THE INFLUENCE OF MULTISTAGE FILTER COMPENSATION DEVICE ON ENERGY GUALITY DURING THE OPERATION OF DRILL RIGS WITH VARIABLE-FREQUENCY ELECTRIC DRIVE
The influence of multistage filter compensation device on power factor, reactive power, voltage deviation and distortion coefficient of sinusoidal form of circuit voltage during the operation of variable-frequency electric drives of drill rigs was explored. The visual model of variable-frequency electric drive with the using of filter compensation device was designed for the calculation of this coefficients. Obtained on the visual model dependences of voltage and current on time on the side of the 6 kV transformer in steady-state operation with absence and inclusion of filter compensation device were shown. It’s shown that the use of semiconductor converter without filter compensation device leads to a distortion of sinusoidal form of voltage and current. Its inclusion leads to the diminution of distortion of sinusoidal form of voltage and current. Dependences of power factor, reactive power, deviations of voltage and distortion coefficient of sinusoidal form of circuit voltage on the length of power line with absence and inclusion of stages of filter compensation device were received. The influence of filters on the diminution of distortion of sinusoidal form of circuit voltage with their various settings on the relative resonance frequency below the fifth harmonic was explored. The expediency of this setting was proved compared with the exact filtration of a certain numbers of higher harmonics. It’s shown that by changing the number of engaged stages of filter compensation device is possible to get permissible values of voltage deviation, distortion coefficient of sinusoidal form of circuit voltage and power factor close to unity.