消除变频器对PLC模拟量的干扰，山东欧姆龙总代
2015-04-21 12:23:22
在控制系统中，使用PLC的模拟量控制多台变频器，由于变频器本身产生强干扰信号的特性和模拟量抗干扰能力不与数字量抗干扰能力强的特性；因此山东欧姆龙总代理为了最大程度的消除变频器对模拟量的干扰，在布线和接地等方面就需要采取更加严密的措施。
In the control system, the simulation quantity using the PLC control of multiple inverters, because the characteristic of the inverter itself generate strong interference signal and analog quantity and digital quantity anti-interference ability is not strong anti-interference ability; therefore, OMRON Shandong general agent for the converter interference of analog to the greatest extent in the elimination, wiring and grounding so we need to take more stringent measures.
一．关于布线
A wiring
1．信号线与动力线必须分开走线
The 1 signal and power lines must be separately.
2．信号线与动力线必须分别放置在不同的金属管道或者金属软管内部
The 2 signal and power lines must be separately placed in the metal pipes of different or metal hose
3．模拟量控制信号线应使用双股绞合屏蔽线，电线规格为0.5～2mm2。在接线时一定
3 analog control signal lines should use double twisted shielded wire, wire specifications for 0.5 ~ 2mm2. In the wiring must
要注意，电缆剥线要尽可能的短（5-7mm左右），同时对剥线以后的屏蔽层要用绝缘胶布包起来，以防止屏蔽线与其它设备接触引入干扰。
Should pay attention to, cable stripping to be as short as possible (about 5-7mm), at the same time of shielding layer stripping later must use insulation tape wrapped shield wire, to prevent contact with other equipment introduce interference.
4．为了提高接线的简易性和可靠性，推荐信号线上使用压线棒端子。压接端子选择如下图：
4 for simplicity and reliability to improve the wiring, recommend the use of line rod terminal signal line. Crimp terminal selection as shown below:
5．如无使用压线端子，接线时请注意：
5 if no using crimping terminal, please note when wiring:
二．关于接地
Two on the ground.
1．变频器的接地应该与PLC控制回路单独接地，在不能够保证单独接地的情况下，为了减少变频器对控制器的干扰，控制回路接地可以浮空，但变频器一定要保证可靠接地。在控制系统中建议将模拟量信号线的屏蔽线两端都浮空，同时由于在机组上PLC与变频器共用一个大地，因此建议在可能的情况下，将PLC单独接地或者将PLC与机组地绝缘开来。
1 inverter control loop grounding should be earthed separately and in PLC, can't guarantee independent grounding circumstances, in order to reduce the interference of frequency converter controller, control circuit grounding can float, but the inverter must ensure the reliable earthing. In the control system proposed ends shielding line will analog signal lines are floating, and because in the unit of PLC and frequency converter share one earth, therefore recommend that where possible, PLC independent grounding or PLC and set to insulate.
2．变频器的接地
Ground 2 inverter
·400V级：C种接地（接地电阻10Ω以下）。
400V grade: C earthing (grounding resistance of 10 ohms or less).
·接地线切勿与焊机及动力设备共用。
And ground is not with the welding machine and power equipment sharing.
·接地线请按照电气设备技术基准所规定的导线线径规格。
And ground please wire line in accordance with the provisions of the electrical equipment technology reference diameter specifications.
如35KW的变频器接地线线径推荐为22mm2，87KW的接地线线径推荐为50mm2。
Such as the 35KW converter grounding wire diameter recommended for 22mm2, the 87KW earthing wire diameter recommended for 50mm2.
·接地线在可能范围内尽量短。由于变频器产生漏电流，与接地点距离太远则接地端子的电位不安定。
And ground within the possible range as short as possible. Because the converter generates the leakage current, the distance is too far, and ground earthing terminal potential instability.
·使用两台以上变频器的场合，请勿将接地线形成回路。
Use more than two inverter occasions, do not put the grounding wire to form a loop.
3．变频器与电机间的接线距离。
The wiring distance 3 between inverter and motor.
变频器与电机间的接线距离较长的场合，来自电缆的高次谐波漏电流，会对变频器和周边设备产生不利影响。因此为减少变频器的干扰，需要对变频器的载波频率进行调整。
Wiring and longer distance between the inverter and the motor of the occasion, the harmonic from the cable leakage current, will have an adverse impact on the frequency converter and peripheral equipment. So in order to reduce the interference of inverter, need to adjust the carrier frequency converter.
