Mathematical Method for Parameters Calculation of electric Characteristic of Photovoltaic Module

The study of photovoltaic systems (PV) in an efficient manner requires a precise knowledge of the I-V characteristic curves of PV modules. An accurate current-voltage (I-V) model of PV modules is inherently implicit and non-linear and calls for iterative computations to obtain an analytical expression of current as a function of voltage. In this paper, numerical approaches are proposed to forecast the PV modules performance for engineering applications. The proposed approaches were implemented in a Matlab script and the results have been compared with the datasheet values provided by manufacturers in standard test conditions (STC). These approaches permit to extract the unknown parameters and also allow quantifying the effects of module temperature and irradiance on key cells parameters. In this work, a comparative study of the performance characteristics for different modules thin films and solid is analyzed by a single-diode equivalent circuit using four- and five-parameter models and two diode model.

Analysis of Electrical Properties Using the four point Probe Method

There has been conducted Physics research on a material, that is, monitoring electric characteristic of a material using four-point probe method. This research measures current and voltage. The result is used to determine resistivity of a material. The research uses 2 samples, that is, chalk and charcoal. The result shows the resistivity of the sample in the form of bulk (t>s) for chalk has high resistivity on voltage of 6.6 Volt. Meanwhile, resistivity on thick sheet (t<s) has high resistivity on voltage of 7 Volt. On the charcoal material, large resistivity (t>s) is in 6 Volt, and on large resistivity (t<s) is in 6.6 Volt.

Early Warning of Electric Characteristic Parameters on Electric Power System Based on Embedded System

In order to avoid the operation accidents of power system caused by the influences of various artificial or nature factors, the paper explored the early warning of characteristic parameters on power system based on embedded system. In the paper, it taken a 110kV substation as an example, studied on therelated algorithm of the electric characteristic parameters, constructed the hardware and software platformbased on embedded microprocessor, and designed the hardware circuit and software control program. The commissioning test demonstrated that it could accurately judge the latent fault of related devices, and send correctly the trip command to make the isolation between the fault device and the power system so as to protect the system from being damaged. The experiment results show that it is effective and available to early warning of power system.

Conducting and Insulating Materials

Conducting materials may be classified into three groups: conductors, semiconductors and imperfect insulators. This section will cover only conductors.In general, metals and alloys are conductors of electricity. The most common metals used in electricity are copper, aluminium and their alloys.The main electric characteristic of conductors is resistance that varies with temperature, presenting copper a lower resistance than aluminium.