This paper presents a new approach to developing an efficient means of minimizing the unbalanced mode in three-phase power supply systems for industrial and civil facilities. The approach is applied to the test task and to the problem of symmetrization of 10/0.4 kV distribution networks of a glass factory. The approach is based on the symmetrization of the three-phase system by introducing several single-phase devices with a controlled reactance. We have developed an original method for finding the locations of these devices in the system and an algorithm for controlling their reactance. It is shown that this approach makes it possible to significantly reduce the variable component of instantaneous power in the entire system using only 2–4 compensators in systems with a significant mutual influence of loads and relatively weak asymmetry. With a weak mutual influence of load modes on each other and significant unbalance of loads, the proposed approach allows to reduce the power of the symmetrization devices by at least a third.