SMA Solar Technology AG (meaning System, Mess and Anlagentechnik) is a German solar energy equipment supplier founded in 1981 and headquartered in Niestetal, Northern Hesse, Germany. SMA is a producer and manufacturer of solar inverters for photovoltaics systems with grid connection, off-grid power supply and backup operations.The company has offices in 18 countries.
As part of the transition to an energy system with 100% renewable generation, renewable energy power plants must increasingly take over responsibility for system stability. A key element in ensuring system stability is grid forming control of generation and storage units. In Germany, scenarios predict a significant expansion of renewable energy generation and storage systems in distribution networks. Integration of grid-forming systems into distribution networks raises several open questions, among them are power system oscillations and temporary island operation: Grid forming inverters may unintentionally lead to oscillation issues like those found in traditional transmission systems. A study reveals that as the level of virtual inertia in the distribution grid increases, these oscillations may become more pronounced which highlights the importance of implementing effective damping measures. Temporary island operation: In principle, grid-forming inverters enable the stable continued operation of critical sub-grids after a fault-related disconnection from the supply grid. Both disconnection and interception of the grid, as well as resynchronization and reconnection of the sub-grid with active generators and consumers are simulated in a series of laboratory tests and the basic suitability of this technology and the necessary requirements for this application are explained.
Robustness against humidity is vital for power semiconductors. Depending on the application, power semiconductors can be subjected to very harsh climatic conditions. Compared to conventional silicon IGBTs, silicon carbide devices also have higher stress due to faster switching. This paper discusses and presents the results of tests in which the impact of humidity combined with switching of the device was investigated using specially prepared sensitive samples. Self-heating, the influence of climate cycling, and other parameters (including voltage) were also examined in these tests. An additional failure mode that is not triggered in the static HV-H3TRB test is observed and discussed. Based on the findings a new qualification test is proposed.
The photovoltaic (PV) industry is a rapidly growing sector of the Polish economy. The motivation for this study is the lack of detailed research on the impact of external factors on PV development in Poland. Therefore, we consider the different interests of various participants in the industry, encompassing installers; engineering, procurement and construction; designers; distributors; and manufacturers. The main objective of the study is to identify and analyse the legal, economic, environmental, technical and social factors that influence the development of PV in Poland and their determinants, considering the specific needs of different market stakeholders. The research is based on analysing the literature, publicly available reports and websites to complement the findings from in-depth interviews and surveys conducted among key PV market participants. Computational methods are employed, including Bartlett's sphericity tests, and the adequacy of the correlation matrix is evaluated using the Kaiser–Mayer–Olkin coefficient. The research results identify the main determinants of PV industry development in Poland, which include the lack of connection capacity, the cost of non-RESs and hourly pricing in the prosumer billing system. The study also determines the different perspectives between market stakeholders, finding that social factors have little impact on PV industry development. The main conclusion of the study is that the identified barriers must be addressed and removed to ensure the stable development of PV in Poland.
The performance of practical millimetre wave (mmWave) communication systems is affected by different hardware impairments. This can significantly impact the channel reciprocity-based physical layer security (PLS) methods. This paper studies the impact of in-and quadrature-phase (IQ) imbalance on the physical layer secure key generation algorithm performance. Numerical analysis is performed in MATLAB by modelling and simulating the IQ imbalance, which is then applied to the 60 GHz channel used to generate secret keys. The study's outcome shows that IQ imbalance increases bit mismatches up to an average of 5% for an amplitude imbalance of 1.4 dB and a phase imbalance of 7°. However, additional iterations of parity bit sequence exchanges can recover these in the reconciliation phase. As a result, the information is slightly more exposed to an eavesdropper.
