Abstract: This article describes the successful application case of Senlan SB70G series inverter in non-ferrous metal alumina production line, analyzes the production process of alumina and puts forward the requirements of alumina production to the frequency converter, and gives detailed description of the SB70 series inverter. Aluminium production line application wiring and related function settings. Keywords: Senlan SB70 frequency changer alumina production Non-ferrous metals industry has high requirements for frequency converters, and the successful use of Senlan SB70 inverters in large areas of the industry is the first time in China-made frequency converters, which marks a significant improvement in the technical level of domestic inverters. In practical applications, Senlan SB70 inverter is not inferior to foreign inverters. It successfully replaces the foreign brand inverters in the alumina industry, and the price is cheaper. I. Alumina production process The production of qualified alumina from bauxite ore requires several major production processes such as raw materials, dissolution, settling, decomposition, and roasting. It is organized into raw materials, dissolution, settling, decomposition, roasting and other major workshops according to the order of the process flow. To make full use of the mother liquor, set up an evaporation process workshop again. The raw material workshop is used to prepare raw ore pulp that meets the requirements for particle size and composition ratio; the dissolution workshop provides high-temperature and high-pressure environment for raw ore slurry through multi-stage preheating casing and pressure cooker, and ensures sufficient dissolution time for the original The alumina component in the slurry dissolves into the sodium aluminate solution. The sedimentation workshop separates the crude liquid in the slurry and the red mud consisting of various impurities through settling and multiple reverse washings. The separated crude liquid is filtered by a leaf filter to obtain semen, and then sent to decomposition. The workshop and the seed crystals are mixed, and each of the decomposition tanks is gradually reduced in temperature and agitated to fully analyze the aluminum hydroxide. The precipitated aluminum hydroxide slurry is classified and then the fine material is passed through the seed filtration to prepare seed crystals. The rough material is sent to the roasting workshop and filtered. High-temperature roasting results in finished alumina. The evaporation plant is used to concentrate the circulating mother liquor to remove excess moisture entering the mother liquor during the process to reach the mother liquor concentration required by the process. Second, the alumina production of the inverter requirements The entire alumina production process is carried by various pumps such as a slurry pump, a feed pump, a discharge pump, a mother liquor pump, a lye pump, and a circulation pump. In the production process, the control of the temperature and pressure of the materials and reaction vessels, the flow rate of the ingredients and other indicators are very strict; at the same time, in order to ensure the continuous operation of the continuous operation of the equipment such as the disintegration tank stirring, the high temperature and high pressure of the diaphragm pump and the pressure cooker are required. High-alkali equipment and roasting system The safe operation of flammable and explosive equipment requires that the various pumps that transport the material be operated at variable speed under the control of the DCS. The alumina production process is more complicated, the production environment is poor, the temperature is high, and the dust is large. The main requirements for the inverter are: 1. The working medium of the slurry pump, feed pump, discharge pump, etc. is a very viscous slurry, and its load characteristics are close to constant torque load characteristics. For some reason, the production will pause for a short time, and the viscous slurry will produce settlement. When the restart production is started again, the starting torque of these pumps is very large. Therefore, the frequency converter is required to have sufficient starting torque and high overload capacity. 2. The alumina production line occupies a large area. The electrical control equipment and frequency converters are installed in the power distribution room. The distance between most of the motors and the frequency converter is 100-300 meters, and the output of the frequency converter is required to be connected to 100. -300 meters of cable can work normally. 3, the inverter output contains high harmonics, the number of inverters used in the field, you must consider the harmonics on the DCS control system and field control instrument interference, the output harmonic content of the required frequency conversion is lower, lower than the national standard GB12668 -2.2002, the harmonic content required by GB12668-3.2003. 