Reducing the hardware requirements in FPGA based controllers: a photovoltaic application

Sistemas fotovoltaicos monofásicos experimentan oscilaciones de voltaje debido a la diferencia entre la potencia promedio generada y la potencia instantánea inyectada a la red. Estas oscilaciones de voltaje degradan la producción de potencia. Este artículo propone una solución para mitigar las oscilaciones propagadas a las terminales del generador, la cual minimiza los recursos de hardware requeridos para implementar la técnica de compensación de un dispositivo FPGA, permitiendo su coexistencia con algoritmos de control adicionales en un solo dispositivo. La efectividad de la solución se valida experimentalmente, y sus requerimientos de hardware se contrastan con soluciones basadas en plataformas comerciales

A fast current-based MPPT technique based on sliding mode control

This paper introduces a novel maximum power point tracking technique aimed at maximizing the power produced by photovoltaic systems. The largest part of the approaches presented in literature are based on the sensing of the photovoltaic generator voltage. On the contrary, in this paper a current-based technique is proposed: the sensing of the current in the capacitor placed in parallel with the photovoltaic source is one of the innovative aspects of the proposal. A dual control loop based on the sliding mode control ensures a very fast tracking of irradiation variations. Features of the proposed algorithm are supported by a theoretical analysis and simulations. The technique described in this paper is patent pending

A fast current-based MPPT technique based on sliding mode control

This paper introduces a novel maximum power point tracking (MPPT) technique aimed at maximizing the power produced by photovoltaic (PV) systems. The largest part of the MPPT approaches presented in the literature are based on the sensing of the PV generator voltage. On the contrary, in this paper, a current-based technique is proposed: the sensing of the current in the capacitor placed in parallel with the PV source is one of the innovative aspects of the proposal. A dual control technique based on an inner current loop plus an outer voltage loop allows to take profit of the fast current tracking capability of the inner current loop while the voltage loop benefits from the logarithmic dependency of the PV voltage on the irradiation level. The features of the proposed algorithm, particularly in terms of tracking of irradiation variations and disturbance rejection, are supported by theoretical analysis, simulations, and experimental results. The technique described in this paper is patent pending

Perturb and Observe MPPT-algorithm with a Current Controller based on the Sliding Mode

In this paper a current controller is used to reject the 100-Hz oscillation of the voltage of the photovoltaic field taking place in any grid connected system. With respect to the classical linear voltage control the current-based sliding-mode approach ensures a wider regulation band but, unfortunately, in presence of a fast irradiance variation the sliding conditions might be violated, so that the operating point, which should be the maximum power point, might not be the expected one. In order to prevent such a drawback, an appropriate voltage compensation loop is used to interface the current-based sliding mode with the Maximum Power Point Tracking algorithm. Simulation and experimental results confirm the goodness of the proposed algorithm