1.Introduction to the Applications

Yanmei Heze Energy Co., Ltd. Zhaoulou Coal mine belongs to Yanzhou Coal Energy Co., LTD. The mine was put into operation in December 2009, with a designed production capacity of 3 million tons. It is located 22kM southeast of Yuncheng County, Heze City, with a length of 12-15.9kM from east to west and an area of 143.36kM2. The mining depth is -600--1200m. The field application is FGI explosion-proof high voltage frequency inverter , model BPBJV1-1400/10/3.3, inverter input voltage 10kV, output voltage 3.3kV, power 1400kW, based on cascade topology, 3 units per phase. The scraper is driven by double motors at the head and tail, which are two 1200KW/3300V variable frequency motors. Taking into account the anti-overload ability and operating stability factors, the frequency conversion power amplification is used in 1 gear. The two frequency converters use master-slave control and the communication mode is optical fiber communication.

Because the scraper is used with the shearer and the hydraulic support, the shearer walks on the scraper, the support pushes the middle groove of the scraper to move, and the coal sheet and scraper chain on the working face will be stuck, the coal amount on the scraper is too large, and the situation of full load will be started, which will produce a large dynamic load.

2.Explosion-proof high voltage inverter control mode and application effect

The problem of uneven load distribution is easy to occur when the scraper is driven by two machines. Because of the difference in material performance and manufacturing process, the speed and torque characteristics of two motors of the same model are often different. The transmission reducer and sprocket are also different due to the manufacturing process, and the multi-deformation characteristics of the sprocket also increase the fluctuation of load distribution, thus affecting the power balance of the master and slave. In order to solve the above problems, master and slave machine regulation schematic FGI explosion-proof high voltage inverter based on VF speed sag control mode of scraper control is based on the change of motor current to dynamically realize the load balance distribution between each motor control mode. The motor current is taken as the feedback quantity in the speed droop mode scraper control system, so as to form a closed-loop control system with motor current as the feedback quantity.

3. Advantages of high pressure explosion-proof inverter in underground application

Low frequency start of large torque: explosion-proof high voltage inverter adopts double loop accurate control of current and speed, which can meet the occasions of 2.2 times starting torque and large changes in underground load;

Power balance adaptive, explosion-proof high voltage inverter adopts droop control mode, automatically adjust the load balance rate of the master and slave machine, without human intervention, the load imbalance rate is less than 5%;
Smart mine communication interface: meet the smart mine communication interface, support optical fiber, network cable, wireless and other network access methods, Zhaolou coal mine uses network port communication to transmit data to the well data monitoring center; Remote monitoring and fault diagnosis: Relevant data monitoring, fault analysis and device life prediction can be carried out through PC or mobile APP.