1 Project profile
Beiping Dong Mine is one of the two mines under Baoyuan Mining Company. The auxiliary well hoist of Beiping dong Mine adopts winding asynchronous motor to drag, and the motor adopts the traditional series resistance speed regulation mode, which is a backward technology and has the following disadvantages:
(1) A large amount of electricity consumption in the transition resistance, resulting in serious energy waste.
(2) The control system is complex, resulting in a high failure rate of the system, the contactors, resistors, winding motor carbon brush are easy to be damaged, and the maintenance workload is very large, which directly affects the production efficiency.
(3) Low speed and crawling stage need to rely on the brake skin friction roller to achieve speed control, especially when the load changes, it is difficult to achieve deceleration control, resulting in discontinuous speed regulation and poor speed control performance.
In view of the above problems, the coal mine decided to transform the original system. According to the development of current science and technology, it is an ideal scheme to adopt the frequency conversion speed regulation with high technical content to replace the original string resistance speed regulation of the winding motor. After inspecting the site of several users in various aspects, the FD5000 series Medium Voltage Drive lifting system produced by FGI was finally selected.
2.Introduction to renovation equipment
Two operating systems are used on the site of Baoyuan Coal Industry Company, and the original operating system controls the power frequency operation. The new operating system is provided by Shanxi Huawei to control the frequency conversion operation. Mutual standby, to ensure the safe operation of the hoist. Two operating systems share a winch system.
2.1 Upgrade the equipment parameters on the site
The device configuration is shown in Table 1. The field equipment is shown in Figure 1-7.
Table 1. Related parameters of the elevator | |||
Model | 2JK-3×1.5/20 | Roller diameter | 3.0m |
Reduction box | |||
Model | MTL300 | Reduction ratio | 20:1 |
Well barrel and container | |||
Well-type | Slope mine | Container type | Trip |
Improve the full schedule | 885m | winding level | Single level |
Motor | |||
Motor model | JRQ1510-10 | Power of motor | 400kW |
rated speed | 590rpm | Power factor | 0.8 |
The stator parameters | 6kV/50.5A | Rotor parameters | 603V/412A |
FD5000 Series medium voltage drive products, with high speed DSP as the control core, combined with advanced speed sensor free vector control technology, integrating advanced energy feedback technology, and reliable lGBT high current drive technology, is a typical representative of the new generation of high performance perfect without harmonic high voltage frequency conversion speed regulation products. The vector control function makes the asynchronous motor have large starting torque, good dynamic torque response and high speed regulation accuracy. The application of energy feedback technology makes the power unit series high voltage frequency converter with the four quadrant operation ability, and the energy can flow between the grid and the motor.
Table 2 Technical indexes of FGI high voltage booster inverter | |||
Model | FD5000 | Power rating | 500kW |
Input / output voltage | 6kV/0~6kV | Rated current | 60A |
Frequency frequency range | 0～50Hz | Overload capacity | 110% continuous, 150% allowed 1min and 220% allowed 1.5s |
3.Reform project
3.1 Main loop scheme
In order to ensure safety and reliability, the frequency conversion speed regulation system and the original speed regulation system coexist, mutual standby, and can be switched at any time.
High voltage elevator frequency converter is a core part of the whole transformation system, which has various interfaces suitable with the electronic control system. When operating with the automatic control console, the electric console sends the "forward operation", "reverse operation" and "sudden stop" of frequency conversion to the frequency converter, and the "given speed" signal of 4 ~ 20 mA. The inverter sends a three-way switching signal of "frequency converter standby", "frequency converter failure" and "safety loop" to the electric console, and the analog output signal for display. The electric console controls the high voltage circuit breaker, and connects it to the corresponding control loop. The shaft encoder installed on the winch signals the motor speed and winch position to the electric console. The electric console receives the operation instructions of the winch driver.
4. operation effect
From the current operation situation, after the frequency conversion transformation of the auxiliary well lifting winch, the real soft start of the motor is realized, the improvement time is shortened, the maintenance workload reduces, and the production efficiency is improved. Greatly improves the safe operation of the hoist.
After the winch transformation, the whole frequency conversion lifting system has the following characteristics:
(1) The FD5000 Series medium voltage drive eliminates the original AC contactor and speed regulation resistance used for electronic control and speed regulation, which improves the reliability of the system and improves the working environment of the operators.
(2) The soft start and soft stop of the winch motor are realized, making the operation more stable, with small mechanical impact.
(3) The impact current in the process of starting and acceleration is small, and the maximum starting current in the acceleration process is not more than 1.3 times. In the rated current, the elevator rises from low speed smoothly and smoothly to the highest speed under heavy load, and there is no large current, which greatly reduces the impact on the power grid.
(4) The DC braking function is added to make the heavy car stop more stable.
