⚡ electrical engineering

A High-Gain Dual-Switch Non-Isolated Boost Converter: Analysis, Control, and Experimental Validation

This paper presents a high-gain dual-switch non-isolated boost converter (DSNIBC) that utilizes a switched-inductor topology and interdependent duty cycles to achieve superior voltage gain with moderate stress, validated through comprehensive theoretical analysis, small-signal modeling, and experimental testing under photovoltaic MPPT conditions.

Original authors: Atul Kumar Lal, Anmol Ratna Saxena

Published 2026-08-24

📖 5 min read🧠 Deep dive

CC BY 4.0

Original authors: Atul Kumar Lal, Anmol Ratna Saxena

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

In the modern world, electricity rarely arrives in the exact form needed to power our devices. Solar panels generate low-voltage direct current, while many electronic systems and electric vehicle components require a much higher voltage to function efficiently. To bridge this gap, engineers rely on a class of devices called DC-DC converters. These circuits act as voltage elevators, taking a modest input and boosting it to a higher level. However, pushing a standard converter to achieve a very high voltage boost is like trying to climb a steep mountain in a single, exhausting leap. As the device is forced to operate at extreme settings to reach high voltages, it suffers from significant energy loss, excessive heat, and stress on its internal components, which can lead to failure or poor efficiency.

To solve this, researchers have developed various complex structures that break the climb into smaller, more manageable steps using extra components. While effective, these solutions often introduce a new problem: they require so many additional parts that the system becomes bulky, expensive, and difficult to control. The challenge, therefore, has been to find a way to achieve high voltage gain without overcomplicating the design or sacrificing reliability. A team of engineers at the National Institute of Technology Delhi has addressed this by creating a new type of converter that balances high performance with a relatively simple structure, offering a practical solution for low-power applications like solar energy systems and battery-powered grids.

The researchers proposed a new design called a dual-switch non-isolated boost converter. Unlike traditional converters that rely on a single switch to control the flow of energy, this new device uses two active switches working in a coordinated dance. By carefully timing the on and off periods of these two switches, the circuit can store energy in its inductors and release it in a way that multiplies the voltage more effectively than older designs. The key innovation lies in how the switches interact. Depending on the specific timing of their operation, the converter can function in three distinct modes. In the most effective mode, one switch operates for a longer duration than the other, allowing the circuit to achieve a high voltage gain while keeping the switches operating at moderate, less stressful levels. This approach avoids the extreme settings that typically cause standard converters to overheat or lose efficiency.

To ensure the design works in the real world, the team did not stop at theory. They built a physical prototype in their laboratory to test the concept under actual operating conditions. The device was constructed using standard electronic components, including two metal switches, five diodes, two inductors, and a capacitor, all controlled by a small digital microcontroller. The goal was to take a low input voltage, such as 12 volts, and boost it up to 48 volts, a common requirement for many modern electronic systems. During testing, the researchers subjected the prototype to various challenges, including sudden changes in the power source and shifts in the electrical load. The results showed that the converter could maintain a steady output voltage even when the input fluctuated or when the demand for power changed rapidly. The device managed to regulate the voltage with very little ripple, or unwanted fluctuation, and the internal components handled the electrical stress without failure.

A critical part of the study involved understanding how the two switches should be controlled to get the best performance. The researchers discovered that one switch has a much stronger influence on the output voltage than the other. By assigning the primary control role to this dominant switch and using the second switch to provide supplementary support, they created a control strategy that is both flexible and robust. This method allows the system to respond quickly to changes without becoming unstable. They also tested the converter in a simulated solar power environment, connecting it to a maximum power point tracking algorithm. This setup mimics the way solar panels behave when sunlight intensity changes throughout the day. The prototype successfully tracked the maximum power available from the simulated source and adjusted its operation accordingly, proving that the design is well-suited for renewable energy applications.

The study concludes that this new converter offers a favorable balance between performance and complexity. It achieves a high voltage gain without requiring the excessive number of components found in other high-gain designs, nor does it force the switches to operate at the extreme limits that cause wear and tear. The experimental validation confirmed that the theoretical predictions were accurate, with the prototype successfully delivering a stable 48-volt output from a 12-volt source. The researchers demonstrated that by using two switches with a specific control strategy, it is possible to create a compact, efficient, and reliable power converter. While the current work focuses on low-power applications, the findings suggest a path toward more efficient power management systems for everything from electric vehicles to telecommunications equipment, where reliable voltage conversion is essential.

Technical Summary: A High-Gain Dual-Switch Non-Isolated Boost Converter

Problem Statement
The integration of low-voltage energy sources (e.g., photovoltaic systems, batteries) into higher-voltage DC distribution networks (e.g., 12 V to 48 V conversions) necessitates high-gain DC-DC converters. Conventional boost converters struggle to achieve high voltage gains (e.g., 4x) without operating at extreme duty ratios (approaching 0.75). This leads to significant conduction and switching losses, high voltage/current stress on semiconductor devices, increased diode reverse-recovery losses, and sensitivity to parasitic elements. While cascading converters or using complex topologies (coupled-inductors, switched-capacitors) can mitigate these issues, they often introduce higher component counts, reduced power density, cumulative losses, and complicated control algorithms. There is a need for a topology that achieves high voltage gain at moderate duty cycles while maintaining a simple structure and manageable component stress.

