EPE Association: EPE 2019 - LS2c: DC Grids: Modelling and Operation

EPE 2019 - LS2c: DC Grids: Modelling and Operation
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 06: Grids, Smart Grids, AC & DC > EPE 2019 - LS2c: DC Grids: Modelling and Operation

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   Auto-Tuning of DC Microgrid Power Converters Based on a Constant Frequency Injection
By Aram KHODAMORADI [View]
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Abstract: In a dc microgrid environment, usually, many power electronic converters, each involving multiple control loops, are connected to the common dc bus. In such a scenario, the performance of some loops can be different from their designed behavior for an individual converter, due to the possible interactions. Thus, in order to maintain the desired dynamic performance of different loops, and to avoid stability issues, it is important to perform on-line tuning of the power converters regulators. This paper presents the application of a closed-loop autotuning technique to the dc microgrid power converters. The technique consists of injecting a small-signal sinusoidal perturbation, at a constant frequency, i.e., the desired crossover frequency, into a generic control loop of the digitally controlled switched-mode power supplies (SMPS). Subsequently, the signals before and after perturbation point are phase-shifted by a certain phase, i.e., half of the desired phase margin, and then subtracted, to define an error signal. Finally, the regulator parameters are tuned to make the error signal converge to zero, allowing, thus, to reach the desired phase margin and crossover frequency. In addition, this paper takes account for the situation in which, a generic loop can not achieve the desired phase margin at a given reference crossover frequency. The proposed technique requires low signal processing effort, and it is robust to noise and perturbations coming from the other converters connected to the common dc bus. So, it allows multiple converters to auto-tune their regulators, simultaneously. The experimental validation of the technique in a laboratory prototype of dc microgrid, confirms the successful achievement of the desired crossover frequency and phase margin.

   Comparison and assessment of implementation techniques for dynamics MMC type models
By Ahmed Islam ZAMA [View]
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Abstract: Modeling Modular Multilevel Converters requires a special attention due to the strong associations between the accuracy and the complexity of models on one hand and the accuracy and simulation speed on the other hand. This paper investigates different implementation techniques for MMC models and gives an overview about their development and rapidity.

   Economic Dispatch by Secondary Distributed Control in Microgrids
By Jacqueline LLANOS [View]
[Download]

Abstract: This paper proposes a distributed controller in order to achieve the economic dispatch (ED) of a microgrid, which complies with the Karush-Kuhn-Tucker optimality conditions for a linear optimal power flow formulation. The consensus over the Lagrange multipliers allows an optimal dispatch without considering an electrical microgrid model, preserving the frequency and voltage restoration into the secondary control level for isolated microgrids.

   ReIne, a flexible laboratory for emulating and testing the Distribution grid
By Mauro CARPITA [View]
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Abstract: The energy transition will generate a strong transformation of the electricity network, in Switzerlandand all over the world. Distribution networks are expected to play a vital role, even though hystoricallythey have not been designed for this purpose. In order to better study and plan the changes to be made, the ReIne (REseaux INtElligents, French acronym for 'Smart Grids') laboratory has been conceived and built to test various solutions. The actual novelty of this laboratory resides in its intrinsic flexibility, allowing reproducing several grid topologies and different situations of loading and generation. It will allow the on field study of a wide range of smart and micro grid problematics, from short-term and midterm scheduling to very fast dynamics issues of connected devices.

EPE 2019 - LS2c: DC Grids: Modelling and Operation
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 06: Grids, Smart Grids, AC & DC > EPE 2019 - LS2c: DC Grids: Modelling and Operation
	[return to parent folder]

	Auto-Tuning of DC Microgrid Power Converters Based on a Constant Frequency Injection By Aram KHODAMORADI	[View] [Download]
Abstract: In a dc microgrid environment, usually, many power electronic converters, each involving multiple control loops, are connected to the common dc bus. In such a scenario, the performance of some loops can be different from their designed behavior for an individual converter, due to the possible interactions. Thus, in order to maintain the desired dynamic performance of different loops, and to avoid stability issues, it is important to perform on-line tuning of the power converters regulators. This paper presents the application of a closed-loop autotuning technique to the dc microgrid power converters. The technique consists of injecting a small-signal sinusoidal perturbation, at a constant frequency, i.e., the desired crossover frequency, into a generic control loop of the digitally controlled switched-mode power supplies (SMPS). Subsequently, the signals before and after perturbation point are phase-shifted by a certain phase, i.e., half of the desired phase margin, and then subtracted, to define an error signal. Finally, the regulator parameters are tuned to make the error signal converge to zero, allowing, thus, to reach the desired phase margin and crossover frequency. In addition, this paper takes account for the situation in which, a generic loop can not achieve the desired phase margin at a given reference crossover frequency. The proposed technique requires low signal processing effort, and it is robust to noise and perturbations coming from the other converters connected to the common dc bus. So, it allows multiple converters to auto-tune their regulators, simultaneously. The experimental validation of the technique in a laboratory prototype of dc microgrid, confirms the successful achievement of the desired crossover frequency and phase margin.

	Comparison and assessment of implementation techniques for dynamics MMC type models By Ahmed Islam ZAMA	[View] [Download]
Abstract: Modeling Modular Multilevel Converters requires a special attention due to the strong associations between the accuracy and the complexity of models on one hand and the accuracy and simulation speed on the other hand. This paper investigates different implementation techniques for MMC models and gives an overview about their development and rapidity.

	Economic Dispatch by Secondary Distributed Control in Microgrids By Jacqueline LLANOS	[View] [Download]
Abstract: This paper proposes a distributed controller in order to achieve the economic dispatch (ED) of a microgrid, which complies with the Karush-Kuhn-Tucker optimality conditions for a linear optimal power flow formulation. The consensus over the Lagrange multipliers allows an optimal dispatch without considering an electrical microgrid model, preserving the frequency and voltage restoration into the secondary control level for isolated microgrids.

	ReIne, a flexible laboratory for emulating and testing the Distribution grid By Mauro CARPITA	[View] [Download]
Abstract: The energy transition will generate a strong transformation of the electricity network, in Switzerlandand all over the world. Distribution networks are expected to play a vital role, even though hystoricallythey have not been designed for this purpose. In order to better study and plan the changes to be made, the ReIne (REseaux INtElligents, French acronym for 'Smart Grids') laboratory has been conceived and built to test various solutions. The actual novelty of this laboratory resides in its intrinsic flexibility, allowing reproducing several grid topologies and different situations of loading and generation. It will allow the on field study of a wide range of smart and micro grid problematics, from short-term and midterm scheduling to very fast dynamics issues of connected devices.