Low frequency direct drive middle-high voltage inverter of mine hoist

Abstract

The invention belongs to the high voltage inverter control technologies, and provides a low frequency direct drive middle-high voltage inverter of a mine hoist. The low frequency direct drive middle-high voltage inverter of the mine hoist provided by the invention uses a rectifier transformer for providing voltage for itself; the rectifier transformer comprises a set of primary windings and 3*j sets of secondary windings; each set of secondary windings is connected with a four-quadrant low frequency power unit in series; the quantity of the four-quadrant low frequency power units is corresponding to that of the secondary windings, which is at least 3*1, and the four-quadrant low frequency power units are formed into an A phase, a B phase and a C phase; each four-quadrant low frequency power unit is provided with a two-level IGBT three-phase rectifier bridge and a two-level IGBT-H type inverter bridge installed on the surface of a same heat sink component; the two-level IGBT three-phaserectifier bridge is connected with the three-phase output end of the secondary windings of the rectifier transformer; and the two-level IGBT three-phase rectifier bridge and the two-level IGBT-H typeinverter bridge separately communicate with a power unit controller via a corresponding IGBT driver. According to the low frequency direct drive middle-high voltage inverter of the mine hoist provided by the invention, the reducer and ancillary facilities thereof are reduced, and thus the overall size and costs including operation and maintenance costs of equipment are reduced.

Description

technical field [0001] The invention belongs to the high-voltage frequency converter control technology, and provides a mine hoist low-frequency direct-drive medium-high voltage frequency converter. Background technique [0002] The mine hoist is usually driven by a high-speed asynchronous motor or a high-speed DC motor. In order to match the rated lifting speed of the mine hoist, it is usually equipped with a reducer; or, without adding a reducer, it is driven by a low-speed AC motor or a low-speed DC motor. direct drive. Now there are mainly the following disadvantages: 1) The existence of the reducer, including the provision of lubrication equipment for the reducer, increases the overall volume and weight of the equipment, thereby increasing the investment cost including equipment and infrastructure, tower multi-rope friction hoist Installed on the well tower, the increase in infrastructure investment will be more prominent; 2) The existence of the reducer, due to the ...

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Problems solved by technology

Now there are mainly the following disadvantages: 1) The existence of the reducer, including the provision of lubrication equipment for the reducer, increases the overall volume and weight of the equipment, thereby increasing the investment cost including equipment and infrastructure, tower multi-rope friction hoist Installed on the well tower, the increase in infrastructure investment will be more prominent; 2) The existence of the reducer, due to the addition of a first-stage transmission, reduces the transmission efficiency and relatively increases energy consumption; 3) With the increase in the installed capacity of the mine hoist , due to the limitations of the manufacturing process, it is difficult to manufacture high-power reducers or the pass rate cannot be guaranteed; 4) The former Ministry of Land and Resources' Guotu Zifa [2014] No. 176 document listed "mine hoisting DC motor" as a restricted technology

Restriction reasons: mine hoist motor DC speed control system has a complex structure, high maintenance costs, motor structure is more complex than AC motors, and energy consumption is high; scope of use: only allowed to be used in small mines and phased out; 5) current low-speed direct drive mine hoist The machine is mainly driven by a medium and low voltage synchronous machine, using AC-AC frequency conversion technology and three-level medium and low voltage frequency conversion technology. The highest voltage level is 3.3kV, which is inconsistent with the national conditions of my country's industrial field power supply voltage level, which is usually 6kV or 10kV, causing many troubles ; AC-AC frequency conversion requires an external dynamic harmonic compensation device because its power factor is too low and the harmonic components are too large. AC-AC frequency conversion technology is basically eliminated by the market

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