EPE Association: EPE 2016 - LS5d: Standard and Advanced Control Techniques for Power Converters

EPE 2016 - LS5d: Standard and Advanced Control Techniques for Power Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 03: Measurement and Control > EPE 2016 - LS5d: Standard and Advanced Control Techniques for Power Converters

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   A Root-Locus Design Methodology Derived from the Impedance Stability Criterion and Its Application for LCL Grid-Connected Converters
By Enrique RODRIGUEZ-DIAZ [View]
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Abstract: This paper presents a systematic methodology for design and tuning of the controller of LCL grid-connected converters. The proposed approach is derived from the impedance/admittance stability formulation, which eases the controller modelling of LCL grid-connected systems. After system modelling, a modified sensitivity function is defined to analyze the closed loop dynamics. For practical development, the control objectives are linked to main requirements in wind turbine applications: 1) the current control time constant should be minimized and 2) active damping actions should effectively mitigate the LCL resonance. After the theoretical development, an insightful case study is provided. It is shown that the tuning problem can be solved approximately by root-loci inspection and an optimum solution can be found by direct search. The theoretical approach is experimentally verified by a lab-scale prototype that uses the same parameters of the case study.

   Accuracy Considerations for Single-Phase Digital Derivative Based AC-Grid Synchronization Unit
By Ilya GALKIN [View]
[Download]

Abstract: Accurate grid synchronization unit is essential for reliable operation of grid converters. Single-phase unit may utilize measured function and its digital derivative as the base for PLL. This paper compares some solutions of accuracy problems typical for such derivative approach: oversampling of measurements, interleaved calculation of derivative and averaged evaluation pulse signals. The proposed methods are described and implemented with a low cost microcontroller. Resulting declinations of space vector and calculated phase angle are compared. It is concluded that all the described methods provide certain accuracy improvement, but measurements in interleaved series are the most accurate method. It is also concluded that the overall evaluation of these methods must include analysis of the hardware and software resources spent for their implementation that requires an extra work.

   Effect of state feedback coupling on the transient performance of voltage source inverters with LC filter
By Federico DE BOSIO [View]
[Download]

Abstract: State feedback coupling between the capacitor voltage and inductor current deteriorates notably the performance during transients of voltage and current regulators in stand-alone systems based on voltage source inverters. A decoupling technique is proposed, considering the limitations introduced by system delays. Laboratory experiments were executed in compliance with the normative for Uninterruptible Power Supply systems to prove the developed analysis.

   Virtual Circuit Control for Multi-Converter Smart Grid Applications
By Bruno HENDRICKX [View]
[Download]

Abstract: This paper presents a scalable synchronous buck converter design. Innovation lies with the design methodand control algorithms. Firmware makes the converter's half-bridges switch as to emulate a resistivelyterminated ladder network. This actively damps filter resonances and prevents circulating currents whenmultiple converters operate in parallel.

EPE 2016 - LS5d: Standard and Advanced Control Techniques for Power Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 03: Measurement and Control > EPE 2016 - LS5d: Standard and Advanced Control Techniques for Power Converters
	[return to parent folder]

	A Root-Locus Design Methodology Derived from the Impedance Stability Criterion and Its Application for LCL Grid-Connected Converters By Enrique RODRIGUEZ-DIAZ	[View] [Download]
Abstract: This paper presents a systematic methodology for design and tuning of the controller of LCL grid-connected converters. The proposed approach is derived from the impedance/admittance stability formulation, which eases the controller modelling of LCL grid-connected systems. After system modelling, a modified sensitivity function is defined to analyze the closed loop dynamics. For practical development, the control objectives are linked to main requirements in wind turbine applications: 1) the current control time constant should be minimized and 2) active damping actions should effectively mitigate the LCL resonance. After the theoretical development, an insightful case study is provided. It is shown that the tuning problem can be solved approximately by root-loci inspection and an optimum solution can be found by direct search. The theoretical approach is experimentally verified by a lab-scale prototype that uses the same parameters of the case study.

	Accuracy Considerations for Single-Phase Digital Derivative Based AC-Grid Synchronization Unit By Ilya GALKIN	[View] [Download]
Abstract: Accurate grid synchronization unit is essential for reliable operation of grid converters. Single-phase unit may utilize measured function and its digital derivative as the base for PLL. This paper compares some solutions of accuracy problems typical for such derivative approach: oversampling of measurements, interleaved calculation of derivative and averaged evaluation pulse signals. The proposed methods are described and implemented with a low cost microcontroller. Resulting declinations of space vector and calculated phase angle are compared. It is concluded that all the described methods provide certain accuracy improvement, but measurements in interleaved series are the most accurate method. It is also concluded that the overall evaluation of these methods must include analysis of the hardware and software resources spent for their implementation that requires an extra work.

	Effect of state feedback coupling on the transient performance of voltage source inverters with LC filter By Federico DE BOSIO	[View] [Download]
Abstract: State feedback coupling between the capacitor voltage and inductor current deteriorates notably the performance during transients of voltage and current regulators in stand-alone systems based on voltage source inverters. A decoupling technique is proposed, considering the limitations introduced by system delays. Laboratory experiments were executed in compliance with the normative for Uninterruptible Power Supply systems to prove the developed analysis.

	Virtual Circuit Control for Multi-Converter Smart Grid Applications By Bruno HENDRICKX	[View] [Download]
Abstract: This paper presents a scalable synchronous buck converter design. Innovation lies with the design methodand control algorithms. Firmware makes the converter's half-bridges switch as to emulate a resistivelyterminated ladder network. This actively damps filter resonances and prevents circulating currents whenmultiple converters operate in parallel.