Application of FGI FD300 series frequency inverter in flexible power transmission project
Recently, the 380V 220kW FD300 series frequency inverter developed by FGI has been successfully applied to the Shanghai Dachen Island Jinfeng GW77-1.1 anti-platform low-frequency wind turbine project in the 35 kV flexible low-frequency transmission demonstration project of State Grid Taizhou, helping the 20Hz low-frequency fan to realize grid-connection. It marks another breakthrough in the construction of domestic flexible low-frequency power transmission projects, and verifies the high performance and high reliability of FGI's new generation of low-voltage frequency conversion devices.
1.Project context
The newly developed low-frequency fan is the "driving force" of Taizhou flexible low-frequency power transmission demonstration project, which can directly output 20Hz low-frequency AC, connect the low-frequency bus of 35kV Dachen Substation, and then transmit the low-frequency through the submarine cable to the 35kV salt farm frequency exchange station and then integrate into the power frequency AC grid. Different from ordinary wind turbines, engineering low-frequency wind turbines are low-frequency models customized for the wind conditions and environmental characteristics of offshore wind areas, and can better cope with extreme environments such as typhoons, low temperatures, high temperatures, and high humidity. In this project, the frequency conversion power supply system is required to take power from the low-frequency power grid and convert it into 50Hz standard power supply to supply power to the electronic control system of the fan and ensure the stable operation of the equipment.
2.System scheme
State Grid Taizhou 35kV flexible low-frequency transmission demonstration project 20Hz low-frequency fan secondary equipment power supply, inverter power supply through the low-frequency power grid inverter output stable 50Hz 380V voltage to ensure the fan main control system, converter system, dehumidification system, cooling system, yaw motor, variable pitch motor, high-power air conditioning and other 380V equipment stable operation.
3.Scheme selection
According to the requirements of the system scheme for variable frequency power supply, FGI FD300 series frequency inverter series platform products are selected for customized development, and sinusoidal filter is installed at the output end. Through high-performance variable frequency power control algorithm, the output 380V 50Hz power supply can meet the national power quality public grid standard and ensure the normal operation of electronic control equipment.
4.Design features and advantages
The control algorithm has single closed loop control of output voltage and double closed loop control of output voltage and current, and the control precision is high;
The variable frequency power supply has the function of self-starting after power failure, which can meet the starting power of the power source during the field low voltage crossing;
The control algorithm has the function of separating the positive and negative sequence of the output voltage and the output current, and the function of controlling the positive and negative sequence of the output voltage to ensure the output stability of the variable frequency power supply;
Add UPS Fault Alarm, Input 20Hz Isolated overtemperature fault, and Output 50Hz Auxiliary Overtemperature fault to the corresponding terminal output and fault display for the inverter power supply to meet application requirements;
Heavy load starting design, to meet the field full load straight up application requirements;
With fault diagnosis and automatic reset function, to achieve unattended.
In this demonstration project of the State Grid, FD300 high-performance vector inverter provided by FGI can fully meet the system load control requirements of variable frequency power supply, ensure the reliable power supply of the fan electronic control system, and help the high-reliability operation of the low-frequency fan system, marking FGI's practice of the national "carbon peak carbon neutral" strategy, and promote the substitution process of China's intelligent manufacturing. It has achieved new breakthroughs in product technology innovation and market expansion.
