Surtension protection principe de régulé alimentation alimentation
Surtension Protection Appareil (SPD), also known as surge protector, is a non-linéaire protecteur dispositif utilisé à limite transitoire surtension et guide décharge surtension courant dans live systems, and is used to protect electrical appliances with low withstand voltage levels or Electronic systems are protected from lightning strikes and lightning electromagnetic pulses or operating overvoltage damage. In recent years, electronic information systems (tel as television, telephone, communication, computer network, etc.) ont développé rapidement, et a grand nombre de électronique information dispositifs ont émergé et deviennent populaires. tels systèmes et équipements sont souvent coûteux et importants, et leur travail tension et avecsupport tension niveau sont très faible, donc ils sont extrêmement vulnérables à foudre électromagnétique impulsions. Therefore, SPD is required for voltage protection.
Due to the different standards follow by various countries, the product specifications are not unified, and the parameter identification also has its own emphase, which is far inferior to other electrical product specifications, which apporting great inconvenience to design and selection. In engineering design, common brands can be divided en domestic products, European products and American products according to the place of origine. Le paramètre paramètres de produits_domestiques sont chaotiques, avec divers spécifications et élevée résiduelle pression. Certains du modèle paramètres de produits_standardisés imiter produits européens, et certains suivent les nationaux calibration paramètres. La plupart des produits sont marqués avec In et Imax. Depuis domestique produits ont relativement faible exigences pour application sites, faible bâtiment grades, et grand équipement avecsupport tension valeurs, certains paramètre exigences peuvent être de manière appropriée détendue.
European products generally mark the maximum discharge current, and the product model is also set according to this parameter. For example, XXX65 and XXX40 of a famous European brand, the values 65 and 40 are Imax. However, the Chinese standard clearly stipulates that the nominal discharge current In should be used for type selection, which is an embarrassing situation encountered in engineering design at present. After checking the product information, the In value of XX65 does not exceed 20kA, and the In value of XX40 does not exceed 15kA. According to the recommended value of GB50343, these two products can only be used for the third-level protection of the equipment terminal, but in the actual design, they are installed on the first and second levels, which is obviously inconsistent with the selection parameters of the national standard, and the residual voltage Higher, ordinary models generally exceed 1200V, once the wiring environment is not good, it is easy to exceed the withstand voltage value of the equipment. Generally, the Uc value of European products is small, and the line voltage is opportunistically marked, so it is easy to be misleading when selecting a model.
The surge protector is suit for 220/380V low-voltage power supply protection. It is a non-linear component. Accordant to the IEC standard, the surge protector is a device that mainly suppresses the overpressure of the conducted line. The surge protector plays a protective role. Le de base exigence est que il doit avecsupport le courant éclair que est attendu à passer à travers, et travers le maximum clampage tension de la surtension, it can efficacement éteindre le puissance-fréquence continu flux généré après le éclair courant passes à travers , et empêcher le instantané surtension dans la ligne puissance et signal transmission ligne. La surtension est limitée dans la tension plage que le équipement ou système peut avecsupport, ou le fort lightning courant est fuite vers le sol pour protéger le protégé l’équipement ou système de dommage dû à impact.
Le type et structure de surtension protecteurs varier accorder à différents fins, mais at least one nonlinear voltage limiting element is included. Communément utilisé surtension protecteurs include MOV (Métal Oxyde Varistor) et gaz décharge tubes. Power surtens contain a lot of energy and can#be stopped. For this reason, the strategy for protecting sensitive electrical equipment from damage from electrical surtens is to shunt the surge away from the équipement et dans le sol.
The surge protector MOV consists of three parts: the middle is a metal oxide material, and two semiconductors are connected to the power and ground. When a surge occurs, the MOV acts immediately, and the response time is 1 to 3 nanoseconds. The "V" in the MOV is a rheostat. At the moment of response, the resistance of the MOV drops from the maximum value to almost zero ohms, and the overcurrent flows into the ground through the MOV. The protected electrical equipment continues to operate under normal working voltage. Its semiconductor elements have the property of changing resistance as voltage changes. When the voltage is below a certain value, the movement of electrons in the semiconductor creates a high resistance. Conversely, when the voltage exceeds that specific value, the movement of electrons changes and the resistance of the semiconductor decreases close to zero ohms. The voltage is normal, and the surge protector MOV is idle, which does not affect the power line.
Le indicateurs des pours et contre de surtension protecteur MOV: (1) serrage tension: Indique la tension valeur que cause le MOV à se connecter à la terre. le inférieur le serrage tension, le mieux la protection performance. (2) Énergie absorption/dissipation capacité: Ceci nominal valeur indique comment beaucoup énergie le surtension protecteur can absorber avant it brûle out, in joules. Le plus élevé la valeur, le mieux la protection performance. (3) Réponse temps: Surtension Protecteurs do not déconnecter immédiatement, ils ont a légère retard dans répondre à la surtension.
Another common surge protection device is a gas discharge tube. Ces gaz décharge tubes do the same thing as MOVs, they move excess current from live to ground by using an inert gas as a conductor bete the two wires. When the the voltage is in a certain range, the composition of the gas determines that it is a poor conductor. If the voltage surtens beyond this range, the current will be strong assez à ioniser le gaz, faire le gaz décharge tube a très bon conducteur. It conducts current to ground until the voltage returns to normal levels, then becomes a poor conductor again.
