In the introduction, the need for optimization of reactive power is described in a few sentences and a description of the work is given. In the second chapter, what is reactive power is briefly explained and the hierarchical levels of reactive power management and the economic aspects of reactive power management are briefly described. In the third chapter, a general description of devices used for voltage regulation and optimization of reactive power in the network is given. The fourth chapter concerns methods of optimal engagement of reactive power. The mathematical formulation of the classical approach to reactive power optimization is given, as well as the general model of reactive power optimization using evolutionary algorithms. The methods of optimal engagement of reactive power are briefly described. The fifth chapter describes the particle swarm method and the application of the particle swarm method for reactive power optimization. The sixth chapter presents the practical part. The network is described, which is taken as an example of reactive power optimization using the particle swarm method, and the basic technical characteristics of the network and devices used for reactive power optimization are given. The second part of the sixth chapter consists of various calculation variants characterized by different input settings of the particle swarm method.