Michael Evzelman | Utah State University (original) (raw)

Papers by Michael Evzelman

Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the ... more Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the practical exploration and eventual economical implementation of switch mode converters topologies that, until now, were conceived as a curiosity or at best, of theoretical value only. Applying the DSP capabilities, we explored in this study the characteristics and advantages of a double-bridge, Gyrator-

IET Power Electronics, 2015

ABSTRACT In many applications of class-E converters, custom made design of the isolation resonant... more ABSTRACT In many applications of class-E converters, custom made design of the isolation resonant network is impractical and off-shelf products are used. In this case, matching between the target output parameters and converter components requires an additional passive matching network that its parameters are found by a tedious optimization routine. This paper introduces a behavioral modeling based optimization method for class-E resonant converter, which significantly simplifies the component selection procedure. The method reduces the number of unknown variables during a simulation based parameter optimization search. The results of the optimization process are demonstrated on an off line, digitally controlled Class-E, PT based AC/DC converter.

2008 Twenty-Third Annual IEEE Applied Power Electronics Conference and Exposition, 2008

An alternative control method for a Boost Active Power Factor Corrector (APFC) operating in Conti... more An alternative control method for a Boost Active Power Factor Corrector (APFC) operating in Continuous Conduction Mode is presented, analyzed and verified by simulation and experiments. The proposed APFC scheme employs average current control to shape the input current. The power level is adjusted by modulating the amplitude of a triangular carrier as a function of the outer loop error signal. The proposed APFC does not require neither line voltage sensing nor an input voltage reference circuitry. The theoretical predictions are well supported by simulation and experimental results. The experimental results demonstrate some improved performance at low power levels as compared to other methods of APFC without sensing of input voltage. Index Terms-AC-DC power conversion, power factor, PFC.

Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the ... more Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the practical exploration and eventual economical implementation of switch mode converters topologies that, until now, were conceived as a curiosity or at best, of theoretical value only. Applying the DSP capabilities, we explored in this study the characteristics and advantages of a double-bridge, Gyratorbehaved switch-mode DC-DC converter. This paper introduces the Gyrator behaved topology, proposes a user-friendly method for simulation-based DSP code development and debugging, and demonstrates the agreement between theoretical predictions and experimental results that were obtained on a laboratory prototype. Figure 6: DSP emulation by a C++ block of "PSIM Professional 7.1.2.121: (a) PSIM simulation model. (b) The copy

ABSTRACT The contribution of the rise and fall times of switches to the losses of Switched Capaci... more ABSTRACT The contribution of the rise and fall times of switches to the losses of Switched Capacitors Converters was evaluated by an approximate analysis applying the equivalent resistance concept. It was found that switch turn-on and turn-off durations increase the equivalent resistance of the converter and, consequently, the losses, except in the case of complete charge/discharge of the flying capacitors within the switching phase. Loss increase is related to the fact that during the current rise/fall state, the instantaneous losses are much higher than when the switch is in a constant ‘on’ state. Theoretical predictions were validated by full circuit simulations and experimental results. The present study integrates the switching losses into the generic equivalent resistance loss model, enabling the calculation and/or simulation of the total losses in switched capacitor converters.

Switched Capacitor Converters (SCC) losses are analyzed and the rules for the selection of SCC pa... more Switched Capacitor Converters (SCC) losses are analyzed and the rules for the selection of SCC parameters (such as switch resistances, capacitors values and switching frequency) to meet specific efficiency requirements, are developed. This is done by first applying an advanced methodology for calculating the equivalent resistance (R e ) of the SCC in general. The impact of each of the parameters on the equivalent resistance is then analyzed and the results are used to develop design rules to meet efficiency targets as defined. The paper clarifies an apparent paradox related to the role of switch resistances in SCC which seem not to affect the efficiency considering the fact that the efficiency is determined by the SCC voltage transfer ratio. The results of this study could help designers of SCC to select optimal values of the SCC parameters that will meet specifications. The analysis developed in this study can also assist users of SCC to better understand the characteristics and limitations of commercially available SCC.

