A miniature city within a DC-DC converter.

Smarter Power: How Advanced Estimation is Revolutionizing DC-DC Converters

Theo Raines in Tech & Innovation August 2025 • 4 min read.

"Unlock efficiency and reliability with immersion and invariance techniques for next-gen DC-DC converter design."

In today's fast-evolving tech landscape, smaller, more efficient devices are king. Current Mode Control has already revolutionized the field, offering quicker transient responses and robust over-current protection. Now, the focus is shifting to switching mode power supplies – the hearts of countless gadgets – demanding designs that are not only compact but also incredibly reliable and cost-effective.

However, designing control systems for power converters is tricky. Traditional methods often require a unique nonlinear observer for each converter type, making it difficult to adapt to varying power levels. The challenge lies in finding unified approaches that streamline control and minimize the need for complex, device-specific adjustments.

This article explores a groundbreaking solution leveraging 'Immersion and Invariance' techniques alongside input-output filtered transformation. This innovative method promises a more accurate and stable way to estimate both the state and parameters of DC-DC converters, paving the way for enhanced performance and unified control strategies.

Immersion and Invariance: A New Approach to Converter Control

A miniature city within a DC-DC converter.

The core problem addressed is the accurate estimation of a DC-DC converter's state and parameters, even when uncertainties exist. Traditional methods often struggle with the bilinear essence of power converters, requiring dedicated nonlinear observers for each configuration. This creates a complex web of control systems that are hard to manage and scale.

The 'Immersion and Invariance' (I&I) technique offers a compelling alternative. By combining I&I with input-output filtered transformation, researchers have developed an estimator that provides uniform global asymptotic convergence, even in the face of parametric uncertainties. This means the estimator's accuracy improves steadily over time, regardless of initial errors or variations in the converter's components.

Unified Approach: Unlike traditional methods, this I&I-based estimator works across a class of DC-DC converters (boost, buck, and buck-boost), reducing the need for device-specific designs.
Robustness: The estimator is designed to handle parametric uncertainties, making it less sensitive to variations in component values.
Reduced Complexity: By eliminating the need for output injection error terms, the estimator's dimension is reduced, simplifying the overall control system.
Input Voltage Estimation: The estimator can estimate input voltage without requiring additional sensors, providing essential feedforward control information.

The key to this approach lies in constructing a proper immersion and an auxiliary dynamic filter. The manifold, which depends on the input-output filtered transformation, is designed to be attractive, ensuring that the estimation error converges to zero. The unmeasurable state is then reconstructed from a function that defines this manifold.

The Future of Power Conversion

This innovative I&I-based estimator marks a significant step toward more efficient, reliable, and easily managed DC-DC converter systems. Its ability to handle uncertainties, reduce complexity, and provide input voltage estimation makes it a valuable tool for designers.

The research demonstrates the effectiveness of this approach through simulations and experimental tests on a DC-DC boost converter. The results confirm the estimator's accuracy and robustness, validating its potential for real-world applications.

As the demand for smaller and more efficient power supplies continues to grow, techniques like 'Immersion and Invariance' will play an increasingly important role in shaping the future of power electronics.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1177/0142331218777563, Alternate LINK

Title: Immersion And Invariance-Based Filtered Transformation With Application To Estimator Design For A Class Of Dc-Dc Converters

Subject: Instrumentation

Journal: Transactions of the Institute of Measurement and Control

Publisher: SAGE Publications

Authors: Milad Malekzadeh, Alireza Khosravi, Mehdi Tavan

Published: 2018-09-18

Everything You Need To Know

What is the 'Immersion and Invariance' technique?

The 'Immersion and Invariance' (I&I) technique is a novel method for estimating the state and parameters of DC-DC converters. It combines 'Immersion and Invariance' with input-output filtered transformation to provide a more accurate and stable estimation. This approach offers a unified method applicable across different types of DC-DC converters like boost, buck, and buck-boost, improving performance and simplifying control strategies. It's designed to be robust against parametric uncertainties, making it more reliable.

Why is 'Immersion and Invariance' important?

The 'Immersion and Invariance' method's significance stems from its ability to streamline the design and control of DC-DC converters. Traditional methods require specific nonlinear observers for each converter configuration, making it complex to adapt to various power levels. 'Immersion and Invariance' provides a unified approach, reducing the need for device-specific designs. It is robust to parametric uncertainties and it reduces the complexity of the control system. This is crucial because smaller, more efficient devices are constantly in demand. It helps to manage and scale these systems better.

What are the implications of using 'Immersion and Invariance'?

The implications of using 'Immersion and Invariance' are far-reaching. By offering a unified and robust estimation method, it simplifies the design process for DC-DC converters. This leads to more efficient, reliable, and easily managed power systems. The estimator's capability to handle uncertainties and estimate input voltage without additional sensors enhances its value for designers. This leads to more effective control strategies and improved performance in various electronic devices.

What is a DC-DC converter?

A DC-DC converter is a type of power converter that efficiently converts a DC voltage source from one voltage level to another. It is the heart of many electronic devices, especially those requiring different voltage levels for various components. These converters are crucial for modern electronics as they enable devices to operate at optimal power levels, improving both efficiency and performance. Different types include boost, buck, and buck-boost converters.

How does input-output filtered transformation work with 'Immersion and Invariance'?

Input-output filtered transformation is used with 'Immersion and Invariance' to enhance the accuracy and stability of DC-DC converter estimations. It helps in constructing a proper immersion and an auxiliary dynamic filter. The manifold, which depends on the input-output filtered transformation, is designed to be attractive, ensuring that the estimation error converges to zero. The unmeasurable state is then reconstructed from a function that defines this manifold. This combination enables the estimation of the state and parameters of DC-DC converters, improving the overall performance and efficiency.