Preventive measures for Fault of Capacitor(III)

Preventing harmonics

There are many harmonic sources in the power network. If although the harmonic is too large at the node of the shunt capacitor, it is directly put into the shunt capacitor, it will often make the harmonic in the power network greater. It poses a great threat to the safety of shunt capacitor.

The method of installing series reactor current limiting reactor XD1/2 can effectively restrain the occurrence of harmonic component and inrush current, and has obvious effect on ensuring the safe operation of shunt capacitor. The harmonic components in the installation of shunt capacitors should be tested in advance where conditions permit, and the capacity of the required series reactors should be determined according to the test results.

The installed capacity of the series reactor can also be determined directly according to the capacity of the installed shunt capacitor. In general, the harmonic at least 5 times should be selected by 6% of the capacitance of shunt capacitor, and the harmonics of more than 3 times should be selected according to 12% of the capacitance of shunt capacitor. In addition, the harmonic amplification of three time should be prevented in the places where the suppression of harmonic amplification is only more than 5 times (that is, the reactor capacity is the capacitance of the capacitor),so as to ensure the safe operation of shunt capacitors.