What is the role of the reactor?

Reactors or what we are more familiar with are inductors, which are magnetic fields in a certain space generated by the energization of conductors, so that the product has a general sense of induction. In addition, we can also find that reactors on the market can be Further detailed and detailed classification, according to the structure and characteristics, including the differences in functional use, is divided into a variety of reactors, friends who are interested in understanding can learn from this, and get a good and satisfactory one. Next, let's learn about the various aspects of the reactor with Xiaobian, including the introduction of the principle of its technology, and the selection recommendations and classification criteria worthy of reference in the later acquisition process.

First, the reactor selection type shunt reactor: The reactor full load test reactor is a prototype of the shunt reactor. Iron core reactors have an attractive magnetic field between the segmented cores, so the noise is generally about 10 dB higher than that of the same capacity transformer. The AC through the shunt reactor, the role of the shunt reactor is to compensate the capacitive reactance of the system. Usually connected in series with the thyristor, the reactance current can be continuously adjusted.

Series reactor: The inside is AC, and the series reactor is connected in series with the compensation capacitor to form a series resonance of the steady-state harmonics (5, 7, 11, 13 times). Usually there are 5~6% reactors, which belong to high-sensitivity reactors. Tuned reactor: The internal passage is AC, and the series reactor acts in series with the capacitor to form a series resonance of the specified nth harmonic component, thereby absorbing the harmonic component, usually n=5, 7, 11, and 13. 19.

Output reactor: Its function is to limit the capacitive charging current of the motor connection cable and limit the voltage rise rate on the motor winding to 54OV/us. The general power is 4-90KW when the cable length between the inverter and the motor exceeds 50m. An output reactor should be provided, which is also used to passivate the inverter output voltage (the steepness of the switch) and reduce the disturbance and impact on components (such as IGBT) in the inverter. Instructions for use of output reactor: In order to increase the distance between the inverter and the motor, the cable can be appropriately thickened to increase the insulation strength of the cable. Unshielded cables should be used as much as possible.

Second, the role of reactors The reactors commonly used in power systems are series reactors and shunt reactors. Series reactors are mainly used to limit the short-circuit current, and are also used in series or in parallel with capacitors in the filter to limit higher harmonics in the grid. The reactors in the 220kV, 110kV, 35kV, and 10kV power grids are used to absorb the capacitive capacitive reactive power of the cable lines. The operating voltage can be adjusted by adjusting the number of shunt reactors.

The ultra-high voltage shunt reactor has various functions for improving the reactive power of the power system, including:

1. The capacitive effect on lightly loaded or lightly loaded lines to reduce the power frequency transient overvoltage.

2. Improve the voltage distribution on long-distance transmission lines.

3. Make the reactive power in the line as balanced as possible on the light load, prevent the irrational flow of reactive power and reduce the power loss on the line.

4. When the large unit is in parallel with the system, reduce the steady-state voltage of the power frequency on the high-voltage bus, which is convenient for the generator to be juxtaposed.

5. Prevent self-excitation resonance phenomenon that may occur in generators with long lines.

6. When the neutral point of the reactor is used to pass the small reactance grounding device, the small reactor can also be used to compensate the phase and phase capacitance of the line to accelerate the automatic extinguishing of the submersible current, which is convenient to adopt. The wiring of the reactor is divided into two ways: series and parallel.

Series reactors usually function as current limiting, and shunt reactors are often used for reactive power compensation.

1. Half-core dry shunt reactor: In the ultra-high voltage long-distance transmission system, it is connected to the tertiary coil of the transformer. It is used to compensate the capacitive charging current of the line, limit the system voltage rise and operate the over voltage, and ensure the reliable operation of the line.

2, half-core dry series reactor: installed in the capacitor circuit, when the capacitor circuit is put into operation.

Restriction and filtering of reactors: The expansion of grid capacity has led to a rapid increase in the rating of the system's short-circuit capacity. For example, on the low voltage 35kV side of a 500kV substation, the maximum effective value of the three-phase symmetrical short-circuit current is already close to 50kA. In order to limit the short-circuit current of the transmission line and protect the power equipment, a reactor must be installed. The reactor can reduce the short-circuit current and keep the voltage of the short-circuit system unchanged. A damper reactor (ie, a series reactor) is installed in the capacitor circuit, and the capacitor circuit is activated to suppress the inrush current. At the same time, together with the capacitor bank, a harmonic circuit is formed to filter the harmonics. For example, in the capacitor circuit of a 35kV reactive power compensation device at a 500kV substation, in order to limit the inrush current when the capacitor is input and to suppress the harmonics of the power system, a damper reactor must be installed in the 35kV capacitor circuit to suppress the third harmonic. It adopts rated voltage 35kV, rated inductance 26.2mH, rated current 350A dry type hollow single-phase outdoor type damper reactor, which forms a resonant circuit with the 3rd harmonic of 2.52Mvar capacitor, that is, 3rd harmonic filter circuit.

Similarly, in order to suppress higher harmonics of 5 times and above, a rated voltage of 35kV, a rated inductance of 9.2mH, and a rated current of 382A single-phase outdoor type damper reactor are used, which is equivalent to 5 times and above harmonics of 2.52Mvar capacitors. A resonant loop is formed. It plays a role in suppressing higher harmonics. It should be noted that the use and technical conditions of the damper reactor are specified in the national standard "Reactor" GB10229-88 and IEC289-88 international standards. However, some departments in China currently refer to the damper reactor as a series reactor, which is strictly inappropriate because there is no such name as a series reactor.

Reactor, which is the inductor. It is a product widely used in the electric power industry. It can control the control to a certain extent, and it also reduces the trouble of manual operation, and it is even more commendable that the reactor on the market can be based on size specifications or requirements. Detailed and detailed classification, sometimes can take care of friends in different fields, and can also give corresponding and appropriate functional performance according to the actual situation, then the above is about the information of the reactor, including the working principle and selection of the product. Description of the standard parameters in terms of recommendations and classification.