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Liao, Jianquan (author), Zhou, Niancheng (author), Qin, Z. (author), Wang, Qianggang (author), Bauer, P. (author)The unbalanced power between positive and negative poles in a bipolar DC distribution network (DC-DN) generates an unbalanced current at the neutral line, which enlarges the power losses of the system and the voltage deviation of DC loads. An unbalanced power suppression strategy based on a series-parallel power flow controller (SP-PFC) is...journal article 2023
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Purgat, P. (author), Shekhar, A. (author), Qin, Z. (author), Bauer, P. (author)Low-voltage direct current (LVdc) systems are a promising technology for systems with a high penetration of renewable sources and storage that operate with bidirectional power flow. In this article, a fundamental building block for LVdc is presented for different applications, such as charge controllers, voltage regulation in street-lighting...journal article 2023
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Yadav, S. (author), Qin, Z. (author), Bauer, P. (author)Balancing converters are an integral part of a bipolar dc grid. In this paper, we propose a balancing converter based on a series resonant converter topology. The converter operates in the capacitive region with phase shift between the upper and lower H-bridges. The converter operation is analyzed and verified with LTSpice simulation. A...conference paper 2022
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Gan, Naifeng (author), Sun, S.Z. (author), Zhang, Zhaosheng (author), Xu, Shiqi (author), Liu, Peng (author), Qin, Z. (author)The overdischarge can significantly degrade a lithium-ion (Li-ion) battery's lifetime. Therefore, it is important to detect the overdischarge and prevent severe damage of the Li-ion battery. Depending on the battery technology, there is a minimum voltage (cutoff voltage) that the battery is allowed to be discharged in common practice. Once the...journal article 2022
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- Yadav, S. (author), Qin, Z. (author), Bauer, P. (author) journal article 2022
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Beloqui Larumbe, L. (author), Qin, Z. (author), Bauer, P. (author)In this article, the Linear Time Invariant (LTI) and Linear Time Periodic (LTP) models of two different implementations of the DDSRF-PLL in the presence of voltage imbalance are derived analytically. The accuracy of the models is investigated with time domain simulations, frequency scans, and stability analysis. On top of this, a guideline for...journal article 2022
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Ahmad, A. (author), Qin, Z. (author), Wijekoon, Thiwanka (author), Bauer, P. (author)The emphasis on clean and green technologies to curtail greenhouse gas emissions due to fossil fuel-based economies has originated the shift towards electric mobility. As on-road electric vehicles (EVs) have shown exponential growth over the last decade, so have the charging demands. The provision of charging facilities from the low-voltage...journal article 2022
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Xiao, J. (author), Wang, L. (author), Qin, Z. (author), Bauer, P. (author)Smart grid steady control relies heavily on the communication infrastructure among sensors, actuators, and control systems, which makes it vulnerable to cyber-attacks. Accurate acquisition of dynamic state information is deemed vital for efficient detection of these cyber-attacks on a smart grid. However, several popular state estimation...conference paper 2022
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Xiao, J. (author), Wang, L. (author), Qin, Z. (author), Bauer, P. (author)Distributed secondary control is deemed necessary to restore the state of AC micro-grids to set points. However, for its limited global information, the power electronic system is vulnerable to cyber-attacks that aim to desynchronize converters or even cause a shutdown of micro-grids by unnecessarily triggering the protection schemes. To this...conference paper 2022
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Nejad, Amir R. (author), Keller, Jonathan (author), Guo, Yi (author), Sheng, Shawn (author), Polinder, H. (author), Watson, S.J. (author), Dong, J. (author), Qin, Z. (author), Ebrahimi, Amir (author)This paper presents the state-of-the-art technologies and development trends of wind turbine drivetrains – the system that converts kinetic energy of the wind to electrical energy – in different stages of their life cycle: design, manufacturing, installation, operation, lifetime extension, decommissioning and recycling. Offshore development and...review 2022
