Negative-sequence compensation device and method for traction-compensation transformer

Abstract

The invention discloses a negative sequence device of a compensation transformer and a method thereof, which relate to the technical field of traction power supply of an electrified railway. The negative sequence compensation device is mounted on the traction-compensation transformer, wherein an input terminal of a measurement and control unit MC is connected with a measurement terminal of a traction port voltage transformer PT and a measurement terminal of a current transformer CT, and an output terminal of the measurement and control unit MC is connected with a control terminal of the firstreactive power compensation unit SVG1 and a control terminal of the second reactive power compensation unit SVG2. The measurement and control unit is connected with the reactive power compensator, andthe reactive power of the first reactive power compensation unit and the second reactive power compensation unit is controlled by calculating the traction port power P and the working condition through the voltage value of the voltage transformer and the current value of the current transformer. The device and method are used to measure the voltage value of the voltage transformer and the currentvalue of the current transformer and calculate the traction port power and operating conditions to control the reactive power of the reactive power compensator.

Description

technical field [0001] The invention relates to the technical field of AC electrified railway power supply, in particular to the technical field of traction transformer structure. Background technique [0002] Electrified railways generally adopt the single-phase power frequency AC system powered by the public power system. In order to make the single-phase traction load be distributed as balanced as possible in the three-phase power system, the electrified railway often adopts the scheme of rotating phase sequence and separate phase and partition power supply. The adjacent power supply areas at the phase-splitting partitions are divided by phase-splitting insulators to form electrical split phases, also known as phase splits. In order to prevent electric locomotives from burning out catenary suspension components due to arcing through electric split-phase emission, and even causing phase-to-phase short-circuit and other accidents, as the train speed continues to increase, w...

AI Technical Summary

Problems solved by technology

[0003] High-speed and heavy-duty railways have widely used high-power AC-DC electric locomotives or EMUs based on full-control devices such as IGBTs and IGCTs. The core is traction converters with multiple sets of four-quadrant PWM control and multiple control. The content is small, and the power factor is close to 1, but the traction power of AC-DC electric locomotives or EMUs is large. For example, the rated power of high-speed EMUs operating in large formations is 25MW, which is equivalent to 5 times that of ordinary-speed railway trains. The main problem of power quality caused by power single-phase load to three-phase grid will be the problem of three-phase voltage unbalance (negative sequence)

Images