What are the main anti-interference measures of PLC control system

( 1) The reasonable processing power, restrain the interference of power grid is introduced into the power supply is introduced into the grid disturbance can be installed a variable ratio of 1:1 with shield isolation transformer, to reduce the interference between the device and ground, you can also pick LC filter circuit in series with the power input. ( 2) Correct selection of location, perfect grounding system good is vital to ensure reliable PLC work, can avoid accidental voltage shock hazard. The purpose of the grounding usually have two, one for the sake of safety, the second is to suppress interference. Perfect grounding system is PLC controller control system is one of the important measures of resistance to electromagnetic interference. PLC control system of earth system, shielding, interact and conservation, etc. Grounding system chaos disturbance to the PLC controller system are mainly the ground potential distribution, between different ground potential difference, causes to the loop current, normal operation system. Must point grounding cable shielding layer, for example, if the cable shielding layer on both ends of A, B are ground, there is A potential difference, has A current flows through the shielding layer, when an exception occurs, such as lightning, ground current will be larger. Besides, shield, ground wire, and the earth could constitute a closed loop, in under the action of magnetic field change, will be induced current in the shield, through shielding layer between the core and coupling, jamming signal circuits. If systematically and other ground handling, the land circulation can produce in the ground potential distribution, affecting the normal work of the PLC logic circuit and analog circuit. PLC logic voltage interference tolerance is low, logically potential distribution of the interference easily affect the PLC logic operation and data storage, data confusion, fly or crash program to run. Analog ground potential distribution will be led to the decrease of the accuracy of measurement, cause serious distortion of signal measurement and control and false action. Safely or power grounding: will the power cord grounding terminal and cabinet put oneself in another's position of attachment for safety grounding. Such as power leakage or cabinet put oneself in another's position of charged, can from safety grounding into underground, won't cause harm to people. Grounding system: PLC controller controller in order to control the various equipment with potential and grounding, grounding system. Grounding resistance value shall not be greater than 4 Ω, general PLC equipment systematically and in control cabinet must be negative termination together, switch power supply to a control system. Signal and shielding grounding: general requirements signal lines must be the only reference to the 'single point grounding, shielding cable may produce the conducted interference occasions, also want to the only ground of in situ or control room, prevent the formation of' ground loop '. Signal grounding, shield should be against the side of the signal grounding; Not grounding, grounding in PLC, Signal lines in the middle joint, shielding layer should be firmly connected and insulating treatment, multipoint earthing must be avoided; Multiple signal measuring point is shielded twisted-pair cable and multi-fiber twisted-pair always shielded cable connection, the shield should be connected, and the insulation treatment, select the appropriate answer is located at a single point of contact. ( 3) To suppress the interference of frequency converter frequency interference processing generally have the following several ways: add isolation transformer, mainly in view of the conducted interference from the power supply, most of the conducted interference can be cut off before the isolation transformer; Use filter, filter has strong in anti-disturbance ability, but also has to prevent the interference of the device itself to power supply, some are both the peak voltage absorption function; Use output reactor, increased between the inverter and motor ac reactor is to reduce the converter output in the process of energy transmission lines to produce electromagnetic radiation, affect other equipment to work normally.
Over the years, has become very popular as more and more people are trying it out.
What are you waiting for? Get out there and buy some of the most effective at Coolmay PLC.
Shenzhen Coolmay Technology Co., Ltd. attach great importance to the quality of our products and R&D services.