Interaction between Sun tracking deviations and inverter MPP strategy in concentrators connected to grid

Concentration PV systems often require Sun tracking to collect the Sun irradiation coming from a narrow solid angle cone centered on the solar disc. Two different tracking systems are then necessary to ensure the maximum power output: a Sun tracking system (STS) which focuses the collector to the Sun and the maximum power point tracking to bias the PV concentrator receivers. The interaction between the STS and the maximum power point tracking (MPPT) has often been a source of problems, since both systems uses the array output as an optimising signal. From the experience of the EUCLIDES™ plant, the necessary conditions to ensure a correct coexistence of both tracking systems have successfully been established. The behaviour of the EUCLIDES™ pointing system with the array connected to the grid has been checked. The "self-learning strategy" implemented for the array aiming has demonstrated excellent features. A new MPPT strategy has been implemented in the inverters, as a required condition for compatibility between the two systems.