Book review: Ralph R. Frerichs: Deadly river - Cholera and cover-up in post-earthquake

As most of PV systems, CPV systems are also affected by mismatching losses, particularly due to misalignment of optics and receivers. As a result, module level power electronics can help to increase their energy yield by making every CPV module deliver it maximum power at the output. Among the different alternatives, solutions based on DC power optimizers exhibit higher conversion efficiencies and lower costs than microinverters. However, while microinverters ensure optimal operation independently from the operating conditions, system design with DC power optimizers must be carefully examined to avoid potential underperformance. This paper describes not only the customized design and validation of a high-efficiency and economical DC power optimizer for HCPV systems, but also a comprehensive analysis of the whole system design to optimize its production under expected working conditions.Main design specifications (electrical parameters of module and number of modules per tracker), as well as supporting information for mismatching losses estimation, have been provided by ASSE within CPVMatch project. This work has received funding from the European Union’s Horizon 2020 research and innovation programme within the project CPVMatch under grant agreement No 640873

Study on the effectiveness of commercial anti‐islanding algorithms in the prospect of mass penetration of PVs in low‐voltage distribution networks

In the coming years, distribution grids will be progressively flooded by renewable energy sources (RES) that will be interconnected with the main grid through power electronic converters. Photovoltaics (PVs) are one of the most promising renewable technologies even for densely built-up areas where space problems are inevitable. The high penetration prospect of PV facilities on low-voltage distribution networks raises questions regarding the necessity of advanced functions that will enable electronically coupled RES to support the operation of distribution grids and to enhance their reliability. In this context, the objective of this study is to investigate the effectiveness of various islanding prevention measures installed in commercial PV inverters, when multiple inverters are operating in parallel with a low-voltage distribution network (LVDN). Extensive experiments were performed under various PV penetration levels, linear/non-linear load and over/under voltage and over/under frequency conditions, as well as for various values of total harmonic distortion of the mains voltage. Further to the primary statistical analysis, the results were analysed in depth by advanced mathematical methods such as box plot and cluster analysis. The findings of this study indicate that commercial anti-islanding techniques present a high probability of failure in the case of multiple PV units at the same point of common coupling, calling for new and more advanced algorithms.European Commission, H2020, 65411

Development and evaluation of open-source IEEE 1547.1 test scripts for improved solar integration

Distributed Energy Resources (DERs) equipped with standardized, interoperable, grid-support functionality have the capability to provide a range of services for power system operators. These requirements have been recently codified in the 2018 revision of the American DER interconnection and interoperability standard, IEEE Std. 1547, as well as the revised Canadian interconnection standard, CSA C22.3 No. 9. Currently, the IEEE standards committee is drafting a new revision of the IEEE Std. 1547.1 test standard, which outlines the test procedures for certifying equipment compliant to IEEE Std. 1547. In addition, it is often referenced as a test standard in CSA C22.3 No. 9. This draft test standard has not been fully exercised yet to identify mistakes, redundancies, and/or implementation challenges. In this work, an international community of research laboratories developed open-source IEEE Std. 1547.1 test scripts. The scripts are used to evaluate grid-support functions – such as constant-power-factor, volt-var, volt-watt, and frequency-watt functions – of several DER devices to the draft standard, EEE1547.1. Sample test results are presented and discussed, and recommendations are offered to improve the draft standard during the balloting process