# Investigation of the Automatic Monitoring System of a Solar Power Plant with Flexible PV Modules
## 3 Results and Discussion
When the battery is very discharged, the PWM charger delivers a maximum current pulse with a long \"on\" cycle and a shorter \"off\" period. This means that most of the time, power is supplied to the battery until it reaches the required charge level, and then PWM starts to reduce the current supply, shortening the \"on\" time to protect the battery from burning. Meanwhile, MPPT (Maximum Power Point Tracking) technology continuously monitors the output parameters of the solar modules and optimizes the energy recovery process, thus ensuring higher efficiency, especially in changing weather conditions. MPPT chargers can operate at any ratio between solar module voltage and battery voltage, and efficiently convert excess energy to achieve maximum energy use. As a result, MPPT chargers perform better in low-light conditions as they are able to maintain maximum power. For example, when a solar module generates more energy than the battery can accept, PWM technology simply loses this energy, while MPPT optimizes the charging process and makes the most of this energy. Such a difference between the technologies leads to different charging periods and final efficiency of the batteries, since PWM technology works most efficiently on sunny days, while MPPT ensures better energy utilization in changing weather conditions and also maintains the battery charging level optimally. Analyzing the efficiency factor of MPPT and PWM chargers during battery charging, it is observed that the total useful work is higher in the case of MPPT than in the case of MPPT. The efficiency factor of MPPT and PWM chargers is higher in the case of MPPT than in the case of MPPT. Figure 2.3 Battery voltage dependence when PWM and MPPT systems are used for charging. PWM. The dependence of efficiency over time, both in the case of PWM and MPPT, is presented in Figure 2.4  
The efficiency of MPPT and PWM chargers depends on the angle of the sun to the surface of the PV module. At a right angle between the solar radiation and the surface of the PV module, the efficiency is the highest and reaches about 75% for PWM and 92% for MPPT. The efficiency of MPPT and PWM chargers is one of the key considerations in understanding the differences in their performance and suitability in certain situations. This analysis and comparison help determine when to use one technology or another to get the most out of solar energy systems. The theoretical efficiency in a PWM charger is limited by its inability to maintain the maximum power point. PWM efficiency is directly related to the voltage difference between the solar module and the battery. Losses are due to unused solar energy. The maximum power of solar modules is usually achieved at a certain voltage, which does not necessarily coincide with the battery voltage. Due to this mismatch, PWM uses the available power inefficiently [4, 5, 6, 7]. The theoretical efficiency in MPPT systems is much higher because the charger adapts to the difference in voltage between the solar module and the battery, converting the excess voltage into current for maximum energy use. An MPPT charger can operate at any ratio of solar module voltage to battery voltage while maintaining the maximum power point (MPT). MPPT is particularly effective in low sunlight or cloudy conditions where the voltage may be unstable. MPPT is able to monitor and maintain the maximum power point, so efficiency remains high even in changing lighting conditions. During this study, error analysis and ensuring the accuracy and reliability of the data were carried out in several ways. First, the instruments used in the measurements, such as digital wattmetters, were calibrated prior to the measurements to ensure that the readings met the established standards. Second, each measurement was performed five times and the results were analyzed by averaging. The deviations of the values from the mean were vanishingly small, so they are not shown in the graphs.