Structure Analysis and Application Characteristics of EC Motor
Fan EC Motor Permanent Magnet Selection Key Part One - Structure Analysis and Application Characteristics of EC Motor
EC(Electrical Commutation) electronically commutation motor, the power supply is a DC power supply, and the controller is internally provided with an AC-to-DC module. DC power supply is only the appearance of EC motor. The essence of EC motor is AC permanent magnet synchronous motor.
The market usually refers to fans equipped with EC motors as EC fans. ZIEHL-ABEGG(Germany) is one of the enterprises that put forward the concept of EC motors for fans earlier in the industry and took the lead in application. EC motor represents a more energy-efficient, stable, quiet and intelligent future for fans.
At present, EC motors are covering high-standard fan fields such as HVAC system fans, air cooling modules, cooling towers, animal husbandry fans, etc. Volcano Electric is one of the earliest domestic enterprises engaged in fan EC motor research.
I. EC Motor Structure
As explained above, the essence of EC motor is to design special structure based on permanent magnet synchronous motor and according to the application and installation characteristics of fan. According to the application characteristics of the fan, the controller module and function are specially designed and developed for high energy efficiency electromechanical integration products.
The motor scheme, high efficiency and quiet permanent magnet synchronous motor (sine wave) scheme, designs and matches the motor scheme according to the fan blade design parameters;
The structure of the motor shall conform to the installation of vertical supports (also 120°× 3) uniformly distributed at 90°× 4 of the fan, and shall be made of high-strength aluminum alloy.
Motor protection, long-term exposure of the fan to outdoor, rain and dust intrusion, the overall protection should be not less than IP55；
1. FOC vector control is selected and the motor is controlled without position sensor.
2. According to the characteristics of outdoor fans, design and develop special functions and control modes such as headwind startup and fire fighting mode.
3. Various comprehensive motor protection measures, including over-voltage and under-voltage, over-current and under-current, overload, locked-rotor and other motor protection measures, shall be put in place.
II. Application Characteristics of EC Motor in Fan Field
1. High power density to improve fan energy efficiency
Permanent magnet of permanent magnet synchronous motor replaces rotor excitation winding, with reduced volume, increased power density and wide high efficiency area. The efficiency of volcanic electric 0.75W permanent magnet synchronous motor is 88%, 2.4% higher than that of 0.75W/4 pole level 1 (85.6%) and 8.4% higher than that of 0.75W/4 pole level 3 energy efficiency motor. The motor meets the national standard level 1 energy efficiency and European Union IE4 standard.
Asynchronous motor has low efficiency and serious heat generation when running at low load. Permanent magnet synchronous motor can output 35%~150% load with high efficiency, which is very suitable for low speed and low load application of fan.
2. Wide speed regulation area, speed change
The FOC vector control driver is adopted, and the motor has preset gear speed adjustment or speed change. Users can adjust the running speed of the fan through panel commands, terminal commands and communication commands according to the needs of the site, adjust the air output volume of the fan, and strengthen the scope of application of the fan.
3. The motor has low temperature rise and high protection level.
Motor temperature rise is mainly caused by iron loss of silicon steel sheet and copper loss of winding. Permanent magnet motor rotor has no excitation winding, iron loss and copper loss are reduced, motor efficiency is high, calorific value is small, the temperature rise of volcanic electric permanent magnet synchronous motor is usually between 25℃ and 50℃, surface cooling has good cooling effect, motor shell can be made into full seal, protection effect is good.
4. Soft start, small starting current and small impact on power grid
The starting current of the three-phase asynchronous motor is 3~5 times of the rated current, and the starting process has great impact on the power grid and even causes motor damage. The starting current of EC motor is 1.5 times of the rated current. The current rises slowly and has little impact on the power grid.
5. Various command modes to improve user convenience
EC motor has excellent control performance, supporting various command modes, panel command, terminal command and communication command, multi-channel analog input (temperature and humidity sensor) terminals, and multi-fan on-line closed-loop control, forming a large ventilation and cooling system with environmental control capability.