Leisuwash specializing in manufacture Automatic Car Wash Machine, Touchless Car Wash , automatic touchless car wash, touchless car wash equipment, robot car wash, smart car wash system, leisuwash 360, leisuwash leibao 360, laserwash 360, leisuwash touchless car wash machine, leisu wash touchless car wash automatic, leisu wash 360 high pressure touchless car wash equipment, robo car wash, touch free car wash, leisuwash 360 touch free car wash, leisuwash 360 price, automatic car wash price, leisuwash in malaysia, no touch automatic car wash machine. Automatic Car Wash Center,Automatic Car Wash Design,Automatic Car Wash Business Plan,Car Wash Business Leisuwash Hangzhou Leisu Cleaning Equipment Co.,Ltd , https://www.sdleisuwashtouchless.com
1. Introduction The speed-changing of AC induction asynchronous motor drives is an epoch-making technological advancement in the field of electric transmission in the 20th century. With the wide application of frequency converters, frequency converters have increasingly become the largest source of electromagnetic pollution in the field of factory automation. It can often be seen that a dozen sets of inverters are installed in a device-intensive factory. The nonlinear equivalent load of the inverter's DC-AC inverter makes the inverter not only pollute the power supply system of the factory in many system integration projects, but also directly interferes with the automation project, causing the misalignment of the measurement and control system and severely damaging the stability of the large system. Sex, even the frequency converter itself is subject to interference, causing a "bootstrap" type of speed regulation fault. Although international standards have strict specifications for electrical equipment EMC (IEC61000 series electromagnetic compatibility design), and China's National Bureau of Quality and Technical Supervision has decided to adopt "equivalent" in the country, at the same time, China's national standard power quality and public power grid harmonics GB/T14549- 93 has been in force for 14 years, but the rapid development of the country's economy and technology has made pollution control of power electronic switching devices without delay.
2. Inverter interference analysis Inverter's interference problems are generally divided into self-interference of the inverter; electromagnetic waves generated by external equipment interfere with the inverter; and the inverter interferes with other weak electrical equipment in three types of situations. The frequency converter itself is an interference source. As we all know, the frequency converter is composed of two main parts: the main circuit and the control circuit. The main circuit of the frequency converter is mainly composed of a rectifier circuit, an inverter circuit and a control circuit. The rectifier circuit and the inverter circuit are composed of power electronics. Device composition, power, electronic devices have non-linear characteristics, when the inverter is running, it must perform fast switching action, and thus produce high-order harmonics, so that the inverter output waveform contains a large number of high-order harmonics in addition to the fundamental wave. Regardless of the type of interference, higher harmonics are the main cause of interference from the frequency converter. The inverter itself is a source of harmonic interference, so it will affect the equipment on the power supply side and the output side. Compared with the main loop, the control loop of the inverter is a small energy, weak signal loop, and is vulnerable to interference from other devices. Therefore, when the inverter is installed and used, it must take anti-jamming measures on the control circuit.
3. Analysis and Treatment of Inverter Interference Cases 3.1 How to Determine Interference in Frequency Converters The interference problems of the inverter are mainly reflected in the operating conditions of the motor. For example, the motor suddenly stops during operation, the motor runs quickly and slowly, the operating speed is unstable, the motor cannot be stopped, the button does not play any role, etc. These are all examples of how the inverter suffers from interference.
3.2 The third way to deal with the general problem of grounding interference is to ensure good grounding, the general requirements of the grounding terminal: grounding terminal in the "third way" to ground (individual grounding), the shorter the grounding line, the better, and must Good grounding; use shielded wire for control circuit line, and the shielding layer at the far end of shielded wire is suspended, and the proximal end is grounded; according to product requirements, reasonable wiring, strong and weak current separation, to maintain a certain distance, to avoid parallel wiring of inverter power line and signal line , should disperse the wiring; Increase anti-wireless interference filter, inverter input and output anti-jamming filter or reactor; To prevent electromagnetic induction shielding measures, even the inverter can be shielded with a metal box; Properly reduce the carrier frequency; With communication function, RS485 communication line uses twisted pair. Below, I will make specific analysis of different interference situations in actual use.
