Background harmonics are a unique scalar quantity, which is usually ignored by most production enterprises, even after the impact of machinery and equipment, it is impossible to determine the interference signal. Now the power supply system unit has clear regulations on the evaluation of power consumption companies. According to the national standard: GB/T12326-2008 (power quality voltage fluctuation and flicker), the power supply bureau stipulates that the voltage fluctuations generated by power consumption companies must be less than THDU (harmonic voltage fluctuation) limit value, but this standard cannot be guaranteed for many companies that use variable frequency loads, especially the harmonic voltage caused by loads such as intermediate frequency induction furnaces and variable frequency speed regulators. It is very easy to exceed the standard with the ruggedness!
Harmonic voltage is “spread” by the power grid for the media, and the source of harmonic voltage is mainly divided into three categories:
①Transportation of unqualified power projects at the power supply system end;
② The harmonic voltage fluctuation rate caused by its own equipment exceeds the standard;
③Use transformers with other companies, and the harmonic source equipment of other companies will be affected;
The key hazards of background harmonics in the power grid mainly include:
1. The automatic control system (frequency conversion speed controller code, PLC) is incorrectly operated and inappropriate;
2. The work of high-precision machinery and equipment and protective devices is chaotic;
3. The relay protection device fails;
4. The inverter device cannot work;
5. The short-circuit fault of the three-phase transformer installed in the conversion of weak current, etc.
This kind of hazard is likely to cause the failure of the company’s machinery and equipment and the collapse of the production line, endangering the overall efficiency and seriously endangering the production safety of machinery and equipment;
In modern industrial production, precision machine tools, automatic production lines, automation equipment, and electronic device metrology and verification equipment are widely used. The automatic control system plays the role of the human brain in all equipment, used for display, high-precision metrology verification, coordinated processes, and precise Stepper motor, speed ratio adjustment and other fully automatic stages, complete rapid manufacturing. However, some companies often have failures such as ablation of the internal power supply circuit of the automatic control system, random jumping of codes, and incorrect PLC commands, which seriously affect normal production and production, causing the company to stop production and reduce economic benefits. The culprit behind this situation is , there are many background harmonics of the power grid! Many companies are usually concerned about the harm caused by the harmonic environmental pollution of their own machinery and equipment. Because the harmonic current exceeds the standard, the reactive power compensation cabinet cannot be switched, resulting in low power factor and being punished by the relevant department. Now it must be emphasized that background harmonics must be taken care of as well. Many companies have stopped using machinery and equipment and derailed production processes due to the harm of background harmonics, which has brought serious economic development losses to the company!
There is a difference between background harmonics and corporate harmonic environmental pollution. The control equipment for the harmonic pollution caused by the company itself is an active filter that everyone is familiar with. It basically depends on compensating for the fluctuation of the harmonic current and preventing the harmonics from affecting or even destroying the company’s own equipment. , to reduce environmental pollution to the power grid; however, some companies’ machinery and equipment do not cause harmonics or cause less harmonics, and some companies have already reasonably equipped with filtering equipment, but machinery and automatic control systems are still often affected by harmonics , causing confusion in the automatic control system, ablation of small transformers, failure of precision machine tools and other common faults! This kind of situation may be caused by background harmonics. Even if an active filter is installed, there will be no progress. At this time, we should choose filter compensation equipment to effectively deal with the impact caused by the variable voltage!
The filter compensation equipment takes the voltage fluctuation as the control goal, and it can well realize the digestion, absorption, reduction and isolation protection of the external background harmonics. Purification treatment equipment. It can repair various voltage fluctuations and provide stable switching power supply for high-precision electronic products. It is based on the basic principles of magnet series resonance and microwave sensor filtering. It has very high stability and can be regarded as a semi-permanent switching power supply. It is especially suitable for applications in extreme natural environments such as industrial production. The filter is different from the general regulated power supply. It can not only output a stable AC voltage, but also remove harmonics, surge protectors, and RF-affected voltages in the input voltage.
Post time: Apr-13-2023