Development of a measuring instrument for measuring the IV characteristics of photovoltaic modules with the maximum power point tracking function

V magistrskem delu se ukvarjamo z razvojem merilnega inštrumenta za merjenje IU-karakteristike fotonapetostnih modulov s funkcijo sledenja točke maksimalne moči. Najprej raziščemo možnosti izvedbe in se posvetimo dvema idejama: - bremenitev fotonapetostnega modula z elektronskim bremenom, - uporaba uporovnega bremena in filtriranega signala pulzno širinske modulacije za bremenitev fotonapetostnega modula. Po simulacijah z računalniškimi orodji izdelamo testno tiskano vezje filtra za filtriranje pulzno širinsko moduliranega signala. To vezje testiramo, po analizi naredimo določene izboljšave in se odločimo za kombinacijo obeh idejnih rešitev. Sledi izdelava celotnega tiskanega vezja, kasneje pa razvoj programske opreme in umestitev v ohišje. Končen inštrument poleg močnostnega dela vsebuje še vse merilne sestave, stikalni napajalnik, mikrokrmilnik, vhodno enoto za priklop senzorja temperature in senzorja sevanja ter enoto za komunikacijo prek protokola RS485. Na inštrument lahko priklopimo PV-modul z napetostjo odprtih sponk do 100 V, kratkostičnim tokom do 10 A in maksimalno močjo do 400 W. Izdelan inštrument krmilimo z osebnim računalnikom in zadostuje meritvam fotonapetostnih modulov v realnih zunanjih pogojih. Je prenosen, napaja se neposredno iz merjenca ter je odporen na prah in vodo po standardu IP65. Omeniti je treba še, da je to prva različica inštrumenta, ki omogoča testiranja in je podlaga za nadaljnji razvoj.The thesis presents the development of a measuring instrument for measurement of IV-characteristic of photovoltaic modules with a maximum power point tracking function. Firstly, we look into some possible design options and focus on two ideas: • loading photovoltaic module with electronic load, • the usage of resistive load and filtered pulse-width modulated signal for loading photovoltaic module. After software tools simulations, we make a test version of a printed circuit board for filtering pulse-width modulated signal. The printed circuit board is tested and analyzed, then we make some improvements and decide to continue with a combination of both researched ideas. This is followed by making the whole printed circuit board and then software development and mounting it into a case. The finalized instrument includes power transistors, measurement module, switching power supply, microcontroller, input amplifier for irradiation sensor, temperature and humidity sensor interface and a RS-485 communication interface. The instrument can be connected to the PV module with open circuit voltage up to 100 V, short circuit current up to 10 A and maximum power up to 400 W. This instrument is controlled by a personal computer and can be used to measure photovoltaic modules in real outdoor conditions. It is portable, supplied directly from the measured module and resistant to dust and water according to the IP65 level. It should be mentioned that this instrument is the first developed version and enables further testing and is the basis for further development