A generic behavioral average-circuit model that analyzes hybrid converters that include a switche... more A generic behavioral average-circuit model that analyzes hybrid converters that include a switched inductor and switched capacitors is developed. The model can be used to calculate or to simulate the average static, dynamic and small signal responses of hybrid converters. The model is valid for all operation modes of the Switched Capacitor Converters operating in CCM and DCM modes of the Switched Inductor Converter and is compatible with circuit simulators that include dependent sources. The model was verified by simulation and experimentally. The experimental converter included a Boost converter followed by x3 switched capacitor converter. Good agreement was found between the behavior of the proposed average model, full circuit simulation and experimental results. I.

A generic behavioral average circuit model of a Switched Capacitor Converter (SCC) is proposed an... more A generic behavioral average circuit model of a Switched Capacitor Converter (SCC) is proposed and verified. The model is based on the average currents concept and assumes that each of the SCC subcircuits can be described or approximated as a first order network. The model can be used to calculate or simulate the average static, dynamic and small signal responses of the SCC. The model is valid for all operational modes of a SCC (complete, partial and no charge) and is compatible with any circuit simulator that includes dependent sources. Excellent agreement was found between the behavior of the proposed average model, full circuit simulation, and experimental results.

A generic modeling methodology that analyzes the losses in Switched Capacitors Converters (SCC) w... more A generic modeling methodology that analyzes the losses in Switched Capacitors Converters (SCC) was developed and verified by simulation and experiments. The proposed analytical approach is unified, covering both hard and soft switched SCC topologies. The major advantage of the proposed model is that it expresses the losses as a function of the currents passing through each flying capacitor. Since these currents are linearly proportional to the output current, the model is also applicable to SCC with multiple capacitors. The proposed model provides an insight into the expected losses in SCC and the effects of their operational conditions such as duty cycle. As such, the model can help in the optimization of SCC systems and their control to achieve desired regulations.

A switched-capacitor based equalization scheme is proposed for overcoming the adverse effect of s... more A switched-capacitor based equalization scheme is proposed for overcoming the adverse effect of shaded panels in a serially connected PV array. The proposed solution is based on a modular approach, in which each two panels are connected to a resonant switched-capacitor converter. The distribution of currents and power extraction improvement have been derived and verified experimentally and design guidelines to meet desired power loss level requirements have been developed. The experimental equalizing module was designed for 185W PV panels and was found to boost the maximum available power by about 50% when interfaced with two serially connected PV panels under insolation ratios between 20% and 100%. The analytical, simulation and experimental results suggest that the proposed approach is effective in extracting all available power with relatively high efficiency.

A generic average model that is capable of predicting the static, large signal dynamics and small... more A generic average model that is capable of predicting the static, large signal dynamics and small signal response of Switched Capacitor Converters (SCC) was developed and tested. The proposed model was verified by full circuit simulation and experimentally, and good agreement was found between the results. The model was used to study dynamic behavior of SCC systems including the small signal responses, which are required for designing control loops. The model can be of great design value as it can be used to optimize the dynamic design of SCC systems and to design the compensator for closed loop operation.

2014 IEEE Energy Conversion Congress and Exposition (ECCE), 2014

ABSTRACT Energy storage systems require battery cell balancing circuits to avoid divergence of ce... more ABSTRACT Energy storage systems require battery cell balancing circuits to avoid divergence of cell state of charge (SOC). A modular approach based on distributed continuous cell-level control is presented that extends the balancing function to higher level pack performance objectives such as improving power capability and increasing pack lifetime. This is achieved by adding DC-DC converters in parallel with cells and using state estimation and control to autonomously bias individual cell SOC and SOC range, forcing healthier cells to be cycled deeper than weaker cells. The result is a pack with improved degradation characteristics and extended lifetime. The modular architecture and control concepts are developed and hardware results are demonstrated for a 91.2 Wh battery pack consisting of four series li-ion battery cells and four dual active bridge (DAB) bypass DC-DC converters.

