Introduction：
Fan loads are widely used, such as supply fans and induced draft fans of various production and domestic boiler systems, central air-conditioning fan units, fresh air units, cooling tower fans, exhaust fans in various production sites, and dryers on production lines. Fans are the main power equipment of industrial and mining enterprises. According to the statistics of relevant departments, the installed capacity of fans and pumps and motors in the country is about 35,000MW, and the power consumption accounts for about 40% of the national power consumption. When using D32 inverter in fan operation, the power saving rate is generally 20%-60%, and the investment recovery period is 1-3 years. The benefits are very significant.
Features：
D32 is a cabinet-mounted inverter, the power range is 0.75KW-500KW, the incoming line voltage is 380V-480V, and the control mode is vector control and vector control without speed sensor. The speed sensorless vector control is a kind of vector control, which estimates the speed feedback value of the motor through the calculation of the motor model. The control accuracy and dynamic performance of the speed sensorless vector control are not as good as the vector control with speed closed loop, but it also has the advantages of simple system, no need to maintain speed sensor, and low price, especially suitable for fan and pump motors. The traditional V/f control also does not need a speed sensor, but for high-power fan and pump motors, such as V/f control without current loop control, it is easy to cause current fluctuations. The speed sensorless vector control not only has a speed closed loop but also a current closed loop, and the steady-state current of the motor is more stable.
D32 has a wealth of client terminals, including 8 digital inputs (LI1-LI8), 2 analog inputs (AI), 2 relay outputs (TA), 2 analog outputs (AO), 5V auxiliary power supply for analog input Fixed input, 24V auxiliary power supply is used for digital input, all LI/TA, AI/AO can be freely programmed to define functions.
D32 series inverter has built-in PID function, which is more flexible in operation. There are many ways to control the interface, which can be hard-wired or communication.
Advantage：
System Introduction：
A total of four motors in this boiler use D32 frequency converters to control steam, hot oil and hot flue gas respectively. The hot flue gas is controlled by two 315KW motors, and sent to the main fan through pipes for drying wood pulp. Two 315KW QD6000 inverters control the two fans respectively, and control the output power of the fans by adjusting the output frequency of D32, so as to realize the precise regulation of the flow of hot smoke, which not only meets the requirements of the process, but also is more efficient than using a windshield. It is more energy efficient to adjust the flow of hot smoke. The other two 132KW motors feed the steam from the steam generator and the hot oil from the thermal oil generator into the mixing chamber respectively. The adjustment of the steam output in the steam generator can control the pressure and temperature in the steam generator, and the adjustment of the thermal oil output in the thermal oil generator can control the temperature of the thermal oil generator. D32 also adjusts the output of steam and hot oil by controlling the output power of the motor, so as to control the pressure and temperature of the steam generator and the temperature of the hot oil generator.
Technical Parameter：
| Inverter technical parameters | Device configuration | |
 Model: D32-X | Output current: 260A 605A | One D32 inverter |
| Input voltage: 3-phase, 380-480V | Frequency range: 0-400Hz | 132kW fans and motors |
| Input frequency: 50/60Hz ±5% | Overload capacity: 150%, 60 seconds | 315kW fans and motors |
| Output power: 132KW 315KW | Ambient temperature: -10-40°C | |
| Output voltage: 0-480V (the maximum value is determined by the input voltage) | Protection level: IP20 | |
On Site Usage：
According to the on-site space situation, a D32 series inverter is installed in the control cabinet, and the inverter installation and on-site motor are as shown in the figure
Running Result：
The boiler fan control system using D32 inverter has been put into operation for more than four years, and has achieved good economic and social benefits:
The control device operates reliably and has a low failure rate;
Significantly less noise;
Precise regulation of hot smoke flow to meet production process requirements;
Extends the service life of the bearings of the motor and fan, reduces the heat generation of the motor, and greatly reduces the amount of maintenance;
The economic benefits are significant, and the entire investment increased by the frequency conversion control system can be recovered in more than one year.
Customer Benefits：
Accurately adjust the flow to meet the production process requirements;
Reduced motor losses and maintenance costs;
The energy-saving effect is remarkable, and the investment increased by frequency conversion control can be fully recovered in more than one year.