Research On Multi-area Load Frequency Control Based On Improved Butterfly Optimization Algorithm

Load Frequency Control(LFC)is an important technology to maintain stable operation of the power system and ensure power quality.When the system is subjected to load perturbations,LFC can maintain the system frequency and tie line power flow at their scheduled values.This paper uses a Fuzzy PID(FPID)controller that combines Fuzzy Logic Control(FLC)and PID.It has the ability to deal with nonlinear system,wide applicability and high cost performance.In order to improve the effect of the FPID controller,this paper proposes an Improved Butterfly Optimization Algorithm(IBOA)to optimize the parameters of the FPID controller,so as to achieve better control performance and ensure the high quality of electrical energy.Firstly,this paper introduces the research status of LFC in power system and the models of various components in detail,and establishes three power system models,which are two-area non-reheat power system,two-area four-source hydrothermal power system with High Voltage Direct Current(HVDC)and three-area nonlinear power system.Secondly,there are some shortcomings for the BOA algorithm to solve the LFC problem,such as the lack of initial population diversity,the poor balance between global search and local search,and the tendency to fall into local best,etc.In this paper,three improved strategies are adopted: one is to introduce Tent chaotic sequence to enhance the diversity and distribution of the initial population of butterflies;the other is to use dynamic switching probability to balance global and local search capabilities;The third is the introduction of cauchy mutation strategy to reduce the probability of falling into local optimum.The introduction of three improved strategies formed the IBOA algorithm proposed in this paper.In addition,this paper combines time-domain performance indicators such as settling time and overshoot with ITAE integral performance indicators to propose a new objective function.Finally,this paper applies the IBOA FPID method to three multi-area power systems,and conducts 10 simulation cases to verify its effectiveness and superiority in dealing with LFC problems.In a two-area non-reheat power system,the simulation results show that the IBOA algorithm makes the system have better dynamic performance and robustness compared to algorithms such as h BFOA-PSO,h PSO-PS and DE.For the two-area four-source hydrothermal power system,the impact of HVDC lines and random step load disturbances on the performance of LFC is mainly considered.The simulation results show that the IBOA algorithm has better transient response than the h PSO-PS algorithm in the literature.For the three-area nonlinear power system under random load disturbances,compared with the h FA-PS and IGWO algorithms,the simulation results show that the IBOA algorithm enables the system to have shorter settling time and smaller oscillation amplitude.In summary,the IBOA FPID method proposed in this paper has obvious advantages in dealing with LFC problems.