The application of Oerui inverter in hoisting wells in coal mines

I. Overview This paper mainly introduces the application of the Oerin inverter in hoisting and hoisting. Through practical application, the reliability and safety of the hoisting hoist using the inverter control and the obvious energy saving effect after the inverter is used are explained.
Second, keyword frequency converter, winch, energy-saving three, foreword In recent years, the country has constantly put forward the slogan of energy saving, and for the mining companies proposed to eliminate the hoist old-fashioned electronic control system, requires a higher replacement safety, use more convenient Electronic control system. The well-paying well (single hook) of a certain shipwreck coal mine in Shanxi Province is responsible for the tasks of the entire coal mine personnel going up and down and transporting materials. If a failure occurs, it will affect the production of the entire coal mine. Therefore, the normal operation of the equipment plays a crucial role. The device control method adopts 185kW/8 pole wound motor rotor series resistor speed control, using AC contactor to achieve speed segment switching, forming a step-down starting, gear switching acceleration, full speed operation, gear switching slowdown, stop working process .
Fourth, the original lifting system analysis 1. The original control system is complex, resulting in a high failure rate of the system, contactors, resistors, winding motor carbon brush is easily damaged, a large amount of maintenance work, a direct impact on the hoist production efficiency.
2. It is necessary to rely on the friction brake roller to achieve speed control when lifting and lowering at low speed. Especially when the load changes, it is difficult to achieve constant deceleration control, resulting in discontinuous speed control and poor speed control performance.
3. The starting impulse current reaches about 800A, which causes a great mechanical impact, which leads to a significant reduction in the service life of the motor. Frequently, the mine ventilation fan will trip due to the low grid voltage, directly affecting the safety of downhole production.
4. The degree of automation is not high, increasing the cost of mining and affecting production.
5. The starting torque is small, the mechanical characteristics are relatively soft, and the load capacity is poor, and constant torque cannot be increased.
Fifth, the system transformation principle (slightly)
System diagram is as follows: (slightly)
Working principle: (slightly)
The electrical schematic is as follows: (slightly)
6. After the transformation, the system will increase the starting current by about 200A when the rated load is two tons of material, and the running current 400A will start to decelerate to 50% of the current speed when it is 40m from the wellhead. (The deceleration point and the reduction ratio can be used by the user. According to the need to set their own), the derating process current is less than 100A, set the feedback voltage 673V, discharge voltage 675V. The entire decentralization process defines that the DC bus voltage does not exceed 675V, and starts to decelerate automatically to 50% of the current speed when it is 40m from the bottom of the well.
Before the transformation, the load-carrying material is 600A, 400A after transformation; before the reform, the passenger (12 nuclear loaders) will increase the current by 400A, and after the reconstruction, 250A; the safety indicators and performances fully meet the requirements of the user and have the following advantages compared with the original system. Some advantages:
(1) Soft start and soft stop are realized, mechanical shock is reduced, operation is more stable and reliable, maintenance work is reduced, and production efficiency is improved.
(2) Convenient speed regulation, continuous smoothing, stepless speed change, and more comfortable ride.
(3) The impact current is very small during start-up and acceleration, which reduces the impact on the power grid. There is no phenomenon that the downhole blower fan trips when the hoist is started, which enhances production safety, simplifies the operation process, and reduces the labor intensity of workers. .
(4) Complete safety protection functions, in addition to the original protection and general overvoltage, undervoltage, overload, short circuit, overheating, overcurrent and other protection, it also has chain protection, automatic speed limit protection, automatic deceleration, etc. Make security more reliable.
The average value of the manned current carrying manned power factor is 0.9. One day is calculated according to 18 hours. One year is calculated according to 10 months. Computation: (slightly)
After comparison, it is obvious that the frequency conversion speed regulation energy-saving effect, and now can not see the maintenance costs and equipment wear and tear will gradually reflect the use of time.
Seven conclusions In summary, after the coal mine hoist has changed the frequency boost system, it not only has obvious power-saving effect, but also reduces the maintenance costs of the equipment and creates great economic benefits for the coal mine enterprises. It also enhances the safety of the coal mine production and makes Coal mining companies increased the winning conditions in the new round of industry merger competition. It can be believed that the application prospect of variable frequency speed control systems in the hoisting and lifting industry will be more and more broad.