EPE Association: EPE 2021 - Dialogue session - Power Supplies and Industry-Specific Applications

EPE 2021 - Dialogue session - Power Supplies and Industry-Specific Applications
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2021 ECCE Europe - Conference > EPE 2021 - Topic 09: Industry-Specific Energy Conversion and Conditioning Technologies > EPE 2021 - Dialogue session - Power Supplies and Industry-Specific Applications

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   A Dynamic Series/Series-Parallel (S/SP) Compensated Wireless Battery Charger with Constant-Current and Constant-Voltage Outputs under Varying Coupling Condition
By Chi Shing WONG [View]
[Download]

Abstract: In this paper, a dynamic series/series-parallel (S/SP) compensation network is proposed to achieveconstant-current (CC) and constant-voltage (CV) outputs for battery charging applications. By modulating the switching frequency and the effective value of the compensation capacitance by switch-controlled capacitor, load-independent output voltage and current and zero-voltage-switching operation of the primary bridge can be maintained over varying load and coupling conditions. Due to the extra controllability of the parallel compensation capacitance, the efficiencies in CC and CV stages are analyzed. An experimental prototype with air gap ranging from 10 - 16 cm is built to verify the idea.

   A Power Sharing Modular Robot with Power Packet Technology
By Hiroshi ARAI [View]
[Download]

Abstract: We propose a modular robot with power sharing mechanism. Each modular robot has its own power source and actuators. Electric power is shared through the power packet bus. By sharing power among modules, fault tolerance of modular robot will be increased. We constructed and evaluated a prototype of single power source with four consuming modules. We also demonstrated bus arbitration for a multiple power source model.

   Circuit Analysis and Loss Evaluation of a Pulsed High-Voltage Generator with a Parallel-Resonant Converter Having a Capacitive Output Filter Operating with Duty
By Evangelos LIAKOS [View]
[Download]

Abstract: This paper provides a detailed circuit analysis along with a loss evaluation of a pulsed high-voltagegenerator with a parallel-resonant converter having a capacitive output filter operating with duty-ratiocontrol. The final paper will include a detailed discussion of the characteristics and a comparison toother operation modes.

   Flying-capacitor Linear Amplifier for Wireless Power Transfer Systems with Flying-capacitor Voltage Balancing
By Rintaro KUSUI [View]
[Download]

Abstract: In this paper, a flying-capacitor linear amplifier (FCLA) for wireless power transfer systems is proposed. The proposed circuit has an n-series FCLA with only N-ch MOSFETs and an unfolder. The flying capacitor (FC) voltages are balanced by selecting the operation state of each MOSFET with phase-shifted carriers. FCLA outputs a continuous voltage that does not contain the harmonics that cause current harmonics. Due to this, the radiation noise from the transmission coils is reduced. The operation of the WPT system with the proposed 16-series FCLA is demonstrated in a simulation. The proposed FCLA output the sinusoidal voltage to the resonance circuit. In addition, the harmonics of the primary coil current are analyzed. From this result, the FCLA significantly reduces the current harmonics than the conventional two-level inverter. Then, The FC voltage balance is verified using the prototype with a 2-series FCLA. From the experimental results with a small-scale prototype, the proposed circuit outputs full-wave rectified sinusoidal output voltage with balanced FC. Furthermore, the harmonics of the unfolder output voltage are analyzed. From the analyzed result, the third-order harmonics are reduced by 19.8dB due to FCLA with MOSFET in the active-state in comparison with the theoretical value of harmonics of square wave voltage.

