With the construction of the railway passenger dedicated line, the high-speed railway has gradually entered people's attention. It is not a dream to arrive at the railway in the morning. As an indispensable part of the high-speed railway, the railway power transformation and distribution system has also undergone tremendous changes. The change.
The railway power transformation and distribution system supplies power to all railway facilities except the train traction power supply. The power supply is to connect two 10kV (35kV) power supplies from the substation of the State Grid, and supply power to railway stations and interval loads through the railway power transformation and distribution station. The distance between the substations is 40-60km, and the individual sections are as long as 80'90km: the ordinary-speed railway feeds out two lines from the power distribution station, one is called the self-closing line, and the other is called the through line. A box-type substation is set up in the station, and the self-closing and through-circuit lines supply power to the interval loads through transformers; the high-speed railway has a load point every 3km or so, and the load types are primary loads such as communications, signals, and some secondary loads. The 2 10kV power lines fed out are laid along the railway to supply power. The power lines are called through lines, one is called a first-level through line, and the other is called a comprehensive through line. Quality, high-speed railway and regular-speed railway power distribution stations are equipped with dedicated 10/10kV voltage regulators, which supply power to the through-line through the voltage regulators.
Differences in the form of power supply lines:
my country's ordinary-speed railway through-line in an overhead way
Mainly, the terrain is difficult to supplement the cable laying. Overhead lines have weak ability to withstand natural disasters. For example, the ice disaster at the end of 2007 led to the damage of overhead lines, typhoons in coastal areas, and floods in inland areas may cause power supply interruptions to overhead through lines.
The entire high-speed railway line is powered by cables, and the weak point of the cable line is the cable head. In order to reduce the cost of cable reconstruction, the entire line of the high-speed railway will use three 70 square cables for power supply. The load is small, the transformer capacity of the power supply point in each section is about 80KVA, and the load current cannot be ignored compared with the charging current. The cable charging current will generate a high terminal voltage rise in the long cable line. In order to ensure the no-load and For full-load voltage quality, shunt reactors are installed at the beginning and end of the through line to suppress the voltage rise of long cable lines. Fixed reactors are installed after the through feeder in the railway substation and distribution station, and the switching of the shunt reactor is incorporated into the power remote control system to achieve Remote monitoring to ensure voltage quality and equipment operation at no-load and full-load.
The difference between the interval power supply mode:
In the constant-speed railway, signal box-type substations are set up in the interval small stations, RTU devices are installed in the signal box-type substations, and the low-voltage switches in the box-type substations are set to remote control, which realizes a certain degree of remote operation.
High-speed railway section power supply generally adopts
10/0. The 4KV intelligent box-type substation is powered by the first-level through and comprehensive through-through power supply, and the high-voltage load switch is incorporated into the function of remote control. When the through-line is faulty, the power dispatching center can automatically or remotely cut off the fault section manually, that is Disconnect the high-voltage load switches of the intelligent box-type substations on both sides of the fault section of the through-line, and supply power to the through-line through the railway substations on both sides, so as to ensure that when a line fault occurs in the through-line, it will not affect the power supply of the primary load, and the low-voltage The switch is incorporated into the telecontrol function to monitor the low-voltage power supply at the primary load power point, prevent the long-distance power supply from affecting the power quality, and timely detect and deal with the low-voltage circuit trip caused by the power load. Transformers and voltage transformers are included in the power remote control. The RTU control device of each switch has the function of current and voltage fault recording, which is convenient for the analysis and search of the cause of the accident, and shortens the search time for the fault of the through line. In order to facilitate the maintenance and remote control of the intelligent box-type substation. Automatic debugging, use the telecontrol channel to set up a telephone to contact the dispatch center, there are no guards along the railway line, the box-type substation is set up with a door sensor and uploads the information, and the box-type substation is opened abnormally, and the box-type substation is equipped with smoke detectors and To upload information, in order to ensure the normal operation of weak equipment such as communication processors, the box-type substation is equipped with a temperature-controlled self-starting ventilation system. Through the above technical measures, the reliability and maintenance of the power supply system of the smart box-type substation are improved.
