High-voltage multilevel converter with regeneration capability

This paper presents a multilevel converter with regeneration capability. The converter uses several power cells connected in series, each working with reduced voltage and with an active front end at the line side. This paper presents the following: 1) the control method of each cell; 2) the use of phase-shifting techniques to reduce the current and voltage distortion; and 3) criteria to select the connection of the cells. The converter generates almost sinusoidal currents at the load and at the input and works with very high power factor.