A Control Scheme without Sensors at the PV Source for Cost and Size Reduction in Two-Stage Grid Connected Inverters

[EN] In order to reduce the cost of PV facilities, the market requires low cost and highly reliable PV inverters, which must comply with several regulations. Some research has focused on decreasing the distortion of the current injected into the grid, reducing the size of the DC-link capacitors and...

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Bibliographic Details
Authors: González-Medina, Raúl|||0000-0003-0378-5045, Liberos, Marian|||0000-0001-6574-1158, Figueres Amorós, Emilio|||0000-0002-0716-3916, Garcerá, Gabriel|||0000-0002-5507-4379, Marzal Romeu, Silvia
Format: article
Publication Date:2019
Country:España
Institution:Universitat Politècnica de València (UPV)
Repository:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Language:English
OAI Identifier:oai:riunet.upv.es:10251/182486
Online Access:https://riunet.upv.es/handle/10251/182486
Access Level:Open access
Keyword:Photovoltaics
Two-stage grid-connected PV inverters
Reduced DC-link
Sensorless MPPT
TECNOLOGIA ELECTRONICA
Description
Summary:[EN] In order to reduce the cost of PV facilities, the market requires low cost and highly reliable PV inverters, which must comply with several regulations. Some research has focused on decreasing the distortion of the current injected into the grid, reducing the size of the DC-link capacitors and removing sensors, while keeping a good performance of the maximum power point tracking (MPPT) algorithms. Although those objectives are different, all of them are linked to the inverter DC-link voltage control loop. Both the reduction of the DC-link capacitance and the use of sensorless MPPTalgorithms require a voltage control loop faster than that of conventional implementations in order to perform properly, but the distortion of the current injected into the grid might rise as a result. This research studies a complete solution for two-stage grid-connected PV inverters, based on the features of second-order generalized integrators. The experimental tests show that the proposed implementation has a performance similar to that of the conventional control of two-stage PV inverters but at a much lower cost.