gas by a feed-forward compensation controller; (3) outputting a basic gas amount through a basic gas amount acquiring module by taking a target air-fuel ratio and every circulating air amount of every cylinder as input; (4) calculating and outputting a PID controller corrected gas amount by setting proportional gain, integral gain and differential gain through an adaptive PID feedback controller based on a universal exhaust gas oxygen sensor and taking an actual air-fuel ratio and the target air-fuel ratio as input; and (5) accumulating the output of the feed-forward compensation controller, the output of the basic gas amount acquiring module and the output of the adaptive PID feedback controller based on the universal exhaust gas oxygen sensor, then outputting the accumulated output to an actual gas amount outputting module through an amplitude limiter, and finally outputting an actual gas amount. Compared with the prior art, the method has the advantages of rapid response, good practicality, high efficiency and the like.

Description

Technical field [0001] The invention relates to the field of engine closed-loop air-fuel ratio control, in particular to a method for transient air-fuel ratio control of a high-power gas engine. Background technique [0002] In recent years, environmental pollution has intensified, and automobile exhaust emissions have become one of the chief culprits of environmental pollution. Natural gas as a clean energy source has also been recognized and used by people, and gas engines have also been widely popularized and developed. As engine efficiency and emission control regulations become stricter, reducing harmful gas emissions is one of the main research directions in the development of natural gas engines under the premise of ensuring the power and economy of natural gas engines. In view of the fact that the engine's emission performance is reflected by the engine's real-time air-fuel ratio; therefore, the real-time precise control of the air-fuel ratio is particularly important. [...

AI Technical Summary

Problems solved by technology

The current gas engines are mainly used for some low-power single-point injection vehicles or high-power generators. The main reason is that the air-fuel ratio closed-loop control strategy of the gas engine is not perfect under transient conditions, which makes the mixture rich. The lean condition is unstable, causing the engine to not work stably

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