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There is a trouble that electrical energy of trains which have a recuperative braking uses partly for DC railway, because there are not different consumers of the electrical energy in this time. The method was offered, it allows to find optimal parameters of a stationary energy storage, which locates on a traction substation. This method can be used for designing and determination efficiency of an energy storage.

There is the way for increasing efficiency of recuperative braking, using an energy storage device on electrical locomotives of DC railway. This device must store a part of recuperative energy. In the article the approach was considered, which allows to find parameters of an energy storage device, this device must be placed on electrical locomotives of DC railway, a part of recuperative energy can be returned to electrical network.

The article describes a method for controlling electrical loads rail consumers using energy storage. Different types of energy storage devices used in rail transport were considered. Performed the optimization problem formulation, selected criteria and the method for its solution. As an optimization method used the method of Hooke-Jeeves. A method is proposed to determine the optimal parameters and the optimal control law of charging and discharging of the energy storage. The criteria and calculation expressions that can be used in the design and feasibility study of the effectiveness of implementation of the stationary energy storage for managing schedules loads rail consumers. The mathematical expression was proposed for the energy storage capacity determination. Two criteria were considered in the optimization problem: a minimum active power losses and minimum reduced costs, and a comparison of results. The form factor used to evaluate the changes in electrical loads. Control of reactive power in the AC mains can realize using semiconductor converters and an energy storage. As a variant the electrochemical cells (lithium-titanate batteries) could be used as energy storage for rail electric consumers. As a result, optimal control of electrical loads allows to get technical and economic effects.

The article considers an approach that allows to reduce the asymmetry of consumed currents by traction substations of railways from a three-phase power supply system using a compensating device with an asymmetric structure installed at the substation. Reactive currents of the compensating device allow to redistribute between phases of the traction transformer active and reactive power of asymmetric traction load and to receive symmetric load of three-phase power supply system. The theorem is proposed to determine the conductivities and reactive currents of the branches of a compensating device with an asymmetric structure depending on the traction loads. The article presents the calculated expressions, which can be used to calculate the conductivity and reactive currents of the branches of the compensating device for any traction load of the feeders, in which the equivalent load, including the reactive currents of the branches of the device and the currents of the feeder zones will be symmetrical and active. As an example of the application of the theorem and the proposed expressions, a test problem is presented in which the secondary winding of a traction transformer with asymmetric traction load of feeders is considered, the conductivity of the branches of the device is calculated. With the use of vector diagrams shows the receipt of a symmetrical system of currents of the secondary winding of the traction transformer. Mathematical expressions allowing to realize the necessary law of regulation of reactive currents of the device are given. The necessary ranges control of reactive currents of the compensating device on traction substation on the set probabilistic laws of change of traction loadings are defined. Various options for the practical implementation of a compensating device that will provide the necessary inductive or capacitive current of each branch are considered.

The article considers one of the ways of improving the energy efficiency of AC electrical system railways 25 kV, 50 Hz. The proposed approach allows to determine the optimal location and capacity of an unregulated device for compensation reactive power according to the criterion of minimum active power losses in a traction electrical system. Modeling of trains on the site was made using instant schemes. Description of the traction power supply system implemented by the node potential method and Steinmetz’s symbolic method. Optimal value of reactive power for all possible locations of a compensating device was calculated numerically by an optimization method of Hooke-Jeeves according to the criterion of minimum active power losses in the traction network. The mathematical model allows to consider the elements of the traction network, schedules of trains, change of traction loads of electric locomotives, schemes of overhead network. The proposed approach was considered on the example test problem, which solution allowed to determinate the optimal location and required value of reactive power of an technical device. The placement of a compensating device in a certain place will allows to minimize the power loss in the contact network, track circuit and traction transformers from the flow of the reactive component of the current in average for all instant schemes with various traction loads. An unregulated technical device for compensating reactive power which is located between two traction substations reduces energy consumption for traction of trains on the 1 - 2 %.

The article considers one of the ways of improving the energy efficiency of three-phase power supply system of industrial and railway enterprises. Presented and proved a theorem, which allows to determine the necessary conductivity and the reactive branch currents compensating device with asymmetric structure, for which the equivalent conductivity of these elements and the load will be symmetrical and active. In three-phase electric circuit of an alternating sinusoidal current reactive elements allow to redistribute active and reactive power between the phases. The use of a compensating device with asymmetric structure will reduce losses from the occurrence of reactive currents, reverse currents and zero sequence in low-voltage three-phase power system. As an example of the use of the theorem and the calculated expressions for determination of conductance of the branches of the asymmetric compensating devices a special test problem was considered. It shows the values of power losses, the coefficients of voltage unbalance with and without using the device. Considered possible options for the practical implementation of such technical devices.