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This article presents low-frequency ripple power steering control strategies for a power conversion topology that comprises a high frequency linked three-port converter (HFL-TPC) and a voltage source inverter (VSI) for PV-BESS/EV applications. The proposed topology has three interfaces, which can be connected with a photovoltaic (PV) port, battery energy storage systems (BESS) and/or electric vehicles (EVs) port, and a four-quadrant ac port. The proposed topology inherently exhibits double line frequency (DLF) power fluctuation that needs to be decoupled and steered away from the PV port. In this article, we have developed and demonstrated two control strategies to deal with the DLF ripple. The first control strategy utilizes loop gain of the closed loop control system to decouple the DLF power, however, a residual DLF power still exists at the ac port. To completely decouple the DLF fluctuations, an improved sequence-based control strategy is proposed where the DLF voltage components are converted into positive and negative sequence components and controlled separately on their respective synchronous reference frames. To verify the practical feasibility of the proposed low-frequency ripple power steering control strategies, a 40 V, 400 W HFL-TPC is built and tested. Experimental results show that the proposed methods decouple the DLF power fluctuation and selectively steer it to the BESS/EV port. Comparative results reveal that the sequence-based control strategy shows a higher degree of DLF ripple suppression. [ABSTRACT FROM AUTHOR]

Abstract In the past five years substantial amounts of rooftop photovoltaic (PV) generation have been installed across the low voltage distribution networks. These networks often have design lifetimes of 40 years. Most of the existing distribution networks were constructed, and the voltage profiles set, prior to the rapid uptake of PV. When power quality difficulties arise reconstruction or some other form of intervention is required. This review will focus on power electronic options for voltage profile management in networks with high penetrations of PV. A voltage profile improvement can be achieved with a range of series or shunt connected devices. The traditional voltage regulator adds a series compensation voltage and electronic and electro-mechanical variations exist. Shunt devices attempt to influence voltage with reactive or real power flows when storage is allowed. A shunt device is additionally capable of phase balancing which may substantially raise the allowable PV fraction. In addition to the topological choices, the converter choice will impact upon capability. This paper will examine full converter solutions which incorporate meaningful energy storage at a DC bus and reduced energy storage scenarios or storage free solutions such as matrix converter (MC) based devices. Highlights • Rooftop PV penetration. • distribution regulator topologies. • Voltage regulator. • MC based voltage regulator. • DSP-FPGA based control. [ABSTRACT FROM AUTHOR]