Long-distance medium-voltage direct current power transmission system for coal mine

Abstract

The invention provides a long-distance medium-voltage direct current power transmission system for a coal mine. The long-distance medium-voltage direct current power transmission system comprises a front power electronic rectifying device, a medium-voltage direct current power transmission device, and a tail power electronic inverting device, wherein the front power electronic rectifying device isconnected with an alternating current power grid; the medium-voltage direct current power transmission device is connected with the front power electronic rectifying device; the tail power electronicinverting device is connected with the medium-voltage direct current power transmission device. Compared with the prior art, the long-distance medium-voltage direct current power transmission systemhas the beneficial effects and advantages that the front end input is a low-voltage working frequency alternating current power source, the voltage in the transmission process is direct current mediumvoltage, the direct current or alternating current is flexibly selected for supplying power for tail end loads according to the load type and required voltage class, the system structure is flexible,and the requirement of various loads under the coal mine can be met; the wire loss is smaller; the construction cost of a line is lower; the size of a high-frequency transformer is smaller, and the efficiency is higher; the flowing of reactive power is avoided, and the electric energy quality and transmission efficiency are higher; the additional reactive compensation equipment is not needed.

Description

technical field [0001] The invention relates to a coal mine long-distance power transmission system, in particular to a long-distance medium-voltage DC power transmission system suitable for coal mines. Background technique [0002] There are a large number of coal mines in my country, most of which use their own dedicated substations, which are relatively independent power supply systems. With the increase in the number of coal mines and the continuous increase in the scale of coal mine power grids, it is becoming more and more difficult to control the safety and power consumption of coal mines. At present, most coal mines use AC distribution networks. With the gradual popularization of power electronic equipment such as high-voltage and high-power inverters and switching power supplies in coal mines, the AC power distribution method is becoming more and more difficult to meet the demand. The main problems include: : [0003] (1) The line loss is large. Long-distance lon...

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Problems solved by technology

[0008] Aiming at the defects in the prior art, the object of the present invention is to propose a long-distance medium-voltage direct current transmission system suitable for coal mines that solves the problems of large terminal voltage drop and large line loss

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