Sensorless Adaptive Voltage Control for Classical DC-DC Converters Feeding Unknown Loads: A Generalized PI...

Area of Science:

• Electrical Engineering
• Control Systems
• Power Electronics

Background:

• Voltage regulation in DC-DC converters is challenging with unknown loads.
• Second-order converters like buck, boost, and buck-boost require advanced control strategies.

Purpose of the Study:

• To develop a nonlinear control method for voltage regulation in DC-DC converters with unknown constant resistive loads.
• To design a passivity-based controller with proportional-integral (PI) actions for improved stability and performance.

Main Methods:

• Utilized averaging modeling to represent various DC-DC converter topologies using a generalized port-Controlled Hamiltonian (PCH) framework.
• Designed a passivity-based controller with PI actions for asymptotic stability.
• Implemented a linear integral estimator for unknown load value determination, reducing sensor requirements.

Main Results:

• The PCH representation revealed a general bilinear structure in second-order DC-DC converters.
• The passivity-based PI controller achieved voltage regulation with first-order behavior.
• The integral load estimator demonstrated exponential convergence for load value estimation.

Conclusions:

• The proposed PI passivity-based control effectively regulates voltage in DC-DC converters under varying unknown loads.
• This method offers superior performance, avoiding oscillations seen with classical PI controllers.
• The integral load estimator enhances control implementation by minimizing sensor needs.