Application of FGI high-voltage frequency converters in power plant circulating water pumps
Alumina plants and electrolytic aluminum plants are major electricity consumers, requiring large amounts of electricity. Relying solely on the national grid would be costly and production would be restricted during power shortages. Therefore, aluminum-electricity bases typically have their own self-owned power plants. One company's power plant consists of three steam turbine generator sets and four boilers. Each turbine is equipped with two circulating water pumps, designated A and B, for a total of six pumps. Under normal operating conditions, each turbine uses only one of the A or B pumps, with the other as a backup. The speed control strategy varies seasonally: high-speed motors are used in summer to accommodate large water demands, while low-speed motors are used in winter to meet smaller water supply needs.
Implementation plan:
The FD5000 series high-voltage frequency converter was selected for the company based on its advanced control technology and highly efficient energy-optimized design. The FD5000 series employs advanced vector control technology, enabling precise control of the high-voltage system's operating status, maximizing system energy efficiency, and minimizing energy consumption.
The FD5000 high-voltage frequency converter enables both remote and local control, thereby improving system safety and operational flexibility. The existing DCS system monitors the converter's operating status and allows for remote control. Furthermore, the system provides local manual and automatic control functions via corresponding buttons and operators. In the FD5000's operating mode, if a fault occurs in the converter or water pump causing the high-voltage circuit breaker to trip, the system automatically activates the backup circulating water pump to ensure the safe operation of the generator set.
Application advantages:
1. Energy Saving and Consumption Reduction: Variable frequency speed control effectively reduces motor power consumption. This helps lower plant power consumption, reduce generation costs, and improve power plant energy efficiency.
2. Vacuum Control: The speed control function of the frequency converter allows for more precise adjustment of circulating water volume to meet the vacuum control requirements of the unit under constantly changing operating conditions.
3. Enhanced Safety: Flexible speed control allows for better adaptation to different seasons and load changes, improving the safety and stability of the unit.
4. Grid Pressure Solution: The existence of a self-owned power plant can solve some of the production constraints caused by power shortages, reducing over-reliance on the national grid and thus improving the reliability of the power plant.
5. Remote Monitoring: High-voltage frequency converters are typically equipped with advanced remote monitoring systems, enabling remote monitoring and adjustment of motors and systems, improving operation and maintenance efficiency.
