Digital LQR control with Kalman Estimator for DC-DC Buck converter

Energy management is critical in electronic systems and an adequate energy transfer is fundamental. Recent circuit requirements lead us to solutions such as the digital controllers, which can accommodate the classical control methods and new algorithms impractical in analog circuits. The linear-quadratic regulators (LQR) offer interesting properties that can be used to control a DC-DC Buck Converter. LQR, when applied with a Kalman State Estimator, can implement a control method that only senses the output voltage, avoiding a current sensor. In this work, a low sampling frequency Digital LQR with a Digital Kalman State Estimator with Buck Converter, working at 2 MHz, is implemented in Matlab. Classical control methods, such as Proportional-Integral-Derivative (PID) with High-Frequency Pole, Average Current-Mode with external Voltage compensation loop, Analog LQR with Kalman State Estimator and the Digital LQR are implemented in Matlab for comparison purposes.