EPE Association: EPE 2019 - DS3f: Solar Energy Systems

EPE 2019 - DS3f: Solar Energy Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 05: Renewable Energy Power Systems > EPE 2019 - DS3f: Solar Energy Systems

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   A Voltage Multiplier Medium Voltage DC Collection (MVDC) Grid Using SiC Devices for Two Large PV Plants.
By Ahmed ALLEHYANI [View]
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Abstract: In this paper, a Medium Voltage DC (MVDC) Collection grid using SiC devices for two large Photo-Voltaic (PV) power plants is proposed. The proposed system consists of a power sharing converter, boost converter, voltage multiplier and grid-tie inverter. The power sharing stage achieves Maximum Power Point Tracking (MPPT) under variable weather conditions. The voltage regulation boost converter stage regulates the boost converter output voltage at 3.2 kV. The voltage multiplier stage multiples the output voltage of the boost converter five times resulting a fixed MVDC output of 16 kV. The devices and diodes used in the proposed system are Silicon Carbide (SiC) to achieve compact volume/weight and high efficiency. Simulation results of the proposed MVDC system are discussed.

   An Experimental Evaluation of Non-Isolated Switched Inductor Boost Converters using GaN HEMTs for Building-Integrated Photovoltaics Applications
By Paul VAN HEMELDONCK [View]
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Abstract: In this paper, the use of switched inductor boost converters is evaluated for Building-Integrated PhotoVoltaics (BIPV) DC/DC converter applications. BIPV is a demanding application in terms of gain, temperature, compactness and desired lifetime. In previous work, transformer isolated topologies were investigated for BIPV module frame-integration. This work will focus on the use of non-isolated high step-up DC/DC converters with switched inductor cells and wide band gap GaN switches. Wide band gap technology allows to operate the converters at higher switching frequencies compared to state-of-the-art solutions, which in turn leads to smaller inductors and a higher power density. The working principle of switched inductor cells is discussed and lay-out recommendations for practical converter design are highlighted. Efficiency results using GaN experimental evaluation boards from different manufacturers are presented. From thermal boundary conditions, the required amount of interleaved converters is discussed.

   Low Voltage Ride-Through Strategy for Distributed Energy Resources According to IEEE 1547-2018 Standard
By Kamilla PITTOL [View]
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Abstract: This paper presents the implementation of a strategy for low voltage ride-through for a distributed energy resource (DER) complying with IEEE 1547-2018 standard. The detection of balanced and unbalanced grid voltage sags are presented and the controller acts on the system according to the standard requirements. As the main contribution, this paper presents a method to track the RMS voltage at the point of common connection (PCC) by a Kalman filter. The results are compared with detection methods based on the Positive Sequence and RMS voltage detection of each phase. As result, the method for LVRT detection based on the Kalman filter has better performance, considering its fast voltage estimation that contributes to early detection of the occurrences of voltage sags that are within the region for LVRT.

   Optimal control of Three-phase PV inverter under Grid voltage unbalance
By Zoran MILETIC [View]
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Abstract: Typical three-phase PV inverter is designed to operate under balanced grid voltage conditions. At low voltage distribution grid, beyond utility power meters, grid unbalance conditions can be often found. Under grid voltage unbalance, a typical three-phase PV inverter with conventional control exhibits poor performance resulting in potential loss of power, long term reliability issue due to power oscillations in the DC bus, potential AC current overloading and over current tripping. This paper presents optimal control of three-phase PV inverter under grid voltage unbalance

   Sub-Module Level Differential Power Processing for Parallel-Connected Architecture in Photovoltaic Systems
By Kamran Ali Khan NIAZI [View]
[Download]

Abstract: The partial shading on parallel-connected photovoltaic (PV) modules introduces severe mismatch issues in PV systems, which significantly affects the overall output power. Distributed maximum power point tracking (DMPPT) is considered as an effective solution to the resultant mismatch in parallel-connected PV sub-modules. In this context, this paper proposes a sub-module level switched-inductor (SL) based differential power processing (DPP) technique for parallel connections to alleviate the mismatch effect. The technique can achieve the maximum output power under mismatch by equalizing the sub-module voltages. The proposed technique is analyzed and compared through simulations with a traditional (Schottky diode) bypassing technique.

