Characteristics of Variable Frequency Drive Control for High-Pressure Centrifugal Blowers

Characteristics of Variable Frequency Drive Control for High-Pressure Centrifugal Blowers

High-pressure centrifugal blower units are employed in large-scale metal and chemical manufacturing and processing enterprises. In actual production processes, the centrifugal principle of high-pressure centrifugal blowers conveys raw materials into blast furnaces. This ensures complete diffusion of materials within boilers while enhancing the purity of smelted products. From a practical efficiency perspective, these high-power, high-pressure centrifugal blowers play a crucial role throughout the entire process. Due to their large size and significant mechanical inertia, these blowers require counter-torque devices to enable free speed adjustment. This effectively mitigates stall-induced overvoltage and overcurrent issues caused by inertia during operation. To meet these requirements, the high-pressure centrifugal blower employs a 280-kilowatt three-phase asynchronous motor with a delta connection during operation. Additionally, inverter control enables frequency conversion and speed adjustment functions. The smelting system features three large boilers, allowing fan speed adjustment based on the opening status of each smelting furnace. When all three smelting boilers operate simultaneously, the fan speed increases; conversely, it decreases when fewer boilers are active. This significantly enhances the fan's operational efficiency, leading to energy savings. Furthermore, during operation, the frequency conversion system also prevents choke and overvoltage. This is because large high-voltage centrifugal blowers possess substantial inertia during operation, making them prone to generating regenerative voltage during shutdown. The inverter effectively deactivates its internal inverter modules, preventing regenerative voltage from affecting the voltage stabilization capacitors. It also withstands voltage surges during fan stoppage. Furthermore, employing frequency converters enhances system reliability and safety. This is because the frequency converter incorporates advanced automation features, overvoltage and overcurrent temperature detection capabilities, monitoring of various operational parameters, overvoltage alarms, undervoltage alarms, overcurrent alarms, and overload alarms. Consequently, the operational reliability of the centrifugal fan is significantly enhanced.