light industry

First, the foreword
Most of the existing coal mine belt conveyor generally use the power frequency drive, less use of frequency converter drive. Motor frequency operation combined with hydraulic coupler efficiency problems, resulting in operation of belt conveyer is not the economy; simultaneously, the motor can not be applied to soft start and soft stop, mechanically produced a dramatic impact, accelerate the mechanical wear; and belt, the hydraulic coupler wear and maintenance problems will bring a great amount of cost to the enterprise. The status quo to create energy-saving society is does not conform to, frequency conversion to save social energy, increase the economic benefit of coal enterprises have very real economic significance and social significance of belt conveyor for coal mining enterprises.
The belt conveyor is driven by the driving wheel drum, and the belt is driven by the friction traction belt. The belt is driven by the tension deformation and the friction force to move the object on the supporting roller wheel. Belt is an elastic energy storage material, in the belt conveyor stop and running are stored in a large number of potential energy, which determines the starting of the belt machine should be used in soft start mode. Most of the coal mine used hydraulic coupler to realize the soft start of the belt conveyor, the adjustment of the mechanical efficiency of the hydraulic coupler at the start of zero, so that the motor no-load start. Although some of the rotor on resistor to improve the startup torque and buck no-load starting and other methods, but the motor starting current is still large, not only will cause violent fluctuation of grid voltage, can also cause inside the motor mechanical shock and fever phenomenon. At the same time, the belt is broken and aging due to the short starting time and large loading force, and the strength of the belt is high. Coupled with hydraulic coupling work for a long time will cause the internal temperature rise, metal parts wear, leakage and efficiency fluctuation etc. happens, it will not only increase the maintenance difficulty and cost, pollution of the environment, but also to make multi machine with a belt drive to solve average power and synchronization problems.

Two, ECF100-U working principle
ECF100-U series inverter can achieve soft start, soft stop function, can reduce the impact of mechanical transmission, can prolong the service life of the belt conveyor, and fundamentally solve the problem of power balance. ECF100-U series inverter using master-slave control, through the control of the inverter output torque, so that the output torque of the master and slave inverter, the bus voltage is basically the same. When the system is in steady state, the output torque percentage error of the master slave inverter is + 1%.

Three, ECF100-U series of advantages
1) the soft starter of the belt conveyor system. Use the frequency converter soft start function, the motor soft start of belt conveyor soft start combined, through the slow speed of the motor starting, driven by belt conveyor slow start, will belt internal storage energy slow release, so that the belt conveyor in starting formed in the process of tension wave minima, almost on the belt will not cause any damage.
2) to achieve the power balance of the belt drive motor. Application of frequency converter on belt conveyor is driven, the general use of a trailer for a control, when the multi motor driving, it adopts the master-slave control, realize the balance of power. In Henan coal mine main shaft belt for 2 * 135kW motor drive, the master-slave control, light load master and slave motor current difference of about 5, loaded with a difference of about 2A. The power balance of the belt machine is realized.
3) lower belt belt. Driven by converter, due to inverter starting time in 1s ~ 6500s adjustable, usually belt conveyor starting time in the 60s to 200s according to setting the scene, belt conveyor starting time prolonged, greatly reducing of the belt of strong requirements, reduce the initial investment of equipment.
4) reduce the maintenance of equipment. Frequency converter is an integration of electronic devices, it will be converted to the life of the mechanical life of electrical equipment, long life, greatly reducing the amount of equipment maintenance. At the same time, the soft starting function of frequency converter is used to realize the soft starting of the belt conveyor, which has no impact on the machine during the starting process and the maintenance of the mechanical part of the belt conveyor is greatly reduced. As a Henan coal mine main shaft belt converter drives, only a belt buckle cost reached ten thousand yuan.
5) start smooth, large torque, no impact current, can achieve heavy load start.
6) energy saving. The energy saving effect is mainly embodied in the two aspects of system power factor and system efficiency, which are mainly embodied in the belt conveyor.
A, improve system power factor
Usually case, relatively large electric motor used in coal mine in the design process on the margin, work most can not run at full capacity, motor work in full voltage, full speed and load are often very small, part time no-load operation. By the motor design and operation characteristics, only when the motor is close to full load is the highest efficiency, power factor is the best, light load is reduced, resulting in unnecessary power loss. This is because when the light load, the active component of the stator current is very small, mainly the reactive power component, so the power factor is very low. After driving by frequency converter, the power factor is more than 0.9 in the whole process, and the reactive power is greatly saved.
B, improve system efficiency
After the inverter driver, the motor and the reducer is a direct hard connection, the middle of the hydraulic coupler to reduce the link. And hydraulic coupler transmission efficiency is not high and mainly through the liquid to drive, the transmission efficiency of the liquid transmission efficiency than direct hard links to many low, and is driven by the inverter system total transfer efficiency to driven than hydraulic coupler efficiency to 5% ~ 10%.

Four, debugging steps
1) according to the specification of the wiring diagram of the inverter wiring all connected.
2) the rated speed of the motor, rated current input to the parameters of the inverter.
3) to determine whether the rotation direction of the motor is correct. Method: first open the host, then judge from the machine, respectively.
4) the recommended parameters of the specification set into the frequency converter.
5) no-load debugging, observing the operation of the master and slave inverter is normal.

Five, the end of the language
After the transformation of the frequency conversion technology, the belt conveyor is running well, and it completely realizes the soft start and stop operation of the belt conveyor, which greatly improves the system's power factor and system efficiency. After the transformation system can automatically adjust the output frequency and the output torque according to the load changes, changed the pattern of previous frequency motor run in constant speed, in a great extent saves electric energy; hydraulic coupler exit more greatly save the equipment maintenance and maintenance costs. The application of energy saving in the coal industry can create enormous economic benefits and social benefits, and is playing an important role in building energy saving and environment friendly society.