Discussion on Inaccurate Resistance Measurement of Photovoltaic Fuses

With the continuous development and popularization of photovoltaic power generation technology, the stability and accuracy of the performance of photovoltaic fuses, as key components of circuit protection, have become particularly important. However, in practical applications, photovoltaic fuses may have inaccurate measurements of resistance, which not only affects the safety and reliability of photovoltaic systems, but also increases the complexity and cost of operation and maintenance. This article will explore the reasons and solutions for inaccurate resistance measurement of photovoltaic fuses from the basic principles of photovoltaic fuses, resistance measurement methods, and factors affecting measurement accuracy

Basic principles of photovoltaic fuses 

Photovoltaic fuses, also known as PV fuses, are mainly used for circuit protection in photovoltaic systems. When the current of the protected circuit exceeds the specified value, the melt inside the fuse will melt due to the heat generated by itself, thereby cutting off the circuit and preventing safety accidents such as equipment damage or fire. The working principle of a fuse is based on the thermal effect of current, and it has the functions of overload protection and short circuit protection.

Resistance measurement method

The measurement of resistance is one of the important indicators for evaluating the performance of photovoltaic fuses. Usually, resistance measurement is carried out using a resistance meter (also known as a multimeter), which measures the voltage across the fuse and the current passing through it, and calculates the resistance value using Ohm's law. However, in practical operation, due to various factors, measurement results may have deviations.

Factors affecting the accuracy of resistance measurement

The accuracy and stability of the error resistance meter of the measuring equipment directly affect the accuracy of the measurement results. If the resistance meter is not calibrated or has faults, it will directly cause measurement errors. In addition, environmental factors such as temperature and humidity during the measurement process may also affect the reading of the resistance meter

2.  Characteristics of Photovoltaic Fuses During use, the internal materials of photovoltaic fuses may undergo changes such as aging, oxidation, etc. due to the thermal effect of current and the accumulation of time, which can affect the resistance value of the fuse. Especially in harsh environments such as high temperature and high humidity, the resistance value of fuses changes more significantly.

3. Improper measurement methods. If the correct operation steps are not followed when measuring resistance, such as not disconnecting the circuit, not selecting the appropriate range, etc., it may lead to inaccurate measurement results. In addition, contact resistance, lead resistance, and other factors during the measurement process can also affect the final results.

4.External interference In photovoltaic systems, external factors such as electromagnetic interference and radio frequency interference may also affect resistance measurement. These interference signals may enter the measurement system through wires, spatial coupling, and other means, causing measurement results to deviate.

Strengthen the protection against external interference

In photovoltaic systems, measures such as strengthening electromagnetic shielding and radio frequency shielding are taken to reduce the impact of external interference on resistance measurement. Meanwhile, during the measurement process, some technical measures can be taken to eliminate or reduce the influence of interference signals## The problem of inaccurate resistance measurement of photovoltaic fuses involves multiple aspects, including errors in the measuring equipment itself, characteristics of photovoltaic fuses themselves, improper measurement methods, and external interference. In order to improve the accuracy of measurement results, it is necessary to start from multiple aspects, including improving the accuracy and stability of measurement equipment, optimizing the design and selection of photovoltaic fuses, standardizing measurement methods and operating procedures, and strengthening protection against external interference. Only in this way can we ensure that photovoltaic fuses play their due role in the photovoltaic system, guaranteeing the safe and stable operation of the photovoltaic system