Long-distance Medium Voltage DC Transmission System for Coal Mine

Abstract

The present invention provides a long-distance medium-voltage DC power transmission system suitable for coal mines, including: a front-end power electronic rectifier device connected to an AC power grid; a medium-voltage DC power transmission device, the medium-voltage DC power transmission device It is connected with the front-end power electronic rectification device; the terminal power electronic inverter device is connected with the medium-voltage direct current transmission device. Compared with the prior art, the beneficial effects of the present invention are as follows: the front-end input is a low-voltage industrial-frequency AC power supply, the transmission process is a DC medium-voltage power supply, and DC or AC can be flexibly selected according to the type of load and the required voltage level for the power supply of the terminal load. The structure is flexible and can meet various load demands in coal mines, and its advantages include: smaller line loss; lower line construction costs; smaller high-frequency transformers with higher efficiency; no reactive power flow, power quality and The transmission efficiency is higher; there is no need to add reactive power compensation equipment.

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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