1. The influence of temperature gradient
In the photovoltaic system environment, temperature gradient is a key factor affecting the measurement accuracy of temperature sensor for photovoltaics. Due to the large area of photovoltaic modules, there may be significant temperature differences between their surface and interior, and between different areas.
For example, when the sun is shining brightly, the edge and center parts of the photovoltaic module may receive different amounts of heat, resulting in inconsistent temperatures. This temperature gradient makes the temperature at the sensor location not representative of the actual average temperature of the entire PV module. If the sensor is installed in a local area with lower or higher temperatures, measurement deviations will occur. Moreover, as the size of photovoltaic modules increases and the working environment changes, the impact of temperature gradient on measurement accuracy will become more significant.
2. The influence of humidity and moisture
Humidity and moisture are also environmental factors that cannot be ignored. High-humidity environments may cause the sensor's outer casing to become damp, affecting the performance of its internal circuitry. When moisture intrudes into a sensor, it may cause a short circuit or change the electrical characteristics of the sensor element.
For example, for some sensors that measure temperature based on electrical principles (such as thermistor type), the presence of moisture may change the resistance value, causing errors in the measurement results. In addition, in the presence of dew or rain, if the sensor does not have good waterproof performance, its measurement accuracy will be greatly interfered with, and the sensor may even be damaged.
3. Impact of Dust and Pollutants
Dust and contaminants are ubiquitous in the operating environment of photovoltaic systems. When dust accumulates on the surface of temperature sensor for photovoltaics, it will affect the heat exchange between the sensor and the surrounding environment.
On the one hand, dust acts as a thermal insulation, preventing the sensor from accurately sensing the outside temperature, causing the measured temperature to be lower than the actual temperature; on the other hand, the chemical components in the dust may react chemically with the sensor shell or sensitive components, causing corrosion. Or damage the sensor, thereby affecting its measurement accuracy. Especially in areas with a lot of sand and dust, the accumulation and erosion of a large amount of sand and dust will gradually reduce the performance of the sensor, requiring regular cleaning and maintenance.
4. The influence of electromagnetic interference
In photovoltaic power plants, there are various electrical equipment and transmission lines, which can produce electromagnetic interference. Electromagnetic interference may affect the signal transmission and processing of the temperature sensor for photovoltaics.
For example, strong electromagnetic interference may induce additional voltage or current in the sensor's signal wire, causing distortion of the measurement signal. For high-precision temperature sensors for photovoltaics, even small electromagnetic interference may cause large deviations in the measurement results. Therefore, when designing and installing temperature sensors for photovoltaics, electromagnetic shielding measures need to be considered to reduce the adverse impact of electromagnetic interference on measurement accuracy.
