The Challenge
As core power equipment in industrial production and civil fields (such as factory ventilation, boiler induced draft, sewage treatment aeration, and building air-conditioning air supply), fans operating in the traditional fixed-frequency mode have problems like "overcapacity operation" (a situation where a high-power motor drives a low-load fan, similar to "using a large horse to pull a small cart"), excessive energy consumption, and difficulty in speed regulation. By adopting inverter-based speed control and combining it with the load characteristics of fans (square torque load, where power is proportional to the cube of speed), this solution enables energy-efficient operation, precise flow control, and intelligent management of fans. It is suitable for fan system transformation and new construction projects in various fields such as metallurgy, chemical engineering, water treatment, and building heating, ventilation, and air conditioning (HVAC).
The Solution
With the core objectives of "energy conservation first, stability and reliability, and intelligent controllability", this solution conducts design from three aspects: hardware selection, system architecture, and control logic. The specific contents are as follows:
Hardware Selection: Matching Fan Load Characteristics
Inverters are selected based on the fan's rated power, rated voltage, and operating conditions (such as whether it involves shock loads and start-stop frequency). The core selection principles are as follows:
1.Inverter power selection: Considering the inrush current during fan startup (usually 1.5-2 times the rated current), the rated power of the inverter must be ≥ 1.1 times the rated power of the fan. If the fan is used in high-temperature and high-dust environments (such as mine ventilation and metallurgical sintering fans), an additional 10%-20% power margin must be reserved to prevent the inverter from overheating and overloading.
Example: For an 11kW three-phase asynchronous fan, a 15kW general-purpose inverter is recommended. If the ambient temperature is > 40°C, it is necessary to upgrade to an 18.5kW inverter and equip it with a matching cooling fan.
System Architecture: Two Modes (Single Unit and Cluster)