Transformation of mine hoist by high voltage variable frequency speed control system

1. Brief introduction of the original mine hoist speed control system and frequency conversion electronic control system Hebei Qifengfeng Mining Group Corporation is a national large-scale enterprise and a national top 100 coal enterprise. The Group's New Third Mine has a pair of vertical mines. The well lifting system adopts 380KW/6KV three-phase asynchronous motor, and the rotor string resistance speed double-speed lifting work mode. Since the New San Mine is a mine built in 1995 on the basis of the original Bei Datun mine, the auxiliary shaft still uses the well of the old well. Due to the limitation of the size of the shaft well, it is necessary to take into account the single-piece equipment with a large size downhole. Therefore, the lifting container is designed as two containers with different widths and widths; in addition, the lifting system is also responsible for lifting personnel, materials, meteorites, etc. The weight of each hook may change, which causes the lifting system to be in the speed regulation stage, and the speed control is more difficult. Due to the short lifting stroke of the new third mine auxiliary shaft (only 175 meters), the time for the lifting system to run in the speed regulation phase accounts for more than 10% of the total running time, and the power consumed in the speed regulating phase is very large. A lot of power is wasted.
Because the auxiliary vertical shaft lifting system is affected by different materials, it is often in a state of negative force increase. In the state of negative force increase, the main motor string resistance speed regulation work mode, the speed regulation stage can only control the vehicle speed by the work brake, the mechanical energy is consumed in the work brake, not only the energy can not be reused, but also the wear of the work brake is aggravated. Increased material consumption and increased system safety have also been greatly affected.
In order to improve the safety of the system operation and achieve energy saving, the company's leaders are determined to transform the electric control system. After many investigations, it was decided to use the JD-BP37-400T four-quad high-voltage inverter produced by Shandong Xinfengguang Electronic Technology Development Co., Ltd. to carry out technical transformation of the winch drive system, and the transformation has achieved the intended purpose.
The relevant parameters of the original mine hoist winch motor are as follows:
Model JR158-8
Power 380KW
Current 47A
Voltage 6000V
Speed ​​735r/min
2. The hoist's requirements on the torque of the inverter are compared with those of ordinary fans and pumps. The hoist has very strict requirements on the torque.
(1) The starting torque is very large: the starting torque is generally 1.8 times or more of the rated torque;
(2) Acceleration torque: During the operation, the acceleration time is required to be short, and a large acceleration torque is required;
(3) Braking torque: The braking torque is divided into three situations: the first one is rapid deceleration at high speed operation, and the corresponding braking torque is required; the second case is with heavy object decentralization; the third case It is in the stop state, the mechanical brake does not work for a certain period of time, the inverter should give the corresponding braking torque to prevent the heavy object from slipping.
(4) Low frequency torque characteristics.
For fans and pumps, the torque decreases with the decrease of the speed. The starting torque is generally less than the rated torque, so the low frequency band can be compensated slightly to meet the demand.
The hoist frequency converter is not. The starting torque should be at least greater than the sum of the rated speed and the maximum static friction. At the same time, the required acceleration torque should be provided at low speed. Therefore, the required starting torque is faster than the steady speed. The running time is much larger, and the torque during acceleration is much larger than the torque at steady speed. This requires sufficient compensation at the low end to increase the starting torque and the torque at low speed.
3. Fengguang Electronics Co., Ltd. JD-BP37/38 series high-voltage lifting frequency converter New Fengguang Electronics Co., Ltd. is one of the earliest companies to develop inverters in China. One of the national standard certification units for inverters, energy feedback technology is at the leading level in China. The frequency converter obtained the national patent for the hoist. Therefore, the JD-BP37-400T (400KW) high-voltage boosting frequency converter produced by the company was selected.
3.1 JD-BP37/38 series high pressure lifting frequency converter introduction JD-BP37 high pressure lifting frequency conversion