Ensuring the Power Quality in the Operation of Variable Frequency Drives of Drilling Rigs

Abstract

The paper considers the ways to ensure the power quality in the operation of variable frequency drives of drilling rigs. The use of multi-pulse rectification circuits as part of a frequency converter reduces the voltage waveform distortion at the semiconductor frequency converter grid-connection point. However, this solution has not completely fixed the grid voltage waveform distortion issue. The main way to improve the power quality in supply systems containing drives with semiconductor converters is the use of harmonic filters. A harmonic filter reduces the total factor of harmonic components and the voltage deviation at the drilling rig input. Reducing the voltage deviation improves the motor current and torque waveforms. A promising way to improve the power quality is the use of an active voltage rectifier as part of a frequency converter. An active voltage rectifier significantly reduces the higher voltage harmonic component at the drilling rig input. Changing the active voltage rectifier's reactive current signal leads to a change in reactive power. As a result, the voltage deviation at the rig input reduces.