EPE 2019 - DS3f: Solar Energy Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 05: Renewable Energy Power Systems > EPE 2019 - DS3f: Solar Energy Systems
	[return to parent folder]

	A Voltage Multiplier Medium Voltage DC Collection (MVDC) Grid Using SiC Devices for Two Large PV Plants. By Ahmed ALLEHYANI	[View] [Download]
Abstract: In this paper, a Medium Voltage DC (MVDC) Collection grid using SiC devices for two large Photo-Voltaic (PV) power plants is proposed. The proposed system consists of a power sharing converter, boost converter, voltage multiplier and grid-tie inverter. The power sharing stage achieves Maximum Power Point Tracking (MPPT) under variable weather conditions. The voltage regulation boost converter stage regulates the boost converter output voltage at 3.2 kV. The voltage multiplier stage multiples the output voltage of the boost converter five times resulting a fixed MVDC output of 16 kV. The devices and diodes used in the proposed system are Silicon Carbide (SiC) to achieve compact volume/weight and high efficiency. Simulation results of the proposed MVDC system are discussed.

	An Experimental Evaluation of Non-Isolated Switched Inductor Boost Converters using GaN HEMTs for Building-Integrated Photovoltaics Applications By Paul VAN HEMELDONCK	[View] [Download]
Abstract: In this paper, the use of switched inductor boost converters is evaluated for Building-Integrated PhotoVoltaics (BIPV) DC/DC converter applications. BIPV is a demanding application in terms of gain, temperature, compactness and desired lifetime. In previous work, transformer isolated topologies were investigated for BIPV module frame-integration. This work will focus on the use of non-isolated high step-up DC/DC converters with switched inductor cells and wide band gap GaN switches. Wide band gap technology allows to operate the converters at higher switching frequencies compared to state-of-the-art solutions, which in turn leads to smaller inductors and a higher power density. The working principle of switched inductor cells is discussed and lay-out recommendations for practical converter design are highlighted. Efficiency results using GaN experimental evaluation boards from different manufacturers are presented. From thermal boundary conditions, the required amount of interleaved converters is discussed.

	Low Voltage Ride-Through Strategy for Distributed Energy Resources According to IEEE 1547-2018 Standard By Kamilla PITTOL	[View] [Download]
Abstract: This paper presents the implementation of a strategy for low voltage ride-through for a distributed energy resource (DER) complying with IEEE 1547-2018 standard. The detection of balanced and unbalanced grid voltage sags are presented and the controller acts on the system according to the standard requirements. As the main contribution, this paper presents a method to track the RMS voltage at the point of common connection (PCC) by a Kalman filter. The results are compared with detection methods based on the Positive Sequence and RMS voltage detection of each phase. As result, the method for LVRT detection based on the Kalman filter has better performance, considering its fast voltage estimation that contributes to early detection of the occurrences of voltage sags that are within the region for LVRT.

	Optimal control of Three-phase PV inverter under Grid voltage unbalance By Zoran MILETIC	[View] [Download]
Abstract: Typical three-phase PV inverter is designed to operate under balanced grid voltage conditions. At low voltage distribution grid, beyond utility power meters, grid unbalance conditions can be often found. Under grid voltage unbalance, a typical three-phase PV inverter with conventional control exhibits poor performance resulting in potential loss of power, long term reliability issue due to power oscillations in the DC bus, potential AC current overloading and over current tripping. This paper presents optimal control of three-phase PV inverter under grid voltage unbalance

	Sub-Module Level Differential Power Processing for Parallel-Connected Architecture in Photovoltaic Systems By Kamran Ali Khan NIAZI	[View] [Download]
Abstract: The partial shading on parallel-connected photovoltaic (PV) modules introduces severe mismatch issues in PV systems, which significantly affects the overall output power. Distributed maximum power point tracking (DMPPT) is considered as an effective solution to the resultant mismatch in parallel-connected PV sub-modules. In this context, this paper proposes a sub-module level switched-inductor (SL) based differential power processing (DPP) technique for parallel connections to alleviate the mismatch effect. The technique can achieve the maximum output power under mismatch by equalizing the sub-module voltages. The proposed technique is analyzed and compared through simulations with a traditional (Schottky diode) bypassing technique.