By hvhipot 
HV Hipot Electric Co., Ltd. specializes in producing series resonant (also known as series resonant withstand voltage equipment), and now we will share with you the selection of series resonant reactors.
The application of series reactors is becoming increasingly widespread, but due to the use of rectifier power supplies in various electrical environments, if appropriate protective measures are not taken, it will affect the stability and reliability of rectifier power supplies and load operation. Practice has proven that appropriately selecting a series reactor and using it in conjunction with a rectifier power supply can effectively prevent the impact of overvoltage and surge current caused by operating the AC incoming switch, reduce the current ripple coefficient, ensure continuous current, and prevent circulating current in the rectifier power supply. At the same time, it can also reduce the pollution of harmonics generated by the rectifier power supply to the power grid and improve the power factor of the rectifier power supply. Therefore, it is necessary to explore how to correctly select series reactors for use with rectifier power supplies.
The ratio of the load capacity of the series reactor that generates harmonics in the low-voltage distribution system to the transformer capacity is greater than 15%. The reactive power compensation capacitor circuit requires a reactor with a certain reactance rate. Most harmonic series resonance loads are generally 6-pulse rectification, mainly consisting of 5th, 7th, 11th, and 13th harmonics. Choosing a reactance rate of 4.5% -7%, if choosing a reactor with a reactance rate of 6%, the resonant frequency is 204Hz, which has a good effect on suppressing the 5th harmonic, but also has a significant effect on amplifying the 3rd harmonic. If choosing a reactor with a reactance rate of 4.5%, the resonant frequency is 235Hz, which has a good effect on suppressing the 5th harmonic, but has a slight amplification effect on the 3rd harmonic, that is, suppressing harmonics above the 5th and reducing the amplification of the 3rd harmonic. Therefore, this choice is also relatively effective. Suitable. In low-voltage distribution systems, if the third harmonic is dominant, reactors with a reactance rate of 12% -14% and a resonant frequency of 141-134Hz should be selected.
What is the reactor ratio of series reactors in low-voltage distribution systems? If the ratio of the load capacity SH that generates harmonics to the transformer capacity ST is less than 15%, and the system harmonics are very small, only when limiting the inrush current during closing, then choosing p=0.5% to 1% can meet the requirements.
1. Choose reactors with good reputation
When choosing a series reactor, one should not rely solely on reading the product manual or relying solely on the supplier’s explanation to understand the product. These methods are not representative, so customers should consider which series reactor has a good reputation when choosing, and choose based on everyone’s feedback to ensure the functionality of the reactor.
2. Select qualified reactors for inspection
Viewing the test report of the series reactor issued by a third-party testing agency is a good option. Therefore, we should check the third-party testing report based on Chinese standards. The third-party report not only proves that the reactor product has been certified by authority, but also serves as a way for us outsiders to identify whether the product quality and safety have passed the standards.
3. Choose reactors with 3C certificates
Legitimate and safe series reactor products will have a strict and standardized production process management, so that the reactor products can meet the production specifications and standards. So we need to choose series reactors that meet production standards to ensure quality. A more direct method is to check if they have a 3C certificate. The acquisition of 3C certificate not only requires the reactor to meet the qualified standards, but also requires checking the overall completeness of the production and manufacturing process of the goods, as well as the completeness of the verification process. If the manufacturer of the series reactor has a 3C certificate, it means that their products are of good quality. So when choosing a more affordable series reactor, you may want to use the three selection criteria mentioned above for screening. By understanding the reputation of the series reactor and whether it has passed third-party testing and is qualified, and also by checking the 3C certificate. Only by comparing the prices of series reactors under these conditions can we purchase satisfactory reactor products.