Application of improved gravitational search algorithm in PID control for boiler drum water level

The boiler drum water level reflects the equilibrium relationship between the steam load and the water supply of the drum boiler, which is an important monitoring parameter in boiler operation. Its object has the characteristics of non-self-balancing and pure delay, and its control quality directly affects the safe operation of a boiler-turbine unit. Based on the improved gravitational search algorithm, the parameter optimization method of the main controller is put forward according to the wide-used cascade control structure of drum water level in power plant. The gravitational search algorithm has the advantages of simple process, little parameter setting, strong universality of the algorithm, but easy to fall into local optimum. Combining with the memory function of particle swarm optimization algorithm and the high precision of other improved algorithms, the formulas of position and velocity are improved, an improved gravitational search algorithm (IGSA) is obtained. By applying this method to the optimization control of the drum water level, and comparing with trial-and-error method (TEM), genetic algorithm (GA), and the standard algorithm (GSA), simulation tests are carried out to verify its effectiveness.