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

This article presents a nonlinear control based on pulsewidth modulation (PWM) and an estimation mechanism of the output power to regulate the output voltage of a boost converter supplying a constant power load (CPL). The controller uses three parameters K
_p
, K
_E
, and K
_A
lending the regulator an adaptive nature. The behavior of the latter can be expressed in terms of the dynamic description of three errors. Namely, first, current error, i.e., difference between the average value of the inductor current and its equilibrium value, second, output voltage error, i.e., deviation between the output voltage and its desired equilibrium value, and, second, power error, i.e., difference between the output power estimated value and its actual value. The analysis of the dynamic behavior of the three errors results in a parametric region in the plane K
_p
- K
_E
in which the system stability is guaranteed. The regulator exhibits fast and precise responses in the presence of disturbances in the input voltage and the load power. Conduction losses provoke steady-state errors in both current and power estimation but do not affect the output voltage tracking.