   HV DAB using loss-minimizing burst sequences for feeding DE transducers
By Samuel JUNGLAS [View]
[Download]

Abstract: This paper introduces a cost-efficient variant of the dual active bridge (DAB) suitable for bidirectional driving of resistive-capacitive loads such as dielectric elastomer transducers (DET) at high output voltages. The blocking voltages of the used HV switches are significantly reduced by using two cascaded HV half bridges on the secondary side. The authors derive a model for calculating the current and voltage waveforms of the proposed converter. The DAB's steady-state operation is discussed, and a way of choosing optimal switching patterns is shown. These patterns enable the bidirectional operation of the converter at low switching and conduction losses. To improve efficiency under light-load conditions, the authors present a control strategy based on an advanced burst mode considering the challenges imposed by the converter's high output voltages. Measurements using an experimental prototype validate the model and demonstrate the advantages of this converter topology and the proposed burst-mode control.

   Input Impedance Analysis of an LCLC type Capacitive Power Transfer Converter
By Diego BERNAL COBALEDA [View]
[Download]

Abstract: In wireless power transfer systems, capacitive power transfer has emerged as an alternative to traditional inductive methods. It offers several advantages like the absence of losses in surrounding metallic elements due to Eddy currents. These systems have several filter topologies presented in the literature, one of them being the LCLC-compensator with a capacitive link filter, which is analysed in this paper. This topology consists of a double network of low-pass LC-type filter that helps, among other characteristics, to downsize some of the elements of the circuit. Additionally, it can boost the voltage in the plates of the capacitive link. The input impedance of the filter is derived for the case when the load does not affect the bifurcation frequencies of the filter and for the case when the input impedance is untied from the load. The analytical solution is compared with simulations and with experimental tests. The design parameters are analysed to determine the bifurcation frequencies.

   On dimensioning the fundamental brick for a scalable DC-DC converter with energy recovery
By Krister HAUGEN [View]
[Download]

Abstract: For the design of a power converter with energy recovery operation, a trade-off is related to the choice of the output and dc-link voltages, which, in turn, determines the choice of the blocking voltage capability of the semiconductor switches. This work investigates the possibility to optimise the capital and operation costs and the performance (ripple) globally for a farm of 350 converters by considering the voltage rating and device type of a fundamental brick used in these modular converters. It is shown how considering the purchasing and operating costs separately can yield in different conclusions. It also highlights the effect of high precision requirements on the converter scalability and final cost. This paper investigates the design of the fundamental brick and optimisation possibilities for such converters in terms of cost, efficiency, reliability and precision. Another important design and operating requirement for a converter is to deliver the required current in a large range of loads, such as electromagnets. In order to keep the maintenance cost low and components availability high, it is desirable to have only one solution for a given converter design. The optimal converter size from the perspective of a large converter farm, could be different from the design of an individual converter, or indeed if the optimisation focuses on cost, efficiency, reliability or precision.

   Online parameter identification process for processor power estimation using performance monitoring information
By Shinichi KAWAGUCHI [View]
[Download]

Abstract: Energy-saving in information and communications technology (ICT) systems has become a high priority issue. The efficiency of processor power supplies has seen significant improvements in recent years. However, efficiency under light load conditions needs further improvements since processor loads tend to be light when running practical applications. As a way to improve power efficiency over a wide range of computer workloads, the concept of adaptive power efficiency control, which adaptively interlocks power control with data processing workloads, has been proposed. With this technique, processor power consumption is estimated based on performance monitoring information from the processor without time overhead. However, to produce precise power consumption estimates, appropriate parameters for each application to be executed on the processor are required, and how best to determine the optimal parameters has not yet been established. This study proposes a new online method for determining the most suitable power estimation parameters for each specific application.The proposed method was verified using performance monitoring information and power load data sampled from an experimental computer. The results of the verification show that the method is effective in generating optimal parameters and that it markedly boosts the accuracy of power consumption estimates, thus suggesting its potential for enabling the inclusion of effective adaptive power efficiency controls on general computers.

