The article considers the problem of reducing the peak loads on the power supply system in the frequency-controlled electric drive. It is shown that at start-up modes of the urban transportation operation in conditions of weak DC contact network there can be significant voltage drops, which negatively affects the work of other consumers. It is proposed to use an additional power source including a block of supercapacitors and bidirectional DC-DC converter with its own automatic control system in the system of frequency-controlled electric drive. The construction of the DC-DC converter automatic control system for the supercapacitor-based energy storage device is based on the theory of subordinate coordinate control systems. The methods of technical linearization of nonlinearities of the control object have been used in the synthesis of the current controller for the single-loop system. To verify the developed control algorithms, methods of mathematical modeling based on structural schemes are applied. The Simulink application of MATLAB software package has been used to obtain transients. When modeling the system of frequency-controlled electric drive of a tramway with electric energy storages, the discreteness of DC-DC converter and frequency converter was not taken into account. The average values of variables for the period of discreteness of the converter were used in models. Several variants of control algorithms for solving the problem of limiting the peak power consumed from the contact power source during the start-up modes of the electric drive of urban transportation have been considered. The variant of the energy storage system limiting the power consumption of the electric drive from the contact line at a given level while providing the necessary technological modes of the tram electric drive operation is proposed. Structural schemes and control algorithms are given. The results of modeling the frequency-controlled tram electric drive with energy storage system proving the efficiency of the developed control algorithms are presented.
