SYSTEM OF BIDIRECTIONAL DC POWER FLOW AT THE ELECTRIC TRANSPORT TRACK SUBSTATIONS

摘要

The invention is related to electrical engineering and to the supply systems of electric transport network in particular. The goal of the invention is to simplify the realization of bidirectional DC power flow at the electric transport track substations. The basic idea of the invention is that in the electrical transport track substation system containing the three-winding three-phase transformer, the primary winding of which is connected to the symmetrical three-phase voltage supply network, the voltages of the first of two secondary windings are in phase with the voltages of primary winding, but those of the other secondary windings are in opposite phase. Zero-points of the secondary windings are connected through reactor with middle-point that forms negative pole of DC system output. Each phase of the secondary windings are connected to the diodes, the united cathodes of which form positive pole of the output voltage. In parallel with each diode in the opposite to their conductivity direction the transistors, each bypassed with reverse diode, in series with capacitors are connected. The non-stop control of each transistor is realized by means of individual diode-resistor-capacitor off-time delay unit from the module of determination of major instantaneous voltage meanings of each phase voltage of the secondary windings for that winding the voltage of which is in phase with that of the primary winding. For the other secondary winding from the module of determination of minor phase voltage meanings, a determination module of the major value activates the transistor of the phase with higher momentary value of the voltage, but the determination module of minor value switches on the transistor of the phase with lower momentary value of the voltage.