A Simple Design and Simulation of Full Bridge LLC Resonant DC-DC Converter for PV Applications BTech EEE Academic projects



 This paper deals with the design and simulation of full bridge LLC resonant converter suitable for photovoltaic applications. LLC converter has several desired features such as high efficiency, low electromagnetic interference (EMI) and high power density. This paper provides a detailed practical design aspect of full bridge LLC resonant converter. The LLC converter is implemented with a full-bridge on the primary side and a fu l-bridge rectifier on the secondary side. It includes designing the transformer turns ratio and selecting the components such as resonant inductor, resonant capacitor and magnetizing inductor. Also performance parameters such as voltage gain and output voltage ripple are calculated. Simulation of LLC resonant converter is carried out using MATLAB / SIMULINK and the results are verified.


  1. LLC resonant converter
  2. Output voltage ripple
  3. Voltage gain




Fig. 1: Simulink diagram of full bridge LLC resonant converter



Fig. 2: Driving pulse of MOSFET Q1&Q3, current and voltage waveforms


Fig. 3: Driving pulse of MOSFET Q2&Q4, current and voltage waveforms


Fig. 4: Output voltage of inverter & current through resonant components

image005Fig. 5: Transformer primary and secondary voltages


Fig. 6: Output current, output voltage and output power of LLC resonant converter


Fig. 7: Output ripple voltage waveform



The design procedure of Full Bridge LLC Resonant Converter is presented for photovoltaic application. Theoretical values of resonant component values are calculated using the design equations. Simulation results are provided for LLC Resonant converter for an input voltage of 33V. The voltage gain and output voltage ripple of LLC resonant converter is calculated which shows that the ripple is less in the proposed converter.


  1. Abramovitz, A. and S. Bronshtein, 2011. A design methodology ofresonant LLC DC-DC converter’ Power Electronics and Applications (EPE2011), Proceedings of the European Conference, pp: 1-10.
  2. Bing Lu, Wenduo Liu, Yan Liang, F.C. Lee and J.D. Van Wyk, 2006.Optimal design methodology for LLC resonant converter’, Applied Power Electronics Conference and Exposition. Twenty-First Annual IEEE, 6: 19-23.
  3. Choi, H.S., 2007. Design consideration of half bridge LLC resonant converter, Journal of Power Electronics, 7(1): 13-20.
  4. Gopiyani, A. and V. Patel, 2011. A closed-loop control of high power LLC Resonant Converter for DC-DC applications, Nirma University International Conference, pp: 1-6.
  5. Senthamil, L.S., P. Ponvasanth and V. Rajasekaran, 2012. Design and implementation of LLC resonant half bridge converter’ Advances in Engineering, Science and Management (ICAESM), International Conference, pp: 84-87.

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