2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014, 2014

ABSTRACT Electric-drive vehicles, including hybrid (HEV), plug-in hybrid (PHEV) and electric vehi... more ABSTRACT Electric-drive vehicles, including hybrid (HEV), plug-in hybrid (PHEV) and electric vehicles (EV), require a high-voltage (HV) battery pack for propulsion, and a low-voltage (LV) dc bus for auxiliary loads. This paper presents an architecture that uses modular dc-dc bypass converters to perform active battery cell balancing and to supply current to auxiliary loads, eliminating the need for a separate HV-to-LV high step-down dc-dc converter. The modular architecture, which achieves continuous balancing of all cells, can be used with an arbitrary number of cells in series, requires no control communications between converters, and naturally shares the auxiliary load current according to the relative state-of-charge (SOC) and capacities of the battery cells. Design and control details are provided for low-voltage, low-power dual active bridge (DAB) power converters serving as bypass converter modules. Experimental results are presented for a system consisting of two series 3.6 Ah NMC battery cells and two DAB bypass converters, with combined outputs rated to supply a 12 V, 35 W auxiliary load.

IEEE Transactions on Power Electronics, 2000

ABSTRACT A resonant switched capacitor converter (RSCC) with high efficiency over a wide and cont... more ABSTRACT A resonant switched capacitor converter (RSCC) with high efficiency over a wide and continuous conversion ratio range is introduced. The efficiency of the topology depends primarily on the conduction losses and is decoupled, to a large extent, from the voltage conversion ratio. This is an advantage over classical switched capacitor converters, for which the efficiency is strongly related to the conversion ratio. The operation principle applies three zero current switching (ZCS) states to charge, discharge and balance the remaining charge of the flying capacitor. This results in a gyrator, i.e. a voltage-dependent current source, with a wide range of voltage conversion ratios (smaller as well as greater than unity) as well as bidirectional power flow capabilities. The analytical expressions for the conversion ratio and expected efficiency are provided and validated through simulations and experiments. The experimental verifications of the converter demonstrate peak efficiency of 96% and above 90% efficiency over a wide range of voltage gains and loading conditions. In addition, the system was found to be highly efficient at the extreme cases of both light and heavy loads.

IEEE Transactions on Power Electronics, 2000

ABSTRACT A generic modeling methodology that analyzes the losses in switched capacitor converters... more ABSTRACT A generic modeling methodology that analyzes the losses in switched capacitor converters (SCC) operating in open loop was developed and verified by simulation and experiments. The proposed analytical approach is unified, covering both hard- and soft-SCC topologies that include active switches and/or diodes. An important feature of the proposed model is that it expresses the losses as a function of the average currents passing through each flying capacitor during each switching phase. Since these currents are linearly proportional to the output current, the model is also applicable to SCC with multiple capacitors if it can be assumed that each of the subcircuits of the modeled SCC can be described or approximated by a first-order system. The proposed model can be used to assess the effect of the operational conditions of the SCC, such as switching frequency and duty cycle, on the expected losses. As such, the model can help in the optimization of SCC systems and their control to achieve high efficiency and the desired regulations.

IEEE Transactions on Industry Applications, 2000

ABSTRACT A behavioral average-circuit model that analyzes hybrid converters that include a switch... more ABSTRACT A behavioral average-circuit model that analyzes hybrid converters that include a switched inductor and switched capacitors is presented. The model can be used to calculate or to simulate the average static, dynamic, and small-signal responses of hybrid converters. The model is valid for all operation modes of the switched capacitor converters (SCCs) operating in the continuous and discontinuous conduction modes of the switched inductor converter and is compatible with circuit simulators that include dependent sources. The model was verified with simulations and experimentally. The experimental converter included a boost converter followed by a times3times 3times3 SCC. Good agreement was found between the behavior of the proposed average model, full circuit simulations, and experimental results.

IEEE Transactions on Power Electronics, 2014

ABSTRACT This paper introduces a unified modeling methodology to describe and explore the loss me... more ABSTRACT This paper introduces a unified modeling methodology to describe and explore the loss mechanism of resonant Switched Capacitor Converter (SCC) operating in a self-commutation zero current switching mode. The conventional equivalent resistance concept, which assumes a single conduction path of the resonant current, is generalized and extended to model the losses in cases where the resonant current is divided across several conduction loops. The new modeling concept is compatible to describe the losses resulting from resistive elements as well as P-N junction devices, offering a solution for the equivalent resistance. Verification of the concept has been carried out by simulations and experiments on 3 – 30W unity, double gain and multiphase Fibonacci resonant SCC with free-wheeling ZCS. A very good agreement is obtained between the theoretical calculations, simulations and experimental results, well demonstrating model capability to identify the loss contributors in each conduction path.

Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the ... more Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the practical exploration and eventual economical implementation of switch mode converters topologies that, until now, were conceived as a curiosity or at best, of theoretical value only. Applying the DSP capabilities, we explored in this study the characteristics and advantages of a double-bridge, Gyrator-

IET Power Electronics, 2015

ABSTRACT In many applications of class-E converters, custom made design of the isolation resonant... more ABSTRACT In many applications of class-E converters, custom made design of the isolation resonant network is impractical and off-shelf products are used. In this case, matching between the target output parameters and converter components requires an additional passive matching network that its parameters are found by a tedious optimization routine. This paper introduces a behavioral modeling based optimization method for class-E resonant converter, which significantly simplifies the component selection procedure. The method reduces the number of unknown variables during a simulation based parameter optimization search. The results of the optimization process are demonstrated on an off line, digitally controlled Class-E, PT based AC/DC converter.

2008 Twenty-Third Annual IEEE Applied Power Electronics Conference and Exposition, 2008

An alternative control method for a Boost Active Power Factor Corrector (APFC) operating in Conti... more An alternative control method for a Boost Active Power Factor Corrector (APFC) operating in Continuous Conduction Mode is presented, analyzed and verified by simulation and experiments. The proposed APFC scheme employs average current control to shape the input current. The power level is adjusted by modulating the amplitude of a triangular carrier as a function of the outer loop error signal. The proposed APFC does not require neither line voltage sensing nor an input voltage reference circuitry. The theoretical predictions are well supported by simulation and experimental results. The experimental results demonstrate some improved performance at low power levels as compared to other methods of APFC without sensing of input voltage. Index Terms-AC-DC power conversion, power factor, PFC.

Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the ... more Recent advances in DSP technology, such as those found in the TI C2000 family, make possible the practical exploration and eventual economical implementation of switch mode converters topologies that, until now, were conceived as a curiosity or at best, of theoretical value only. Applying the DSP capabilities, we explored in this study the characteristics and advantages of a double-bridge, Gyratorbehaved switch-mode DC-DC converter. This paper introduces the Gyrator behaved topology, proposes a user-friendly method for simulation-based DSP code development and debugging, and demonstrates the agreement between theoretical predictions and experimental results that were obtained on a laboratory prototype. Figure 6: DSP emulation by a C++ block of "PSIM Professional 7.1.2.121: (a) PSIM simulation model. (b) The copy

ABSTRACT The contribution of the rise and fall times of switches to the losses of Switched Capaci... more ABSTRACT The contribution of the rise and fall times of switches to the losses of Switched Capacitors Converters was evaluated by an approximate analysis applying the equivalent resistance concept. It was found that switch turn-on and turn-off durations increase the equivalent resistance of the converter and, consequently, the losses, except in the case of complete charge/discharge of the flying capacitors within the switching phase. Loss increase is related to the fact that during the current rise/fall state, the instantaneous losses are much higher than when the switch is in a constant ‘on’ state. Theoretical predictions were validated by full circuit simulations and experimental results. The present study integrates the switching losses into the generic equivalent resistance loss model, enabling the calculation and/or simulation of the total losses in switched capacitor converters.

Switched Capacitor Converters (SCC) losses are analyzed and the rules for the selection of SCC pa... more Switched Capacitor Converters (SCC) losses are analyzed and the rules for the selection of SCC parameters (such as switch resistances, capacitors values and switching frequency) to meet specific efficiency requirements, are developed. This is done by first applying an advanced methodology for calculating the equivalent resistance (R e ) of the SCC in general. The impact of each of the parameters on the equivalent resistance is then analyzed and the results are used to develop design rules to meet efficiency targets as defined. The paper clarifies an apparent paradox related to the role of switch resistances in SCC which seem not to affect the efficiency considering the fact that the efficiency is determined by the SCC voltage transfer ratio. The results of this study could help designers of SCC to select optimal values of the SCC parameters that will meet specifications. The analysis developed in this study can also assist users of SCC to better understand the characteristics and limitations of commercially available SCC.