Methodology
The authors propose a Dual-Switch Non-Isolated Boost Converter (DSNIBC) that integrates a switched-inductor topology with an additional switch-diode pair. The system utilizes two active switches ( $S_1, S_2$ ) and five diodes ( $D_1$ – $D_5$ ) with two equal-value inductors ( $L_1, L_2$ ) and one output capacitor ( $C_o$ ).

Operational Analysis: The converter operates in Continuous Conduction Mode (CCM) with three distinct modes based on the relationship between duty cycles $d_1$ and $d_2$ ( $d_2 > d_1$ , $d_1 > d_2$ , and $d_2 = d_1$ ). The topology allows for partial energy transfer where the inductor is charged by both the input source and the output capacitor energy during specific switching intervals, thereby increasing stored energy and voltage gain.
Steady-State Modeling: Generalized expressions for voltage and current gain were derived for all operating modes. The analysis confirms that the converter can achieve high gain (e.g., 12 V to 48 V) at moderate duty cycles ( $d \approx 0.5$ ).
Design and Sensitivity: Design guidelines for inductors and capacitors were established to ensure CCM operation and limit current ripple (10–30%). A sensitivity analysis was conducted to determine the influence of $d_1$ and $d_2$ on voltage gain. Results indicated that the $d_2 > d_1$ region (Case I) offers superior voltage gain characteristics compared to the $d_1 > d_2$ region.
Control Strategy: A small-signal state-space model was developed to facilitate controller design. A "dominant duty-cycle control" strategy was implemented using a single PI controller. In this scheme, the output of the controller ( $d_c$ ) is distributed to the two switches using weighting factors ( $\alpha_1 = 0.15, \alpha_2 = 0.7$ ), assigning primary control authority to $S_2$ while $S_1$ provides supplementary boosting. This approach simplifies implementation and ensures coordinated operation.
Experimental Validation: A 24 W laboratory prototype was built using a TMS320F28335 DSP. The system was tested under closed-loop control, MPPT operation (using an Incremental Conductance algorithm), and dynamic load/source variations.

Key Contributions

Topology Innovation: The introduction of a DSNIBC that combines a switched-inductor structure with an extra switch-diode pair to achieve high voltage gain without requiring extreme duty cycles or complex coupled inductors.
Control Architecture: The development of a dominant duty-cycle control strategy that utilizes a single PI controller to manage two active switches, ensuring stable regulation and flexible transient response.
Comprehensive Analysis: A complete derivation of steady-state gains, component stress analysis, and sensitivity analysis to identify the optimal operating region ( $d_2 > d_1$ ) for high-gain applications.
Experimental Verification: Successful validation of the theoretical models through a hardware prototype, demonstrating stable operation under MPPT conditions and dynamic disturbances.

Results

Performance: The experimental prototype successfully regulated a 48 V output from a 12 V input (4x gain) at a switching frequency of 50 kHz.
Efficiency and Stress: The converter operated with moderate duty cycles ( $d_1 \approx 0.12, d_2 \approx 0.56$ ). The output voltage ripple was maintained below 5%, and inductor current ripple was kept under 20% of the rated current. Voltage stress on switches and diodes was found to be moderate compared to other high-gain topologies.
Dynamic Response: Under a 50% load step (24 W to 48 W), the system exhibited a transient undershoot of approximately 7 V with a settling time of 35 ms. Under input voltage variations (12 V to 15 V and 15 V to 11 V), the controller effectively rejected disturbances, maintaining the output at the reference value.
MPPT Integration: When coupled with an INC MPPT algorithm, the converter demonstrated stable tracking of the maximum power point under varying solar irradiance (1000 W/m² down to 400 W/m²), with negligible steady-state oscillation.
Comparative Analysis: Compared to existing high-gain converters, the DSNIBC offers a favorable trade-off between voltage gain, component count (Total Device Count), and semiconductor stress, avoiding the complexity of multi-stage or coupled-inductor solutions.

Significance
The paper claims that the proposed DSNIBC provides a compact and effective solution for low-power high-gain DC-DC conversion. By integrating a dual-switch operation with a switched-inductor topology and a dominant duty-cycle control strategy, the converter achieves high voltage gain with a simple, robust structure. The work demonstrates that it is possible to bridge the gap between high performance and implementation simplicity, offering a practical alternative to conventional boost converters and more complex high-gain topologies. The authors note that future work will focus on higher-power implementations, soft-switching techniques to minimize losses, and multi-input versions for hybrid energy systems.

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