Harmonics and unbalanced load compensation by a modular multilevel cascaded converter active power conditioner

Abstract

This paper presents a novel control scheme for a modular multilevel cascaded converter (MMCC) functioning as an active power conditioner (APC) to control the reactive power, eliminate the current harmonics, and compensate unbalanced load current simultaneously. This combines a modified predictive current controller with the inter-cluster and intra-cluster voltage balance control for MMCC sub-module capacitors. Simulation studies of this MMCC-APC for a power network containing both an unbalanced thyristor controlled rectifier and a reactive load are performed and results verifying its performance under varying degrees of load current distortion measured by THD levels are presented.

Keywords

• power harmonic filters
• voltage control
• active filters
• harmonic distortion
• reactive power
• predictive control
• power convertors
• thyristors
• electric current control
• power supply quality
• static VAr compensators
• unbalanced load compensation
• modular multilevel cascaded converter active power conditioner
• novel control scheme
• reactive power
• current harmonics
• unbalanced load current
• modified predictive current controller
• inter-cluster
• intra-cluster voltage balance control
• MMCC-APC
• power network
• unbalanced thyristor controlled rectifier
• reactive load
• load current distortion