Browsing by Author "Neira, Sebastián"
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- ItemA Novel Three-Port NPC Converter for Grid-Tied Photovoltaic Systems with Integrated Battery Energy Storage(IEEE, 2020) Neira, Sebastián; Lizana Gajardo, Alonso Javier; Pereda Torres, Javier EduardoThe variable behaviour of the photovoltaic (PV) generation arises as the main drawback of this technology. Therefore, Battery Energy Storage (BES) units appear as a promising solution to overcome the inherent intermittent generation profile of PV systems. BES can be implemented separated from the PV generation units or integrated within a single power system. The latter option gives a better dynamic response, as the variable generation can be directly complemented with the BES, controlling the power flow between both elements with the grid. Thus, there is a need for power converters with capability of interface both PV and BES with the grid in a reliable and efficient way. This paper proposes a Three-Port NPC converter to connect a PV array and a BES unit with the ac grid using a single power processing stage. The converter is based in the H-NPC inverter and allows the connection of a low voltage battery to act as a power buffer ensuring a firm energy dispatch to the grid. Furthermore, simulation results show that the proposed topology maintains the good performance of the H-NPC in terms of efficiency, voltage harmonic distortion and reduced leakage current
- ItemNew dual H-bridge converter for continuous space vector modulation(2019) Durán Godoy, Tomás Antonio; Neira, Sebastián; Pereda Torres, Javier Eduardo; Rojas, FélixMultilevel converters are a significant improvement in the DC-AC conversion technology, reaching higher power quality in medium-voltage applications and using standard semiconductors in a smarter way than conventional converters, without necessarily increasing the cost. However, multilevel technology remains discrete and its only way to reduce the overall total harmonic distortion leads on the generation of several discrete levels on the output voltage. Therefore, it is not possible to reduce the harmonic distortion to negligible values, unless a big number of semiconductors are used, which is not cost-effective for low-voltage applications, limiting the reliability of the system. This study proposes a new dual H-bridge inverter that generates a three-phase output voltage with negligible distortion using two variable DC-DC power sources and a new continuous space vector modulation. Simulation and experimental results show high-quality output voltages. The topology is simple and uses only 12 semiconductors, but it requires special attention in the variable DC voltage converters, which can limit the maximum output frequency. Therefore, the solution is suitable for low power applications that require high power quality using small filters or none filters at the AC side. The results were obtained and validated using an experimental laboratory prototype under different operating conditions.
- ItemSequential Phase-Shifted Model Predictive Control for a Multilevel Converter with Integrated Battery Energy Storage(2020) Neira, Sebastián; Poblete, Pablo; Cuzmar Leiva, Rodrigo Hernán; Pereda Torres, Javier Eduardo; Aguilera, Ricardo P.Cascaded converters have risen as a suitable solution for the connection of Utility-scale Battery Energy Storage Systems (BESS) to the grid. These converters allow to split the battery array into the power modules, reducing the total series-connected battery cells and improving the reliability of the system. Different types of modules have been proposed to integrate the batteries in the converter. The three-port full-bridge module connects the batteries through a second deport decoupled from the harmful low-frequency oscillations and current peaks. However, the multi-variable controller required to manage the power interaction between the battery and the grid presents a challenge in terms of computational burden and scalability. This work proposes the use of the Sequential Phase-Shifted Model Predictive Control (PS-MPC) in a multilevel BESS implementation using three-port full-bridge modules. The proposed controller outperforms a standard FCS-MPC, as it obtains the optimal duty cycles for the operation of the converter with the same fast dynamic response, but also with the fixed spectrum of the PS-PWM and low computational burden, which facilitates its scalability to multilevel BESS with a large number of cells. Simulation results show the ability of the system to exchange different amounts of power with the grid, ensuring the best battery operational conditions
- ItemSequential Phase-Shifted Model Predictive Control for a Multilevel Converter with Integrated Battery Energy Storage(2020) Neira, Sebastián; Poblete, Pablo; Cuzmar Leiva, Rodrigo Hernán; Pereda Torres, Javier Eduardo