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Analysis Of Reactor Performance In Substation
- Nov 20, 2017 -

The reactor used in the power network is essentially a hollow coil with no magnetically conductive material. It can be arranged according to the needs of vertical, horizontal and shape three kinds of assembly form. In the event of a short circuit in the power system, a large amount of short-circuit current results. Without limitation, it is very difficult to maintain the dynamic stability and thermal stability of electrical equipment. Therefore, in order to meet the capacity requirements of some circuit breakers, it is common to connect reactors at outlet circuit breakers to increase the short-circuit impedance and limit the short-circuit current.


As a result of the reactor, in the event of a short circuit, the reactor voltage drop is large, it also played a role in maintaining the bus voltage level, so that the voltage fluctuations on the bus less to ensure that non-fault line user electrical equipment Operational stability.


In recent years, remarkable results have been achieved in the power system in order to eliminate capacitor faults caused by high-voltage harmonics and currents, and to use series reactors in capacitor circuits to change system parameters.


Series reactor is mainly used to limit the short-circuit current, but also in the filter with capacitors in series or in parallel to limit the higher harmonics in the power grid.


Shunt reactors are used to absorb capacitive reactive power in the grid, such as high-voltage reactors in 500kV power grids and low-voltage reactors in 500kV substations, which are used to absorb the reactive power of the charging capacitors in the line; 220kV, 110kV, 35kV, 10kV power grids The reactor is used to absorb the capacitive charging of the cable line. The operating voltage can be adjusted by adjusting the number of shunt reactors. EHV shunt reactors have several functions that improve the reactive power of the power system in relation to operating conditions, including:


1. Capacitive effect on light-load or light-load lines to reduce power frequency transient over-voltage.


2. Improve the voltage distribution on long transmission line.


3. Make the reactive power in the line as light load as possible balance on the ground, prevent unreasonable flow of reactive power, and reduce the power loss on the line at the same time.


4.When the large unit and the system are in parallel, reduce the steady-state voltage on the high-voltage bus to facilitate generators to be in parallel over the same period.


5.To prevent the generator with long lines possible self-excitation resonance phenomenon.


6.When the reactor neutral point through the small reactance grounding device, you can also use small reactors to compensate the line phase and phase capacitance to speed up the sub-supply current automatically extinguished, easy to adopt single-phase fast reclosing.