Converter is the general name of three working modes: rectifier, countercurrent and frequency conversion. Rectifier is the most widely used one. The characteristic of rectifier equipment is to output the input AC to DC after rectification and filtering. Rectifier transformer is the power transformer of rectifier equipment. Most industrial rectifier DC power supplies are obtained by rectifier transformer and rectifier equipment.
2 What is a power transformer
Power transformer generally refers to the transformer that supplies power to the electric drive system. Most of the transformers in the power grid are power transformers.
3 Difference between rectifier transformer and power transformer
(1) Functional difference
Functions of rectifier transformer: 1. Supply appropriate voltage to rectifier system; 2. It is to reduce the pollution of power grid caused by waveform distortion caused by rectifier system.
The output of rectifier transformer is still AC, which only provides power for rectifier equipment. Usually, the primary side is connected into a star shape and the secondary side is connected into an angle shape to suppress high-order harmonics. The secondary side is connected into an angle, and the neutral point is not grounded. When the rectifier equipment is grounded at one point, it will not cause equipment damage, and the grounding fault alarm signal will be sent through the grounding detection equipment. 1 Shielding isolation is added between the secondary.
Rectifier transformers are mainly used in electrolysis, smelting, excitation, transmission, cascade speed regulation, electrostatic dust removal and high-frequency welding. The structure is a little different. In order to make the waveform smooth, some rectifier transformers for electrolysis are made into six phase output, and a six phase rectifier bridge is added outside to get a relatively smooth waveform. According to the current waveform characteristics and anti harmonic requirements of thyristor rectifier circuit for smelting and high-frequency welding, the eddy current loss in rectifier transformer winding and stray loss in structural parts are optimized for some data and processes. In fact, the general structure is also similar.
The power transformer is usually Y / y connected neutral grounding (providing single-phase power supply). If it is used for rectifier equipment, the rectifier equipment will be damaged in case of grounding fault, and its ability to suppress high-order harmonics generated by rectifier equipment is also poor.
(2) Different uses
The transformer used as the power supply of rectifier is called rectifier transformer. Most of the rectifier DC power supply used in industry is obtained by the rectifier equipment composed of rectifier transformer and rectifier in AC power grid. In today's highly modern society, its great use can be seen directly or indirectly in almost every field. Power transformer is mainly used for power system, daily lighting and plant power. The main purposes of rectifier transformer are as follows:
1. Electrochemical industry;
2. DC power supply for traction;
3. DC power supply for transmission;
4. DC power supply for DC transmission;
5. DC power supply for electroplating or machining;
6. DC power supply for excitation;
7. DC power supply for charging;
8. DC power supply for electrostatic precipitator;
(1) Differences in address
Due to the close combination with the rectifier, the output voltage of the rectifier transformer is called valve side voltage, which is named because of the unidirectional conductivity of the diode.
(2) Differences in calculation methods
Due to the different waveforms of load current of rectifier, the calculation method of output current is not only very different from that of power transformer, but also different for different rectifier circuits.
4 Differences in design and manufacturing
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