A Position Control With a Field Programmable Gate Array-Sun-Tracking System for Photovoltaic Panels

Abstract

Photovoltaic system applications should operate under good conditions. The maximum power point depends on the sunlight angle on the panel surface. In this chapter, an induction motor (IM) controlled with a direct torque control (DTC) is used to control the photovoltaic panel position. The conventional DTC is chosen thanks to its capability to develop the maximum of torque when the motor is standstill. However, the DTC produces a torque with high ripples and it is suffer from the flux demagnetization phenomenon, especially at low speed. To overcome these problems, two DTC approaches are proposed in this chapter: (1) the DTC based on the fuzzy logic and (2) the DTC based on space vector modulation (SVM) and proportional integral (PI) controllers (DTC-SVM-PI). The suggested approaches are implemented on a field programmable gate array (FPGA) Virtex 5 circuit in order to reduce the sampling period of the system and the delay in the control loop. The simulation and hardware implementation results demonstrate that the DTC-SVM-PI offers best the results in terms of ripples.