EPE Association: EPE 2016 - LS4d: Renewable Energy Systems

EPE 2016 - LS4d: Renewable Energy Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 05: Renewable Energy Power Systems > EPE 2016 - LS4d: Renewable Energy Systems

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   Improving double-line frequency voltage ripple rejection capability of DC/DC converter in grid connected two-stage PV inverter using DC-link voltage feedforward
By Jukka VIINAMAKI [View]
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Abstract: The power fed to the grid by a single-phase photovoltaic (PV) inverter fluctuates at twice the grid frequency. This fluctuation causes double-line-frequency ripple component to the DC-link voltage in two-stage PV inverter. If the DC/DC converter is not able to attenuate this ripple, also the PV generator voltage will fluctuate decreasing the maximum power point tracking (MPPT) efficiency. The ripple of the DC-link voltage can be decreased by increasing the capacitance or by using different types of active power decoupling topologies. However, it is also possible to allow higher ripple in the DC-link voltage if this ripple is prevented from affecting the PV generator voltage. This can be made by using DC-link voltage feedforward in the DC/DC converter. In this paper, the effect of DC-link voltage feedforward on the attenuation capability is studied by using small-signal model. It is shown that the most significant factors affecting the maximum attenuation are the value of the DC-link voltage, the tolerance of the voltage measurement gain and the balance between the losses of upper and lower switches. It is also shown that the DC-link voltage feedforward has similar effect on the output impedance of the converter as input voltage control: The converter will have constant power output.

   Novel equivalent lead-acid battery circuits development with separated simulation of chemical and electrical domains
By Moshe AVERBUKH [View]
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Abstract: Article denotes a new approach for development equivalent electrical circuit of lead-acid batteries. It is based on a separated representation of chemical and electrical domains. Main advantage of the proposed simulation method is more accurate description of the battery behavior in different dynamic regimes without the need of additional fitting equivalent circuit parameters.

   Optimization Strategies of PEM Electrolyser as Part of Solar PV System
By Antti KOSONEN [View]
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Abstract: Solar and wind power have intermittent nature, and hence they require energy storage systems or bridges between different energy sectors. Hydrogen is a potential candidate for both of these sectors. Hence, it is interesting to study the practical dynamic properties and limitations of electrolysers in the viewpoint of renewable energy production. This paper studies optimization strategies of a proton exchange membrane (PEM) electrolyser together with a solar photovoltaic (PV) system.

   The effect of including power converter losses when modelling energy storage systems: a UK Domestic Study.
By Konstantina PANAGIOTOU [View]
[Download]

Abstract: Energy storage systems (ESS) are seen as an increasingly important technology for managing electrical distribution systems, and there is now much research into both the underlying technologies of these systems, and their 'optimum' management especially for applications within a single household. Optimum management usually depends on many factors and assumptions, for example what should be optimized (self-consumption of local renewable resources, consumer cost, peak reduction), prediction of local generation and load patterns, and the assumptions concerning the operation of the ESS itself. This paper aims to quantify one of the usual assumptions made (especiallyby non-electrical engineers) i.e. that the assumption that the power converter in the ESS is 100\% efficient does not lead to substantial errors in the ESS performance and cost-benefit analysis. Three different ESS power converter models have been created and their behaviour as part of a house based ESS management system over a one year period has been analysed using five different control approaches, a variety of battery and solar panel sizes and employing a time of use tariff (Economy 7). By observing the ESS charging pattern through the year and monitoring of the annual electricity costalong with the system's losses for the household, relationships between the battery and PV size, the control algorithms, the electricity cost and the system losses were created.

EPE 2016 - LS4d: Renewable Energy Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 05: Renewable Energy Power Systems > EPE 2016 - LS4d: Renewable Energy Systems
	[return to parent folder]

	Improving double-line frequency voltage ripple rejection capability of DC/DC converter in grid connected two-stage PV inverter using DC-link voltage feedforward By Jukka VIINAMAKI	[View] [Download]
Abstract: The power fed to the grid by a single-phase photovoltaic (PV) inverter fluctuates at twice the grid frequency. This fluctuation causes double-line-frequency ripple component to the DC-link voltage in two-stage PV inverter. If the DC/DC converter is not able to attenuate this ripple, also the PV generator voltage will fluctuate decreasing the maximum power point tracking (MPPT) efficiency. The ripple of the DC-link voltage can be decreased by increasing the capacitance or by using different types of active power decoupling topologies. However, it is also possible to allow higher ripple in the DC-link voltage if this ripple is prevented from affecting the PV generator voltage. This can be made by using DC-link voltage feedforward in the DC/DC converter. In this paper, the effect of DC-link voltage feedforward on the attenuation capability is studied by using small-signal model. It is shown that the most significant factors affecting the maximum attenuation are the value of the DC-link voltage, the tolerance of the voltage measurement gain and the balance between the losses of upper and lower switches. It is also shown that the DC-link voltage feedforward has similar effect on the output impedance of the converter as input voltage control: The converter will have constant power output.

	Novel equivalent lead-acid battery circuits development with separated simulation of chemical and electrical domains By Moshe AVERBUKH	[View] [Download]
Abstract: Article denotes a new approach for development equivalent electrical circuit of lead-acid batteries. It is based on a separated representation of chemical and electrical domains. Main advantage of the proposed simulation method is more accurate description of the battery behavior in different dynamic regimes without the need of additional fitting equivalent circuit parameters.

	Optimization Strategies of PEM Electrolyser as Part of Solar PV System By Antti KOSONEN	[View] [Download]
Abstract: Solar and wind power have intermittent nature, and hence they require energy storage systems or bridges between different energy sectors. Hydrogen is a potential candidate for both of these sectors. Hence, it is interesting to study the practical dynamic properties and limitations of electrolysers in the viewpoint of renewable energy production. This paper studies optimization strategies of a proton exchange membrane (PEM) electrolyser together with a solar photovoltaic (PV) system.

	The effect of including power converter losses when modelling energy storage systems: a UK Domestic Study. By Konstantina PANAGIOTOU	[View] [Download]
Abstract: Energy storage systems (ESS) are seen as an increasingly important technology for managing electrical distribution systems, and there is now much research into both the underlying technologies of these systems, and their 'optimum' management especially for applications within a single household. Optimum management usually depends on many factors and assumptions, for example what should be optimized (self-consumption of local renewable resources, consumer cost, peak reduction), prediction of local generation and load patterns, and the assumptions concerning the operation of the ESS itself. This paper aims to quantify one of the usual assumptions made (especiallyby non-electrical engineers) i.e. that the assumption that the power converter in the ESS is 100\% efficient does not lead to substantial errors in the ESS performance and cost-benefit analysis. Three different ESS power converter models have been created and their behaviour as part of a house based ESS management system over a one year period has been analysed using five different control approaches, a variety of battery and solar panel sizes and employing a time of use tariff (Economy 7). By observing the ESS charging pattern through the year and monitoring of the annual electricity costalong with the system's losses for the household, relationships between the battery and PV size, the control algorithms, the electricity cost and the system losses were created.