Single-Phase to Three-Phase Unified Power Quality Conditioners Applied to Electrical Distribution Grids in Remote Areas

Abstract

In remote areas, electrical distribution grids are typically single-phase due to infrastructure and cost limitations, which makes the direct supply of three-phase loads unfeasible. Conventional solutions generally rely on transformers or full power processing converters, leading to increased system size, cost, and power losses. This article proposes two transformerless $1\phi 3\phi$ Unified Power Quality Conditioner topologies capable of supplying three-phase loads from a single-phase distribution system while providing power quality enhancement. The proposed topologies also enable the connection of four-wire loads, allowing the supply of loads requiring a neutral conductor. By operating under a partial power processing principle, only a fraction of the total load power is actively processed by the power electronic stages, contributing to reduced component ratings and improved system-level efficiency. The operating principle, mathematical modeling and the associated control diagram of each topology are discussed. Simulation results at multi-kW power levels are used to assess scalability, while experimental results obtained from a laboratory prototype demonstrate the effectiveness of the proposed solutions under steady-state operation as well as during voltage disturbances and transient conditions. In addition, efficiency and partial power processing analyses are presented.