Rectifiers for corrosion control
We desingn and produce rectifiers mostly for corrosion control, these are the so called cathode stations. Products are partly diode rectifiers without control, partly thyristore or controllable ones. Number of produced items can be found in the reference list. Furtermore we produced mobile cathode stations, too.
A few words about corrosion control rectifiers:
The same way as in the industrial practice, we need to realize the followings:
Constuction using up-to-date material and components
Using high-qualitatiy production tecnology
Esthetic construction and appearance
Transformer rectifier are usually installed open-air but some equipment work in air-conditioned rooms.(Latter ones were made for China).
Open-air installation requires resistance of:
- heliation (70 °C inside)
- cool in winter (-20 °C)
- atmospheric overvoltage or damage
In some cases companies also need remote computer setting of workplace, or remote reading of operation parameters. These information arrive via satellites from all over the area of Hungary to the operator desk. Nowadays 30-40 power supplies resolve the mentioned tasks, that’s so called „Remote Control Run”. All controllable transformer rectifier are applicable for remote operation.
Finished developments without demand for serial production:
- transistor cathode… with 48V/10A parameters for operation on cos Φ =1.
- thyristor cathode… (48V/50A parameters) with potential control. On it’s LCD we can read the cathode potential; DC voltage, DC power, and the temperature of the switched-mode MOS-FET’s heatsink. Power suppy changes automatically for voltage or current regulating mode in case of damage.
„BUILDING Element System” for building or produce stable and controlled thyristor rectifier: these elements are basic parts of a complete rectifier with thyristor. Considering economical or technical aspects someone only need to order those elements what a fabricant can’t „work out well” (but can all other parts). This way it’s possible to make a really modern controlled rectifier.
Products made for corrosion control: diode rectifiers, thyristore rectifiers, switched-mode power supplies, regulator blocks for thyristore rectifiers, regulator blocks for AC choppers.
Type: NHDC and GL. Made for single phase voltage, nominal output DC voltage 24 or 48 V, nominal current: 20A -100A (depends on type). Contains multi tapping transformer and Graetz bridge diode rectifier. Output voltage is variable by tappings. If it’s needed, inrush current can be reduced by serial resistences connected before the ransformer. Resistance is short circuited automatically after the turn on process finished. Output current is measured by a shunt, voltage can be controlled by a voltage divider. Device is built into a metal box with steel frame, suitable for outdoor installation. These diode rectifiers were used mainly in active corrosion control of gas and oil pipelines, number of produced items can be found in the reference list.
Nowadays become more important the remote corrosion control systems so we developed th „VSZ” type single phase pimary side antiductor regulator block which makes rectifier remote controlable by bulit it into the box of rectifier.
Type:”TTf”. Made for single or 3-phase voltage, nominal output DC voltage is 24 or 48 V, nominal DC is 20A -100A (depends on type). To the transformer’s seconday coil connects a thyristore rectifier. Inrush current can be reduced by serial resistences if required. Resistance is short circuited automatically after the turn-on process finished. Power supply controls constant voltage up to the currnet limit then controls the constant current („UI’” characteristic curve). Range of voltage and current control is between 0 and the nominal values. Single phase device’s voltage is 230V 50 Hz, three-phase ones’ is 3x400V %0 Hz. Regulator’s input signal: 60 mV DC shunt signal for current backflow, voltage backflow from DC output connector. +0...3.3 V current and voltage are basic signals for remote operation. If power supply is used for corrosion control, tact impulse is 3,3 V. Basic signals can be set locally by potenciometers. Local or remote control operation options are eligible by switch, LEDs indicate the status. Device is built into a metal box with steel frame, suitable for outdoor installation. These thyristor rectifiers were used mainly in active corrosion control of gas and oil pipelines.