   Role of Parasitics in a Dual Active Bridge DC-DC Converter with Gallium Nitride devices
By Aniket KULKARNI [View]
[Download]

Abstract: Owing to the large di/dt and dv/dt introduced by Gallium Nitride (GaN) switching devices, optimization of parasitic elements in a converter becomes very critical. This paper evaluates the impact of the parasitics of an high-frequency isolation transformer and printed circuit board (PCB) on the performance of a GaN based Dual Active Bridge isolated DC-DC converter. An iterative optimization tool is built to optimize the isolation transformer in terms of its weight and ef_ciency. Initial testing of the prototype revealed that parasitic elements of the PCB have adverse affects on the converter and it did not work beyond 35 VDC. Hence, based on practical results, PCB parasitic elements were optimized. With optimized layout design, converter did operate as it was intended to. However, due to excessive ringing in the switching voltages, converter ef_ciency was below the target ef_ciency (_ sup. 90\%). To eliminate this high-frequency ringing, inter-winding capacitance of the transformer was reduced by changing the winding con_guration. This successfully reduced the ringing and aided the converter to reach its target ef_ciency.

   Two-level state-space-based control strategy of Katium-power-converter-based Li-ion battery charger for railway applications
By Antoneta Iuliana BRATCU [View]
[Download]

Abstract: This paper proposes a two-level cascaded control strategy for a DC-DC-Katium-power-converter-based battery charger for railway applications. The Katium converter represents a particular DC-DC power converter topology, which is employed in the considered application as a Li-ion battery charger and a low-voltage power supply for a load composed of a resistive part and a constant-power part. The system model has a bilinear nature. A control-oriented modelling leads to obtaining a family of linear parameter-varying models by linearization around successive operating points, which mainly depend on the load power to be supplied. The battery current regulation is a disturbance-rejection problem, involving both constant and periodic (sinusoidal) disturbances. This problem is here solved by means of a two-level cascaded control structure whose lower level relies upon a pole-placement-based control on the previously derived state-space linear parameter-varying model, enriched with both usual integrators - for constant disturbance rejection - and resonant integrators, ensuring sinusoidal disturbance rejection. MATLAB®/Simulink® is chosen as software environment for numerical simulation closed-loop validation.

EPE 2021 - Dialogue session - Power Supplies and Industry-Specific Applications
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2021 ECCE Europe - Conference > EPE 2021 - Topic 09: Industry-Specific Energy Conversion and Conditioning Technologies > EPE 2021 - Dialogue session - Power Supplies and Industry-Specific Applications
	[return to parent folder]

	A Dynamic Series/Series-Parallel (S/SP) Compensated Wireless Battery Charger with Constant-Current and Constant-Voltage Outputs under Varying Coupling Condition By Chi Shing WONG	[View] [Download]
Abstract: In this paper, a dynamic series/series-parallel (S/SP) compensation network is proposed to achieveconstant-current (CC) and constant-voltage (CV) outputs for battery charging applications. By modulating the switching frequency and the effective value of the compensation capacitance by switch-controlled capacitor, load-independent output voltage and current and zero-voltage-switching operation of the primary bridge can be maintained over varying load and coupling conditions. Due to the extra controllability of the parallel compensation capacitance, the efficiencies in CC and CV stages are analyzed. An experimental prototype with air gap ranging from 10 - 16 cm is built to verify the idea.

	A Power Sharing Modular Robot with Power Packet Technology By Hiroshi ARAI	[View] [Download]
Abstract: We propose a modular robot with power sharing mechanism. Each modular robot has its own power source and actuators. Electric power is shared through the power packet bus. By sharing power among modules, fault tolerance of modular robot will be increased. We constructed and evaluated a prototype of single power source with four consuming modules. We also demonstrated bus arbitration for a multiple power source model.

	Circuit Analysis and Loss Evaluation of a Pulsed High-Voltage Generator with a Parallel-Resonant Converter Having a Capacitive Output Filter Operating with Duty By Evangelos LIAKOS	[View] [Download]
Abstract: This paper provides a detailed circuit analysis along with a loss evaluation of a pulsed high-voltagegenerator with a parallel-resonant converter having a capacitive output filter operating with duty-ratiocontrol. The final paper will include a detailed discussion of the characteristics and a comparison toother operation modes.