A generic behavioral average-circuit model that analyzes hybrid converters that include a switche... more A generic behavioral average-circuit model that analyzes hybrid converters that include a switched inductor and switched capacitors is developed. The model can be used to calculate or to simulate the average static, dynamic and small signal responses of hybrid converters. The model is valid for all operation modes of the Switched Capacitor Converters operating in CCM and DCM modes of the Switched Inductor Converter and is compatible with circuit simulators that include dependent sources. The model was verified by simulation and experimentally. The experimental converter included a Boost converter followed by x3 switched capacitor converter. Good agreement was found between the behavior of the proposed average model, full circuit simulation and experimental results. I.

A generic behavioral average circuit model of a Switched Capacitor Converter (SCC) is proposed an... more A generic behavioral average circuit model of a Switched Capacitor Converter (SCC) is proposed and verified. The model is based on the average currents concept and assumes that each of the SCC subcircuits can be described or approximated as a first order network. The model can be used to calculate or simulate the average static, dynamic and small signal responses of the SCC. The model is valid for all operational modes of a SCC (complete, partial and no charge) and is compatible with any circuit simulator that includes dependent sources. Excellent agreement was found between the behavior of the proposed average model, full circuit simulation, and experimental results.

A generic modeling methodology that analyzes the losses in Switched Capacitors Converters (SCC) w... more A generic modeling methodology that analyzes the losses in Switched Capacitors Converters (SCC) was developed and verified by simulation and experiments. The proposed analytical approach is unified, covering both hard and soft switched SCC topologies. The major advantage of the proposed model is that it expresses the losses as a function of the currents passing through each flying capacitor. Since these currents are linearly proportional to the output current, the model is also applicable to SCC with multiple capacitors. The proposed model provides an insight into the expected losses in SCC and the effects of their operational conditions such as duty cycle. As such, the model can help in the optimization of SCC systems and their control to achieve desired regulations.

A switched-capacitor based equalization scheme is proposed for overcoming the adverse effect of s... more A switched-capacitor based equalization scheme is proposed for overcoming the adverse effect of shaded panels in a serially connected PV array. The proposed solution is based on a modular approach, in which each two panels are connected to a resonant switched-capacitor converter. The distribution of currents and power extraction improvement have been derived and verified experimentally and design guidelines to meet desired power loss level requirements have been developed. The experimental equalizing module was designed for 185W PV panels and was found to boost the maximum available power by about 50% when interfaced with two serially connected PV panels under insolation ratios between 20% and 100%. The analytical, simulation and experimental results suggest that the proposed approach is effective in extracting all available power with relatively high efficiency.

A generic average model that is capable of predicting the static, large signal dynamics and small... more A generic average model that is capable of predicting the static, large signal dynamics and small signal response of Switched Capacitor Converters (SCC) was developed and tested. The proposed model was verified by full circuit simulation and experimentally, and good agreement was found between the results. The model was used to study dynamic behavior of SCC systems including the small signal responses, which are required for designing control loops. The model can be of great design value as it can be used to optimize the dynamic design of SCC systems and to design the compensator for closed loop operation.

2014 IEEE Energy Conversion Congress and Exposition (ECCE), 2014

ABSTRACT Energy storage systems require battery cell balancing circuits to avoid divergence of ce... more ABSTRACT Energy storage systems require battery cell balancing circuits to avoid divergence of cell state of charge (SOC). A modular approach based on distributed continuous cell-level control is presented that extends the balancing function to higher level pack performance objectives such as improving power capability and increasing pack lifetime. This is achieved by adding DC-DC converters in parallel with cells and using state estimation and control to autonomously bias individual cell SOC and SOC range, forcing healthier cells to be cycled deeper than weaker cells. The result is a pack with improved degradation characteristics and extended lifetime. The modular architecture and control concepts are developed and hardware results are demonstrated for a 91.2 Wh battery pack consisting of four series li-ion battery cells and four dual active bridge (DAB) bypass DC-DC converters.