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Lan, Dun (author), Wu, Y. (author), Soeiro, Thiago Batista (author), Granello, P. (author), Qin, Z. (author), Bauer, P. (author)This paper presents the study of a 100kW electric vehicle (EV) fast charger based on a 12-pulse rectifier cascaded with two buck-type DC-DC converters. The proposed circuit operates with a triangular current shaping method which considerably improves the current harmonics performance of the system. The studied circuit is particularly suited...conference paper 2022
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Qiang, Rui (author), Wu, Y. (author), Soeiro, Thiago Batista (author), Granello, P. (author), Qin, Z. (author), Bauer, P. (author)This paper proposes a solution to the circuit topology of heavy-duty electric vehicle (HDEV) chargers. In light of the original hybrid rectifier, a new unidirectional Input-Parallel-Output-Series (IPOS) three-phase hybrid rectifier is proposed and analyzed. The IPOS topology is advantageous at ultra-high power rating to interface the next...conference paper 2022
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Sun, Jian (author), Wu, Y. (author), Soeiro, Thiago B. (author), Qin, Z. (author), Bauer, P. (author)An efficient, compact and lightweight three-phase AC-DC power factor correction (PFC) converter becomes a necessity for electric vehicles (EVs) On-board chargers (OBCs) in conventional grid-to-vehicle (G2V) and vehicle-to-grid (V2G) charging methods. The commercially available OBCs have very limited power density despite the moderate efficiency...conference paper 2022
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Liang, Y. (author), Wang, L. (author), Qin, Z. (author), Bauer, P. (author)In emerging fast-charging stations, DC fast chargers (DCFCs) are employed which rely on power electronics and control to achieve the required performance. Harmonic emission induced by the complex system behavior is of great concern in the DCFC system. This paper proposes a harmonic emission model for the typical electric vehicle charger...conference paper 2022
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Yadav, S. (author), Qin, Z. (author), Bauer, P. (author)Balancing converters are an integral part of a bipolar dc grid. Resonant converter topologies are interesting for power electronics engineers due to their soft switching capabilities. A series resonant converter topology is promising as a balancing converter in a bipolar dc grid. The series resonant converter is usually a non-inverting...conference paper 2022
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Sun, S.Z. (author), Wang, Zhenpo (author), Liu, Peng (author), Qin, Z. (author), Chen, Yong (author), Han, Yang (author), Wang, Peng (author), Bauer, P. (author)Battery fault diagnosis is crucial for stable, reliable, and safe operation of electric vehicles, especially the thermal runaway early warning. Developing methods for early failure detection and reducing safety risks from failing high energy lithium-ion batteries has become a major challenge for industry. In this article, a real-time early...journal article 2022
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Qin, Z. (author), Wang, L. (author), Bauer, P. (author)Electric vehicles (EVs) are playing a crucial role in achieving the carbon neutral goal. To make the charging experience comparable with the refueling of the gasoline cars, more and more chargers are installed and connected to the grid. Meanwhile, the charging power is going up. As a result, more and more power quality issues associated with EV...conference paper 2022
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Wang, L. (author), Qin, Z. (author), Beloqui Larumbe, L. (author), Bauer, P. (author)To accurately simulate the harmonic emission of EV DC fast chargers (DCFCs) and the harmonic voltage of the power grid to which the chargers are connected, a small time-step, i.e., typically smaller than 10μs, is required. However, for harmonic assessment, a long timescale, typically a day, is required. A conflict between accuracy and time...conference paper 2021
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Liao, Jianquan (author), Zhou, Niancheng (author), Qin, Z. (author), Purgat, P. (author), Wang, Qianggang (author), Bauer, P. (author)The two main challenges of medium voltage direct current (MVDC) distribution network are the flexible control of power flow (PF) and fault protection. In this paper, the power flow controller (PFC) is introduced to regulate the PF and inhibit the fault current during the DC fault. The coordination strategy of series-parallel PFC (SP-PFC) and...journal article 2021
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Beloqui Larumbe, L. (author), Qin, Z. (author), Wang, L. (author), Bauer, P. (author)This article presents a small-signal model for power-electronics converters that use a typical control structure in wind energy applications: the double synchronous reference frame current control. The article considers the presence of unbalanced currents and voltages, and analyzes their impact on the frequency couplings of the converter. In...journal article 2021