A new maximum power point tracking method and its application in PV systems based on inductor current transient analysis

In recent years, energy consumption has been increasing due to increasing technological developments and industrial production in the world. In the face of increasing energy demand, the use of alternative and sustainable energy sources is also gaining importance. In particular, the limited utilization capacity of fossil fuels and the negative environmental impacts resulting from their use have increased the demand for renewable energy sources. Solar energy is one of the widely used renewable energy sources today, thanks to its advantages such as its unlimited resource and its very low negative environmental impacts. Since the potential of renewable energy sources varies depending on atmospheric conditions, it is very important to control and use them efficiently. Especially in solar panel systems, ambient conditions such as temperature, radiation and humidity directly affect the operating efficiency. Although the sunshine duration in certain areas of the world is statistically certain, instantaneous changes affect the output power of solar panel systems considerably. In solar panel systems, Maximum Power Point Tracking (MPPT) systems have been developed to obtain the highest possible power under ambient conditions. In this thesis, a MPPT method is developed to obtain the highest possible power from the solar panel system under varying operating environment conditions. In the developed method, MPP detection is performed with the instantaneous measurement data of the operating current and voltage of the panel. The feature that distinguishes the designed MPPT system from the existing measurement-based methods in the literature is that the panel I-V values are measured by analyzing the instantaneous change of the inductor current. The system developed in this study consists of a 40 W solar panel, STMF32F407 controller, power converter circuit and load. In the power converter part of the system, an interleaved boost converter, which has a simple structure and the inductor measurement method is easily applicable, is preferred in accordance with the panel power. Since the developed MPPT method is measurement-based, panel current and voltage are measured instantaneously and panel power is monitored. In case of a 5% change in panel power, panel I-V values are measured and a new MPP is determined. In accordance with this new MPP, the switching frequency of the circuit is determined. While the switching frequency changes according to the detected MPP, the switch duty ratio remains constant 0.5. The accuracy of the developed method in MPP detection is checked with an experimental study. In the experimental study, the irradiance is changed gradually and the MPP detected by the system is compared with the MPP that should be detected. The power values found by the system and the required power values are very close to each other and the accuracy of the method is calculated as 96.4%. In the developed method, since the MPP is obtained directly as a result of measurement, MGNI is provided with high accuracy. In addition, the circuit design and control algorithm of the developed method are very simple and easy to implement.