Protection system for pipelines

Abstract

A protection system ( 10 ) for pipes ( 12 ) comprises a cathodic corrosion protection system ( 18 ) which comprises a rectifier ( 22 ) and a corrosion protection switching element ( 24 ) which is electrically conductively connected to the rectifier ( 22 ), wherein the cathodic corrosion protection system ( 18 ) is set up to switch between a corrosion protection mode and a measuring mode, wherein the rectifier ( 22 ) is not connected in the measuring mode. The protection system ( 10 ) also includes a decoupler ( 18 ) which comprises a first capacitor ( 28 ) and a second capacitor ( 30 ) and a capacitor switching element ( 32 ). The capacitor switching element ( 32 ) is electrically conductively connected to the first capacitor ( 28 ) in a first switch position when the cathodic corrosion protection system ( 18 ) is in the corrosion protection mode. In a second switch position, the capacitor switching element ( 32 ) is electrically conductively connected to the second capacitor ( 30 ) when the cathodic corrosion protection system ( 18 ) is in the measuring mode. Furthermore, the use of such a protection system is specified.

1 . A protection system ( 10 ) for pipes ( 12 ), comprising
 a cathodic corrosion protection system ( 18 ) which comprises a rectifier ( 22 ) and a corrosion protection switching element ( 24 ) which is electrically conductively connected to the rectifier ( 22 ), wherein the cathodic corrosion protection system ( 18 ) is set up to switch between a corrosion protection mode and a measuring mode, wherein the rectifier ( 22 ) is not connected in the measuring mode, and   a decoupler ( 20 ) which comprises a first capacitor ( 28 ) and a second capacitor ( 30 ) and a capacitor switching element ( 32 ),   wherein the capacitor switching element ( 32 ) is electrically conductively connected to the first capacitor ( 28 ) in a first switch position when the cathodic corrosion protection system ( 18 ) is in the corrosion protection mode, and   wherein the capacitor switching element ( 32 ) is electrically conductively connected to the second capacitor ( 30 ) in a second switch position when the cathodic corrosion protection system ( 18 ) is in the measuring mode.   
     
     
         2 . The protection system according to  claim 1 , wherein the pipe ( 12 ) is a metallic pipe having a coating ( 14 ) of an insulating material. 
     
     
         3 . The protection system according to  claim 1 , wherein the capacitor switching element ( 32 ) is a power semiconductor switch. 
     
     
         4 . The protection system according to  claim 1 , wherein the protection system ( 10 ) is set up to charge the first capacitor ( 28 ) to a switch-on potential and to charge the second capacitor ( 30 ) to a switch-off potential in a training phase of the protection system ( 10 ), and wherein the switch-on potential corresponds to the potential of the pipe ( 12 ) to be protected in the corrosion protection mode and the switch-off potential of the second capacitor corresponds to the potential of the pipe ( 12 ) to be protected in the measuring mode. 
     
     
         5 . The protection system according to  claim 4 , wherein the switch-on potential is more negative than the switch-off potential. 
     
     
         6 . The protection system according to  claim 1 , wherein the first capacitor ( 28 ) and/or the second capacitor ( 30 ) has/have a capacitance in the range of 0.1 to 1.0 F. 
     
     
         7 . The protection system according to  claim 1 , wherein the decoupler ( 20 ) has a grounding device ( 34 ) which is electrically conductively connected to the first capacitor ( 28 ) and the second capacitor ( 30 ). 
     
     
         8 . The protection system according to  claim 1 , wherein a clipping diode ( 56 ) is connected in parallel with the second capacitor ( 30 ). 
     
     
         9 . The protection system according to  claim 1 , wherein the cathodic corrosion protection system ( 18 ) and the decoupler ( 20 ) have switching control elements ( 60 ,  62 ) which are time-synchronized. 
     
     
         10 . Use of the protection system ( 10 ) according to  claim 1  for protecting a pipe ( 12 ), wherein the corrosion protection switching element ( 24 ) and the capacitor switching element ( 32 ) are connected to the pipe ( 12 ).