In this chapter, various power quality problems created by the widespread use of conventional diode bridge rectifiers and line-commutated AC/DC converters have been discussed. The impact of these problems on the health of power systems and working of sensitive equipments has also been discussed. Need for addressing these burning power quality issues has been emphasized. Recent trends of addressing these issues have been briefly discussed. A new breed of improved power quality AC/DC converters has been discussed in details. Development of various topologies and state-of-art of this breed of converters has been discussed briefly. The state-of-the-art multilevel converters used as improved power quality converters have been covered in this chapter with emphasis on three-level neutral-point clamped converters. This converter has been investigated for improved power quality and various simulation results have been presented to prove their effectiveness in terms of excellent power quality like nearly unity input power factor and negligible harmonic distortion of source current. The simulation results have been obtained with sinusoidal PWM and sapce-vector PWM modualtion algorithms. Simulation restls have been validated through experimental results which are obtained on a three-level converter by real-time implementation of space-vector PWM technique using a real-time DSP board. The performance investigation of the converter proves the effectiveness of three-level converter in elegantly addressing the burning power quality issues. We know that power systems are designed to operate at frequencies of 50 or 60 Hz. However, certain types of loads produce harmonic currents in the power system. The power system harmonics are not a new phenomenon. Concern over harmonic distortions has ebbed and flowed during the history of electrical power systems. Traditionally the saturated iron in transformers and induction machines, electric arc furnaces, welding equipment, fluorescent lamps (with magnetic ballasts), etc. have been responsible for the generation of harmonics in electric power systems. Most of these equipments also cause the flow of reactive component of current in the system. In recent years, many power electronic converters utilizing switching devices are being widely used in domestic, commercial and industrial applications, ranging from few watts to MWs. However these converters suffer from the drawbacks of harmonic generation and reactive power flow from the source and offer highly non-linear characteristics. The generation of harmonics and reactive power flow in the power systems has given rise to the ‘Electric Power Quality’ problems. Any significant deviation in the magnitude of the voltage, current and frequency, or their waveform purity may result in a