4. The production of alumina has continuity. The production of aluminum oxide in the entire production line will cause a great loss due to the failure of one equipment. Therefore, the reliability of the inverter is extremely high. Third, the application of SB70 series inverter in alumina production line From the above, it can be seen that alumina production puts high demands on the frequency converter. When designing aluminum-magnesium design institutes, all foreign converters such as ABB, Schneider, Siemens, and AB are used without exception. In recent years, domestic inverter technology has made considerable progress, and rotor flux-link oriented speed sensorless vector control has been successfully developed. Its technical performance is close to the advanced level of foreign inverters, coupled with the improvement of process technology and management levels. High-performance, high-reliability vector control inverters that meet the requirements of alumina production lines are not difficult, and are relatively inexpensive compared to foreign inverters, and have certain advantages in competition with foreign inverters. A Sino-foreign joint venture alumina producer in Henan Province, which produces 1.2 million tons of alumina annually, according to the requirements of the production process, selects a new generation of low-noise, high-performance, rotor-field oriented SB70 independently developed by Hope Senlan Drive Manufacturing Co., Ltd. Speed ​​sensorless vector control frequency converter provides variable frequency speed control (power from 22kW to 450kW) for each process of its production process. A total of 78 units are used for installation. The specific use of the station is as follows: Inverter power (kW) Device name 450 Seed pump 250 Dilution pump, discharge pump, feed pump, evaporator feed pump, evaporator discharge pump, efflux pump, single-pole double-suction centrifugal pump, semen pump 220 Mud pump, feed pump 200 Slurry pump, feed pump, evaporation liquid pump, crude liquid pump 160 Liquid Alkaline Storage Tank / Qualified Liquor Pump, Qualified Lye Pump / Mother Liquid Pump, Horizontal Circulation Pump 132 Hot water station washing pump, slurry speed control pump 110 Overflow pump, feed pump, submerged variable speed pump, intermediate cooling pump 90 Normal pressure desiliconization power distribution room circulation pump, settlement pump, seed mother liquid pump 55 Strong filtrate pump, weak filtrate pump, mother liquor pump 45 Hot water pump 37 Salt bottom pump twenty two Salt bottom pump For the main requirements of alumina production on the inverter, the high-performance SB70 speed sensorless vector control inverter can achieve 200% torque at 1Hz without closed-loop operation; considering the overload factor, the motor capacity will increase in practical applications. In the first grade, the capacity of the inverter is also properly increased; the SB70 inverter adopts a variety of harmonic suppression technologies and the total harmonic content is lower than the national standard. Considering that more inverters are used in the entire production line, input reactors and input filters must also be installed on the input side of the inverter to ensure that it will not interfere with the calculation control system and digital instruments in any case; the inverter output cable The limited distance is generally within 50 meters, the length of the output cable increases, and the distributed capacitance and distributed inductance also increase accordingly. For a certain harmonic wave may cause oscillation or form a standing wave, which will seriously affect the operation of the motor. When designing an inverter control system, install an output reactor or an output filter on the output side of the inverter to stabilize the dU/dt spike output from the inverter. Fourth, the inverter wiring diagram and function settings 1, wiring diagram: The inverter control principle of each process is basically the same, so draw only one graph as a representative. In addition, there are some differences in the function setting between the different sections and procedures. The table only lists the parameter setting parameters of the mud pump SB70G220 for reference only. The inverter sub-functions are as follows No. Terminal number Features Comments 1 P10 Near ground speed regulation power supply; 2 AI1 Near ground speed given; 3 AI2 Centralized control (DCS system) speed reference; 4 GND Analog signal common ground; 5 FWD Inverter start/stop; 6 X1 Analog current/voltage switching 7 COM Digital signal ground; 8 TA1 Relay output (frequency conversion operation) To DCS system 9 TB1 10 TA2 Relay output (frequency conversion fault) To DCS system 2. Inverter function setting table: function code Function Description Note F0-01=3 Running the main channel speed reference Controlled by DCS system F0-02=1 Run command channel selection External terminal control F1-00=30 acceleration time F1-01=30 deceleration time F4-00=42 Multi-function digital input selection Given frequency channel switching F5-02=1 T1 relay output function Inverter running F5-02=1 T2 relay output function Inverter fault output F6-00=2 Analog current input Given speed by DCS F6-14=0 Analog current input Given speed by DCS F6-15=1 Analog current output Provide DCS display speed V. Conclusion SB70 inverter has been put into operation for nearly one year since the alumina production line was installed. There have been no failures, and the reliability rate has reached 100%. It has a very high reliability and is comparable to foreign inverters. 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The SB70G series inverter is a new generation of low-noise, high-performance, high-reliability, and powerful engineering frequency converter independently developed by the hoped Senlan Inverter Manufacturing Co., Ltd. It adopts a rotor field-oriented vector control method to achieve a large-scale motor revolution. Moment of high precision control. Its operation panel has functions of programming, operation, parameter copying and hot-plugging, which greatly facilitates the modification of parameters by the operator (only one inverter is set with parameters, and other parameters can be copied to reduce the workload in the debugging process). Speed ​​setting can be switched by terminals to reduce the externally locked cables. In case of instantaneous power failure, the bus voltage control enables uninterrupted operation; the carrier frequency can also be automatically adjusted according to the load characteristics and ambient temperature. 