2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014, 2014

ABSTRACT Electric-drive vehicles, including hybrid (HEV), plug-in hybrid (PHEV) and electric vehi... more ABSTRACT Electric-drive vehicles, including hybrid (HEV), plug-in hybrid (PHEV) and electric vehicles (EV), require a high-voltage (HV) battery pack for propulsion, and a low-voltage (LV) dc bus for auxiliary loads. This paper presents an architecture that uses modular dc-dc bypass converters to perform active battery cell balancing and to supply current to auxiliary loads, eliminating the need for a separate HV-to-LV high step-down dc-dc converter. The modular architecture, which achieves continuous balancing of all cells, can be used with an arbitrary number of cells in series, requires no control communications between converters, and naturally shares the auxiliary load current according to the relative state-of-charge (SOC) and capacities of the battery cells. Design and control details are provided for low-voltage, low-power dual active bridge (DAB) power converters serving as bypass converter modules. Experimental results are presented for a system consisting of two series 3.6 Ah NMC battery cells and two DAB bypass converters, with combined outputs rated to supply a 12 V, 35 W auxiliary load.

IEEE Transactions on Power Electronics, 2000

ABSTRACT A resonant switched capacitor converter (RSCC) with high efficiency over a wide and cont... more ABSTRACT A resonant switched capacitor converter (RSCC) with high efficiency over a wide and continuous conversion ratio range is introduced. The efficiency of the topology depends primarily on the conduction losses and is decoupled, to a large extent, from the voltage conversion ratio. This is an advantage over classical switched capacitor converters, for which the efficiency is strongly related to the conversion ratio. The operation principle applies three zero current switching (ZCS) states to charge, discharge and balance the remaining charge of the flying capacitor. This results in a gyrator, i.e. a voltage-dependent current source, with a wide range of voltage conversion ratios (smaller as well as greater than unity) as well as bidirectional power flow capabilities. The analytical expressions for the conversion ratio and expected efficiency are provided and validated through simulations and experiments. The experimental verifications of the converter demonstrate peak efficiency of 96% and above 90% efficiency over a wide range of voltage gains and loading conditions. In addition, the system was found to be highly efficient at the extreme cases of both light and heavy loads.

IEEE Transactions on Power Electronics, 2000

ABSTRACT A generic modeling methodology that analyzes the losses in switched capacitor converters... more ABSTRACT A generic modeling methodology that analyzes the losses in switched capacitor converters (SCC) operating in open loop was developed and verified by simulation and experiments. The proposed analytical approach is unified, covering both hard- and soft-SCC topologies that include active switches and/or diodes. An important feature of the proposed model is that it expresses the losses as a function of the average currents passing through each flying capacitor during each switching phase. Since these currents are linearly proportional to the output current, the model is also applicable to SCC with multiple capacitors if it can be assumed that each of the subcircuits of the modeled SCC can be described or approximated by a first-order system. The proposed model can be used to assess the effect of the operational conditions of the SCC, such as switching frequency and duty cycle, on the expected losses. As such, the model can help in the optimization of SCC systems and their control to achieve high efficiency and the desired regulations.

IEEE Transactions on Industry Applications, 2000

ABSTRACT A behavioral average-circuit model that analyzes hybrid converters that include a switch... more ABSTRACT A behavioral average-circuit model that analyzes hybrid converters that include a switched inductor and switched capacitors is presented. The model can be used to calculate or to simulate the average static, dynamic, and small-signal responses of hybrid converters. The model is valid for all operation modes of the switched capacitor converters (SCCs) operating in the continuous and discontinuous conduction modes of the switched inductor converter and is compatible with circuit simulators that include dependent sources. The model was verified with simulations and experimentally. The experimental converter included a boost converter followed by a times3times 3times3 SCC. Good agreement was found between the behavior of the proposed average model, full circuit simulations, and experimental results.

IEEE Transactions on Power Electronics, 2014

ABSTRACT This paper introduces a unified modeling methodology to describe and explore the loss me... more ABSTRACT This paper introduces a unified modeling methodology to describe and explore the loss mechanism of resonant Switched Capacitor Converter (SCC) operating in a self-commutation zero current switching mode. The conventional equivalent resistance concept, which assumes a single conduction path of the resonant current, is generalized and extended to model the losses in cases where the resonant current is divided across several conduction loops. The new modeling concept is compatible to describe the losses resulting from resistive elements as well as P-N junction devices, offering a solution for the equivalent resistance. Verification of the concept has been carried out by simulations and experiments on 3 – 30W unity, double gain and multiphase Fibonacci resonant SCC with free-wheeling ZCS. A very good agreement is obtained between the theoretical calculations, simulations and experimental results, well demonstrating model capability to identify the loss contributors in each conduction path.