EPE Association: EPE 2017 - LS6c: Control Techniques for Power Converters IV (DC/DC Converters)

EPE 2017 - LS6c: Control Techniques for Power Converters IV (DC/DC Converters)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 03: Measurement and Control > EPE 2017 - LS6c: Control Techniques for Power Converters IV (DC/DC Converters)

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   Digital Peak Current Mode Control with Adaptive Slope Compensation for DC-DC Converters
By Karsten Holm ANDERSEN [View]
[Download]

Abstract: This paper presents an adaptive slope compensation method for peak current mode control of digital controlled DC-DC converters, which controls the quality factor of the complex conjugated poles at half the switching frequency. Using quality factor control enables optimization of the dynamic performance and stability of current mode control. The presented method adapt to DC-DC converter operating conditions by estimating the rising and falling inductor current slopes, to apply a current slope compensation value to obtain a constant quality factor. The experimental results verifies the theoretical analysis of this paper and show a controller capable of controlling the quality factor of the complex poles at half the switching frequency.

   Modeling of Load-Transient Response of Direct-Duty-Ratio-Controlled Buck Converter
By Teuvo SUNTIO [View]
[Download]

Abstract: This paper provides a simple analytical model for the closed-loop output impedance of a direct-duty-ratio-controlled buck converter, which can be used to predict the behavior of the output voltage during a load-current transient. The modeling method utilizes standard control theory to obtain the model for the sensitivity function based on the crossover frequency and phase margin of the output-voltage feedback loop as well as on a clever estimate for the corresponding open-loop output impedance. The modeling method is validated by means of simulations and experimental tests.

   Online Impedance Spectroscopy Estimation of a dc-dc converter connected Battery using an Earth Leakage Monitoring Circuit
By Mina ABEDI VARNOSFADERANI [View]
[Download]

Abstract: Electrochemical Impedance Spectroscopy (EIS) techniques are useful tools for being able to look atthe characterisation of batteries under different conditions and/or with different material components.However, EIS analysis is mostly undertaken offline with bespoke equipment. This paper describes amethod of undertaking EIS measurement on-line without the use of additional equipment bymanipulating the earth leakage monitoring circuit to generate low frequency excitation signals to analysea battery system connected to a dc/dc converter. This paper describes the methodology and presentssome experimental results compared with off line EIS results generated with more traditional EISequipment under the same conditions to illustrate the concept.

   Predictive Digital Peak Current Mode Controller for DC-DC Converters Capable of Operating Over the Full 0-100\% Duty Cycle Range
By Karsten Holm ANDERSEN [View]
[Download]

Abstract: In this paper, a high performance fully digital peak current mode controller for DC-DC converters whichsupports the full duty cycle range from 0-100\% is presented. Support for low duty cycle is very importantduring short circuit or converter overload and support for high duty cycle is important for faster responseduring a transient and for providing a larger output voltage range. The digital current controller is basedon a new method, which estimates the inductor current in the middle of the falling current slope. Theestimated inductor current is based on sampling the inductor current in either the rising or fallinginductor current depending on the duty cycle of the switching period. The controller uses the estimatedinductor current to calculate the inductance of the inductor in order to optimally predict and control thecurrent loop. The controller can be used in both continuous (CCM) and discontinuous conduction mode(DCM) and supports high switching frequencies even with low cost A/D converters. The proposedcontroller is implemented in a Field Programmable Gate Array (FPGA) to control a 450 W buckconverter and the experimental results verify the controller's capability to operate in the full duty cyclerange of 0-100\%. The experimental results furthermore demonstrate the achievement of a very fastdigital controller with a crossover frequency about 1/10 of the switching frequency, which is comparableto that obtained by analog peak current mode control.

EPE 2017 - LS6c: Control Techniques for Power Converters IV (DC/DC Converters)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 03: Measurement and Control > EPE 2017 - LS6c: Control Techniques for Power Converters IV (DC/DC Converters)
	[return to parent folder]

	Digital Peak Current Mode Control with Adaptive Slope Compensation for DC-DC Converters By Karsten Holm ANDERSEN	[View] [Download]
Abstract: This paper presents an adaptive slope compensation method for peak current mode control of digital controlled DC-DC converters, which controls the quality factor of the complex conjugated poles at half the switching frequency. Using quality factor control enables optimization of the dynamic performance and stability of current mode control. The presented method adapt to DC-DC converter operating conditions by estimating the rising and falling inductor current slopes, to apply a current slope compensation value to obtain a constant quality factor. The experimental results verifies the theoretical analysis of this paper and show a controller capable of controlling the quality factor of the complex poles at half the switching frequency.

	Modeling of Load-Transient Response of Direct-Duty-Ratio-Controlled Buck Converter By Teuvo SUNTIO	[View] [Download]
Abstract: This paper provides a simple analytical model for the closed-loop output impedance of a direct-duty-ratio-controlled buck converter, which can be used to predict the behavior of the output voltage during a load-current transient. The modeling method utilizes standard control theory to obtain the model for the sensitivity function based on the crossover frequency and phase margin of the output-voltage feedback loop as well as on a clever estimate for the corresponding open-loop output impedance. The modeling method is validated by means of simulations and experimental tests.

	Online Impedance Spectroscopy Estimation of a dc-dc converter connected Battery using an Earth Leakage Monitoring Circuit By Mina ABEDI VARNOSFADERANI	[View] [Download]
Abstract: Electrochemical Impedance Spectroscopy (EIS) techniques are useful tools for being able to look atthe characterisation of batteries under different conditions and/or with different material components.However, EIS analysis is mostly undertaken offline with bespoke equipment. This paper describes amethod of undertaking EIS measurement on-line without the use of additional equipment bymanipulating the earth leakage monitoring circuit to generate low frequency excitation signals to analysea battery system connected to a dc/dc converter. This paper describes the methodology and presentssome experimental results compared with off line EIS results generated with more traditional EISequipment under the same conditions to illustrate the concept.

	Predictive Digital Peak Current Mode Controller for DC-DC Converters Capable of Operating Over the Full 0-100\% Duty Cycle Range By Karsten Holm ANDERSEN	[View] [Download]
Abstract: In this paper, a high performance fully digital peak current mode controller for DC-DC converters whichsupports the full duty cycle range from 0-100\% is presented. Support for low duty cycle is very importantduring short circuit or converter overload and support for high duty cycle is important for faster responseduring a transient and for providing a larger output voltage range. The digital current controller is basedon a new method, which estimates the inductor current in the middle of the falling current slope. Theestimated inductor current is based on sampling the inductor current in either the rising or fallinginductor current depending on the duty cycle of the switching period. The controller uses the estimatedinductor current to calculate the inductance of the inductor in order to optimally predict and control thecurrent loop. The controller can be used in both continuous (CCM) and discontinuous conduction mode(DCM) and supports high switching frequencies even with low cost A/D converters. The proposedcontroller is implemented in a Field Programmable Gate Array (FPGA) to control a 450 W buckconverter and the experimental results verify the controller's capability to operate in the full duty cyclerange of 0-100\%. The experimental results furthermore demonstrate the achievement of a very fastdigital controller with a crossover frequency about 1/10 of the switching frequency, which is comparableto that obtained by analog peak current mode control.