Application of FGI FD5000s high voltage frequency inverter in iron and steel industry

1.project overview

Fujian Sansteel (Group) Co., Ltd. is the largest steel complex in Fujian Province, with an annual output of more than 5 million tons of steel. It is a large-scale enterprise group with cross-industry, cross-region and cross-ownership, and the largest steel production base and fertilizer production base in Fujian Province. Fujian Sanming Iron and Steel Co., LTD. Oxygen plant, is for the production of steel production of high-purity oxygen enterprises, plays an important role in steel production.

Oxygen compressor is one of the key equipment in the oxygen plant of iron and steel enterprises, the general power is large, and the current will cause a huge impact on the power grid when starting, and even cause power grid paralysis, causing hidden dangers to the power supply of iron and steel enterprises.

2.field technology

Steel-making involves heating pig iron and other raw materials to high temperatures and then conducting chemical reactions such as dissolution, reduction and carbonization to produce high-quality steel. In this process, a large amount of oxygen is needed to react with the fuel in the furnace (such as coke), so the pure oxygen manufacturing machine plays a great role.

The working principle of the oxygen compressor is to remove the water, carbon dioxide, nitrogen and other impurities of the compressed air through cooling, membrane separation and adsorption technology, so that the remaining main component is oxygen. The resulting high concentration of oxygen can then be delivered directly to the furnace for the combustion reaction. Compared with the traditional air oxygen mixing method, the pure oxygen gas supply can increase the oxygen concentration in the furnace and reduce some secondary reactions, so the quality of the steel can be more stable.

3.allocation plan

 According to the site conditions, the load is 12500kW/10kV centrifugal oxygen compressor, and the high-power and FD5000s high voltage frequency inverter configured by FGI is designed to switch the power frequency without disturbance.

The high voltage frequency inverter adopts soft start mode and switches to power frequency mode. Due to the large power of the on-site motor, the power frequency steering can not be activated. After sending the control power, simulate the process of commissioning to power frequency, the simulation debugging is normal, and the starting cabinet trips normally after 5S of power frequency.

High performance

FD5000 high voltage frequency inverter adopts non-inductive vector control technology, the compressor starts smoothly at low frequency, large torque, small current, fast response time, unique non-disturbance switching technology, to meet the soft start of high-power load.

High reliability

FD5000 high voltage frequency inverter adopts voltage transformer detection and phase-locked loop technology to accurately follow the frequency and phase of power grid voltage and inverter output voltage in real time, with high precision. When connected to the grid, there is basically no impact on the motor, and it can fully meet the soft start requirements of high-power motors.

Strong adaptation

FD5000 high voltage frequency inverter has wide speed range, high precision, and super high and low voltage crossing function. When the power grid fails for a short time, it has the function of instantaneous power failure and restart to ensure the stable operation of the user's load.

manageability

FD5000 high voltage frequency inverter support Modbus-RTU, Profibus-DP, UDP/IP, ProfiNET multiple communication protocols, easy to connect with the user DCS system, to achieve centralized equipment management.

The undisturbed switching technology of the FGI power frequency inverter, the starting current is controlled within the rated current, which greatly reduces the impact on the power grid. Send high voltage, with air compressor operation to normal frequency. After the use of the frequency inverter, the harmonic pollution to the power grid is small, the input power factor is high, the output waveform quality is good, worthy of promotion in the industry, can be used in LNG, steel, chemical industry, test power supply, air compression energy storage and other high standards, high reliability fields.

4.application performance

System characteristics and energy-saving effect

（1）Realizes the soft start of the high-power motor, and the starting process is smooth;

（2）Reduced maintenance workload and maintenance costs, bringing practical value to users;

（3）Wide speed range, high precision, oxygen compressor can be changed according to the process needs;

（4）Inverter has a number of protection functions, very perfect, better protect the motor;

（5）Improve operating conditions and reduce labor intensity;

（6）Small instantaneous current of switching frequency, recognized by customers.