With the rapid development of the types and quantities of inverters, more and more electrical and electronic devices use this device. In particular, it is the inverter that controls the speed of electric motors. Find out how important they are in the industry through the following article.
The role of controlling and stabilizing engine speed in the industry
In the industry, there are many activities that are related to electric motor speed. Sometimes the stability of engine speed is a vital factor in the industry. Especially for product quality, the stability of the system … For example plastic injection molding machine for shoe soles, steel rolling; automatic mixing system of materials; Centrifugal fixture when casting … Therefore, controlling and stabilizing the engine speed is considered as the essential problem of industrial control systems.
Adjusting the engine speed is to use artificial measures to change the source parameters. For example, voltage or circuit parameters such as auxiliary resistors, magnetic fluxes … From there, create new mechanical properties to achieve new working speeds. They match the requirements of mechanical load. In order to control and stabilize engine speed, the most commonly used device is the inverter.
Electric motor control cabinet by inverter
Methods to adjust engine speed
There are two methods to adjust engine speed including:
- Change the parameters of mechanical parts: It means to convert the transfer ratio from the motor shaft to the production machine structure.
- Variation of angular speed of electric motor: This method reduces the complexity of the structure. At the same time, it improves the tuning characteristics. This method is particularly flexible when applied in electronic control systems.
Therefore, the inverter is used to control the motor speed according to this method. A survey showed that:
- Momentary controllers account for 30% of the inverter market.
- In the motor moment controllers, the fan applications account for 55%. Most of them are HAVC systems (central air conditioning). The rest are pump applications, mainly used in heavy industry.
- Inverter helps to upgrade and improve pump and fan systems from a constant speed control system to an adjustable speed system. This use has great benefits in reducing fuel consumption.
The usefulness of the inverter in pump and fan applications
Suitable features of the inverter in pump and fan applications include:
- Adjust the flow corresponding to adjusting the pump speed and fan.
- Adjust the pressure corresponding to adjusting the valve opening angle.
- Reduce industrial noise.
- The energy used is proportional to the power of three of the engine speed.
- Helping in maximum power saving.
- High cost due to the use of large capacity transformers.
- The loss on the transformer accounts for up to 50% of the total loss on the inverter system.
- Occupying a large installation area, leading to difficulties in installation, maintenance, maintenance and replacement.
- Difficult to control, the control range is not wide and easily over output voltage due to the magnetic saturation of the transformer core.
In addition, transmission systems and many other parameters need to be changed and monitored. Examples are voltage, current, smooth start (Ramp start or Soft start), load properties … In this case, only the inverter using semiconductor devices is most suitable for use.
Through this article, we can see the role of inverter in the industry is not small. Do not forget to follow the following articles to update useful information!