The choke limits the rate of current rise in the input circuit of the frequency converter, thereby protecting the frequency converter from sudden voltage fluctuations in the network (for example, when switching on/off large consumers). Also, the choke improves the sinusoidal shape of the input current of the frequency converter, thereby reducing interference in the network and extending the service life of the frequency converter. The use of a network choke is most appropriate in the following situations:
- when several closely placed transducers are switched on in parallel;
- if there is significant interference in the power supply from other equipment, for example-large consumers;
- at asymmetry of supply voltage between phases more than 1,8% of rated voltage;
- when the converter is powered from a line with low impedance the converter is located next to a powerful transformer, the power is 3 times or more superior to the converter;
- when installing a large number of converters on the same line;
- to reduce the overload of capacitors that increase cos f, if the unit is equipped with a capacitor Bank to increase the power factor.
ONI chokes differ with their stability of the declared characteristics due to use at production of high-quality materials, strict observance of subtleties of technological process and rigid output control of finished goods.
