EPE Association: EPE 2007 - Subtopic 07-2 - LS: Application of control methods to electrical systems

EPE 2007 - Subtopic 07-2 - LS: Application of control methods to electrical systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2007 - Conference > EPE 2007 - Topic 07: 'Application of control methods to electrical systems' > EPE 2007 - Subtopic 07-2 - LS: Application of control methods to electrical systems

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   New algorithm for grid synchronization based on Fourier series.
By FREIJEDO Francisco; DOVAL-GANDOY Jesus; LOPEZ Oscar; M. PENALVER Carlos [View]
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Abstract: This paper presents a new digital open loop architecture as an alternative to Phase locked loops (PLLs) for grid synchronization. The system calculates in real time the Fourier coefficients of the input signal fundamental component using a heterodyning algorithm. Once the fundamental components are calculated the system can reconstruct the input fundamental signal and calculate its phase angle, frequency and amplitude. The measuring process of the Fourier components require to filter even harmonic components internally generated; this process is made with a moving average comb filter (MVA) tuned for these even harmonics. The performance of the system is demonstrated with experimental results.

   Stability Analysis of Converter-Grid Interaction using the Converter Input Admittance
By BONGIORNO Massimo; LUNDBERG Stefan; HARNEFORS Lennart [View]
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Abstract: A grid-connected power electronic converter can cause local instabilities when interacting other subsystems - particularly poorly damped resonances - that are electrically nearby. However, oscillations at a certain frequency cannot build up due to the converter if its differential input admittance has positive conductance (real part) at that frequency, since power is then dissipated. Input-admittance expressions for a voltage-source converter are derived in this paper. By adjusting the controller parameters, the admittance can be shaped in order to get positive conductance in desired frequency regions.

   QFT-Based Robust Controller Design for a DC-DC Switching Power Converter
By ALTOWATI Ali [View]
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Abstract: In this paper, a Quantitative Feedback Theory (QFT) was applied successfully to design a robust controller for a DC-DC buck converter operating in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The controller is designed to provide optimum attenuation of the load disturbances in spite of practical limitations on the achievable closed-loop performance and in the presence of other design constraints including closed-loop tracking and robust stability. The derived analytical results are verified by computer simulation of a voltage-mode (VM) controlled buck converter.

EPE 2007 - Subtopic 07-2 - LS: Application of control methods to electrical systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2007 - Conference > EPE 2007 - Topic 07: 'Application of control methods to electrical systems' > EPE 2007 - Subtopic 07-2 - LS: Application of control methods to electrical systems
	[return to parent folder]

	New algorithm for grid synchronization based on Fourier series. By FREIJEDO Francisco; DOVAL-GANDOY Jesus; LOPEZ Oscar; M. PENALVER Carlos	[View] [Download]
Abstract: This paper presents a new digital open loop architecture as an alternative to Phase locked loops (PLLs) for grid synchronization. The system calculates in real time the Fourier coefficients of the input signal fundamental component using a heterodyning algorithm. Once the fundamental components are calculated the system can reconstruct the input fundamental signal and calculate its phase angle, frequency and amplitude. The measuring process of the Fourier components require to filter even harmonic components internally generated; this process is made with a moving average comb filter (MVA) tuned for these even harmonics. The performance of the system is demonstrated with experimental results.

	Stability Analysis of Converter-Grid Interaction using the Converter Input Admittance By BONGIORNO Massimo; LUNDBERG Stefan; HARNEFORS Lennart	[View] [Download]
Abstract: A grid-connected power electronic converter can cause local instabilities when interacting other subsystems - particularly poorly damped resonances - that are electrically nearby. However, oscillations at a certain frequency cannot build up due to the converter if its differential input admittance has positive conductance (real part) at that frequency, since power is then dissipated. Input-admittance expressions for a voltage-source converter are derived in this paper. By adjusting the controller parameters, the admittance can be shaped in order to get positive conductance in desired frequency regions.

	QFT-Based Robust Controller Design for a DC-DC Switching Power Converter By ALTOWATI Ali	[View] [Download]
Abstract: In this paper, a Quantitative Feedback Theory (QFT) was applied successfully to design a robust controller for a DC-DC buck converter operating in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The controller is designed to provide optimum attenuation of the load disturbances in spite of practical limitations on the achievable closed-loop performance and in the presence of other design constraints including closed-loop tracking and robust stability. The derived analytical results are verified by computer simulation of a voltage-mode (VM) controlled buck converter.