Interference analysis in control system of 400 ton press mac
Author: Zhengzhou Haloong Machinery Manufacturing Co., Ltd. Time: 2017-05-27 09:48
In recent years, with the rapid development of communication technology and sensor technology, the numerical control technology of press has also made great progress and gradually become mature in use, such as automatic mold change system, fully functional touch screen monitoring technology. The numerical control of technology of press is improved, then the precision of press products are improved a lot, and the safety and comfort of operation is also improved. However the use of high-precision electrical elements (sensor and transducer) takes lots of advantages, at the same time it also brings some interference problems. The reliable operation of the whole press will be effected by the interference inner and outer control system. If the interference is strong, the press even stop to work. Therefore, to ensure the safe and stable operation of the press, it’s necessary to fully consider the anti-interference design of control system and take some anti-interference measures for designing and installing peripheral circuit.
Main Control System
Analysis of Interference Source and Transmission Route of Control System
In general, except the useful signal, all other electronic signals are called noise, when the noise signal reaches to a certain extent, it will interfere the control system. The electrical interference of the press control system is very wide, and they can be divided into two aspects: the outer lead interference source and the internal interference source.
Outer lead interference source
Outer lead interference source mainly refers to the power line interference outer the control system, including two sources: power interference and interference of grounding system.
Power interference is a very complex interference. Because the power of the control box is supplied by the industrial power network, and the power interference will happen when there is over-voltage, under-voltage, surge, sink or peak which are caused by some big equipment’s starting or stopping. At the same time, the power lines in control system will have common mode interference with the ground and series mode interference among the power lines. All these interference will be collected to control system through internal resistance of power, and then effect the stability of control system.
Usually, the grounding system is an important means to suppress noise and prevent interference. Good grounding system can greatly improve the anti-interference ability of the system. However, the interference of grounding system will happen, if the grounding system is confused, or each ground point are unevenly distributed, or there is the potential difference between the ground points.
Measures for Power anti-interference
Power interference has greater affection on the stability of the control system. The interference can be greatly weakened by the design of power anti-interference to increase anti-interference ability of the power circuit. As to the interference caused by the big equipment’s starting and stopping, it can be added high-performance AC voltage stabilizer at the 220V power inlet terminals. And the stabilizer should be no self-excitation and lower ripple wave, so that it can prevent outer interference, at the same time there is no interference brought by itself.
Measures for interference from Grounding system
The correct grounding system can not only restrain the influence of electromagnetic interference, but also can suppress send out the electromagnetic interference. The ground system can make the share grounding between power and press frame with floating circuit way. It means the grounding system of press frame and the ground system of power are connected together and the grounding system of power is separated to avoid interference of ground potential and ground loop. In order to have good insulation between circuit block and press frame, usually the power circuit and plug-in frame in control box are separated with press frame by insulation supports, the grounding point of power should be installed at the special copper-clad plate on plug-in frame, and the control system should be connected with grounding system separately with power grounding system, and pay attention to the series grounding connection among control system, motor, transducer and transformer etc.
So in the actual production, it should choose flexible effective anti-interference measures according to the characteristics of control system design and environmental requirements, then it can improve the whole anti-interference ability and keep stability of the press in operation.
Main Control System
Analysis of Interference Source and Transmission Route of Control System
In general, except the useful signal, all other electronic signals are called noise, when the noise signal reaches to a certain extent, it will interfere the control system. The electrical interference of the press control system is very wide, and they can be divided into two aspects: the outer lead interference source and the internal interference source.
Outer lead interference source
Outer lead interference source mainly refers to the power line interference outer the control system, including two sources: power interference and interference of grounding system.
Power interference is a very complex interference. Because the power of the control box is supplied by the industrial power network, and the power interference will happen when there is over-voltage, under-voltage, surge, sink or peak which are caused by some big equipment’s starting or stopping. At the same time, the power lines in control system will have common mode interference with the ground and series mode interference among the power lines. All these interference will be collected to control system through internal resistance of power, and then effect the stability of control system.
Usually, the grounding system is an important means to suppress noise and prevent interference. Good grounding system can greatly improve the anti-interference ability of the system. However, the interference of grounding system will happen, if the grounding system is confused, or each ground point are unevenly distributed, or there is the potential difference between the ground points.
Measures for Power anti-interference
Power interference has greater affection on the stability of the control system. The interference can be greatly weakened by the design of power anti-interference to increase anti-interference ability of the power circuit. As to the interference caused by the big equipment’s starting and stopping, it can be added high-performance AC voltage stabilizer at the 220V power inlet terminals. And the stabilizer should be no self-excitation and lower ripple wave, so that it can prevent outer interference, at the same time there is no interference brought by itself.
Measures for interference from Grounding system
The correct grounding system can not only restrain the influence of electromagnetic interference, but also can suppress send out the electromagnetic interference. The ground system can make the share grounding between power and press frame with floating circuit way. It means the grounding system of press frame and the ground system of power are connected together and the grounding system of power is separated to avoid interference of ground potential and ground loop. In order to have good insulation between circuit block and press frame, usually the power circuit and plug-in frame in control box are separated with press frame by insulation supports, the grounding point of power should be installed at the special copper-clad plate on plug-in frame, and the control system should be connected with grounding system separately with power grounding system, and pay attention to the series grounding connection among control system, motor, transducer and transformer etc.
So in the actual production, it should choose flexible effective anti-interference measures according to the characteristics of control system design and environmental requirements, then it can improve the whole anti-interference ability and keep stability of the press in operation.
