Rectifier transformer is the power transformer of rectifier equipment. The characteristic of rectifier equipment is that the original party inputs AC, while the auxiliary party outputs DC after rectifying the original. Converter is the general name of rectifier, countercurrent and frequency conversion. Rectifier is the most widely used one. The transformer used as the power supply of rectifier is called rectifier transformer. Most industrial rectifier DC power supplies are obtained from AC power grid through rectifier transformer and rectifier equipment.
Rectifier transformer is the power transformer of rectifier equipment. The characteristic of rectifier equipment is that the primary side inputs AC, while the secondary side outputs DC after passing through the rectifier element. The transformer used as the power supply of rectifier is called rectifier transformer. Most industrial rectifier DC power supplies are obtained from AC power grid through rectifier transformer and rectifier equipment. Rectifier transformer is a transformer specially used for rectifier system.
Rectifier converter function:
1. Supply proper voltage to the rectifier system;
2. To reduce the pollution of power grid caused by waveform distortion caused by rectifier system.
Characteristics of rectifier transformer
A transformer that forms rectifier equipment with rectifier to obtain DC power from AC power supply. Rectifier equipment is the most commonly used DC power supply in modern industrial enterprises. It is widely used in DC transmission, electric traction, steel rolling, electroplating, electrolysis and other fields.
The primary side of the rectifier transformer is connected to the AC power system, which is called the grid side; The secondary side is connected to the rectifier, which is called the valve side. The structural principle of rectifier transformer is the same as that of ordinary transformer, but its load rectifier has the following characteristics because it is different from general load:
① Each arm of the rectifier turns on in a cycle, and the conduction time only accounts for a part of a cycle. Therefore, the current waveform flowing through the rectifier arm is not a sine wave, but close to an intermittent rectangular wave; The current waveforms in the primary and secondary windings are also non sine waves. The figure shows the current waveform of three-phase bridge Y / Y connection. When rectifying with thyristor, the greater the lag angle, the steeper the current fluctuation and the more harmonic components in the current, which will increase the eddy current loss. Since the conduction time of the secondary winding only accounts for a part of a cycle, the utilization rate of the rectifier transformer is reduced. Compared with ordinary transformer, the rectifier transformer has larger volume and weight under the same conditions.
② The power of the primary and secondary sides of an ordinary transformer is equal (ignoring loss), and the capacity of the transformer is the capacity of the primary winding (or secondary winding). However, for the rectifier transformer, the power of the primary and secondary windings may be equal or unequal (when the current waveforms of the primary and secondary sides are different, such as half wave rectifier), so the capacity of the rectifier transformer is the average of the apparent power of the primary and secondary sides, which is called equivalent capacity, that is, S1 is the apparent power of the primary side and S2 is the apparent power of the secondary side.
③ Compared with ordinary transformer, the ability of rectifier transformer to withstand short-circuit electrodynamic force must strictly meet the requirements. Therefore, how to make the product have short-circuit dynamic stability is an important topic in design and manufacturing.