Aug 22, 2020
Purpose and advantages of using inverter
Frequency conversion speed regulation has been recognized as one of the most ideal and most promising speed regulation methods. The main purpose of using general-purpose frequency converters to form a frequency conversion speed regulation transmission system is to increase labor productivity, improve product quality, and improve equipment. Requirements for automation, improving the quality of life and improving the living environment; the second is to save energy and reduce production costs. Users can choose different types of inverters according to their actual process requirements and application occasions.
The correct selection of general-purpose inverters is critical to the normal operation of the drive control system. First of all, the purpose of using general-purpose inverters must be clarified, according to the type of production machinery, speed range, speed response and control accuracy, starting torque and other requirements , Fully understand the characteristics of the load driven by the inverter, decide which function of the general inverter to use to form the control system, and then decide which control method is most suitable. The general frequency converter selected should not only meet the requirements of the production process, but also be reasonable in terms of technical and economic indicators. Improper selection, system design, and use of general-purpose inverters will often cause the same-used inverters to fail to operate normally, fail to achieve the expected goals, and even cause equipment failures, causing unnecessary losses. In addition, in order to ensure the long-term reliable operation of general-purpose inverters, the connection of the inverter ground wire is also very important.
1. The function and purpose of the inverter
The adjustable speed drive formed by the frequency converter and the AC motor is called the frequency converter drive, and its functions are as follows.
2. Advantages of using inverter
(1) Energy saving of frequency conversion speed regulation
As the frequency conversion speed regulation is adopted, the energy saving effect of fans and pump loads is the most obvious, and the power saving rate can reach 20% to 60%. This is because the power consumption of the fan and pump is proportional to the third power of the speed. When the user needs When the average flow rate is small, the speed of the fan and water pump is low, and the energy saving effect is also very considerable. However, when the traditional baffle and method are used for flow adjustment [industrial electrical appliance network-cnelc], the power consumption changes little. Since there are many such loads, accounting for about 20% to 30% of the total capacity of AC motors, their energy saving is of great significance.
For some constant torque loads running at low speeds, such as conveyor belts, variable frequency speed regulation can also save energy. In addition, the original speed control methods that consume more energy (such as wound rotor motors, etc.), the original speed control methods are more complicated and less efficient (such as gantry planers, etc.), after adopting frequency conversion speed control, The energy saving effect is also obvious.
(2) Advantages of variable frequency speed regulation in motor operation
Frequency conversion speed regulation can easily realize the forward and reverse rotation of the motor. Only need to change the switching sequence of the inverter tube inside the frequency converter to realize the output commutation, and there is no problem of burning the motor due to improper commutation.
Most of the frequency conversion speed control system starts from a low speed and the frequency is low. The acceleration and deceleration time can be set arbitrarily, so the acceleration and deceleration time is relatively smooth, the starting current is small, and higher frequency start and stop can be performed.
When the frequency conversion speed regulation system is braking, the inverter can use its own braking circuit to consume the energy of the mechanical load on the braking resistor, and it can also feed back to the power supply grid, but the feedback to the grid requires special accessories, which requires a large investment. In addition, the frequency converter also has a DC braking function. When braking is required, the frequency converter applies a DC voltage to the motor for braking, and no additional braking control circuit is required.
(3) Application for the purpose of improving process level and product quality
In addition to the application of variable frequency speed regulation in fans and pump loads, it can also be widely used in various mechanical equipment control fields such as conveying, winding, lifting, extrusion, and machine tools. It can increase the peculiar yield rate, extend the normal working cycle and service life of the equipment, simplify the operation and control system, and some can even change the original process specifications, thereby improving the control level of the entire equipment.