Buck-boost converters

This work shows the design and tuning procedure of a discrete PID controller for regulating buck boost converter circuits. The buck boost converter model is implemented using Simscape Matlab library without having to derive a complex mathematical model. A new tuning process of digital PID controllers based on identification data has been proposed. Simulation results are introduced to examine the potentials of the designed controller in power electronic applications and validate the capability and stability of the controller under supply and load perturbations. Despite controller linearity, the new approach has proved to be successful even with highly nonlinear systems. The proposed controller has succeeded in rejecting all the disturbances effectively and maintaining a constant output voltage from the regulator.

An impedance source buck-boost converter (BBC) prototype for renewable energy (RE) application in the transportation industry is proposed. Its functions include stabilizing the variable output voltage of the RE sources such as fuel cells and photovoltaic cells. The converter utilized a topology of DC-DC quasi-impedance source converters (q-ZSCs) to achieve the gain curve of the BBC. With BBC gain curve, the converter earned advantages over the two other classes of non-isolated DC-DC q-ZSCs. These advantages include ecient buck-boost capability at the ecient duty ratio range of 0:35-0:65 and continuous and non-zero gain at the ecient duty ratio range. The converter's q-ZSC topology implies using two capacitors and two inductors. These two capacitors and inductors formed two separate LC filters that provides second order filtering compared to the first order filtering in BBC. Its other advantages over the traditional BBC include elim-ination of dead and overlap-time, simple contol...

A double output port DC-DC quasi impedance source converter (q-ZSC) is proposed. Each of the outputs has a different voltage gain. One of the outputs is capable of bidirectional (four-quadrant) operation by only varying the duty ratio. The second output has the gain of traditional two-switch buck-boost converter. Operation of the converter was verified by simulating its responses for different input voltages and duty ratios using MATLAB SIMULINK software. Its average steady-state output current and voltage values were determined and used to determine the ripples that existed. These ripples are less than 5% of the average steady-state values for all the input voltage and duty ratio ranges considered.

A double output port DC-DC quasi impedance source converter (q-ZSC) is proposed. Each of the outputs has a different voltage gain. One of the outputs is capable of bidirectional (four-quadrant) operation by only varying the duty ratio. The second output has the gain of traditional two-switch buck-boost converter. Operation of the converter was verified by simulating its responses for different input voltages and duty ratios using MATLAB SIMULINK software. Its average steady-state output current and voltage values were determined and used to determine the ripples that existed. These ripples are less than 5% of the average steady-state values for all the input voltage and duty ratio ranges considered.