Finite automated system to design a high efficiency LLC resonant converter system for 3 kW. PV solar array

Abstract

• LLC resonant converters are popular for their high efficiency when used with PV systems, they can further improve the overall efficiency of the system, resulting in better energy conversion and reduced power losses. • LLC resonant converters offer soft switching, which means that the switching of power devices occurs at low current and voltage levels. This reduces the stress on the power devices, extends their lifespan and minimizes the generation of electromagnetic interference (EMI). • LLC resonant converters can be easily integrated with PV systems due to their flexible input and output voltage requirements. They can efficiently step up or step down the voltage levels as required by the PV system, making them suitable for applications such as grid-tie solar inverters or battery charging systems. • LLC resonant converter can operate over a wide input voltage and load range, which is particularly beneficial for PV systems as the input voltage from the PV modules can vary based on factors such as solar irradiance and temperature. This allows for a more stable and reliable operation of the PV system under varying conditions. • LLC resonant converters can improve the power quality of PV systems by reducing the presence of harmonics, fluctuations and distortions in the output voltage. This leads to a cleaner and more stable power supply, which is crucial for grid-tie applications, where strict power quality standards need to be met. • Calculate the coefficients of transfer gain function with six coefficients with a novel method. • Provide a new model for evaluating and selecting the LLC main parameters to get the main high performance values. A combination of electrical circuit design and the Finite Automation model leads to improved efficiency in terms of memory usage, computation time, and overall performance. LLC resonant converters are known for their high efficiency and ability to convert DC voltage from solar panels into the desired AC voltage for grid-tied or off-grid PV systems. However, designing, testing, and implementing LLC in a PV system requires careful consideration of various factors, including voltage and current requirements, resonant frequency, and compliance with standards and regulations. Eight cases are taken for this purpose with a special case of a 3kW-PV module. The major parameters for the LLC resonant Converter were 480-500V. as output voltage for 36-40V. input voltage range with a 39V. nominal voltage. The calculated coefficients for these values were as follows: A = C = 7.29, B = -50.58, D = -0.25, and E = -11. Combining LLC circuit design with FA, it is providing 94.5 % efficiency through selecting precise parameters that minimized overall calculated losses such as conductive and switching types. The right path and accepted words for different cases are given to provide several solutions with the correct path of design. ZVS and ZCS have been obtained through precise selection process of phase shift between Half Bridge of LLC circuit achieved by this design.