With the development of the processing and manufacturing industry, high speed cnc vertical milling machine is widely used in the processing industry due to its high degree of automation, high efficiency, and good processing quality. For CNC machine tools, especially large-scale CNC machine tools, the selection of machine tool accessories is an urgent problem to be solved according to the different parts to be processed. The article mainly introduces the relevant knowledge of the machine tool center frame.
Since the power of the motor is proportional to the product of current and voltage, the direct power frequency starting consumes more energy than the variable frequency starting motor. In some cases, the power distribution system has reached its maximum limit, and the surge generated when the motor is started under direct power frequency will have a serious impact on other users in the same network.
If the PLC is used to control the variable frequency motor to start the motor, such problems will not occur. There is no need for multiple machines or workers to manage different systems and equipment. The PLC controller can complete various tasks at one time through the built-in I/O modules (input and output). Programmable controllers are very common and are widely used in many industrial fields.
How to use PLC to control variable frequency motor to realize motor acceleration and deceleration
At present, the output signal of the motor is mostly 4-20 mA or 1-5 volts (for meters above category 3), which is the standard. In addition, the analog signal input to the PLC cannot be directly output to control the variable frequency motor. The input analog signal is compared with the known signal, and then through PID control, the output signal is used to control the variable frequency motor.
PLC control variable frequency motor
According to a certain calculation method, the variable frequency motor is used to control the output frequency and adjust the motor speed. The analog signal input by the frequency modulation motor can not directly control the output frequency of the frequency converter. It also needs to be compared with the given signal, and the speed of the frequency conversion motor is controlled by PID.
In short, no matter whether the signal is sent to the PLC or the variable frequency motor (of course, the analog signal can also be sent to the PLC first, and the PLC controls the variable frequency motor), these two kinds of electrical equipment should be programmed or parameterized. If the program design or parameter setting is wrong, the frequency conversion motor acceleration and deceleration cannot be controlled.
PLC controller type
1. Integrated PLC controller: The integrated PLC controller is also called compact or integrated PLC. It is a relatively simple type of PLC controller and is suitable for simple processes. A single PLC will have a certain number of I/O points and an integrated CPU with connection ports. Usually, these controllers can also be directly connected to related devices or applications.
2. Modular PLC controller: Modular PLC, also known as rack type, can provide greater flexibility. Modular PLC controller requires a basic module containing CPU, input and power supply. However, you can customize the PLC by adding additional I/O modules. You can basically add as many modules as the PLC allows here. An analog-to-digital signal converter can also be inserted.
PLC control variable frequency motor
PLC controllers are widely used and can be said to be ubiquitous, such as traffic lights. PLC controllers have existed for more than 50 years and will continue to exist. However, with the rise of "big data", robot integration and cloud computing, PLC controllers will have to adapt to these new changes as the manufacturing industry continues to become more Faster and more efficient.
