Frequency domain identification of oxygen-coal ratio system in gasifier based on improved Firefly algorithm

The oxygen-coal ratio system of the gasifier is the key component of the pulverized coal gasification unit. This paper utilizes first-order model with time-delay to describe the system. Since the time delay is mainly reflected in the phase-frequency characteristics of the controlled object, this paper utilizesthe method of frequency domain identification to identify the system. Firstly, based on the time-domain input and output data of the controlled object, the frequency characteristics of the controlled object are extracted by discrete Fourier transform, and then the identification process is regarded as an optimization process, and firefly algorithm is used to optimize the identification of the parameters of the transfer function. The firefly algorithm is a swarm intelligence optimization algorithm. Aiming at the problem that the algorithm is easy to fall into the local optimum, the optimization parameters and attraction model of firefly algorithm are improved based on the optimal light intensity difference ratio and light intensity difference respectively. Finally, the simulation experiment is carried out with the oxygen-coal ratio system of gasifier as a simulation object. Simulation results show that compared with the standard firefly algorithm, the improved firefly algorithm has a higher probability of finding the global optimal solution and has a higher identification accuracy.