3.3 Three-phase five-wire system has encountered such a situation, the inverter has been running, press the stop button does not work, after inspection found that the inverter's ground wire is only connected with the transformer's neutral line, and the transformer's The line is not connected to earth, and the inverter is returned to normal after grounding the neutral line of the transformer. Nowadays many small factories do not attach importance to the connection of the ground wire. When the machine leaves the factory, according to the standards stipulated by the National Electrical Code, the ground wire and the middle The lines are strictly separated. There is a dedicated terminal in the neutral line of the power distribution cabinet, and there is a dedicated ground screw for the ground cable. Because the user came from the transformer three phase lines and a neutral line, only the neutral line is connected to the "N" terminal, and the ground line is not connected with the neutral line, although the control line uses a shielded wire, the shielding layer also The grounding screw was received, but it was not connected to the ground and did not provide shielding. As a result, the inverter could not stop due to the disturbance of the uncontrolled motor. After the neutral and ground cables in the power distribution cabinet are connected, they will return to normal, and the ground in the distribution cabinet can also be directly connected to the earth. Many users adopt the method of connecting the ground wire to the neutral wire. However, there are drawbacks in using this method. If the neutral wire is disconnected, starting one action of the machine tool may cause the machine tool to be charged and pose a safety hazard to the human body. This interference belongs to the interference type of the drive itself.
3.4 External Equipment Interference to Frequency Converters (1) Phenomenon. Occasionally, the motor cannot be stopped. After checking that the shield is properly grounded, reducing the carrier frequency does not work. Inverter input and output side magnetic loop filters do not work.
(2) Analysis. The distribution cabinet where the inverter is installed is too close to the power distribution room. The distribution room distribution cabinet has a large current flowing through it. There is a strong magnetic field around the current, which interferes with the normal operation of the inverter and keeps the distribution cabinet away from the power distribution. After the room is back to normal, this is outside equipment interference to the inverter.
3.5 Inverter interference with external equipment Case (1) Phenomenon. After starting the inverter, the motor does not operate.
(2) Analysis. The frequency converter is given the operating frequency by the external 4-20ma, 4-20MA DC signal is sent by the transmitter, see the display board, the frequency display is 0.00. The ammeter was used to measure the output of the transmitter and no output was found. At the output terminal of the transmitter and a 102 capacitor, and then start, the device returns to normal, indicating that the signal source is disturbed. In engineering practice, a simple signal line shunt capacitor solves the big problem is a practical and often practical method. This is the inverter's interference with external devices.
4. Concluding remarks With the rapid development of industrial automation, the use of frequency converters has become more and more common, and the interference problems of frequency inverters will also encounter many problems. Many end users often do not know how to solve them when they encounter this problem. I hope this article will provide them with some help.
Leisuwash 360 touchless car wash machine high intelligent high quality, with car wash + car care + drying process totally, each car wash takes time 1 minute to 5 minutes which depends on the car wash mode.
Automatic car wash equipment more and more popular in car wash business market, as can save employee fees and wash time mostly, bring investor much more benefit profit return. That's why choose the automatic car washing system.
Analysis and Treatment of Delta Inverter Interference Cases
Abstract: The author of this article is from the front line of automation integration engineering. In recent years, customer service often encounters the interference problem of the frequency converter , causing the device to malfunction , making the factory's production line unable to run , and the cause of this type of problem is also difficult to find , after consulting the relevant information , and then dealing with the problem in the work Some of the experiences to specifically talk about the source of the inverter interference , the way of transmission and some of the different situations of dealing with interference problems in practical applications, the hope is different from the dogmatic preaching of textbooks.