	Flying-capacitor Linear Amplifier for Wireless Power Transfer Systems with Flying-capacitor Voltage Balancing By Rintaro KUSUI	[View] [Download]
Abstract: In this paper, a flying-capacitor linear amplifier (FCLA) for wireless power transfer systems is proposed. The proposed circuit has an n-series FCLA with only N-ch MOSFETs and an unfolder. The flying capacitor (FC) voltages are balanced by selecting the operation state of each MOSFET with phase-shifted carriers. FCLA outputs a continuous voltage that does not contain the harmonics that cause current harmonics. Due to this, the radiation noise from the transmission coils is reduced. The operation of the WPT system with the proposed 16-series FCLA is demonstrated in a simulation. The proposed FCLA output the sinusoidal voltage to the resonance circuit. In addition, the harmonics of the primary coil current are analyzed. From this result, the FCLA significantly reduces the current harmonics than the conventional two-level inverter. Then, The FC voltage balance is verified using the prototype with a 2-series FCLA. From the experimental results with a small-scale prototype, the proposed circuit outputs full-wave rectified sinusoidal output voltage with balanced FC. Furthermore, the harmonics of the unfolder output voltage are analyzed. From the analyzed result, the third-order harmonics are reduced by 19.8dB due to FCLA with MOSFET in the active-state in comparison with the theoretical value of harmonics of square wave voltage.

	HV DAB using loss-minimizing burst sequences for feeding DE transducers By Samuel JUNGLAS	[View] [Download]
Abstract: This paper introduces a cost-efficient variant of the dual active bridge (DAB) suitable for bidirectional driving of resistive-capacitive loads such as dielectric elastomer transducers (DET) at high output voltages. The blocking voltages of the used HV switches are significantly reduced by using two cascaded HV half bridges on the secondary side. The authors derive a model for calculating the current and voltage waveforms of the proposed converter. The DAB's steady-state operation is discussed, and a way of choosing optimal switching patterns is shown. These patterns enable the bidirectional operation of the converter at low switching and conduction losses. To improve efficiency under light-load conditions, the authors present a control strategy based on an advanced burst mode considering the challenges imposed by the converter's high output voltages. Measurements using an experimental prototype validate the model and demonstrate the advantages of this converter topology and the proposed burst-mode control.

	Input Impedance Analysis of an LCLC type Capacitive Power Transfer Converter By Diego BERNAL COBALEDA	[View] [Download]
Abstract: In wireless power transfer systems, capacitive power transfer has emerged as an alternative to traditional inductive methods. It offers several advantages like the absence of losses in surrounding metallic elements due to Eddy currents. These systems have several filter topologies presented in the literature, one of them being the LCLC-compensator with a capacitive link filter, which is analysed in this paper. This topology consists of a double network of low-pass LC-type filter that helps, among other characteristics, to downsize some of the elements of the circuit. Additionally, it can boost the voltage in the plates of the capacitive link. The input impedance of the filter is derived for the case when the load does not affect the bifurcation frequencies of the filter and for the case when the input impedance is untied from the load. The analytical solution is compared with simulations and with experimental tests. The design parameters are analysed to determine the bifurcation frequencies.

	On dimensioning the fundamental brick for a scalable DC-DC converter with energy recovery By Krister HAUGEN	[View] [Download]
Abstract: For the design of a power converter with energy recovery operation, a trade-off is related to the choice of the output and dc-link voltages, which, in turn, determines the choice of the blocking voltage capability of the semiconductor switches. This work investigates the possibility to optimise the capital and operation costs and the performance (ripple) globally for a farm of 350 converters by considering the voltage rating and device type of a fundamental brick used in these modular converters. It is shown how considering the purchasing and operating costs separately can yield in different conclusions. It also highlights the effect of high precision requirements on the converter scalability and final cost. This paper investigates the design of the fundamental brick and optimisation possibilities for such converters in terms of cost, efficiency, reliability and precision. Another important design and operating requirement for a converter is to deliver the required current in a large range of loads, such as electromagnets. In order to keep the maintenance cost low and components availability high, it is desirable to have only one solution for a given converter design. The optimal converter size from the perspective of a large converter farm, could be different from the design of an individual converter, or indeed if the optimisation focuses on cost, efficiency, reliability or precision.

