Nonlinear Control for Output Voltage Regulation of a Boost Converter With a Constant Power Load

A nonlinear control strategy is proposed for the output voltage regulation in a boost converter that supplies a constant power load. State-feedback linearization is used to transform the nonlinear average dynamics of the inductor current in the converter into a linear average dynamics of the inductor current in a virtual mesh, which consists in the series connection of a voltage source, a resistor, and the converter inductor. In the virtual mesh, the resistor introduces damping to contribute to the system stability, while the voltage source indirectly regulates the output voltage. Conditions for the control parameters to ensure the system stability are given. The control can be implemented analogically, this requiring some linear circuits based on operational amplifiers, an analogue divider, and a pulsewidth modulator. Experimental results show a fast recovery and zero steady-state output voltage error in the response to large-signal disturbances in both input voltage and output power.