Switch mode rectifiers for cathodic protectionCathodic protection (CP) is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded "sacrificial metal" to act as the anode. The sacrificial metal then corrodes instead of the protected metal. For structures such as long pipelines, where passive galvanic cathodic protection is not adequate, an external DC electrical power source is used to provide sufficient current.Cathodic protection systems protect a wide range of metallic structures in various environments. Common applications are: steel water or fuel pipelines and steel storage tanks such as home water heaters; steel pier piles; ship and boat hulls; offshore oil platforms and onshore oil well casings; offshore wind farm foundations and metal reinforcement bars in concrete buildings and structures. Another common application is in galvanized steel, in which a sacrificial coating of zinc on steel parts protects them from rust.Why Green Power's switch mode power supplies replace SCR rectifier? Green Power's Switch mode power supplies have many advantages over SCR rectifier, therefore, they are now more and more used for electroplating process to replace SCR rectifier. The main advantages of Green Power pulse plating rectifiers over thyristor rectifiers include but not limited to:Low maintenanceLight weight, small size, in far areas, don't need crane truck, like heavy oil-cooled SCR rectifier which is difficult and expensive.Same high reliability as SCR rectifier, long time 7 days 24 hours continuous runningHigh conversion efficiency, power saving at least 15% than SCR rectifier.Not affected by power fluctuation, 100% output, don't need extra capacityIGBT rectifier adopts AC-DC-AC-DC topology, 3 phase AC is firstly converted to DC, which has capacitors for energy charging and discharging, it will suppress power fluctuation, so rectifiers don't need bigger capacity than actual use. SCR rectifier doesn't have energy buffer function, it is affected directly by the grid power fluctuation, so it always keep much extra capacityand increase user's investment cost.Pulse output needs less plating time, customer feedback 40% shorter time needed for platingModular design:Rectifier won't break down: in case of one module failed, the rectifier continue working with reduced powerLess downtime and easy recovering:plug-in structure, replace module directly, downtime is shorten to minimum, this reduces potential high cost of your plant stop and increase your plant's availability.Current expansion available:thanks to the modular design and supporting parallel connection, if you need more power, you only need to add more modules.Reduce current rating to save power: if you don't need all modules working, you can switch off some modules, rectifier can work at lower rating.Less floor space occupied: the rectifiers can be built on top of each other, making them easy to fit into your plant's design, optimizingfloor space.Easy to install and maintain: each rectifier consists of up to ten modules and naturally two or more stacks can be connected to allow higher currents (40kA) and voltages (200V DC).Separate output or parallel running output available: you can let the rectifier module separate output to connect to more tanks, or parallel connecting to get higher current for one tank.Compact size, modular structure, e.g. air cooling 1000A 12V size only 450*560*300mm, weight is only 58kg. much less size and weight than SCR rectifier, don't need forkliftLow pollution to grid, power factor 0.93Lower costfor the same specificationComparison chartThyristor rectifierGreen Power   switchingpower supplyEfficiencylowhigh88% (typ.)Power factorbadhigh0.93SizebigsmallAt least 1/2 smaller than SCR typeWeightheavylightRegulation speedslowhighResponse time to load variationslowvery highvery high (≈1ms)Accuracyacceptablevery high1/1000 of max current or voltageShift phaseyesnoParallelability (multi-tower)very difficulteasy in current and voltage modeLosses at no load /Vout ONhighlowLosses at no load /Vout OFFhighlowReverse speedvery slowFast in both voltage and current modefastest in both voltage and current modeMain Technical Parameters Input voltage: 3 phase 4 line, 220V, 380V, 415V, 480VInput voltage protection range: +/-10%Cooling method: Water cooling, forced air cooling, natural coolingPower factor: 0.93Efficiency: 92% at rated outputRegulation range: 0-100%Duty cycle: 100% continuous runningControl mode: constant voltage, constant currentAccuracy: 1%Ambient temperature: Max. 40℃Elevation: 4000mConvenient use and operationModule structureEasy to move and replacementFlexible combination, get different current outputCompact size, light weightSave space, could be installed stackedStandard design, short lead time, lower costEasy remote control by communicationDSP digital control support multiple remote control option:0-10V/4-20mA analog signal+dry contacts to be controlled by PLCCommunication with PLC through RS485, Profibus, ProfinetWe provide remote control box, distance up to 30 meters longTouch panel operationCould set output value accuratelyCould set step lengthCould realize timer function, automatic stop after timing upCould set protection parameters on touch panelCould save history data for inquirySet local control/remote controlSet CC/CV modeEasy and quick fault judge and troubleshooting Rectifier provide full protections and self alarmDSP realize self fault diagnosisTouch panel shows protection type automaticallyTouch panel provide history protection record for inquiryProvide detailed troubleshooting guidance with pictures in manualUser-oriented mechanical design, easy for disassembly to change parts