	Online parameter identification process for processor power estimation using performance monitoring information By Shinichi KAWAGUCHI	[View] [Download]
Abstract: Energy-saving in information and communications technology (ICT) systems has become a high priority issue. The efficiency of processor power supplies has seen significant improvements in recent years. However, efficiency under light load conditions needs further improvements since processor loads tend to be light when running practical applications. As a way to improve power efficiency over a wide range of computer workloads, the concept of adaptive power efficiency control, which adaptively interlocks power control with data processing workloads, has been proposed. With this technique, processor power consumption is estimated based on performance monitoring information from the processor without time overhead. However, to produce precise power consumption estimates, appropriate parameters for each application to be executed on the processor are required, and how best to determine the optimal parameters has not yet been established. This study proposes a new online method for determining the most suitable power estimation parameters for each specific application.The proposed method was verified using performance monitoring information and power load data sampled from an experimental computer. The results of the verification show that the method is effective in generating optimal parameters and that it markedly boosts the accuracy of power consumption estimates, thus suggesting its potential for enabling the inclusion of effective adaptive power efficiency controls on general computers.

	Role of Parasitics in a Dual Active Bridge DC-DC Converter with Gallium Nitride devices By Aniket KULKARNI	[View] [Download]
Abstract: Owing to the large di/dt and dv/dt introduced by Gallium Nitride (GaN) switching devices, optimization of parasitic elements in a converter becomes very critical. This paper evaluates the impact of the parasitics of an high-frequency isolation transformer and printed circuit board (PCB) on the performance of a GaN based Dual Active Bridge isolated DC-DC converter. An iterative optimization tool is built to optimize the isolation transformer in terms of its weight and ef_ciency. Initial testing of the prototype revealed that parasitic elements of the PCB have adverse affects on the converter and it did not work beyond 35 VDC. Hence, based on practical results, PCB parasitic elements were optimized. With optimized layout design, converter did operate as it was intended to. However, due to excessive ringing in the switching voltages, converter ef_ciency was below the target ef_ciency (_ sup. 90\%). To eliminate this high-frequency ringing, inter-winding capacitance of the transformer was reduced by changing the winding con_guration. This successfully reduced the ringing and aided the converter to reach its target ef_ciency.

	Two-level state-space-based control strategy of Katium-power-converter-based Li-ion battery charger for railway applications By Antoneta Iuliana BRATCU	[View] [Download]
Abstract: This paper proposes a two-level cascaded control strategy for a DC-DC-Katium-power-converter-based battery charger for railway applications. The Katium converter represents a particular DC-DC power converter topology, which is employed in the considered application as a Li-ion battery charger and a low-voltage power supply for a load composed of a resistive part and a constant-power part. The system model has a bilinear nature. A control-oriented modelling leads to obtaining a family of linear parameter-varying models by linearization around successive operating points, which mainly depend on the load power to be supplied. The battery current regulation is a disturbance-rejection problem, involving both constant and periodic (sinusoidal) disturbances. This problem is here solved by means of a two-level cascaded control structure whose lower level relies upon a pole-placement-based control on the previously derived state-space linear parameter-varying model, enriched with both usual integrators - for constant disturbance rejection - and resonant integrators, ensuring sinusoidal disturbance rejection. MATLAB®/Simulink® is chosen as software environment for numerical simulation closed-loop validation.