Research On Module Parallel Application And Multi-phase Interleaving Technology In Current Mode Buck Converter

The supply mode of Switch Power Supply has been an important part of the power electronics technology. Considering the limitations of a single power supply mode, the paralleled power supply mode has become an essential part of the current research direction. This kind of structure has many advantages, such as large capacity, high efficiency and reliability, etc. Also, interleaving control of the paralleled structure will make a great effect on output ripple, frequency, the size of the components, circuit layout, etc.In this thesis, based on the theory of single-phase Buck- type converter, we design a current controlled Buck circuit with multiple power in parallel operation mode, and study the technology of module parallel and interleaving control. These two kinds of models are simulated in MATLAB/Simulink environment, respectively. In single-phase Buck converter, the main work is to make a clear understand about how the circuit components affect the stability of the circuit as well as the ripple of the output. In multi-phase Buck converter, the double-phase and triple- phase paralleled structure are simulated, the simulation results show that the module in paralleled structure can effectively reduce the size of the output ripple, improve ripple frequency, to improve the quality of the output voltage and current. The design of multiple module parallel structure power supply can provide a reference for the design of low voltage high current mode circuit.In order to verify the correctness of the theoretical analysis and the operability of modules in paralleled structure, adopting integrated chip LTC3855 of Linear technology in the experiment, we designed a two-phase interleaved parallel type Buck converter with output voltage 1.2V, output current 40A, the switching frequency 250 KHz. According to the test and analysis, the power could supply output voltage of 1.1985 V, output voltage ripple is 19 mV, each branch current is 20 A, and the structure has a good ability of current share. Then, also the load regulation is tested, the adjustment rate of load regulation is 0.8%.The application of the module in parallel technology can effectively improve the stability and output quality of the power supply system, and lay a foundation for the modularization and miniaturization of the switching power supply as well as circuit integration.