Type: „ktf”. Mainly used in corrosion control. Voltage: 230V, nominal output voltage 24V or 48V. Nominal current: 20A - 80 A (depends on type). Power supply is built into a metal box with steel frame, suitable for outdoor installation. Elements: inverter made of PCB, switchboard for terminal connectors, fuses, and switch; remote control unit for the wireless remote operation. Inverter is an independent unit with control devices, digital voltmeter and ammeter, status indicator LEDs. Inside the inverter a diode Graetz bridge rectifies the mains voltage. MOSFETs transform DC voltage into 60kHz PWM AC voltage. This voltage is galvanically isolated and transformed by a ferrit-core transformer. Rectified secondary voltage runs throuh the ferrit-core choking-coil to the output switch. Power supply controls constant voltage up to the current limit then controls the constant current („UI’” characteristic curve). Range of voltage and current control is between 0 and the nominal values. Value of voltage and current can be set locally by potenciometers, or by remote control unit in case of remote operation. Local or remote control operation options are eligible by a switch.
Regulator blocks for thyristor rectifiers:
Also as buliding element
Single-phase block type: TY1, three-phase block type: TY3. Regulator blocks are independent units. Applicable for controlling single-phase or three-phase Graetz bridge thyristor rectifiers. Device contains 2 PCBs built into steel frame. Unit contains all essential elements needed for Gratz bridge rectifiers’ regulation, except DC smooting choke and high performance thyristors. TY blocks regulate constant voltage up to the current limit then controls the constant current („UI’” characteristic curve). Range of voltage and current control is between 0 and the nominal values. Blocks’s input signal: 60 mV DC shunt for current backflow, voltage backflow from output switch. +0...3.3 V current and voltage are basic signals for remote operation. If it’s used for corrosion control, tact impulse is 3,3 V. Basic signals can be set locally by potenciometers. Local or remote operation option, eligible by switch, LED status indicator lights. Output signals: transformer isolated tiriger pulse. Control signal for inrush current reducing unit, galvanically isolated by opto-coupler.
Thyristor rectifier block
Also as building element
Control block for AC chopper (primer thyristor regulator):
Also as building element
Type: VSZ. Regulator block is an independent unit for single phase AC antiductor (a pair of thyristors) regulation. Comprises 2 PCBs built in steel frame. Unit contains all needed elements for regulation (excepting high performance thyristors). Connected to a diode rectifier’s transformer the power supply works as regulated single phase device with UI characteristic curve. Swiching on power supply voltage, soft-start limites the inrush current. Input signals: 230 V power supply voltage, 60 mV DC shunt for current backflow, voltage backflow from output switches. +0…3,3 V current and voltage are basic signals for remote control. If it works as power supply in corrosion control, tact impulse is 3,3 V. Basic signals can be set locally by potenciometers. Local or remote operation option, eligible by switch, LED status indicator lights. Output: 0…180 degrees firing pulse, galvanically isolated by pulse transformers.
Also as building element
Oil-ccoling rectifiers, galvanizing power supplies:
High current elements of rectifiers are oil cooled. The case containing the regulator it is situated on the top of he oil tank. Rectifier part has 2x3-phase, interphase transformer connection. 3–phase tyristor chopper connected before the transformer’s primary coil regulates voltage by current limiting. Power supply’s (photo) nominal output voltage is 8V, nominal DC 5000A. These rectifiers are applicable for other use, e.g. hydrolysis, corrosion control of seaports, etc. (with required U-I parameters).
Transformers, choking-coils are made according to a special technology into all cathode stations. Nominal loading values are for natural cooling.
- primary and secondary coils are not wound on each other
- between colis there’s dpop channel what is optimal for rectifying and improves cooling
- operation security is 100% due to this construction and technology
- hypersil cores
- transformer’s smaller size and weight
- safety construction for all 1- and 3-phase transformers
- DC smoothing chokes are cylindrical coiled. Inductivitycan be set by alteration of the air gap.
Needed parameters in case of order:
- inductivity at nominal DC
- nominal DC
Box for outdoor rectifier:
- double coverage
- front opening self-supported steel box
- sintered about shade card colour
- cylinder lock, ELA locking mechanism
- door seals: silicone-containing rubber