Fully controlled three-phase bridge rectifiers are known as the most common AC to DC converters. Fully controlled bridge converters are widely used in controlling the output voltage of power exchangers by electrochemical processes and can be formed simply by placing six thyristors instead of six rectifier diodes. Thyristors are three-ended semiconductor components that conduct current when a suitable trigger pulse is applied to their gate and their anode-cathode voltage is positive. Therefore, by delaying the trigger pulse time (fire angle), we can delay. As a result, by controlling a three-phase rectifier that uses a thyristor instead of a diode, we can control the amount of DC output voltage by controlling the firing angle of the pair of thyristors, thus rectifying the output voltage as a function of the firing angle α.
 
 

Most power electronics designers and high-powered drives use multi-pulse rectifiers in the input section to achieve the requirements stated in IEEE519. These rectifiers are divided into 12, 18 and 24 pulse models and are powered by phase shifted transformers.
An important feature of multipulse rectifiers is their ability to reduce the harmonic current of the line. LC filters or power factor compensators will usually not be needed and potential LC resonances will be eliminated. The use of phase shifted transformers is an effective way to block common mode voltages generated by rectifiers and inverters in MV level drives.
 
 

Twelve-pulse rectifiers with saturable reactors are the most durable and accurate option for electrochemical processes, which are controlled by saturable reactors with the ability to connect to the PLC unit, in which case their adjustment and monitoring is done by HMI. Saturable reactor technology is the safest, most stable and most durable technology in the manufacture of rectifiers, which is used only by reputable international manufacturers such as ABB. In this system, the output voltage of the reactors is Adjusted by moving on the hysteresis loop and saturating them using a DC power supply
 

Based on the power electronics knowledge of research and development engineers, for the first time in Khazar Transfo Company, a switching power supply system with a cool air cooling system was produced. One of the major challenges of this product, which has not been made available to other competitors, is the design and construction of high-frequency transformer, the choice of core and type of wiring, as well as the cooling technique using only the air-cooled system in the current range of several thousand amps.
- Input power supply: 3Ph, 400V, 50Hz
- Transformer type: Dry type AF
- Output current: 1000 - 10000 ADC
- Output voltage: 10 - 60 VDC
- Rectifier: Fast Diodes
- Control: PLC & HMI
- Output settings: CC / CV
- Insulation class: F
- Operating frequency: 15 kHz
- protection: Over Current, Over Temperature, Phase Sequence
- Power factor:> = 93%
- Work cycle: 100%
- Harmonic distortion rate: <= 5%
 

In a half-controlled three-phase rectifier, three diodes and three thyristors are used to generate a constant average output voltage according to the amount of input AC voltages. Thyristors are three-ended semiconductor components that conduct current when a suitable trigger pulse is applied to their gate and their anode-cathode voltage is positive. Therefore, by delaying the trigger pulse time (fire angle), we can delay.
By increasing the number of phases and diodes in the bridge configuration, a higher average DC output voltage with a lower ripple amplitude can be achieved; For example, with a six-phase rectifier, in which each diode conducts only one-sixth of the alternating current. In addition, the ripple frequency of the output voltage of multi-phase rectifiers is higher, and therefore have a softer output. Therefore, 6, 12, 15 and even 24 phase rectifiers can be used to improve the ripple coefficient in various applications.
 

Double Star topology is a suitable product for high power DC power supplies due to the presence of interphase transformer (IPT). This transformer reduces the current peak and, like the parallelism of the two sources, creates a path for the current to pass and divides the peak between the two parts. Reduction of THD and a series of harmonics, no current flow in the device idle and only reactive power transmission are the features of IPT.
Based on the remarkable engineering capability in a short period of time, responding to the needs of the country's industries for advanced high power rectifiers in the fields of metal extraction by electrowinning method, wastewater treatment by electrocoagulation method, bleach production by electrochlorination method, plasma generation by bread-transfer burners, Heat treatment by induction heating method, removal of heavy metals from drinking water by plasma cavitation method, hydrogen production by electrolysis method, preparation of metals by electropolishing method and many other industrial technologies were given with complete success. Thus, the needs of mineral processing units, refineries and petrochemical complexes, water and wastewater treatment plants and other industries were met. In this way, power electronics technologies with different topologies have been used to make the rectifiers required by the industries. Double Star rectifiers with interphase transformers have been welcomed as a powerful and durable product by all mineral units and were able to provide the megawatt requirement of javel water units of petrochemical complexes and power plants at the highest quality level.