Electric split-phase non-interruption flexible connection-compensation device and method for traction electric network

Abstract

The invention relates to an electric split-phase non-interruption flexible connection-compensation device and method for a traction electric network, belonging to the technical fields of railway transportation equipment and electric power and electronics. The device comprises a two-phase back-to-back converter set and three position sensors, wherein the two-phase back-to-back converter set comprises two single-phase converter sets Va and Vb sharing a DC side capacitor set, and two single-phase reduction transformer sets Ta and Tb respectively connected with AC sides of the two single-phase converter sets Va and Vb, or a single-phase reduction transformer set Ta or Tb connected with the AC side of the single-phase converter set Va or Vb, and also comprises three electric quantity sensors, a killer switch, a controllable fling-cut switch and a main controller. The device can work in two modes, and realizes that an electric locomotive passes through split phases without interruption and with loads. The device has functions of active power transfer, reaction power compensation and harmonic compensation, and can solve the problems of three-phase voltage imbalance, voltage fluctuation, low power factor, harmonic pollution and the like in a traction substation.

Description

technical field [0001] The invention belongs to the technical fields of railway transportation equipment and power electronics, and in particular relates to a device capable of simultaneously realizing the automatic passage of an electric locomotive with load without power failure through the phase separation link of an AC traction network and comprehensive compensation for power quality of a traction substation. Background technique [0002] Like most other countries, China's electrified railway power supply system adopts a single-phase power frequency AC power supply mode, in which the traction power supply system implements a segmented current receiving and phase-sequence access mode to reduce large-capacity single-phase unbalanced traction The serious negative sequence effect caused by the load on the power system. In order to prevent short circuit between different phases, each phase needs to be separated by air or insulators to form a so-called "electrical phase separa...

AI Technical Summary

Problems solved by technology

Although the closing surge can be suppressed to a certain extent by limiting the command current of the locomotive to zero, and then controlling the current rise rate after it passes through the electrical split phase, the delay of restarting the locomotive will be more than 6s, which is harmful to high-speed electric power. The running speed of the locomotive has a great influence. It is estimated that in the Beijing-Shanghai high-speed railway in China, the total running time loss caused by the electric locomotive passing through the electric phase separation will reach more than half an hour.

It can be seen that the electric phase separation link and automatic over-phase separation in the traction power supply system have been seriously restricting the safe and reliable operation of high-speed and heavy-duty trains. So far, there is no cure for the disease, and it is imperative to find a new solution

Moreover, these methods inevitably cause the locomotive to have a "power-off-re-power" process, and a series of transitional processes resulting from this will form a transient hazard, which seriously restricts the high-speed and reliable operation of the electric railway.

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