Multi-Cell Boost Converter Control via State Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Boost converters with N switching cells face challenges in achieving stable and fast control, particularly due to their non-minimum phase nature and non-linear control dynamics, which limits their responsiveness to external disturbances and stability.
Innovation Solution
A method involving global linearization and duty cycle calculation based on the second derivative of the output vector and power variation to control each switching cell, ensuring stable asymptotic convergence and dynamic response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If cascaded loops control is used for Boost converter, then control stability is improved, but control dynamics and responsiveness to external disturbances are limited
Solution Approach 1:
The patent changes the control parameters by using non-linear control techniques with state feedback and exact linearization. Instead of traditional cascaded loops with fixed gains, the controller dynamically adjusts control parameters based on system state variables, achieving both stability and fast response to disturbances.
Solution Approach 2:
The patent implements a dynamic control approach where the controller adapts to changing system conditions. The non-linear state feedback controller continuously adjusts duty cycles based on real-time measurements of inductor currents and capacitor voltages, enabling fast response to external disturbances while maintaining stability.
2Speed
If switching frequency is increased to improve control speed, then responsiveness to disturbances is improved, but resonance frequency issues on DC bus are exacerbated
Solution Approach 1:
The patent uses feedback from state variables (inductor currents and capacitor voltages) to dynamically adjust switching duties. This feedback mechanism allows the system to respond to disturbances without simply increasing switching frequency, thereby avoiding resonance issues on the DC bus while maintaining fast response through intelligent control adjustments.
3Stability of the object's composition
If non-linear control is applied to globally linearize the system, then control stability and asymptotic convergence are improved, but computational complexity increases
Solution Approach 1:
The patent segments the control of multi-cell Boost converter into individual cell control equations. Each cell's duty cycle is calculated based on its own state variables and the overall system requirements, breaking down the complex non-linear control into manageable per-cell calculations that reduce overall computational burden while maintaining stability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for controlling a boost converter having N switching cells using synchronous pulse width modulation, in which N is a natural integer that does not equal zero, said method comprising: - a step of measuring input voltages (Vin) and output voltages (Vout) of said boost converter; - a step of determining an output vector (y) designed to define a representation of the linear state of the boost converter; - a step of calculating the variation in power of the electrical load (Pout ); - a step of determining the N duty factors (α k) as a function of the second derivative (ÿ) of the output vector (Y), the derivative of the power of the electrical load (Pout) and the ratio between the input voltage (Vin) and the output voltage (Vout) that have been measured; and - a step of controlling each switching cell (k) of the converter depending on the duty factor (α k) that has been determined.