This monograph provides a structured introduction to DC/AC power converters, focusing on current source, voltage source, and resonant inverters. It presents a unified framework for analysing and designing inverter circuits based on the study of electromagnetic processes in equivalent RLC models.

Combining theory, simulation in MATLAB/Simulink and LTspice, and practical design methods, the book aims to connect academic concepts with real-world power electronics applications such as electric drives, renewable energy systems, and uninterruptible power supplies.

In this article, we speak with Prof. Hinov to gain additional insight into the modeling approach and its practical applications.

Your book brings CSIs, VSIs, and resonant inverters together under one modeling approach. What led you to unify these converter types, and what benefits does this give engineers and researchers?

The motivation to unify current-source, voltage-source, and resonant inverters under a single analytical framework came from a long-standing observation in both teaching and research: although these converters are usually presented separately, they are governed by the same fundamental electromagnetic processes.

In the book, I show that by focusing on the behavior of the equivalent series RLC circuit and the switching function, it is possible to interpret CSIs, VSIs, and resonant inverters as different manifestations of the same physical principles. This unified approach allows engineers to move from one topology to another without “starting from zero.” Instead of memorizing isolated formulas, they understand the structural dualities and energy-transfer mechanisms common to all DC/AC converters.

For researchers, this creates a comparative framework. For practicing engineers, it shortens the design cycle and reduces conceptual fragmentation. The goal was to replace topology-driven thinking with physics-driven thinking.

You rely heavily on MATLAB/Simulink and LTspice in your examples. What common challenges do engineers face when using simulation for inverter design, and how does your framework help address them?

Simulation is extremely powerful—but also potentially misleading.

One of the most common challenges engineers face is confusing numerical accuracy with physical correctness. A model may converge and produce clean waveforms, yet still fail to represent the true electromagnetic behavior of the converter—especially during switching transitions, discontinuous conduction modes, or resonance.

Another challenge is the improper selection of solver methods and integration parameters, particularly when dealing with stiff differential equations or high-frequency switching.

In the book, I emphasize staged modeling and adequacy assessment. Instead of jumping directly into complex simulations, the methodology begins with analytical derivation, then moves to switching-function models, and only afterward to full simulation environments. MATLAB/Simulink and LTspice are used not as black boxes, but as verification tools.

By grounding simulation in unified analytical models, engineers gain confidence that what they observe numerically corresponds to real physical processes.

You focus on electromagnetic processes inside inverter circuits. Which of these processes are most often misunderstood in traditional teaching, and how does your book clarify them?

The most frequently misunderstood processes are related to commutation and energy exchange within reactive components.

In traditional teaching, students often focus on voltage and current waveforms without deeply understanding how energy oscillates between inductance and capacitance, or how detuning affects switching behavior. As a result, soft and hard commutation modes are sometimes treated as abstract switching strategies rather than consequences of resonant dynamics.

In this book, I emphasize:

• The role of detuning in resonant converters,
• The physical meaning of damping and oscillation coefficients,
• The relationship between input characteristics (open or closed source) and output behavior.
• The duality between CSI and VSI structures.

By analyzing converters through equivalent circuits and electromagnetic processes rather than only control diagrams, the mechanisms behind ZVS, ZCS, and natural commutation become intuitive rather than purely mathematical.

You introduce design methods that work across many converter topologies. Can you give an example of how this broad approach helps with new or emerging applications?

A good example is high-frequency applications such as induction heating, wireless power transfer, or compact EV auxiliary converters.

When engineers approach a new application, they often debate whether to use a CSI, VSI, or resonant inverter. With a unified design methodology, the decision becomes structured rather than heuristic.

For instance, if high switching frequency and reduced losses are required, the unified framework quickly shows how detuning, quality factor, and equivalent RLC transformation affect current shape and stress in semiconductor devices. The same analytical structure can then be applied whether the topology is series–parallel, parallel–series, or includes reverse diodes.

This flexibility is particularly valuable in emerging fields where converter requirements evolve rapidly. Instead of redesigning from scratch, engineers adapt the unified model to new boundary conditions.

A key goal of the book is to connect academic theory with practical engineering. Where do you see the biggest gap between inverter models and real-world implementation today?

The biggest gap lies in the treatment of non-idealities.

Academic models often assume ideal switches, negligible parasitics, and stable load conditions. In real systems, however, parasitic inductances, device capacitances, thermal effects, electromagnetic interference, and control delays significantly influence performance.

Another gap concerns dynamic behavior under abnormal conditions—overload, detuning, parameter drift, or component tolerances.

In the book, I attempt to narrow this gap by:

• Including steady-state and transient analyses,
• Discussing practical switching limits,
• Comparing analytical results with simulation data,
• Emphasizing operating modes such as CCM, DCM, BCM, and hard commutation.

Bridging this gap requires a mindset shift: models must not only be mathematically elegant but physically meaningful and verifiable.

Looking ahead, which areas of DC/AC converter research do you think offer the most promising opportunities for future breakthroughs?

Several directions appear especially promising:

1. AI-assisted design and optimization. Intelligent algorithms can significantly reduce the time needed for topology selection, parameter tuning, and loss minimization.
2. Digital twins for power converters. Real-time digital replicas of converters could enable predictive maintenance and adaptive optimization.
3. Wide-bandgap semiconductor integration (SiC, GaN). These devices allow higher frequency operation, but require refined electromagnetic modeling due to faster switching dynamics.
4. High-frequency resonant systems for wireless energy transfer. This area demands deeper understanding of resonant behavior under varying coupling coefficients.
5. Grid-interactive intelligent inverters. As renewable penetration increases, inverters will become active participants in grid stabilization rather than passive power interfaces.

The future of DC/AC converters will increasingly combine advanced materials, digital control, artificial intelligence, and unified physical modeling.

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