Series Active Power Compensator Based on Single-Phase Current-Source Converters with Minimum DC Current Operation

A Series Active Compensator based on Single-Phase Current Source Converters is studied. The proposal has two advantages; first, it requires just a first order capacitive filter on the ac side as compared to the second order LC filter needed by voltage source based topologies. As a result, sags and swells can be compensated without the hassle of oscillations at the load voltage side; second, an external control loop is added to regulate the dc current value. This technique is based on the converter modulating vector magnitude control, and it guarantees the system operation at minimum dc link current, which minimizes the conducting and commutating losses. The topology and control scheme can be extended to multi-level configurations, which makes the arrangement suitable for medium to high voltage applications using standard semiconductors. The work includes preliminary results that prove the topology and control scheme feasibility.