EPE Association: EPE 2020 - LS4c: Estimation and Identification Methods

EPE 2020 - LS4c: Estimation and Identification Methods
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 03: Measurement and Control > EPE 2020 - LS4c: Estimation and Identification Methods

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   Estimation of an Unbalanced Grid Impedance Using a Three-Phase Power Converter
By Jarno KUKKOLA [View]
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Abstract: This paper proposes a real-time method for estimating an unbalanced grid impedance using a three-phase converter. In the method, a periodic single-frequency or multi-frequency excitation signal is added to the converter voltage reference. The converter measures currents and voltages at the point of common coupling. The impedance estimate is obtained from the measurements using sliding discrete Fourier transform (SDFT). The method is experimentally validated.

   Grid Impedance Estimation with Oversampling for Grid-Connected Converters
By Niklas HIMKER [View]
[Download]

Abstract: This paper presents a computationally simple estimation method of the grid impedance with the usage of a harmonic signal. To minimise the interference with the grid, an algorithm to define the start of the measurement is presented. Furthermore, oversampling of the current and voltage at the point of common coupling (PCC) is used to reduce the amplitude of the injected signal while still guaranteeing a high signal-to-noise ratio.

   Signal Injection for Sensorless Current Sharing with Experimental Verification on 1 MHz GaN Prototype
By Nikola BOSKOVIC [View]
[Download]

Abstract: The drawback of estimation-based sensorless current sharing applied in multiphase converters is thatit requires an injection of a lengthy perturbation signal into the system, which can influence the loadcurrent or stress the components. This paper experimentally demonstrates the effectiveness of a method to reduce the duration of the perturbation signal. By modifying the shape of the signal which is injected, the steady-state, needed for sensorless balancing, can be reached faster, although the duration of the injected signal is much shorter.

   Single-Phase Measurement of the Output Impedance of the Four-Quadrant Cascaded H-Bridge Converter Cell Using Wideband Signals
By Marko PETKOVIC [View]
[Download]

Abstract: The development and integration of power electronics equipment and converters for medium voltageac and dc application has created different subsystem interactions that require proper investigation, understanding, description and estimation of global system stability through impedance-admittance measurements and identification. Four-quadrant Cascaded H-Bridge topology features high output voltage resolution and high effective switching frequency which enables high-dynamic, high-fidelity voltage perturbation injection for medium voltage impedance and admittance measurement. While being a perturbation injection and a measurement instrument it also needs to assure that it does not cause instabilities in the device under test. Hence, a mechanism to determine the output impedance of a single cell of a Cascaded H-Bridge converter is needed. To validate the theoretical developments, a new method to measure the single-phase output impedance in the dq-frame is proposed.

EPE 2020 - LS4c: Estimation and Identification Methods
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 03: Measurement and Control > EPE 2020 - LS4c: Estimation and Identification Methods
	[return to parent folder]

	Estimation of an Unbalanced Grid Impedance Using a Three-Phase Power Converter By Jarno KUKKOLA	[View] [Download]
Abstract: This paper proposes a real-time method for estimating an unbalanced grid impedance using a three-phase converter. In the method, a periodic single-frequency or multi-frequency excitation signal is added to the converter voltage reference. The converter measures currents and voltages at the point of common coupling. The impedance estimate is obtained from the measurements using sliding discrete Fourier transform (SDFT). The method is experimentally validated.

	Grid Impedance Estimation with Oversampling for Grid-Connected Converters By Niklas HIMKER	[View] [Download]
Abstract: This paper presents a computationally simple estimation method of the grid impedance with the usage of a harmonic signal. To minimise the interference with the grid, an algorithm to define the start of the measurement is presented. Furthermore, oversampling of the current and voltage at the point of common coupling (PCC) is used to reduce the amplitude of the injected signal while still guaranteeing a high signal-to-noise ratio.

	Signal Injection for Sensorless Current Sharing with Experimental Verification on 1 MHz GaN Prototype By Nikola BOSKOVIC	[View] [Download]
Abstract: The drawback of estimation-based sensorless current sharing applied in multiphase converters is thatit requires an injection of a lengthy perturbation signal into the system, which can influence the loadcurrent or stress the components. This paper experimentally demonstrates the effectiveness of a method to reduce the duration of the perturbation signal. By modifying the shape of the signal which is injected, the steady-state, needed for sensorless balancing, can be reached faster, although the duration of the injected signal is much shorter.

	Single-Phase Measurement of the Output Impedance of the Four-Quadrant Cascaded H-Bridge Converter Cell Using Wideband Signals By Marko PETKOVIC	[View] [Download]
Abstract: The development and integration of power electronics equipment and converters for medium voltageac and dc application has created different subsystem interactions that require proper investigation, understanding, description and estimation of global system stability through impedance-admittance measurements and identification. Four-quadrant Cascaded H-Bridge topology features high output voltage resolution and high effective switching frequency which enables high-dynamic, high-fidelity voltage perturbation injection for medium voltage impedance and admittance measurement. While being a perturbation injection and a measurement instrument it also needs to assure that it does not cause instabilities in the device under test. Hence, a mechanism to determine the output impedance of a single cell of a Cascaded H-Bridge converter is needed. To validate the theoretical developments, a new method to measure the single-phase output impedance in the dq-frame is proposed.